Acute hemodynamic benefits of bi-atrial atrioventricular sequential pacing with the optimal atrioventricular delay.
OBJECTIVE
We evaluate the acute effects on hemodynamics of bi-atrial (BiA) pacing with the optimal atrioventricular (AV) delays, in comparison with high right atrial (HRA) pacing and coronary sinus (CS) pacing.


BACKGROUND
Bi-atrial pacing has been suggested as one of the alternative therapy for preventing the recurrence of atrial fibrillation (AF). There are, however, few reports on the hemodynamic effects of BiA pacing, and the results that exist are controversial.


METHODS
Twenty patients were paced from HRA, left lateral site of CS, and both sites with the optimal AV delays at 80 and 100 beats/min, in random order. After 5-min pacing, maximal P-wave duration in a 12-lead electrocardiogram, cardiac output (CO), pulmonary capillary wedge pressure (PCWP), and the transmitral flow pattern by transthoracic echocardiography were measured.


RESULTS
Compared with HRA and CS pacing, BiA pacing delivered the shortest P-wave duration (HRA: 130 +/- 14 ms, CS: 132 +/- 19 ms, and BiA: 94 +/- 8 ms, respectively, p < 0.001) and the most improvement in CO and PCWP (HRA: 3.63 +/- 0.67 l/min and 9.2 +/- 4.3 mm Hg, CS: 3.71 +/- 0.70 l/min and 8.8 +/- 3.4 mmHg, and BiA: 3.88 +/- 0.63 l/min and 8.0 +/- 3.1 mmHg, respectively, p < 0.01). Bi-atrial pacing also significantly increased the mitral flow time velocity integral and peak A-wave velocity by transthoracic echocardiography, compared with HRA and CS pacing (HRA: 7.6 +/- 1.4 cm and 68.8 +/- 12.2 cm/s, CS: 7.8 +/- 1.4 cm and 70.5 +/- 14.5 cm/s, and BiA: 8.2 +/- 1.2 cm and 76.3 +/- 14.2 cm/s, respectively, p < 0.01). Bi-atrial pacing most significantly decreased the intervals between the atrial pacing spike and the peak of A-wave (HRA: 180 +/- 28 ms, CS: 165 +/- 21 ms, and BiA: 157 +/- 19 ms, respectively, p < 0.01). These improvements in hemodynamics significantly correlated with interatrial conduction delay.


CONCLUSIONS
Bi-atrial pacing made the most significant improvements of hemodynamics. These benefits may be due to the improvements in interatrial conduction delay and atrial dyssynchrony.
Doi
Atsushi
A
Department of Internal Medicine and Cardiology, Osaka City University Graduate School of Medicine, Osaka, Japan.
Takagi
Masahiko
M
Toda
Iku
I
Yoshiyama
Minoru
M
Takeuchi
Kazuhide
K
Yoshikawa
Junichi
J
D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000517:prevention & control*; D016279:Atrial Function, Left / Q000502:physiology; D001283:Atrioventricular Node / Q000503:physiopathology*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004452:Echocardiography; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D013997:Time Factors