Biventricular Pacemaker Optimization Guided by Comprehensive Echocardiography—Preliminary Observations Regarding the Effects on Systolic and Diastolic Ventricular Function and Third Heart Sound
published online 31 May 2010.
Background
Doppler echocardiography of mitral inflow or aortic outflow or both has been validated and advocated to guide biventricular (Biv) pacemaker optimization. A comprehensive and tailored Doppler echocardiographic evaluation may be required in patients with heart failure to assist with Biv pacemaker optimization. The third heart sound (S3), an acoustic cardiographic parameter, has been demonstrated to be a highly specific finding for hemodynamic evaluation in patients with heart failure. The aims of this study were to evaluate the use of comprehensive Doppler echocardiography as a guide during Biv pacemaker optimization in patients after cardiac resynchronization therapy and to evaluate the feasibility of S3 intensity to be a cost-efficient parameter for Biv pacemaker optimization compared with Doppler echocardiography.
Methods
Comprehensive Doppler echocardiographic evaluations were performed during Biv pacemaker optimization in 44 patients referred for pacemaker optimization (mean age, 71 ± 12 years; mean left ventricular ejection fraction, 34 ± 11%). Blinded assessment of S3 intensity was performed simultaneously using acoustic cardiography. The correlation and improvement in cardiac hemodynamics were analyzed between the methods.
Results
Echocardiographically guided optimization resulted in significant improvements in the left ventricular outflow velocity-time integral (15.92 ± 4.77 to 18.51 ± 5.19 cm, P < .001), ejection time (278 ± 40 to 293 ± 40 ms, P < .001), myocardial performance index (0.57 ± 0.19 to 0.44 ± 0.14, P < .002), and peak pulmonary artery systolic pressure (42 ± 13 to 36 ± 11 mm Hg, P < .04) and decreased S3 intensity from 4.81 ± 1.84 at baseline to 3.96 ± 1.22 after optimization (P < .02) for the overall study group and from 6.63 ± 1.37 to 4.85 ± 1.13 (P < .001) in the 18 patients with baseline S3 intensity > 5.0. The correlation between echocardiographic and acoustic cardiographic S3 intensity for optimal atrioventricular delay was 0.86 (P < .001) and for optimal interventricular delay was 0.64 (P < .001). Optimal atrioventricular delay was identical by echocardiographic and acoustic cardiographic S3 intensity in 56%, and optimal interventricular delay was identical in 75% of patients. Pacemakers were permanently programmed on the basis of echocardiographic evaluation. In 35 patients available for follow up, the mean New York Heart Association class reduced from 2.55 ± 0.81 to 1.77 ± 0.90 (P < .001) and the mean quality-of-life score as assessed by Minnesota Living With Heart Failure Questionnaire improved from 45 ± 28 to 32 ± 28 (P = .08) at 2.5 ± 2.1 months.
Conclusion
Comprehensive echocardiographically guided Biv pacemaker optimization produces significant improvement in Doppler echocardiographic hemodynamics, a reduction in S3 intensity, and an improvement in functional class in patients after cardiac resynchronization therapy.
Non Invasive Diagnostic Services and Echocardiography Laboratory, Cardiovascular and Thoracic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California
Reprint requests: Tasneem Z. Naqvi, MBBS, FRCP, FACC, FASE, University of Southern California, Keck School of Medicine, 1510 San Pablo Street, Suite 322, Los Angeles, CA 90033.
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