CLINICAL STUDY: CLINICAL APPLICATION OF ECHOCARDIOGRAPHIC FINDINGS
Cardiac resynchronization therapy tailored by echocardiographic evaluation of ventricular asynchrony
Maria Vittoria Pitzalis, MD, PhD*,*,
Massimo Iacoviello, MD*,
Roberta Romito, MD ,
Francesco Massari, MD,
Brian Rizzon, MD*,
Giovanni Luzzi, MD*,
Pietro Guida, MS*,
Andrea Andriani, MD*,
Filippo Mastropasqua, MD and
Paolo Rizzon, MD*
* Institute of Cardiology, University of Bari, Bari, Italy
Cardiology, "S. Maugeri" Foundation, IRCCS, Cassano Murge, Bari, Italy
Manuscript received January 28, 2002;
revised manuscript received April 9, 2002,
accepted June 24, 2002.
* Reprint requests and correspondence: Dr. Maria Vittoria Pitzalis, Institute of Cardiology, University of Bari, Policlinico, Piazza Giulio Cesare 11, 70124 Bari, Italy.
mariavittoria.pitzalis{at}cardio.uniba.it
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Abstract
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OBJECTIVES: The value of interventricular and intraventricular echocardiographic asynchrony parameters in predicting reverse remodeling after cardiac resynchronization therapy (CRT) was investigated.
BACKGROUND: Cardiac resynchronization therapy has been suggested as a promising strategy in patients with severe heart failure and left bundle branch block (LBBB), but the entity of benefit is variable and no criteria are yet available to predict which patients will gain.
METHODS: Interventricular and intraventricular mechanical asynchrony was evaluated in 20 patients (8 men and 12 women, 63 ± 10 years) with advanced heart failure caused by ischemic (n = 4) or nonischemic dilated cardiomyopathy (n = 16) and LBBB (QRS duration of at least 140 ms) using echocardiographic Doppler measurements. Left ventricular end-diastolic volume index (LVEDVI) and left ventricular end-systolic volume index (LVESVI) were calculated before and one month after CRT. Patients with a LVESVI reduction of at least 15% were considered as responders.
RESULTS: Cardiac resynchronization therapy significantly improved ventricular volumes (LVEDVI from 150 ± 53 ml/m2 to 119 ± 37 ml/m2, p < 0.001; LVESVI from 116 ± 43 ml/m2 to 85 ± 29 ml/m2, p < 0.0001). At baseline, the responders had a significantly longer septal-to-posterior wall motion delay (SPWMD), a left intraventricular asynchrony parameter; only QRS duration and SPWMD significantly correlated with a reduction in LVESVI (r = –0.54, p < 0.05 and r = –0.70, p < 0.001, respectively), but the accuracy of SPWMD in predicting reverse remodeling was greater than that of the QRS duration (85% vs. 65%).
CONCLUSIONS: In patients with advanced heart failure and LBBB, baseline SPWMD is a strong predictor of the occurrence of reverse remodeling after CRT, thus suggesting its usefulness in identifying patients likely to benefit from biventricular pacing.
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Abbreviations and Acronyms
| | AUC | | areas under the curve | | CI | | confidence interval | | CRT | | cardiac resynchronization therapy | | ECG | | electrocardiogram/electrocardiographic/electrocardiography | | EIVD | | electrographic interventricular delay | | ICC | | intraclass correlation coefficient | | IVD | | interventricular delay | | LBBB | | left bundle branch block | | LVEDVI | | left ventricular end-diastolic volume index | | LVEF | | left ventricular ejection fraction | | LVEMD | | left ventricular electromechanical delay | | LVESVI | | left ventricular end-systolic volume index | | MR | | mitral regurgitation | | MRa | | mitral regurgitation area | | MRd | | mitral regurgitation duration | | NYHA | | New York Heart Association | | ROC | | receiver operating characteristic | | SPWMD | | septal-to-posterior wall motion delay |
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Chamber enlargement in patients with chronic heart failure is often associated with asynchrony between right and left ventricular contractions and within the left ventricle. Late contraction of the left free wall gives rise to a further worsening of hemodynamic function (1,2), which contributes to the development of ventricular remodeling (3). It has been suggested that cardiac resynchronization therapy (CRT), which involves the simultaneous stimulation of the right ventricle and left free wall, reduces left ventricular volumes and increases the ejection fraction (4–7). However, the response in terms of reverse remodeling (7) and clinical benefit (6–9) is heterogeneous and difficult to predict (7,10–12).
Given the mechanisms by which resynchronization therapy works, it can be speculated that the greater the asynchrony, the greater the benefit. In clinical practice, a prolonged QRS duration and, in particular, complete left bundle branch block (LBBB) are regarded as the index of ventricular asynchrony, guiding patient selection for CRT (13). However, LBBB may not be precise enough to reflect interventricular or intraventricular mechanical asynchrony accurately and, if this is the case, the use of imaging techniques to visualize ventricular asynchrony may do better in identifying patients who will show reverse remodeling.
The aim of this prospective study was to evaluate whether interventricular or intraventricular asynchrony parameters identify patients with stable severe heart failure and LBBB who are most likely to benefit from CRT in terms of reverse remodeling.
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Methods
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Study population.
We studied patients with New York Heart Association (NYHA) functional class III, chronic heart failure of any origin who had been taking optimal drug therapy for at least three months; all of them were in sinus rhythm and had LBBB with a QRS duration  140 ms and a left ventricular ejection fraction (LVEF)  35%. Their condition had to be stable, without any spontaneous or provoked angina, or the need for revascularization procedures. The other exclusion criteria were acute heart failure, coronary artery bypass graft surgery or myocardial infarction within the previous three months, valvular stenosis, previous valve replacement or reconstruction, the presence of a pacemaker or any indication for one, or a history of chronic atrial fibrillation.
The study was approved by the local ethics committee, and all of the patients gave written, informed consent.
Protocol
Between 10 and 5 days before implantation, all of the patients underwent a clinical examination, 12-lead electrocardiography (ECG), and mono-dimensional and two-dimensional echocardiographic and Doppler evaluations. The same evaluations were repeated one month after implantation (during which time care was taken to keep the drug treatment unchanged), when the patients were paced using the optimal mode and settings. The QRS duration was measured as the maximum of leads II, V1, and V6; the PQ interval duration was calculated as the longest interval found on the 12-lead ECG.
Echocardiographic examination
Mono-dimensional and two-dimensional echocardiography recordings were made using a phased-array echocardiographic Doppler system (Sonos 5500, Hewlett-Packard [Agilent], Andover, Massachusetts) equipped with a 3-MHz transducer. Briefly, after resting for 10 min, the patients were examined in the left lateral recumbent position using standard parasternal short- and long-axis and apical views. Left ventricular end-diastolic and end-systolic volumes were calculated using Simpson’s rule (14) and indexed for body surface area. Reverse remodeling was assessed on the basis of the reduction in the left ventricular end-systolic volume index (LVESVI). The patients were considered as responders if LVESVI decreased by 15%, and as nonresponders in all other cases (7,15). Left ventricular systolic function was evaluated using LVEF (14). Mitral regurgitation (MR) was quantified by calculating the area (MRa) and duration (MRd) of the regurgitation (16).
Intraventricular asynchrony was evaluated on the basis of the left ventricular electromechanical delay (LVEMD) (i.e., the time [ms] from QRS onset to aortic flow onset) (6) and the delay between the motion of the septum and left posterior wall (septal-to-posterior wall motion delay [SPWMD]; ms), calculated as the shortest interval between the maximal posterior displacement of the septum and the maximal displacement of the left posterior wall using a mono-dimensional short-axis view at the papillary muscle level (Fig. 1). Interventricular asynchrony (interventricular delay [IVD]; ms) was evaluated on the basis of the delay in LVEMD in comparison with the right electromechanical delay (measured as the time between the simultaneously recorded onset of the QRS interval and pulmonary flow) (6).
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Figure 1 Mono-dimensional short-axis view of the echocardiographic image taken at the level of the papillary muscles. Calculation of septal-to-posterior wall motion delay (SPWMD) obtained by measuring the shortest interval between the maximal posterior displacement of the septum (a) and the posterior wall (b).
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The intraobserver and interobserver reproducibilities of all of the aforementioned echocardiographic measures of asynchrony were calculated.
The data obtained before implantation were compared with those found during follow-up by two skilled and independent operators (R. R. and B. R.), who were unaware of the baseline interventricular and intraventricular conduction delays.
Pacemaker implantation
Twenty-one consecutive patients were implanted with a biventricular pacemaker (Guidant Contak TR CHFD, Guidant Inc., St. Paul, Minnesota or Medtronic InSync III 8040, Medtronic Inc., Minneapolis, Minnesota), and four received a biventricular cardioverter-defibrillator (Guidant Contak CD CHFD or Contak Renewal, Guidant Inc.; or Medtronic InSync ICD 7272, Medtronic Inc.). Left ventricular pacing was obtained transvenously in all cases. After coronary sinus angiography, a unipolar lead with an over-the-wire system (Easytrak, Guidant Inc. or Medtronic 4193-78, Medtronic Inc.) was advanced into the lateral or posterolateral cardiac vein. The final position was chosen on the basis of visual inspection by using the right and left anterior oblique views; the most lateral region was reached (15 through the lateral and 10 through the posterolateral vein), and the final position was validated on the basis of both the best left ventricular stimulation threshold (1.48 ± 0.81 V/0.5 ms; minimum 0.3 V; maximum 3.0 V) and the best left ventricular amplitude signal. The right atrium and ventricle were then stimulated by positioning standard bipolar catheters in the right atrial appendage and right ventricular apex, respectively. During cardioverter-defibrillator implantation, a dual-coil catheter for right ventricular pacing, sensing, and cardioversion/defibrillation was inserted in the right ventricle. The biventricular pacing mode was programmed in DDD, and the lower rate was set at 40 beats/min. The atrioventricular interval was optimized for maximal diastolic filling by Doppler echocardiography (17). In the control group, the pacing mode was programmed in DDD, with a lower rate of 40 beats/min and an atrioventricular delay of 300 ms. If these settings resulted in ventricular pacing, the device was programmed in VVI, with lower rate at 40 beats/min.
At the site of the best left ventricular pacing, the local left electrogram was recorded and the conduction time between the right and left electrograms was calculated as a measure of IVD (electrographic interventricular delay [EIVD]; ms).
Control group
Interventricular and intraventricular asynchrony measures were analyzed in five patients with chronic heart failure who, in accordance with another study protocol, underwent device implantation followed by a six-month period during which it was kept inactive. These control subjects were used to evaluate whether the interventricular and intraventricular asynchrony measures had any post-implantation spontaneous modification not related to CRT. Once again, the measurements at one month after implantation were taken by operators who had no knowledge of the baseline values.
Statistical analysis
The data are shown as the mean value ± SD. Continuous variables were compared using the t test, and frequencies using the Fisher exact test. The percent variations were compared using the Mann-Whitney U test. Correlations between variables were assessed using Pearson’s linear correlation. Interobserver and intraobserver reproducibilities were evaluated by means of the intraclass correlation coefficient (ICC) (18), with reproducibility being considered almost perfect if the ICC was between 0.81 and 1.0. The receiver operating characteristics (ROC) curves for sensitivity and specificity were constructed to evaluate the predictive values of the studied variables, and the areas under the curve (AUC) were statistically compared to estimate the accuracy of the variables. The tests were considered statistically significant at p < 0.05.
Results.
We enrolled 25 patients: 5 with ischemic and 20 with nonischemic heart disease (by World Health Organization criteria) (19). The demographic, clinical, and therapeutic characteristics of the patient population are shown in Table 1.
Reproducibility of echocardiographic asynchrony parameters
The intraobserver reproducibility of SPWMD, LVEMD, and IVD (ICC: 0.96, 0.96, and 0.95, respectively), as well as the interobserver reproducibility (ICC: 0.91, 0.92, and 0.83, respectively), was very high. The values of these parameters before and one month after implantation were similar to those of the control group, thus again showing a very high degree of reproducibility (ICC: 0.97, 0.94, and 0.92, respectively).
Correlations between asynchrony parameters before implantation
The baseline QRS duration significantly correlated only with SPWMD (r = 0.62, p < 0.01); LVEMD and IVD did not correlate with the QRS interval, SPWMD, or EIVD. Baseline EIVD significantly and positively correlated with LVEMD (r = 0.50, p < 0.05), but not with the QRS duration, SPWMD, or IVD.
ECG and asynchrony parameters changes after CRT
Changes in the electrocardiographically and echocardiographically studied variables after one month of CRT are shown in Table 2. As expected, there was a significant reduction in the PQ interval and QRS duration, but no significant change in the heart rate. There was a significant reduction in all of the parameters reflecting intraventricular and interventricular asynchrony, and left ventricular volumes, ejection fractions, and MR significantly improved.
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Table 2 Differences in Electrocardiographic and Echocardiographic Parameters Before and After One Month of Cardiac Resynchronisation Therapy
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Correlations between baseline asynchrony parameters and reverse remodeling
The SPWMD and QRS duration measures before implantation significantly correlated with the reductions in both left ventricular end-diastolic volume index (LVEDVI) (r = –0.73, p < 0.001 and r = –0.55, p < 0.05, respectively) and LVESVI (Figs. 2 and 3) (i.e., the longer the baseline SPWMD and QRS duration, the greater the reverse remodeling). In contrast, LVEMD, IVD, and EIVD did not significantly correlate with the changes in left ventricular volumes.
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Figure 2 Two-dimensional apical four-chamber view of echocardiographic images. Left ventricular end-systolic volumes before (pre) device implantation (left images) and one month after cardiac resynchronization therapy (right images) in two different patients. (A) This patient had a prolonged pre-implantation septal-to-posterior wall motion delay (SPWMD) and a marked left ventricular end-systolic volume reduction after one month. (B) This patient had a short pre-implantation SPWMD and no reverse remodeling.
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Comparison between responders and nonresponders
Twelve patients were responders (reduction in LVESVI 15%). At baseline, there were no differences between the responders and nonresponders in terms of the heart rate, QRS duration, ventricular volumes, and MR, but the responders had a longer PQ interval and a longer SPWMD (Table 3).
In Table 4, the percent variations of the studied parameters in responders and nonresponders are shown. The reductions in LVEDVI, LVESVI, and MRa were significantly greater in responders than in nonresponders. No differences between the two groups were found when ECG parameters, asynchrony measures, LVEF, and MRd variations were taken into account. Seventeen patients improved in their NYHA functional class, from III to II. The responders were more likely to improve their NYHA functional class, as compared with nonresponders (100% vs. 63%; p < 0.05).
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Table 4 Comparison of One-Month Percent Variations Occurring in the Studied Parameters Between Responders and Nonresponders
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Predictive value of asynchrony parameters
The ROC curves for post-CRT reverse remodeling showed that the AUC for SPWMD (0.95; confidence interval [CI] 0.76 to 0.99) was significantly greater than those for the QRS duration (0.59; CI 0.35 to 0.80) (Fig. 4), LVEMD (0.60; CI 0.34 to 0.83), IVD (0.68; CI 0.38 to 0.89), or EIVD (0.54; CI 0.30 to 0.76), but not statistically different from that of the PQ interval (0.78; CI 0.54 to 0.93). All of the responders had a baseline SPWMD 130 ms, a QRS duration 150 ms, and a PQ interval 180 ms. Using these cut-off values, the specificity of SPWMD was 63%, with a positive predictive value of 80% and an accuracy of 85%, whereas the specificity of both the QRS duration and PQ interval was 13%, with a positive predictive value of 63% and an accuracy of 65%.
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Figure 4 The receiver operating characteristic curves for septal-to-posterior wall motion delay (SPWMD), PQ interval, and QRS duration to predict reverse remodeling. The areas underlying SPWMD and QRS duration are statistically different.
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Discussion.
Cardiac resynchronization has recently been proposed as a long-term treatment for patients with severe heart failure despite optimal medical therapy. This electrical strategy is currently offered to patients with complete LBBB in the belief that this ECG parameter reflects mechanical asynchrony (1,2), but a benefit in terms of improved symptoms and ventricular reverse remodeling is evident in only some patients (6–8).
The main result of the present study is that an echocardiographically derived measure of intraventricular mechanical asynchrony identifies patients with severe heart failure who are likely to show reverse remodeling more accurately than LBBB alone. The relevance of our findings comes from the fact that they are the result of pathophysiologic speculation (1–3,20), and this sheds new light on the possibility of changing the selection criteria used to identify heart failure patients suitable for CRT.
Left ventricular remodeling is the result of the complex interaction between structural and functional abnormalities favoring the progressive dilation of the left ventricle (21), which takes on a spherical shape that is unfavorable from an energetic point of view and becomes dyssynergic (i.e., the posterolateral wall contracts later than does the septum). These abnormalities are responsible for MR and further hemodynamic deterioration (22) and are worsened by the appearance of LBBB (2). It is believed that stimulation of the left posterolateral wall in order to synchronize this area with the septum blunts these alterations and gives rise to so-called "reverse remodeling."
However, the possibility of achieving this favorable result depends on a number of factors, such as the presence of a left ventricular area with delayed contraction, the possibility of identifying it, and, finally, the ability to reach and stimulate this area by using a catheter positioned through the coronary sinus. The first two factors are particularly relevant for guiding patient selection. On the basis of these considerations and our results, it is possible to hypothesize that nonresponders are the consequence of inadequate patient selection, which is currently based on the presence of LBBB (13). This ECG abnormality should be considered as only a generic marker of conduction disturbance, because the fact that left intraventricular asynchrony is often associated with LBBB is not sufficient to presume that the latter is a specific marker of any degree of mechanical asynchrony. Also, LBBB may be the result of abnormalities that do not necessarily cause late contraction of the left free wall (e.g., peripheral conduction defect or global left ventricular dysfunction).
Seen in this light, the weak correlation between QRS duration and echocardiographically visualized mechanical asynchrony is not surprising. Furthermore, our hypothesis explains the low specificity of even a very wide QRS interval (as in the case of our patient population) in predicting the occurrence of reverse remodeling. In contrast, by providing information on the delayed mechanical asynchrony between the left free wall and septum, the echocardiographic parameter is highly specific and has a positive predictive value: the longer the delay, the greater the reduction in ventricular volumes.
The parameter analyzing IVD by taking into account the onset of the QRS interval and aortic flow does not provide the same information as that of SPWMD. It is possible that this measure is not sufficiently precise to identify the presence of delayed left free wall contraction and, in particular, its asynchrony with the septum. This echocardiographic Doppler parameter correlates well with the electrical delay recorded between the right and left catheter during implantation. In addition, EIVD is not useful in predicting reverse remodeling. The electrogram recorded at the level of the lateral free wall is greatly influenced by the position of the catheter in the coronary sinus tree and, therefore, by its anatomy. Furthermore, in patients with a previous myocardial infarction, the presence of slowed conduction in the peri-infarcted myocardium may give rise to a locally prolonged delay that does not reflect real intraventricular asynchrony.
Another interesting finding is the very high predictive value of the baseline PQ interval: the longer the interval, the greater the improvement. It has been previously suggested that prolonged atrioventricular conduction has pathophysiologic significance (23–25) and may lead to worsening hemodynamic function that is independent of intraventricular asynchrony (26). Although the number of patients enrolled in this study did not allow us to perform multivariate analysis, analysis of the independent and incremental value of these parameters would be of interest in defining patient selection criteria.
To the best of our knowledge, this is the first study that has prospectively demonstrated the value of electrocardiographically and echocardiographically derived Doppler measures in predicting reverse remodeling in patients receiving CRT. However, it must to be acknowledged that Stellbrink et al. (7) have recently suggested that patients with very large left ventricular volumes at baseline are unlikely to benefit from CRT. This hypothesis was not confirmed in our patient population, because a long SPWMD retained its ability to predict improvement, even in the presence of a very dilated heart. This difference may be due to the fact that Stellbrink et al. (7) analyzed ventricular volumes without considering the degree of left lateral wall motion delay. Therefore, it is possible that their patients with very dilated ventricles had global hypokinesia with little intraventricular asynchrony (a phenomenon that is not unusual in markedly remodeled hearts).
The intraventricular asynchrony parameter we suggest combines the advantages of the echocardiographic technique with a high level of accuracy in identifying responders. It is therefore a very promising measure in the clinical setting. The use of mono-dimensional echocardiography to evaluate all patients with severe heart failure, LBBB, and a wide QRS interval would make it possible to avoid implanting the device in those whose cardiac function is unlikely to improve.
Conclusions
This study suggests that patients with stable and severe heart failure (while receiving optimal therapy) and LBBB need to be further evaluated echocardiographically to identify the possible presence of a long SPWMD, which would allow the selection of patients most likely to achieve reverse remodeling after CRT. However, LBBB alone (even if the QRS duration is very prolonged) cannot be considered an adequate marker of intraventricular asynchrony and, therefore, cannot be used as the only parameter guiding the decision to implant a biventricular device.
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Acknowledgments
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The authors thank Maurizio Corrente and Luciano Sallusti for their helpful cooperation.
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Footnotes
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This study was partially supported by Guidant Italy.
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References
|
|---|
1. Grines CL, Bashore TM, Boudoulas H, Olson S, Shafer P, Wooley CF. Functional abnormalities in isolated LBBB: the effect of interventricular asynchrony. Circulation. 1989;79:845–853[Abstract/Free Full Text]
2. Little WC, Reeves RC, Arciniegas J, Katholi RE, Rogers EW. Mechanism of abnormal interventricular septal motion during delayed left ventricular activation. Circulation. 1982;65:1486–1491[Abstract/Free Full Text]
3. Eriksson P, Hansson PO, Eriksson H, Dellborg M. Bundle-branch block in a general male population: the study of men born 1913. Circulation. 1998;98:2494–2500[Abstract/Free Full Text]
4. Xiao HB, Brecker SJ, Gibson DG. Differing effects of right ventricular pacing and LBBB on left ventricular function. Br Heart J. 1993;69:166–173[Abstract/Free Full Text]
5. Kervin WF, Botvinick EH, O’Connell JW, et al. Ventricular contraction abnormalities in dilated cardiomyopathy: effect of biventricular pacing to correct interventricular dyssynchrony. J Am Coll Cardiol. 2000;35:1221–1227[Abstract/Free Full Text]
6. the InSync Italian Registry InvestigatorsPorciani MC, Puglisi A, Colella A, et al. Echocardiographic evaluation of the effect of biventricular pacing: InSync Italian Registry. Eur Heart J. 2000;2(Suppl J):J23–30
7. Stellbrink C, Breithardt OA, Franke A, et al. Impact of cardiac resynchronization therapy using hemodynamically optimized pacing on left ventricular remodeling in patients with congestive heart failure and ventricular conduction disturbances. J Am Coll Cardiol. 2001;38:1957–1965[Abstract/Free Full Text]
8. InSync Italian Registry InvestigatorsZardini M, Tritto M, Bargiggia G, et al. The InSync Italian Registry: analysis of clinical outcome and considerations on the selection of candidates to left ventricular resynchronization. Eur Heart J. 2000;2(Suppl J):J16–22
9. the MUltisite STimulation In Cardiomyopathies (MUSTIC) Study InvestigatorsCazeau S, Leclercq C, Lavergne T, et al. Effects of multisite biventricular pacing in patients with heart failure and intraventricular conduction delay. N Engl J Med. 2001;344:873–880[Abstract/Free Full Text]
10. Alonso C, Leclercq C, Victor F, et al. Electrocardiographic predictive factors of long-term clinical improvement with multisite biventricular pacing in advanced heart failure. Am J Cardiol. 1999;84:1417–1421[CrossRef][Medline]
11. Kass DA, Chen CH, Curry C, et al. Improved left ventricular mechanics from acute VDD pacing in patients with dilated cardiomyopathy and ventricular conduction delay. Circulation. 1999;99:1567–1573[Abstract/Free Full Text]
12. Nelson GS, Curry CW, Wyman BT, et al. Predictors of systolic augmentation from left ventricular pre-excitation in patients with dilated cardiomyopathy and intraventricular conduction delay. Circulation. 2000;101:2703–2709[Abstract/Free Full Text]
13. Morris-Thurgood JA, Frenneaux MP. Pacing in congestive heart failure. Curr Control Trials Cardiovasc Med. 2000;1:107–114
14. Shiller NB, Shah PM, Crawford M, et al. Recommendations for quantitation of the left ventricle by two-dimensional echocardiography. J Am Soc Echocardiogr. 1989;2:358–367[Medline]
15. Himelman RB, Cassidy MM, Landzberg JS, Schiller NB. Reproducibility of quantitative two-dimensional echocardiography. Am Heart J. 1988;115:425–431[CrossRef][Medline]
16. Spain MG, Smith MD, Grayburn PA, Harlamert EA, DeMaria AN. Quantitative assessment of mitral regurgitation by Doppler color flow imaging: angiographic and hemodynamic correlations. J Am Coll Cardiol. 1989;13:585–590[Abstract]
17. Kindermann M, Frohlig G, Doerr T, Schieffer H. Optimizing the AV delay in DDD pacemaker patients with high degree AV block: mitral valve Doppler versus impedance cardiography. Pacing Clin Electrophysiol. 1997;20:2453–2462[CrossRef][Medline]
18. Fleiss JL. The Design and Analysis of Clinical Experiments. New York, NY: Wiley; 1986. p. 5–12
19. Richardson P, McKenna W, Bristow M, et al. Report of the 1995 World Health Organization/International Society and Federation of Cardiology Task Force on the definition and classification of cardiomyopathies. Circulation. 1996;93:841–842[Free Full Text]
20. Silvet H, Amin J, Padmanabhan S, Pai RG. Prognostic implications of increased QRS duration in patients with moderate and severe left ventricular systolic dysfunction. Am J Cardiol. 2001;88:182–185[CrossRef][Medline]
21. Mann DL. Mechanism and models in heart failure: a combinatorial approach. Circulation. 1999;100:999–1008[Free Full Text]
22. Kono T, Sabbah HN, Rosman H, Alam M, Jafri S, Goldstein S. Left ventricular shape is the primary determinant of functional mitral regurgitation in heart failure. J Am Coll Cardiol. 1992;20:1594–1598[Abstract]
23. Panidis IP, Ross J, Munley B, Nestico P, Mintz GS. Diastolic mitral regurgitation in patients with atrioventricular conduction abnormalities: a common finding by Doppler echocardiography. J Am Coll Cardiol. 1986;7:768–774[Abstract]
24. Brecker SJ, Xiao HB, Sparrow J, Gibson DG. Effects of dual-chamber pacing with short atrioventricular delay in dilated cardiomyopathy. Lancet. 1992;340:1308–1312[CrossRef][Medline]
25. Nishimura RA, Hayes DL, Holmes DR Jr, Tajik AJ. Mechanism of hemodynamic improvement by dual-chamber pacing for severe left ventricular dysfunction: an acute Doppler and catheterization hemodynamic study. J Am Coll Cardiol. 1995;25:281–288[Abstract]
26. Auricchio A, Stellbrink C, Block M, et al. Effect of pacing chamber and atrioventricular delay on acute systolic function of paced patients with congestive heart failure. Circulation. 1999;99:2993–3001[Abstract/Free Full Text]
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|
|
J. J. Bax and J. Gorcsan III
Echocardiography and noninvasive imaging in cardiac resynchronization therapy: results of the PROSPECT (Predictors of Response to Cardiac Resynchronization Therapy) study in perspective.
J. Am. Coll. Cardiol.,
May 26, 2009;
53(21):
1933 - 1943.
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. M. Hawkins, M. C. Petrie, M. I. Burgess, and J. J.V. McMurray
Selecting patients for cardiac resynchronization therapy: the fallacy of echocardiographic dyssynchrony.
J. Am. Coll. Cardiol.,
May 26, 2009;
53(21):
1944 - 1959.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. Parsai, B. Bijnens, G. R. Sutherland, A. Baltabaeva, P. Claus, M. Marciniak, V. Paul, M. Scheffer, E. Donal, G. Derumeaux, et al.
Toward understanding response to cardiac resynchronization therapy: left ventricular dyssynchrony is only one of multiple mechanisms
Eur. Heart J.,
April 2, 2009;
30(8):
940 - 949.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. Mele, T. Toselli, F. Capasso, G. Stabile, M. Piacenti, M. Piepoli, S. Giatti, C. Klersy, L. Sallusti, and R. Ferrari
Comparison of myocardial deformation and velocity dyssynchrony for identification of responders to cardiac resynchronization therapy
Eur J Heart Fail,
April 1, 2009;
11(4):
391 - 399.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
W. Mullens, R. A. Grimm, T. Verga, T. Dresing, R. C. Starling, B. L. Wilkoff, and W.H. W. Tang
Insights from a cardiac resynchronization optimization clinic as part of a heart failure disease management program.
J. Am. Coll. Cardiol.,
March 3, 2009;
53(9):
765 - 773.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
W. Mullens, T. Verga, R. A. Grimm, R. C. Starling, B. L. Wilkoff, and W.H. W. Tang
Persistent hemodynamic benefits of cardiac resynchronization therapy with disease progression in advanced heart failure.
J. Am. Coll. Cardiol.,
February 17, 2009;
53(7):
600 - 607.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
H.-M. Cheng, W.-C. Yu, S.-H. Sung, K.-L. Wang, S.-Y. Chuang, and C.-H. Chen
Usefulness of systolic time intervals in the identification of abnormal ventriculo-arterial coupling in stable heart failure patients
Eur J Heart Fail,
December 1, 2008;
10(12):
1192 - 1200.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T Z Naqvi, A M Rafique, C Swerdlow, S Verma, R J Siegel, K Tolstrup, W Kerwin, J Goodman, D Gallik, E Gang, et al.
Predictors of reduction in mitral regurgitation in patients undergoing cardiac resynchronisation treatment
Heart,
December 1, 2008;
94(12):
1580 - 1588.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
W. H. W. Tang, W. Mullens, A. G. Borowski, W. Tong, K. Shrestha, R. W. Troughton, M. G. Martin, K. Kassimatis, D. Agler, S. Jasper, et al.
Relation of mechanical dyssynchrony with underlying cardiac structure and performance in chronic systolic heart failure: implications on clinical response to cardiac resynchronization
Europace,
December 1, 2008;
10(12):
1370 - 1374.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Q. A. Truong, J. P. Singh, C. P. Cannon, A. Sarwar, K. Nasir, A. Auricchio, F. F. Faletra, A. Sorgente, C. Conca, T. Moccetti, et al.
Quantitative Analysis of Intraventricular Dyssynchrony Using Wall Thickness by Multidetector Computed Tomography.
J. Am. Coll. Cardiol. Img.,
November 1, 2008;
1(6):
772 - 781.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. A. Marsan, O. A. Breithardt, V. Delgado, M. Bertini, and L. F. Tops
Predicting response to CRT. The value of two- and three-dimensional echocardiography
Europace,
November 1, 2008;
10(suppl_3):
iii73 - iii79.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R Chung, R Sutton, and M Y Henein
Beyond dyssynchrony in cardiac resynchronisation therapy
Heart,
August 1, 2008;
94(8):
991 - 994.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. H. Lim, G. Y.H. Lip, and J. E. Sanderson
Ventricular optimization of biventricular pacing: a systematic review
Europace,
August 1, 2008;
10(8):
901 - 906.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
B. Kirn, A. Jansen, F. Bracke, B. van Gelder, T. Arts, and F. W. Prinzen
Mechanical discoordination rather than dyssynchrony predicts reverse remodeling upon cardiac resynchronization
Am J Physiol Heart Circ Physiol,
August 1, 2008;
295(2):
H640 - H646.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
F. W. Prinzen and A. Auricchio
Is echocardiographic assessment of dyssynchrony useful to select candidates for cardiac resynchronization therapy?: Echocardiography Is Not Useful Before Cardiac Resynchronization Therapy if QRS Duration Is Available
Circ Cardiovasc Imaging,
July 1, 2008;
1(1):
70 - 78.
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. S. Chung, A. R. Leon, L. Tavazzi, J.-P. Sun, P. Nihoyannopoulos, J. Merlino, W. T. Abraham, S. Ghio, C. Leclercq, J. J. Bax, et al.
Results of the Predictors of Response to CRT (PROSPECT) Trial
Circulation,
May 20, 2008;
117(20):
2608 - 2616.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L. J. Anderson, C. Miyazaki, G. R. Sutherland, and J. K. Oh
Patient Selection and Echocardiographic Assessment of Dyssynchrony in Cardiac Resynchronization Therapy
Circulation,
April 15, 2008;
117(15):
2009 - 2023.
[Full Text]
[PDF]
|
|
|
|
|
|
|
B. W.L. De Boeck, M. Meine, G. E. Leenders, A. J. Teske, H. van Wessel, J. H. Kirkels, F. W. Prinzen, P. A. Doevendans, and M. J. Cramer
Practical and conceptual limitations of tissue Doppler imaging to predict reverse remodelling in cardiac resynchronisation therapy
Eur J Heart Fail,
March 1, 2008;
10(3):
281 - 290.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. G. Delfino, K. R. Johnson, R. L. Eisner, S. Eder, A. R. Leon, and J. N. Oshinski
Three-directional Myocardial Phase-Contrast Tissue Velocity MR Imaging with Navigator-Echo Gating: In Vivo and in Vitro Study
Radiology,
March 1, 2008;
246(3):
917 - 925.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Tomaske, J. Janousek, V. Razek, R. A. Gebauer, V. Tomek, G. Hindricks, W. Knirsch, and U. Bauersfeld
Adverse effects of Wolff-Parkinson-White syndrome with right septal or posteroseptal accessory pathways on cardiac function
Europace,
February 1, 2008;
10(2):
181 - 189.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L. Rao, Y. Ling, R. He, A. L. Gilbert, N. G. Frangogiannis, J. Wang, S. F. Nagueh, and D. S. Khoury
Integrated multimodal-catheter imaging unveils principal relationships among ventricular electrical activity, anatomy, and function
Am J Physiol Heart Circ Physiol,
February 1, 2008;
294(2):
H1002 - H1009.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. F. Beshai, R. A. Grimm, S. F. Nagueh, J. H. Baker II, S. L. Beau, S. M. Greenberg, L. A. Pires, P. J. Tchou, and the RethinQ Study Investigators
Cardiac-Resynchronization Therapy in Heart Failure with Narrow QRS Complexes
N. Engl. J. Med.,
December 13, 2007;
357(24):
2461 - 2471.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. Leclercq, G. B. Bleeker, C. Linde, E. Donal, J. J. Bax, M. J. Schalij, and C. Daubert
Cardiac resynchronization therapy: clinical results and evolution of candidate selection
Eur. Heart J. Suppl.,
December 1, 2007;
9(suppl_I):
I94 - I106.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. Ritter, S. Cazeau, D. Gras, and J.-C. Daubert
Cardiac resynchronization therapy implantation: a blend of skill and technology
Eur. Heart J. Suppl.,
December 1, 2007;
9(suppl_I):
I107 - I112.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. Yoshida, Y. Seo, H. Yamasaki, K. Tanoue, N. Murakoshi, T. Ishizu, Y. Sekiguchi, S. Kawano, S. Otsuka, S. Watanabe, et al.
Effect of triangle ventricular pacing on haemodynamics and dyssynchrony in patients with advanced heart failure: a comparison study with conventional bi-ventricular pacing therapy
Eur. Heart J.,
November 1, 2007;
28(21):
2610 - 2619.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. B Bleeker, C.-M. Yu, P. Nihoyannopoulos, J. de Sutter, N. Van de Veire, E. R Holman, M. J Schalij, E. E van der Wall, and J. J Bax
Optimal use of echocardiography in cardiac resynchronisation therapy
Heart,
November 1, 2007;
93(11):
1339 - 1350.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. Gorcsan III, M. Tanabe, G. B. Bleeker, M. S. Suffoletto, N. C. Thomas, S. Saba, L. F. Tops, M. J. Schalij, and J. J. Bax
Combined Longitudinal and Radial Dyssynchrony Predicts Ventricular Response After Resynchronization Therapy
J. Am. Coll. Cardiol.,
October 9, 2007;
50(15):
1476 - 1483.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. Luzi, A. Montalto, V. Polizzi, C. C D'Alessandro, M. Vicchio, and F. Musumeci
Best Site on Right Ventricle for Open-Chest Biventricular Pacing
Asian Cardiovasc Thorac Ann,
October 1, 2007;
15(5):
427 - 431.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Authors/Task Force Members, P. E. Vardas, A. Auricchio, J.-J. Blanc, J.-C. Daubert, H. Drexler, H. Ector, M. Gasparini, C. Linde, F. B. Morgado, et al.
Guidelines for cardiac pacing and cardiac resynchronization therapy: The Task Force for Cardiac Pacing and Cardiac Resynchronization Therapy of the European Society of Cardiology. Developed in Collaboration with the European Heart Rhythm Association
Europace,
October 1, 2007;
9(10):
959 - 998.
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Becker, A. Franke, O. A Breithardt, C. Ocklenburg, T. Kaminski, R. Kramann, C. Knackstedt, C. Stellbrink, P. Hanrath, P. Schauerte, et al.
Impact of left ventricular lead position on the efficacy of cardiac resynchronisation therapy: a two-dimensional strain echocardiography study
Heart,
October 1, 2007;
93(10):
1197 - 1203.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. I Burgess, C. Jenkins, J. Chan, and T. H Marwick
Measurement of left ventricular dyssynchrony in patients with ischaemic cardiomyopathy: a comparison of real-time three-dimensional and tissue Doppler echocardiography
Heart,
October 1, 2007;
93(10):
1191 - 1196.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Authors/Task Force Members, P. E. Vardas, A. Auricchio, J.-J. Blanc, J.-C. Daubert, H. Drexler, H. Ector, M. Gasparini, C. Linde, F. B. Morgado, et al.
Guidelines for cardiac pacing and cardiac resynchronization therapy: The Task Force for Cardiac Pacing and Cardiac Resynchronization Therapy of the European Society of Cardiology. Developed in Collaboration with the European Heart Rhythm Association
Eur. Heart J.,
September 2, 2007;
28(18):
2256 - 2295.
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. Vernooy, R. N.M. Cornelussen, X. A.A.M. Verbeek, W. Y.R. Vanagt, A. van Hunnik, M. Kuiper, T. Arts, H. J.G.M. Crijns, and F. W. Prinzen
Cardiac resynchronization therapy cures dyssynchronopathy in canine left bundle-branch block hearts
Eur. Heart J.,
September 1, 2007;
28(17):
2148 - 2155.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. Lim, C. Bars, L. Mitchell-Heggs, C. Roiron, N. Elbaz, B. Hamdaoui, N. Lellouche, J.-L. Dubois-Rande, and P. Gueret
Importance of contractile reserve for CRT
Europace,
September 1, 2007;
9(9):
739 - 743.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. N. Kirkpatrick, M. A. Vannan, J. Narula, and R. M. Lang
Echocardiography in Heart Failure: Applications, Utility, and New Horizons
J. Am. Coll. Cardiol.,
July 31, 2007;
50(5):
381 - 396.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Chalil, B. Stegemann, S. Muhyaldeen, K. Khadjooi, R. E.A. Smith, P. J. Jordan, and F. Leyva
Intraventricular Dyssynchrony Predicts Mortality and Morbidity After Cardiac Resynchronization Therapy: A Study Using Cardiovascular Magnetic Resonance Tissue Synchronization Imaging
J. Am. Coll. Cardiol.,
July 17, 2007;
50(3):
243 - 252.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Becker, R. Kramann, A. Franke, O.-A. Breithardt, N. Heussen, C. Knackstedt, C. Stellbrink, P. Schauerte, M. Kelm, and R. Hoffmann
Impact of left ventricular lead position in cardiac resynchronization therapy on left ventricular remodelling. A circumferential strain analysis based on 2D echocardiography
Eur. Heart J.,
May 2, 2007;
28(10):
1211 - 1220.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. Kelly, P. M. Hickey, J. Davies, L. L. Ng, and D. Chin
Acute management of pregnancy associated cardiomyopathy with cardiac resynchronisation therapy
Eur J Heart Fail,
May 1, 2007;
9(5):
542 - 544.
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Schmidt, J. Bromsen, C. Herholz, K. Adler, F. Neff, C. Kopf, and M. Block
Evidence of left ventricular dyssynchrony resulting from right ventricular pacing in patients with severely depressed left ventricular ejection fraction
Europace,
January 1, 2007;
9(1):
34 - 40.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L. P. Badano, O. Gaddi, C. Peraldo, G. Lupi, M. Sitges, F. Parthenakis, S. Molteni, M. R. Pagliuca, B. Sassone, P. Di Stefano, et al.
Left ventricular electromechanical delay in patients with heart failure and normal QRS duration and in patients with right and left bundle branch block
Europace,
January 1, 2007;
9(1):
41 - 47.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Cannesson, B. Gostoli, P. Rosamel, C. Flamens, G. Derumeaux, P. Chevallier, J.-F. Obadia, O. Bastien, and J.-J. Lehot
Successful Cardiac Resynchronization Therapy After Cardiac Surgery
Anesth. Analg.,
January 1, 2007;
104(1):
71 - 74.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C M C van Campen, F C Visser, C C de Cock, H S Vos, O Kamp, and C A Visser
Comparison of the haemodynamics of different pacing sites in patients undergoing resynchronisation treatment: need for individualisation of lead localisation
Heart,
December 1, 2006;
92(12):
1795 - 1800.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L. F. Tops, M. J. Schalij, E. R. Holman, L. van Erven, E. E. van der Wall, and J. J. Bax
Right Ventricular Pacing Can Induce Ventricular Dyssynchrony in Patients With Atrial Fibrillation After Atrioventricular Node Ablation
J. Am. Coll. Cardiol.,
October 17, 2006;
48(8):
1642 - 1648.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C-M Yu, Q Zhang, Y-S Chan, C-K Chan, G W K Yip, L C C Kum, E B Wu, P-W Lee, Y-Y Lam, S Chan, et al.
Tissue Doppler velocity is superior to displacement and strain mapping in predicting left ventricular reverse remodelling response after cardiac resynchronisation therapy
Heart,
October 1, 2006;
92(10):
1452 - 1456.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Gasparini, A. Auricchio, F. Regoli, C. Fantoni, M. Kawabata, P. Galimberti, D. Pini, C. Ceriotti, E. Gronda, C. Klersy, et al.
Four-Year Efficacy of Cardiac Resynchronization Therapy on Exercise Tolerance and Disease Progression: The Importance of Performing Atrioventricular Junction Ablation in Patients With Atrial Fibrillation
J. Am. Coll. Cardiol.,
August 15, 2006;
48(4):
734 - 743.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. V. Pitzalis, M. Iacoviello, R. Romito, G. Luzzi, M. Anaclerio, and C. Forleo
Role of Septal to Posterior Wall Motion Delay in Cardiac Resynchronization Therapy
J. Am. Coll. Cardiol.,
August 1, 2006;
48(3):
596 - 597.
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. V. Pitzalis, M. Iacoviello, F. Di Serio, R. Romito, P. Guida, E. De Tommasi, G. Luzzi, M. Anaclerio, L. Varraso, C. Forleo, et al.
Prognostic value of brain natriuretic peptide in the management of patients receiving cardiac resynchronization therapy
Eur J Heart Fail,
August 1, 2006;
8(5):
509 - 514.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. M. Hawkins, M. C. Petrie, M. R. MacDonald, K. J. Hogg, and J. J.V. McMurray
Selecting patients for cardiac resynchronization therapy: electrical or mechanical dyssynchrony?
Eur. Heart J.,
June 1, 2006;
27(11):
1270 - 1281.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. Mele, G. Pasanisi, F. Capasso, A. De Simone, M.-A. Morales, D. Poggio, A. Capucci, G. Tabacchi, L. Sallusti, and R. Ferrari
Left intraventricular myocardial deformation dyssynchrony identifies responders to cardiac resynchronization therapy in patients with heart failure
Eur. Heart J.,
May 1, 2006;
27(9):
1070 - 1078.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Load dependence of cardiac output in biventricular pacing: left ventricular volume overload in pigs.
J. Thorac. Cardiovasc. Surg.,
March 1, 2006;
131(3):
666 - 670.
|
|
|
|
|
|
|
F. A Flachskampf and J.-U. Voigt
Echocardiographic methods to select candidates for cardiac resynchronisation therapy.
Heart,
March 1, 2006;
92(3):
424 - 429.
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. S. Suffoletto, K. Dohi, M. Cannesson, S. Saba, and J. Gorcsan III
Novel Speckle-Tracking Radial Strain From Routine Black-and-White Echocardiographic Images to Quantify Dyssynchrony and Predict Response to Cardiac Resynchronization Therapy
Circulation,
February 21, 2006;
113(7):
960 - 968.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. D'Ascia, A. Cittadini, M. G. Monti, G. Riccio, and L. Sacca
Effects of biventricular pacing on interstitial remodelling, tumor necrosis factor-{alpha} expression, and apoptotic death in failing human myocardium
Eur. Heart J.,
January 2, 2006;
27(2):
201 - 206.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. J. Bax, T. Abraham, S. S. Barold, O. A. Breithardt, J. W.H. Fung, S. Garrigue, J. Gorcsan III, D. L. Hayes, D. A. Kass, J. Knuuti, et al.
Cardiac Resynchronization Therapy: Part 1--Issues Before Device Implantation
J. Am. Coll. Cardiol.,
December 20, 2005;
46(12):
2153 - 2167.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. Kashani and S. S. Barold
Significance of QRS Complex Duration in Patients With Heart Failure
J. Am. Coll. Cardiol.,
December 20, 2005;
46(12):
2183 - 2192.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. M. Aranda Jr, G. W. Woo, R. S. Schofield, E. M. Handberg, J. A. Hill, A. B. Curtis, S. F. Sears, J. S. Goff, D. F. Pauly, and J. B. Conti
Management of Heart Failure After Cardiac Resynchronization Therapy: Integrating Advanced Heart Failure Treatment With Optimal Device Function
J. Am. Coll. Cardiol.,
December 20, 2005;
46(12):
2193 - 2198.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. M. Marcus, E. Rose, E. M. Viloria, J. Schafer, T. De Marco, L. A. Saxon, E. Foster, and for the VENTAK CHF/CONTAK-CD Biventricular Pacing
Septal to Posterior Wall Motion Delay Fails to Predict Reverse Remodeling or Clinical Improvement in Patients Undergoing Cardiac Resynchronization Therapy
J. Am. Coll. Cardiol.,
December 20, 2005;
46(12):
2208 - 2214.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. J.M. Zwanenburg, M. J.W. Gotte, J. T. Marcus, J. P.A. Kuijer, P. Knaapen, R. M. Heethaar, and A. C. van Rossum
Propagation of Onset and PeakTime of Myocardial Shortening in Time of Myocardial Shortening in Ischemic Versus Nonischemic Cardiomyopathy: Assessment by Magnetic Resonance Imaging Myocardial Tagging
J. Am. Coll. Cardiol.,
December 20, 2005;
46(12):
2215 - 2222.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. C. Lardo, T. P. Abraham, and D. A. Kass
Magnetic Resonance Imaging Assessment of Ventricular Dyssynchrony: Current and Emerging Concepts
J. Am. Coll. Cardiol.,
December 20, 2005;
46(12):
2223 - 2228.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
I. Schuster, G. Habib, C. Jego, F. Thuny, J.-F. Avierinos, G. Derumeaux, L. Beck, C. Medail, F. Franceschi, S. Renard, et al.
Diastolic Asynchrony Is More Frequent Than Systolic Asynchrony in Dilated Cardiomyopathy and Is Less Improved by Cardiac Resynchronization Therapy
J. Am. Coll. Cardiol.,
December 20, 2005;
46(12):
2250 - 2257.
[Abstract]
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J. Gorcsan III
Echocardiographic Strain Imaging for Myocardial Viability: An Improvement Over Visual Assessment?
Circulation,
December 20, 2005;
112(25):
3820 - 3822.
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K. Dohi, M. Suffoletto, S. Murali, R. Bazaz, and J. Gorcsan
Benefit of cardiac resynchronization therapy to a patient with a narrow QRS complex and ventricular dyssynchrony identified by tissue synchronization imaging
Eur J Echocardiogr,
December 1, 2005;
6(6):
455 - 460.
[Abstract]
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Top
Abstract
Methods
LVESVI. (Bottom) Correlation between baseline QRS duration and