Ventricular Restraint Therapy for Heart Failure: Is the Right Ventricle Different from the Left Ventricle?
Lawrence S. Lee, MD, Suyog A. Mokashi, MD, Jan D. Schmitto, MD, PhD, Otavio Coelho-Filho, R., MD, Morton Bolman III, MD, Frederick Y. Chen, MD, PhD
Brigham and Women’s Hospital, Boston, MA
PURPOSE OF STUDY
The effects of ventricular restraint on the left ventricle (
This study was performed in two parts:
Part I: Acute Studies. We studied the acute effects of restraint on
Part II: Chronic Studies. We studied the chronic effects of passive restraint therapy over four months in an ovine model of ischemic dilated cardiomyopathy. Heart failure was induced in sheep (n=6) by coronary artery ligation, and a polypropylene mesh was wrapped around the heart to simulate current clinical restraint therapy. All subjects were followed with serial cardiac magnetic resonance imaging to assess
SUMMARY OF RESULTS
In acute studies, restraint decreased LV Ptm (p<0.05) and indices of MvO2 (p<0.05) but did not affect LV Cd (p=0.52) or LV Ees (0.72). Restraint had no effect on RV Ptm (p=0.82), indices of MvO2 (p=0.72), or RV Ees (0.43), but caused a reduction in RV Cd (p<0.05). In chronic studies, restraint led to a decrease in LV EDV (p<0.05) but did not have any effect on RV EDV (p=0.82).
Ventricular restraint affects the
TABLES AND CHARTS
Figure 1. (Left) Ventricular transmural myocardial pressure (Ptm) as a function of restraint level. LV Ptm decreases (a beneficial change) as restraint is increased, but RV Ptm stays unchanged. (Right) Change in the ventricular diastolic compliance (Cd) as a function of restraint level. Increasing restraint level causes a significant reduction in RV Cd (an adverse effect) but does not affect LV Cd. *p<0.05