Paracorporeal Artificial Heart in Postoperative Heart Failure

Abstract

A pneumatically driven artificial heart with a tubular silicone rubber membrane and disc valves was used for functional heart replacement in the paracorporeal mode. A fluidic drive system allows adjustment of the heart rate, positive and negative pressures and systole/diastole ratio. dextran, 500 ml/day; and aspirin, 4 x 0 5 gm/day)

Right ventricular function in an operating room model of mechanical left ventricular assistance and its effects in patients with depressed left ventricular function.

“…Under control conditions, stroke volume and cardiac output were significantly lower in the poor left ventricular function group than in the normal left ventricular function group, and right ventricular end-diastolic pressure, mean pulmonary arterial pressure, and pul- (9) 4 ± 3A (9) 56+ 11B (10) 68 ± 3B (9) 281 + 39A (9) 1804 + 206 The most common cause of right ventricular failure is the increase in right ventricular afterload resulting from left ventricular failure.20 Although at least one study has shown normal right ventricular performance in patients with mitral stenosis and moderate pulmonary hypertension,2' most studies show the right ventricle to be markedly afterload dependent, with right ventricular ejection fraction being lower in patients with elevated pulmonary arterial pressure than in normal subjects. 22 24 In a preliminary transesophageal echocardiographic study in humans, we have shown right ventricular cross-sectional area to decrease by 29% in diastole and by 54% in systole, and fractional area change to increase from 42% to 63%, in response to a 19 mm Hg decrease in pulmonary arterial pressure during left heart bypass.…”

Right heart interaction with the mechanically assisted left heart

“…Right ventricular (RV) failure has been reported to be a major complication associated with the clinical use of LVADs. A review of the literature on clinical LVAD experience [1][2][3][4][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] along With our own results reveals that of 213 patients who received LVADs at 12 centers (not including patients with RVAD and IABP), 20 required the additional use of an RVAD for RV dysfunction and 29 died as a direct result of RV failure (Table 1). Thus, 49 patients (23%) treated with an LVAD for LV failure were candidates for biventricular support.…”

EACTS Presidential Address The contraindications of today are the indications of tomorrow

“…A fairly similar observation can be made for mechanical circulatory support, where the first surviving patients [11] had their chests kept open for the connection of para-corporeal ventricular assist devices (VADs), and were therefore not only tied to heavy drivers with back-up and monitoring equipment, but also to the bed. As a matter of fact, it was sometimes contraindicated to turn the patients on their side, with all the unpleasant implications for the skin, especially if vaso-constricting drugs had to be used in addition.…”