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Effects of Single‐Site Versus Biventricular Epicardial Pacing on Myocardial Performance in an Immature Animal Model of Atrioventricular Block
Author(s) -
COJOC ANCA,
REEVES JAMES G.,
SCHMARKEY LAURA,
STRIEPER MARGARET J.,
JOYNER RONALD W.,
WAGNER MARY B.,
CAMPBELL ROBERT M.,
VINTENJOHANSEN JACOB,
FRIAS PATRICIO A.
Publication year - 2006
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.2006.00504.x
Subject(s) - medicine , cardiology , qrs complex , sinus rhythm , ventricular pacing , doppler imaging , apex (geometry) , ablation , catheter , heart failure , diastole , atrial fibrillation , blood pressure , surgery , anatomy
Single‐site ventricular pacing results in dyssynchronous ventricular activation and may contribute to ventricular dysfunction. We evaluated epicardial biventricular (BiV) pacing as a means of maintaining synchronous ventricular activation in an acute piglet model of AV block with normal ventricular anatomy and function. Methods and Results: We used left ventricular (LV) impedance catheters and tissue Doppler imaging to assess the cardiodynamics of immature piglets (n = 6, 33–78 days, 9.35 ± 0.85 kg). Following catheter ablation of the AV node, a pacemaker was programmed 20 beats per minute above the intrinsic atrial rate. The animals were paced at 5‐minute intervals via the following AV sequential configurations: Right atrial appendage (RA)‐RV apex (RVA), RA‐LV apex (LVA), and RA‐biventricular (RVA/LVA). RA‐RVA was the experimental control. LV systolic mechanics, measured by the slope of the end‐systolic pressure–volume relationship (E es ), increased with BiV pacing (12.8 ± 3.4 mmHg/mL, P < 0.02) or single‐site LVA pacing (10.6 ± 3.4 mmHg/mL, P < 0.05) compared with single‐site RVA pacing (8.3 ± 1.4 mmHg/mL). QRS duration lengthened compared with sinus rhythm (42 ± 8 msec) with either RVA (56 ± 9 msec, P < 0.02) or LVA (54 ± 7 msec, P < 0.03), but not with BiV (48 ± 7 msec, P = 0.08) pacing. Tissue Doppler imaging showed LV dyssynchrony with RVA (septal‐to‐lateral delay 46.0 ± 51.7 msec), with return toward normal with LVA (−9.6 ± 33.6 msec, P < 0.04) or BiV (−4.1 ± 33.8 msec, P < 0.04) pacing. Conclusions: In this acute immature piglet model of AV block, LV performance improved with single‐site pacing from the LVA and BiV pacing (RVA/LVA), as compared with single‐site pacing from the RVA. These changes correlated with tissue Doppler indices of mechanical synchrony, though not necessarily with QRS duration.