title: Invasive left ventricular energetics during enhanced external counterpulsation.
abstract: Enhanced external counterpulsation (EECP) is a noninvasive technique that provides beneficial effects for patients with chronic, symptomatic angina pectoris. However, the direct left ventricular effects of EECP have not been studied invasively. We examined invasive right atrial pressure and left ventricular hemodynamics during EECP. Ten patients referred for diagnostic evaluation underwent left heart catheterization from the radial artery. At baseline and during EECP, left ventricular pressure and volume were measured using a micromanometer pressure-conductance catheter, along with recording of right atrial and central aortic pressures. Hemodynamics were recorded at different lower extremity cuff configuration and cuff inflation pressures. As cuff inflation pressure increased, EECP resulted in a dose-dependent increase in right atrial and aortic diastolic pressure (P < 0.0001). The increase in ventricular preload resulted in increased left ventricular volume. Maximum positive (P = 0.0003) and negative left ventricular dP/dt (P < 0.0001) increased. Left ventricular diastolic pressure decreased. There was a neutral effect on myocardial mechanical efficiency. In conclusion, EECP acutely increased right atrial and central aortic diastolic pressure. The increase in preload attenuated the reduction in left ventricular diastolic pressure resulting from systolic unloading. The increased preload counterbalanced the afterload reduction, resulting in a neutral effect on myocardial efficiency.
authors.affiliation: Division of Cardiology, University of Utah, 30 North 1900 East, Room 4A100, Salt Lake City, UT 84132-2401, USA. andrew.michaels@hsc.utah.edu
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Michaels
authors.forename: Theresa
authors.initials: T
authors.lastname: Tacy
authors.forename: David
authors.initials: D
authors.lastname: Teitel
authors.forename: Mia
authors.initials: M
authors.lastname: Shapiro
authors.forename: William
authors.initials: W
authors.lastname: Grossman
mesh_terms: D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000628:therapy; D006328:Cardiac Catheterization; D015908:Counterpulsation / Q000379:methods*; D003971:Diastole; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D013599:Systole; D016277:Ventricular Function, Left