CORRESPONDENCE: LETTER TO THE EDITOR
Reply
Ivan Barac, MD and
Mark V. Sherrid, MD*
* St. Luke’s-Roosevelt Hospital Center, Columbia University College of Physicians and Surgeons, 1000 10th Avenue, 3B-30, New York, New York 10019 (Email: msherrid{at}chpnet.org).
We appreciate the comments of Drs. Breithardt, Stolle, and Kuhn on our paper concerning premature termination of systolic left ventricular contraction in hypertrophic cardiomyopathy (HCM) with severe obstruction (1). Their results are in a similar group of patients, acquired by color-coded tissue Doppler imaging (TDI). Although the data on timing of events recorded by TDI are not available in their reports (2,3), we agree that they have described the same phenomenon: an abnormal drop in left ventricular longitudinal shortening velocities in obstructive HCM. This abnormality was not observed in nonobstructed patients. The fact that it was abolished by reduction of the gradient either with pharmacologic intervention (1) or with alcohol ablation (2,3) confirms that the drop is caused by the acute imposition of afterload.
Breithardt et al. (2,3) observed a second late systolic velocity peak of TDI velocities after the midsystolic drop. We observed premature termination of contraction. We offer 2 possible explanations for the differences between our findings:
- 1 Our group included only patients with very severe left ventricular outflow track gradients: All of the patients had gradients of >60 mm Hg, with a mean gradient of 132 mm Hg. Dr. Breithardt’s obstructed group included patients with gradients >30 mm Hg, with a mean gradient of 71 mm Hg (3). We believe that more severe obstruction among our patients produced the more pronounced abnormality: premature termination of septal longitudinal shortening. We also found these abnormalities in the lateral wall, which was not reported by Breithardt et al.
- 2 We used spectral TDI, in contrast to Breithardt et al., who used color-coded TDI. The differences between techniques have been described (4) and may have contributed to the differences observed. Comparisons in the same patients of peak spectral versus mean color-coded TDI tracings would be of interest, particularly with respect to the timing of contraction abnormalities.
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References
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- Barac I, Upadya S, Pilchik R, et al. Effect of obstruction on longitudinal left ventricular shortening in hypertrophic obstructive cardiomyopathy J Am Coll Cardiol 2007;49:1203-1211.[Abstract/Free Full Text]
- Breithardt OA, Stolle B, Franke A, Janssens U, Hanrath P, Kuhn H. Mid-systolic septal deceleration—a new sign of left ventricular outflow obstruction obtained by color-coded tissue Doppler echocardiography Z Kardiol 2003;92:1003-1007.[CrossRef][ISI][Medline]
- Breithardt OA, Beer G, Stolle B, et al. Mid-systolic septal deceleration in hypertrophic cadiomyopathy: clinical value and insight into pathophysiology of outflow tract obstruction by tissue Doppler echocardiography Heart 2005;91:379-380.[Free Full Text]
- McCulloch M, Zoghbi WA, Davis R, Thomas C, Dokainish H. Color tissue Doppler myocardial velocities consistently underestimate spectral tissue Doppler velocities: impact on calculation peak transmitral pulsed Doppler velocity/early diastolic tissue Doppler velocity (E/Ea) J Am Soc Echocardiogr 2006;19:744-748.[CrossRef][ISI][Medline]
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