Abstracts: ASAIO Cardiac Abstracts
TRANSVALVULAR INTRA-AORTIC VENTRICULAR ASSIST DEVICE ACHIEVES FUNCTIONAL CARDIAC IMPROVEMENT IN COMPUTER HEART FAILURE MODEL
The field of heart failure has recently witnessed a large growth in the development of ventricular assist devices (VADs). We seek to determine the impact of transvalvular intra-aortic axial flow pumps (TVAFPs) on ventricular performance in the settings of both acute heart failure/cardiogenic shock (AHF) and chronic heart failure (CHF).
The Heart Simulator (http://www.columbia.edu/ccnmtl/draft/heart/CatheterVAD/) is a computer program that uses well established models of ventricular function and generates real-time pressure-volume (PV) loops, arterial tracings, and hemodynamic values. A TVAFP was modeled using pump flow characteristics from Impella CardioSystems AG. TVAFP flow ranged from 0–4 L/min. AHF and CHF models were established and PV loops were obtained at baseline and after TVAFP activation. The impact of TVAFP on cardiac output (CO), stroke work (SW), and myocardial perfusion was then determined.
In AHF, CO improved from 1.5 to 3.0 L/min and SW decreased from 719 to 200 mmHg × ml. In CHF, CO improved from 2.9 to 3.6 L/min and SW decreased from 3217 to 1545 mmHg × ml. Aortic diastolic pressure was increased in both conditions.
In CHF, TVAFP results in cardiac improvement primarily from decreased SW, while in AHF, improvement is achieved primarily by increased CO. Enhanced diastolic pressure leads to increased coronary blood flow. These findings support the applicability of a TVAFP to a broad spectrum of heart failure syndromes.Copyright © 2005 by the American Society for Artificial Internal Organs