Temporary left ventricular bypass: factors affecting patient survival.

Abstract

Circulatory support (range, 2 hours-8 days) was undertaken in eight cardiac surgical patients (with two survivors) exhibiting intractable cardiogenic shock. A paracorporeal, pneumatic, xenograft-valve pump was interposed between the left ventricular apex and ascending aorta. Pumping lowered left atrial and ventricular pressure while maintaining cardiac output (1.8--2.6 l/min/m2). Following implantation, plasma hemoglobin and erythrocyte mechanical fragility values were elevated but decreased to normal when renal function was not impaired. Mild thrombocytopenia was noted in three patients and was severe in five others with persistent hemorrhage. Anticoagulation agents were used during tapering of pump flow (three patients) after 100, 105 and 120 hours of bypass. Otherwise, for the major portion of the interval of mechanical circulatory support, anticoagulants were not administered. Despite this fact, no systemic embolization was detected in any of the patients. It appears that assist pump support can be life-saving in acute left ventricular failure in patients following cardiac surgery.

Left- and Right-Heart Assistance by Retrosternal Intermittent Cardiac Compression in Dogs

“…[5][6][7][8] Extracorporeal bypass that pumps blood from the heart or peripheral vessels has yielded poor results because of inadequately considered problems arising from right ventricular failure, lack of ventricular decompression, complexity of the mechanical apparatus, and the methods of cannulation. [9][10][11] Since the prototype of the intraaortic balloon pump (IABP) introduced by Moulopoulos et al, 12…”

“…10,11,14,16 Cardiac Indexes and Stroke Indexes of Groups A and B ' CI = cardiac index, SI = stroke index, LCO = low cardiac output, SD = standard deviation, t = t value, NS = nonsignificant (P > 0.5), $ = significant (P < 0.01). chamber of the heart have not solved the physiologic need in most cases, except for the use of venoarterial bypass with oxygenator in problems of pulmonary hypertension and right ventricular failure.…”

Invited commentary

“…Nous avons utilis6, pour bypass ventriculaire gauche transapical de longue dur6e chez 36 veaux et 11 malades, un circuit de vinyl avcothanis6 comportant un filtre Pall, 2 Cardiac patients who exhibit severe myocardial failure at the conclusion of cardiopulmonary bypass (CPB) initially undergo resuscitation with inotropic agents, vasodilators, and cardiac pacing. These modalities are routinely employed in conjunction with an additional period of CPB with the heart in a vented, contracting, but nonworking state.…”

“…Both of these patients had severe coronary artery disease and LV aneurysms and required 6 days [2] and 61/2 hours, respectively, of total LV bypass before recovery of ventricular function and removal of the apex cannula. Left atrial pressures in both of these patients were above 35 mm Hg, and there was no ventricular output without TALVB.…”

Review article : Mechanical ventricular support in the management of postcardiotomy cardiogenic shock

“…47,48 Experience in the management of postcardiotomy cardiogenic shock has been principally obtained using three types of ventricular assist devices ( Table 2). …”