Cellular and hemodynamics responses of failing myocardium to continuous flow mechanical circulatory support using the DeBakey-Noon left ventricular assist device: a comparative analysis with pulsatile-type devices.

Background: An increasing number of continuous flow pumps are currently under clinical studies, however very little data exist on the hemodynamic and cellular responses of the failing heart to continuous flow support. The purpose of this investigation was to characterize the response of the failing myocardium to continuous flow support.

Methods: We compared echocardiographic and cellular markers of failing myocardium at the time of left ventricular assist device (LVAD) implantation and explantation in 20 consecutive patients (12 pulsatile flow [Novacor] and 8 continuous flow [DeBakey-Noon]).

Plasma neurohormone levels correlate with left ventricular functional and morphological improvement in LVAD patients.

Objective: Brain natriuretic peptide (BNP) and endothelin-1 (ET-1) have been shown to be markers of left ventricular (LV) function. To determine the feasibility of using serial assays of these neurohormones in the assessment of cardiac status in the left ventricular assist device (LVAD) setting, we examined the relationship between LV function, myocardial morphology, and plasma levels of these hormones in LVAD recipients.

Methods: Plasma BNP and ET-1 levels were serially assayed in 19 end-stage congestive heart failure (CHF) patients before and after LVAD implantation with various devices (i.

Role of mast cells and their mediators in failing myocardium under mechanical ventricular support.

Background: Mast cells have been implicated in tissue remodeling and fibroblast stimulation. We explored the effect of mechanical support by left ventricular assist device (LVAD) in failing myocardium and looked into grade and distribution of interstitial fibrosis, mast cell density, mast cell phenotypes and basic fibroblast growth factor (bFGF) expression pre- and post-LVAD.

Methods: Myocardial tissue was obtained from 20 patients with end-stage cardiomyopathy at the time of LVAD implantation and LVAD removal and from 7 donor hearts not used for transplantation.

Evidence of improved right ventricular structure after LVAD support in patients with end-stage cardiomyopathy.

Background: Although many reports demonstrate the hemodynamic benefits of left ventricular assist devices (LVAD) in right-sided circulation, it is not known whether the right ventricular myocardium goes through reverse remodeling after left ventricular mechanical circulatory support. Accordingly, the purposes of our studies were 1). to investigate the right ventricular changes that occur in fibrosis, in cellular hypertrophy, and in intra-myocardial tumor necrosis factor alpha (TNF-alpha) levels in patients receiving LVAD support; and 2).

New surgical therapies for heart failure.

A growing number of patients present with heart failure. Some of them may qualify for surgical correction of their cardiac condition. Since heart transplantation will always be available to only a small number of patients, several new surgical techniques have been developed for approval in heart failure patients.

Patient selection for assist devices: bridge to transplant.

Patients in severely progressed states of heart failure can be bridged to successful heart transplantation with mechanical assist devices. Experience has demonstrated that patient selection and timing of device implantation are crucial for obtaining acceptable results when using this expensive technology. The degree of irreversible secondary organ dysfunction before re-establishing adequate cardiac output determines the chance of reaching transplantation.

Use of a donor heart that had undergone previous cardiac surgery for ASD closure.

We report the use of a heart from a 19-year-old female donor who had undergone open heart surgery for closure of an atrial septal defect at the age of 12. The explantation procedure was modified to prevent hemodynamic instability. The recipient, a 59-year-old male with increased pulmonary vascular resistance had an uneventful recovery after transplantation.