Background:In chronic aortic regurgitation, eccentric hypertrophy, with combined concentric hypertrophy of the left ventricle, is an important adaptive response to volume overload, which in itself is a compensatory mechanism for permitting the ventricle to normalize its afterload and to maintain normal ejection performance (physiologic hypertrophy). However, progressive dilatation of the left ventricle leads to depressed left ventricular 0.V) contractility and myocardial structural changes, including cellular hypertrophy and interstitial fibrosis (pathological hypertrophy).Hypothesis: The study was undertaken to determine the relationship between left ventricular myocardial structure and contractile function in 14 patients with chronic aortic regurgitation by cardiac catheterization and endomyocardial biopsies.Methods: Myocardial cell diameter and percent interstitial fibrosis were obtained from biopsy samples. Contractile function was evaluated from the ratio of end-systolic wall stress to end-systolic volume index (ESSESVI) and the ejection fraction-end-systolic stress (EF-ESS) relationship, which was obtained from 30 normal control subjects.Resulrs: Myocardial cell diameter correlated significantly with the ESVI (r = 0.72, p

A total of eight patients, including three infants, received left or biventricular assist using centrifugal pump (CFP) following open heart surgery. Three infants, aged 9-11 months and with complex cardiac lesions, were supported by left heart bypass (LHB) using pediatric type CFP for 63 h, 64 h, and 13 days. All were weaned from LHB, but long-term survival was not obtained, mainly due to complications. In five adult patients, LHB alone was used in three, and biventricular support in two for 33-240 h with three survivals. The factors related to unsuccessful recovery were delayed start of support and multiorgan failure.

These results suggest that a composite straight radial and internal thoracic artery graft without a change in shear stress behaves like an extended arterial graft, with remodeling and vasoreactive capacity.

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