Right ventricular systolic function and cardiac resynchronization therapy.
OBJECTIVE
The effect of cardiac resynchronization therapy (CRT) on right ventricular ejection fraction (RVEF) has not been well studied. Furthermore, it is unclear whether baseline RVEF influences response to CRT. To evaluate the acute and chronic effects of CRT on right ventricular systolic function, and to investigate whether baseline RVEF impacts response to CRT.


RESULTS
Forty-four patients with a standard indication for CRT underwent radionuclide angiography at baseline and after at least 6 months' follow-up for measuring RVEF, right ventricular synchrony (using phase analysis), and left ventricular ejection fraction (LVEF). In addition, NYHA functional class and 6-min walking distance (6MWD) were evaluated. There were no significant acute changes in RVEF with CRT. After a mean follow-up of 9 +/- 5 months, RVEF was slightly improved (by 1.9 +/- 5.0% in absolute terms, P = 0.016), and to a lesser extent than LVEF (5.1 +/- 9.0%, P = 0.009 compared with RVEF). Right ventricular dyssynchrony was significantly improved at follow-up (P = 0.016). Patients with a baseline RVEF < or = 0.35 (n = 19) were less likely to improve in NYHA class (P = 0.016), and also tended to improve less in 6MWD and LVEF (P < 0.06).


CONCLUSIONS
Cardiac resynchronization therapy has no acute effect on RVEF, and only slightly improves RVEF at follow-up. Patients with reduced RVEF at baseline were less likely to respond to CRT, indicating that right ventricular systolic dysfunction may play a role in patient selection.
Burri
Haran
H
Cardiology Service, University Hospital of Geneva, 23, Micheli-du-Crest, Geneva 1211, Switzerland. haran.burri@hcuge.ch
Domenichini
Giulia
G
Sunthorn
Henri
H
Fleury
Eric
E
Stettler
Carine
C
Foulkes
Ines
I
Shah
Dipen
D
D000368:Aged; D002304:Cardiac Pacing, Artificial; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging; D013318:Stroke Volume / Q000502:physiology*; D013599:Systole / Q000502:physiology*; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D016277:Ventricular Function, Left / Q000502:physiology; D016278:Ventricular Function, Right / Q000502:physiology*