Effect of left atrioventricular interphase on cardiac function after dual-chamber pacemaker implantation in patients with high-degree atrioventricular block / 中国医师进修杂志

ABSTRACT

Objective:To study the effect of left atrioventricular interphase (LAVI) via esophageal electrocardiogram on cardiac function after dual-chamber pacemaker implantation in patients with high-degree atrioventricular block.Methods:Using a prospective approach, 40 patients with high-degree atrioventricular block who would undergo dual-chamber pacemaker implantation from January 2017 to March 2018 in Department of Cardiovascular Medicine, Dalian Municipal Central Hospital Affiliated of Dalian Medical University were enrolled. All patients accepted esophageal electrocardiogram tests at 3 months after the implantation, to exam the interatrial conduction time (IACT) of sinus rhythm and pacing rhythm, and interventricular conduction time (IVCT). Then based on the outcome of the echocardiography test, the optimal atrioventricular delay (AVD) of the pacemaker of each patient was determined while the LAVI differed from 100 ms to 150 ms. The left ventricular ejection fraction (LVEF), peak speed of blood flow velocity in early mitral orifice diastole (E), E peak deceleration time (EDT), peak speed of early mitral annular diastolic movement (e′), isovolumic relaxation time (IVRT) and left atrial volume (LAV) were tested by echocardiogram before implantation, before AVD adjustment at 3 months after implantation, after AVD adjustment at 3 months after implantation, and 6, 12, and 18 months after implantation. Then, the left atrial volume index (LAV/body surface area) and E/e′ were calculated.Results:Among the 40 patients, the IACT of sinus rhythm was (55.55 ± 10.33) ms, the IACT of pacing rhythm was (93.95 ± 12.77) ms, and the mean IVCT was (63.20 ± 17.84) ms; the optimal LAVI was 110 to 150 (132.00 ± 10.43) ms, and notably, the optimal LAVI between 120 and 140 ms was 82.5% (33/40). The LVEF, EDT, IVRT, left atrial volume index and E/e′ from before AVD adjustment of 3 months after implantation to follow-up endpoint (18 months after implantation) were significantly improved compared with those before implantation, and there were statistical differences ( P<0.01); the EDT and IVRT after AVD adjustment at 3 months after implantation were significantly improved than those before AVD adjustment at 3 months after implantation (142.15 ± 35.58) ms vs. (125.94 ± 31.13) ms and (119.52 ± 22.15) ms vs. (133.92 ± 23.87) ms, and there were statistical differences ( P<0.05); the IVRT and left atrial volume index 18 months after implantation were significantly improved compared with those before AVD adjustment at 3 months after implantation (122.07 ± 16.99) ms vs. (133.92 ± 23.87) and 32.94 ± 3.22 vs. 35.43 ± 5.76, and there were statistical differences ( P<0.05). Conclusions:Optimizing the LAVI after dual-chamber pacemaker implantation via esophageal electrocardiogram can improve the long-term prognosis of patients with high-degree atrioventricular block.