The first two authors contributed equally to this work.
Concordance Between Mechanical and Electrical Dyssynchrony in Heart Failure Patients: A Function of the Underlying Cardiomyopathy?
Article first published online: 30 JUL 2007
Journal of Cardiovascular Electrophysiology
Volume 18, Issue 10, pages 1022–1027, October 2007
How to Cite
TOURNOUX, F., DONAL, E., LECLERCQ, C., DE PLACE, C., CROCQ, C., SOLNON, A., COHEN-SOLAL, A., MABO, P. and DAUBERT, J.-C. (2007), Concordance Between Mechanical and Electrical Dyssynchrony in Heart Failure Patients: A Function of the Underlying Cardiomyopathy?. Journal of Cardiovascular Electrophysiology, 18: 1022–1027. doi: 10.1111/j.1540-8167.2007.00900.x
Manuscript received 29 November 2006; Revised manuscript received 26 May 2007; Accepted for publication 28 May 2007.
- Issue published online: 30 JUL 2007
- Article first published online: 30 JUL 2007
- mechanical dyssynchrony;
- electrical dyssynchrony;
- tissue Doppler imaging;
- heart failure etiology;
- QRS duration
Background: Cardiac resynchronization therapy (CRT) improves heart failure (HF) symptoms through a reduction of cardiac mechanical dyssynchrony. Mechanical dyssynchrony is currently estimated by electrical dyssynchrony (QRS duration). It is known that electrical and mechanical dyssynchrony are not well correlated in HF patients. However, there is limited information about whether this relationship might be influenced by the underlying cardiomyopathy.
Methods: Doppler echocardiography was performed in 88 patients presenting with heart failure due to ischemic (n = 42) or nonischemic (n = 46) heart disease, left ventricular ejection fraction <40%, New York Heart Association class II–IV, regardless of their QRS duration. Interventricular dyssynchrony was assessed by the time interval between preaortic and prepulmonary ejection times. Intraventricular dyssynchrony was ascertained by (1) the delay between the earliest and the latest peak negative longitudinal strain recorded in the basal and mid-segments of the lateral and septal walls (TMinMax) and (2) the standard deviation of time-to-peak in the same segments (SDdys).
Results: The correlation coefficient between QRS duration and mechanical interventricular dyssynchrony was r = 0.47 (P < 0.001) in patients with nonischemic disease and nonsignificant in patients with ischemic disease. Similarly, the correlation coefficient between QRS duration and mechanical intraventricular dyssynchrony was significant in patients with nonischemic disease (r = 0.37, P = 0.01 for TMinMax; r = 0.42, P = 0.003 for SDdys) and nonsignificant in patients with ischemic disease.
Conclusion: The concordance between electrical dyssynchrony assessed by QRS duration and mechanical dyssynchrony assessed by myocardial strain is dependent upon the underlying cardiomyopathy. This observation may improve our understanding of the various responses observed in CRT patients.