LETTER TO THE EDITOR
Reply
Tomotsugu Tabata, MD, FACC
Department of Digestive and Cardiovascular Medicine, The University of Tokushima, 2-50-1 Kuramoto, Tokushima, 770-8503 Japan
Allan L. Klein, MD, FACC
Cardiovascular Imaging Center, Department of Cardiovascular Medicine, The Cleveland Clinic Foundation, 9500 Euclid Ave., Desk F-15, Cleveland, OH 44195, USA
tommy{at}clin.med.tokushima-u.ac.jp kleina{at}ccf.org
We thank Drs. Arques and Roux for their comments concerning the increasing use of the deceleration time of the pulmonary venous early diastolic flow (PV-DT) in published reports. We agree that the PV-DT is a useful tool for estimating pulmonary capillary wedge pressure (PCWP) as a measure of the left ventricular (LV) filling pressure, especially in patients with normal sinus rhythm. As mentioned in our study (1), it is important to recognize the influence of several factors regarding use of pulmonary venous flow velocities in clinical practice.
When evaluating PV-DT to estimate PCWP, the influences of heart rate, mitral regurgitation (MR), atrial fibrillation (AF), and LV systolic function have to be taken into account. Of those factors, heart rate may have the largest influence on the PV-DT. Chirillo et al. (2) specifically paid attention to the two components of the deceleration slope of PV-DT. They speculated that the first component was mainly dependent on the initial driving pressure of the pulmonary venous flow, and the second component was affected by the duration of LV relaxation, LV compliance, and heart rate as reported by Little et al. (3). They found a strong correlation between the initial deceleration slope of PV-DT and PCWP during chronic AF with controlled ventricular rates. With faster heart rates, it would be difficult to separate the first and second components. Thus, PV-DT can estimate PCWP only when the heart rates are relatively slow. Matsukida et al. (4) have also reported that the PV-DT accurately predicted PCWP in patients with AF, whereas they only included patients with a heart rate of 60 to 80 beats/min. Both of the above investigators (2,4) excluded patients with AF and a rapid ventricular rate. It is well recognized that the loading conditions during AF are constantly changing; therefore, even when an average of consecutive several cardiac cycles of PV-DT is used, the value would vary depending on the selected beats.
The final issue is the effect of MR. Pozzoli et al. (5) reported that the PCWP can be reliably estimated by combining mitral inflow and pulmonary venous flow velocities even when MR was present. Although they have not evaluated PV-DT, the investigators have reported that the correlation between mitral deceleration time and PCWP was stronger in patients without MR. Furthermore, they have limited their results to apply to patients without atrial arrhythmias or tachycardia.
Thus, we conclude that the evaluation of the PV-DT for estimating PCWP is most useful in patients without MR with sinus rhythm and a relatively slower heart rate. As suggested by Drs. Arques and Roux, we believe that the improvement in the quality of pulmonary venous Doppler flow profile obtained by transthoracic techniques will enhance the future use of PV flow in clinical practice.
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References
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1. Tabata T, Thomas JD, Klein AL. Pulmonary venous flow by Doppler echocardiography: revisited 12 years later. J Am Coll Cardiol. 2003;41:1243–1250[Abstract/Free Full Text]
2. Chirillo F, Brunazzi MC, Barbiero M, et al. Estimating mean pulmonary wedge pressure in patients with chronic atrial fibrillation from transthoracic Doppler indexes of mitral and pulmonary venous flow velocity. J Am Coll Cardiol. 1997;30:19–26[Abstract]
3. Little WC, Ohno M, Kitzman DW, Thomas JD, Cheng CP. Determination of left ventricular chamber stiffness from the time for deceleration of early left ventricular filling. Circulation. 1995;92:1933–1939[Abstract/Free Full Text]
4. Matsukida K, Kisanuki A, Toyonaga K, et al. Comparison of transthoracic Doppler echocardiography and natriuretic peptides in predicting mean pulmonary capillary wedge pressure in patients with chronic atrial fibrillation. J Am Soc Echocardiogr. 2001;14:1080–1087[CrossRef][Medline]
5. Pozzoli M, Capomolla S, Pinna G, Cobelli F, Tavazzi L. Doppler echocardiography reliably predicts pulmonary artery wedge pressure in patients with chronic heart failure with and without mitral regurgitation. J Am Coll Cardiol. 1996;27:883–893[Abstract]
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