Cardiac resynchronization therapy: a novel adjunct to the treatment and prevention of systemic right ventricular failure.
OBJECTIVE
This study aimed to evaluate the technical feasibility and hemodynamic benefit of cardiac resynchronization therapy (CRT) in patients with systemic right ventricle (RV).


BACKGROUND
Patients with a systemic RV are at high risk of developing heart failure. Cardiac resynchronization therapy may improve RV function in those with electromechanical dyssynchrony.


METHODS
Eight patients (age 6.9 to 29.2 years) with a systemic RV and right bundle-branch block (n = 2) or pacing from the left ventricle (LV) (n = 6) with a QRS interval of 161 +/- 21 ms underwent CRT (associated with cardiac surgery aimed at decrease in tricuspid regurgitation in 3 of 8 patients) and were followed-up for a median of 17.4 months.


RESULTS
Change from baseline rhythm to CRT was accompanied by a decrease in QRS interval (-28.0%, p = 0.002) and interventricular mechanical delay (-16.7%, p = 0.047) and immediate improvement in the RV filling time (+10.9%, p = 0.002), Tei index (-7.7%, p = 0.008), estimated RV maximum +dP/dt(+45.9%, p = 0.007), aortic velocity-time integral (+7.0%, p = 0.028), and RV ejection fraction by radionuclide ventriculography (+9.6%, p = 0.04). The RV fractional area of change increased from a median of 18.1% before resynchronization to 29.5% at last follow-up (p = 0.008) without a significant change in the end-diastolic area (+4.0%, p = NS).


CONCLUSIONS
The CRT yielded improvement in systemic RV function in patients with spontaneous or LV pacing-induced electromechanical dyssynchrony and seems to be a promising adjunct to the treatment and prevention of systemic RV failure.
Janousek
Jan
J
Kardiocentrum, University Hospital Motol. Prague, Czech Republic. jan.janousek@lfmotol.cuni.cz
Tomek
Viktor
V
Chaloupecký
V Aclav
VA
Reich
Oleg
O
Gebauer
Roman A
RA
Kautzner
Josef
J
Hucín
Bohumil
B
D000293:Adolescent; D000328:Adult; D002037:Bundle-Branch Block / Q000503:physiopathology / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D002648:Child; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D010138:Pacemaker, Artificial; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology; D013318:Stroke Volume / Q000502:physiology; D016896:Treatment Outcome; D018497:Ventricular Dysfunction, Right / Q000503:physiopathology / Q000517:prevention & control