1. Comparison of Efficacy of Reverse Remodeling and Clinical Improvement for Relatively Narrow and Wide QRS Complexes After Cardiac Resynchronization Therapy for Heart Failure.
- Author
-
YU, CHEUK‐MAN, FUNG, JEFFREY WING‐HONG, CHAN, CHI‐KIN, CHAN, YAT‐SUN, ZHANG, QING, LIN, HONG, YIP, GABRIEL W.K., KUM, LEO C.C., KONG, SHUN‐LING, ZHANG, YAN, and SANDERSON, JOHN E.
- Subjects
HEART failure ,HEMODYNAMICS ,CARDIAC contraction ,CARDIAC pacemakers ,DOPPLER echocardiography ,HEART conduction system ,CARDIAC pacing - Abstract
Efficacy of CRT for Mildly Prolonged QRS.. Introduction:Cardiac resynchronization therapy (CRT) has been shown to reverse left ventricular (LV) remodeling and improve symptoms in heart failure patients with wide QRS complexes; however, its role in patients with mildly prolonged QRS complexes is unclear. This study investigated if CRT benefited patients with mildly prolonged QRS complexes>120 to 150 ms and explored if the severity of systolic asynchrony determined such a response.Methods and Results:Fifty-eight patients (age 66± 11 years, 66% male) who had undergone CRT were studied prospectively. Of these patients, 27 had QRS duration between 120 and 150 ms (group A), and 31 had QRS duration>150 ms (group B). Tissue Doppler echocardiography and clinical assessment were performed at baseline and 3 months after CRT. Both groups had significant reduction of LV volume and increased ejection fraction,+dP/dt, and sphericity index (all P<0.05). These improvements were greater in group B and were explained by the higher prevalence of systolic intraventricular asynchrony. Significant reverse remodeling (reduction of LV end-systolic volume>15%) was evident in 46% of group A patients and 68% of group B patients. Improvement in clinical endpoints was observed in both groups (all P<0.01), although the changes in metabolic equivalent and New York Heart Association functional class were greater in group B. In both groups, systolic asynchrony index (T
S -SD) was the most important predictor of reverse remodeling (r=−0.78, P<0.001) and was the only independent predictor in the multivariate model (β=−1.80, confidence interval=−2.18 to−1.42, P<0.001); QRS duration was not. A predefined TS -SD value>32.6 ms had a sensitivity of 94% and specificity of 83% to predict reverse remodeling. Improvement of intraventricular asynchrony after CRT was evident only in responders (P= 0.01).Conclusion:Improvement of LV remodeling and clinical status is evident after CRT in heart failure patients with QRS duration>120 to 150 ms. These responders are closely predicted by the severity of prepacing intraventricular asynchrony but not QRS duration.(J Cardiovasc Electrophysiol, Vol. 15, pp. 1-8, September 2004) [ABSTRACT FROM AUTHOR]- Published
- 2004
- Full Text
- View/download PDF