Clinical significance of preserving spontaneous QRS wave in the therapy of DDD pacing for sick sinus syndrome.
The aim of this clinical crossover study was to elucidate the effects of atrioventricular (AV) synchronous pacing on cardiac function in patients with sick sinus syndrome (SSS). Thirty SSS patients, each with dual chamber pacemaker (DDD), were enrolled and divided into two groups based on echocardiographic findings. Group A (n = 16) had hypertensive heart disease (wall thickness 11 approximately 12 mm) or mitral or aortic regurgitation (Grade I or II). Group B (n = 14) had no organic heart disease. Three successive 3-month pacing periods were tested. For the first 3 months, long AV delay that achieved > 80% ventricular sensing was chosen. For the next 3 months, AV delay was abbreviated to achieve > 80% ventricular pacing at an optimal AV interval. For the final 3 months, the first setting was resumed. At the end of each period, M mode echocardiography, pulsed-Doppler study, and measurement of plasma brain natriuretic peptide (BNP) level were conducted. In both groups, echocardiographic parameters were not significantly changed during the evaluation. In group A, plasma BNP level was significantly higher at the end of the short AV delay period than at the long AV delay period (P = 0.009), while in group B it did not differ during each period. AV synchronous pacing (> 80% ventricular pacing) in the SSS patients with a DDD pacemaker implanted could increase the ventricular load, and it is better to preserve the spontaneous QRS with the DDD mode with prolonged AV delay in patients with mild hypertensive or valvular disease.
Department of Clinical Molecular Genetics and Laboratory Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan. mani@koto.kpu-m.ac.jp
Hiroki
H
Mani
Takeshi
T
Shirayama
Yoko
Y
Suzaki
Tomohiko
T
Sakatani
Takashi
T
Sakamoto
Midori
M
Yamamura
Hiroaki
H
Matsubara
Masafumi
M
Taniwaki
D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D009202:Cardiomyopathies / Q000150:complications; D004452:Echocardiography; D018619:Echocardiography, Doppler, Pulsed; D005260:Female; D006349:Heart Valve Diseases / Q000150:complications; D006801:Humans; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood; D012804:Sick Sinus Syndrome / Q000097:blood / Q000150:complications / Q000503:physiopathology / Q000628:therapy*
D020097:Natriuretic Peptide, Brain