Effect of Left Ventricular Endocardial Activation Pattern on Echocardiographic and Clinical Response to Cardiac Resynchronization Therapy

Jeffrey W H Fung ^1*, Joseph Y S Chan ¹, Gabriel W K Yip ², Hamish C K Chan ¹, Winnie W L Chan ¹, Qing Zhang ² and Cheuk-Man Yu ²

¹ Prince of Wales Hospital, Hong Kong
² The Chinese University of Hong Kong, Hong Kong

^* To whom correspondence should be addressed. E-mail: jwhfung{at}cuhk.edu.hk.

Accepted 8 January 2007

Abstract

Objective To explore the left ventricular (LV) electrical activation pattern in heart failure (HF) and its implication to cardiac resynchronization therapy (CRT).

Design Observational study

Setting University Teaching Hospital

Patients 23 optimally treated HF patients with New York Heart Association class III, QRS duration >120ms and LV ejection fraction <35%.

Interventions The LV endocardial activation pattern and total activation time (Tat) was determined by non-contact mapping and the LV mechanical dyssynchrony was determined by standard deviation (Ts-SD) and maximal difference (Ts-diff) of time to peak systolic contraction (Ts) among 12 LV segments using tissue Doppler imaging before receiving CRT.

Main outcome measures Correlation between electrical and mechanical dyssynchrony; volumetric responder to CRT at 3 months; HF hospitalization or death by Kaplan Meier analysis

Results Homogenous (Type I, n= 8) and presence of conduction block (Type II, n=15) patterns were identified. Significant correlation between Tat and Ts-SD/Ts-diff was noted only in Type II (r = 0.73/0.56, p = 0.002/0.03). Ts-SD and Ts-diff in Type II were significantly longer than Type I. 12 patients (80%) in Type II and 2 (25%) in Type I were CRT responders (p=0.01). After 487 ± 447 days, patients with Type II pattern had significantly lower risk of HF hospitalization or death than those with Type I (Log rank GBP q2= 5.25; p=0.02).

Conclusion Patients with Type II LV endocardial activation pattern had a more favorable echocardiographic and clinical response to CRT than those with Type I pattern.

Keywords: cardiac resynchronization therapy, heart failure, non-contact mapping, tissue Doppler imaging

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

Relevant Article

WEB TOP 10
Heart 2007 93: 791. [Extract] [Full Text] [PDF]

This article has been cited by other articles:

• Fang, F., Chan, J. Y.-S., Yip, G. W.-K., Xie, J.-M., Zhang, Q., Fung, J. W.-H., Lam, Y.-Y., Yu, C.-M. (2009). Prevalence and determinants of left ventricular systolic dyssynchrony in patients with normal ejection fraction received right ventricular apical pacing: a real-time three-dimensional echocardiographic study. Eur J Echocardiogr 0: jep171v1-jep171 [Abstract] [Full Text]  
• Sanderson, J. E. (2009). Echocardiography for cardiac resynchronization therapy selection: fatally flawed or misjudged?. J Am Coll Cardiol 53: 1960-1964 [Abstract] [Full Text]  
• Kautzner, J., Peichl, P. (2008). Selecting CRT candidates: the value of intracardiac mapping. Europace 10: iii106-iii109 [Abstract] [Full Text]  
• Chung, R, Sutton, R, Henein, M Y (2008). Beyond dyssynchrony in cardiac resynchronisation therapy. Heart 94: 991-994 [Abstract] [Full Text]  
• Fung, J. W H, Yip, G. W K, Yu, C.-M. (2008). Does atrial fibrillation preclude biventricular pacing?. Heart 94: 826-827 [Full Text]  
• Kimmel, M. W., Skadsberg, N. D., Byrd, C. L., Wright, D. J., Laske, T. G., Iaizzo, P. A. (2007). Single-site ventricular and biventricular pacing: investigation of latest depolarization strategy. Europace 9: 1163-1170 [Abstract] [Full Text]