[Effects of temporary dual-chamber cardiac pacing in refractory cardiac failure].
The authors studied 18 patients (15 men, 3 women) with an average age of 67 +/- 8 years with refractory cardiac failure. In order to determine the potential of pacing to raise cardiac output in severe cardiac failure. The average ejection fraction was 26 +/- 6.5%. All patients were in sinus rhythm:resting cardiac output was 3.35 l/min. Two temporary pacing catheters were positioned in the right atrium and at the apex of the right ventricle for dual-chamber mode pacing triggered by the spontaneous P waves. Changes in cardiac output were measured by Doppler echocardiography at different values of atrioventricular delay. Patients were considered to be responders if their cardiac outputs rose by 15%. In 7 patients meeting this criterion, the average increase in cardiac output was 27% (2.99 +/- 0.7 to 3.81 +/- 0.86 l/mn; p < 0.01); all had dilated cardiomyopathies with left bundle branch block and the optimal AV delay was 103 +/- 21 ms (80-140 ms); the duration of diastolic filling increased from 212 +/- 98 to 292 +/- 116 ms (p = 0.02). In the non-responding group (11 patients with an increase of cardiac output of only 3.6 +/- 0.09 to 3.9 +/- 0.92 l/mn; p < 0.01), the underlying disease process was mainly ischaemic. Two predictive factors of efficacy of dual-chamber pacing were identified: a short ventricular filling period (29 +/- 8% of the RR interval in the responders vs 44 +/- 9% in the non-responders; p < 0.01) and the presence of 1st degree atrioventricular block. Dual-chamber pacing could be a valuable method of increasing resting cardiac outputs in a selected group of patients with severe, refractory, cardiac failure.
Scanu
P
P
Service de cardiologie, CHU de Caen.
Lecluse
E
E
Michel
L
L
Bureau
G
G
Saloux
E
E
Cleron
S
S
Valette
B
B
Grollier
G
G
Potier
J C
JC
Foucault
J P
JP
D000368:Aged; D000369:Aged, 80 and over; D002302:Cardiac Output; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015150:Echocardiography, Doppler; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D017211:Treatment Failure; D016896:Treatment Outcome