Abstract 167: Left Ventricular Ischemia: Beneficial Effects of Chronic Periodic Acceleration in Rats
BACKGROUND: Whole body periodic acceleration (pGz) is the sinusoidal head-foot motion in the spinal axis. pGz increases pulsatile vascular shear stress to the endothelium, and microvascular flow. pGz activates endothelial and neuronal nitric oxide synthase (eNOS, nNOS) promoting increased release of nitric oxide (NO) in pigs, sheep, rats, isolated aorta, and humans. The purpose of this study was to ascertain whether long term (4 weeks) daily treatments with pGz, improves myocardial function in a rat model of chronic left ventricular ischemia.
METHODS Forty male rats (310±9 g) were anesthetized and underwent myocardial infarction (MI) by coronary artery ligation, followed by randomization to pGz or Control (CONT). Twenty four hours after ligation, unsedated restrained rats, were treated with daily 1 hr, pGz (f=6 cps, a= ±3.4 m/s2), or placed in the same restrainer without pGz (CONT). Echocardiograms where performed at; post-infarction (PI), 2days,1, 3,and 4 weeks after ligation. Infarct size and, invasive hemodynamics where performed at PI, 2 or 4 weeks after ligation.
RESULTS: Infarct size was not different between groups (CONT 38% (4) vs. pGz 36%(3) ). Four weeks of pGz improved survival (CONT 50% vs. pGz 80% †). Ejection Fraction (EF%), Fractional Shortening (FS%) and Anterior Wall Thickness (AWT) where significantly better in pGz vs. CONT. (TABLE); Data X(SD) †P<0.001 CONT vs. pGz.
CONCLUSIONS: Despite similar infarct size, treatment with pGz after ischemia improved survival, increased EF, and FS, ameliorated thinning of the anterior wall and decreased transmural infarct size. This simple non-invasive therapeutic method of cardioprotection has the potential to improve functional and ventricular remodeling outcomes after MI.
- Myocardial infarction
- Ventricular function
- Ventricular remodeling
- Post cardiac resuscitation
- Experimental heart failure
- © 2012 by American Heart Association, Inc.