TY - JOUR
T1 - Immediate impairment of left ventricular mechanical performance and force-frequency relation by rate-responsive dual-chamber, but not atrial pacing
T2 - Implications from intraventricular isovolumic relaxation flow
AU - Lin, Mao Shin
AU - Lin, Jiunn Lee
AU - Liu, Yen Bin
AU - Wu, Chau Chung
AU - Lin, Lung Chun
AU - Chen, Ming Fong
PY - 2006/5/24
Y1 - 2006/5/24
N2 - Background: Despite the maintenance of atrioventricular (AV) synchrony, the detrimental effect of left ventricular asynchronization on mechanical performance and intraventricular flow by nonphysiologic right ventricular apical pacing in dual-chamber pacing, with and without rate adaptation, is not clear. Method: Twenty-seven consecutive patients receiving permanent pacemakers for symptomatic bradyarrhythmias (18 with DDD and 9 with AAI mode pacemakers) were evaluated with standard and tissue Doppler echocardiography before and 24 h after pacemaker implantation. The rate-response effect of pacing was studied by programmed rate with increments of 20, from 60 to 100/min. Results: Color M-mode echocardiography demonstrated that much more DDD patients developed new biphasic intraventricular flow during isovolumic relaxation period than AAI patients (13 / 18 versus 0 / 9, P < 0.001). In DDD patients, the ventricular relaxation represented by mitral annulus velocity in early diastole significantly attenuated (before vs. after DDDR, 8.5 ± 2.8 vs. 5.2 ± 1.2 cm/s, P < 0.05), and also the mitral flow propagation velocity (33 ± 11 vs. 25 ± 5 cm/s, P < 0.01). The myocardial performance index increased after DDD (0.70 ± 0.15 vs. 0.79 ± 0.24, P < 0.05) but not after AAI (0.61 ± 0.1 vs. 0.59 ± 0.08, P = NS). For both pacing groups, the accelerated pacing rate prolonged the isovolumic relaxation time and shortened the diastole period (P < 0.001). However, only DDD patients had a decreased mitral flow propagation velocity (P = 0.026) and an attenuated force-frequency relation in programmed rate acceleration. Conclusion: Despite the AV synchrony, right ventricular apical pacing immediately attenuates the left ventricular contraction and relaxation performance, which deteriorated further and suppressed the physiologically positive force-frequency relation after accelerated pacing rate.
AB - Background: Despite the maintenance of atrioventricular (AV) synchrony, the detrimental effect of left ventricular asynchronization on mechanical performance and intraventricular flow by nonphysiologic right ventricular apical pacing in dual-chamber pacing, with and without rate adaptation, is not clear. Method: Twenty-seven consecutive patients receiving permanent pacemakers for symptomatic bradyarrhythmias (18 with DDD and 9 with AAI mode pacemakers) were evaluated with standard and tissue Doppler echocardiography before and 24 h after pacemaker implantation. The rate-response effect of pacing was studied by programmed rate with increments of 20, from 60 to 100/min. Results: Color M-mode echocardiography demonstrated that much more DDD patients developed new biphasic intraventricular flow during isovolumic relaxation period than AAI patients (13 / 18 versus 0 / 9, P < 0.001). In DDD patients, the ventricular relaxation represented by mitral annulus velocity in early diastole significantly attenuated (before vs. after DDDR, 8.5 ± 2.8 vs. 5.2 ± 1.2 cm/s, P < 0.05), and also the mitral flow propagation velocity (33 ± 11 vs. 25 ± 5 cm/s, P < 0.01). The myocardial performance index increased after DDD (0.70 ± 0.15 vs. 0.79 ± 0.24, P < 0.05) but not after AAI (0.61 ± 0.1 vs. 0.59 ± 0.08, P = NS). For both pacing groups, the accelerated pacing rate prolonged the isovolumic relaxation time and shortened the diastole period (P < 0.001). However, only DDD patients had a decreased mitral flow propagation velocity (P = 0.026) and an attenuated force-frequency relation in programmed rate acceleration. Conclusion: Despite the AV synchrony, right ventricular apical pacing immediately attenuates the left ventricular contraction and relaxation performance, which deteriorated further and suppressed the physiologically positive force-frequency relation after accelerated pacing rate.
KW - Diastolic dysfunction
KW - Echocardiography
KW - Pacemaker
KW - Tissue Doppler imaging
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U2 - 10.1016/j.ijcard.2005.06.055
DO - 10.1016/j.ijcard.2005.06.055
M3 - Article
C2 - 16054251
AN - SCOPUS:33646257534
SN - 0167-5273
VL - 109
SP - 367
EP - 374
JO - International Journal of Cardiology
JF - International Journal of Cardiology
IS - 3
ER -