MULLINS,~HARLES B., WINFRED L. SUGG,BRIAN M. KENNELLY, DAN C. JONES, AND JERE H. MITCHELL. Effect of arterial counterpulsatil>n on left ventricular volume and pressure. Am. J. physiol. 220(3) : 694-698. 197 1 .-The influence of arterial counterpulsation by means of the SIMAS circulatory assist device on left ventricular volume and pressure was studied. Fifteen studies in nine dogs were complete...

BACKGROUND AND OBJECTIVES It is not well understood whether the left ventricular geometry is associated with such diastolic parameters as the left atrial volume and the left ventricular filling pressure, as assessed by the Doppler indices. Accordingly, this study aimed to evaluate the influence of the left ventricular geometry on the left atrial volume and the left ventricular filling pressure,...

OBJECTIVE This study aimed to investigate the effect of left ventricular aneurysm (LVA) volume and left ventricular global torsion on cardiac function by real time three-dimensional echocardiography (RT-3DE) and two-dimensional speckle tracking imaging(2D-STI), to determine the accuracy of RT-3DE and 2D-STI in assessing LV function. METHODS Thirty New Zealand rabbit models of with LVA were pr...

We investigated how pacing from different endocardial sites affects the left ventricular three-dimensional contraction pattern and performance in intact anesthetized dogs. We used data from the motion of radiopaque markers implanted in the left ventricular endocardium in an analysis based on the polar decomposition theorem to determine the left ventricle's three-dimensional principal directions...

OBJECTIVE Volume reduction surgery for dilated cardiomyopathy has not yielded predictable outcomes. The purpose of this study was to clarify the efficacy of modified volume reduction surgery in preserving the left ventricular apex and reducing the left ventricular diameter at the base to maintain fiber continuity. METHODS Heart failure was induced with propranolol in 12 dogs, and the animals ...

To investigate the effects of verapamil on left ventricular systolic and diastolic function in patients with hypertrophic cardiomyopathy, we studied 14 patients at catheterization with a nonimaging scintillation probe before and after serial intravenous infusions of low-, medium-, and high-dose verapamil (total dose 0.17 to 0.72 mg/kg). Percent change in radionuclide stroke counts after verapam...

BACKGROUND The importance of the mitral apparatus to left ventricular function has been suggested in clinical studies. The effect of disruption of the mitral apparatus on left ventricular diastolic and systolic properties has not been fully documented. METHODS AND RESULTS We investigated the end-diastolic and end-systolic pressure-volume and stroke work-end-diastolic volume relations and meas...

BACKGROUND Most out-of-hospital ventricular fibrillation (VF) is prolonged (>5 minutes), and defibrillation from prolonged VF typically results in asystole or pulseless electrical activity. Recent visual epicardial observations in an open-chest, open-pericardium model of swine VF indicate that blood flows from the high-pressure arterial system to the lower-pressure venous system during untreate...

Previous studies have shown that left atrial pressure increases when measured relative to pleura! pressure during positive end-expiratory pressure (PEEP). We studied the factors leading to this increase in anesthetized mechanically ventilated dogs. Cardiac output was maintained nearly constant before and during PEEP, and heart rate did not change. Left atrial pressure measured relative to pleur...

BACKGROUND Continuous-flow rotary pumps with axial design are increasingly used for left ventricular assist support. The efficacy of this design compared with pulsatile, volume displacement pumps, with respect to characteristics of left ventricular unloading, and exercise performance remains largely unstudied. METHODS AND RESULTS Thirty-four patients undergoing implantation with a pulsatile, ...