Assessment of myocardial perfusion in the empty beating porcine heart with laser Doppler flowmetry.

Laser Doppler flowmetry was applied to the empty beating heart of six pigs. Cardiopulmonary bypass was instituted and the preparation allowed continuous and simultaneous measurement of coronary sinus blood flow and local tissue perfusion. An epicardial and an intramuscular probe were used. Significant linear correlation coefficients were obtained between changes of laser Doppler signal and coronary sinus blood flow changes in all seven experiments in four animals (r from 0.71 to 0.94, p less than 0.005) and between laser Doppler signal and changes of extracorporeal bypass in five out of six experiments in four animals (r from 0.82 to 0.99, p less than 0.001). The correlation between coronary sinus flow and bypass flow of four pigs was significant (r from 0.81 to 0.98, p less than 0.001), the coronary flow being about 10% of bypass flow. Muscular activity of the heart contributed to the laser Doppler signal, the magnitude of this "noise level" varying between different experiments even in the same animal. A key question for the applicability of laser Doppler flowmetry to the beating heart is whether it will become possible to discriminate between flow and muscular contribution to the laser Doppler output.

Persistent cardiac failure after mitral valve replacement due to free-floating intracardiac thrombus formation. Case report.

A case of free-floating left atrial-ventricular thrombus early after mitral valve replacement (Carpentier-Edwards pericardial bioprosthesis) is presented. Successful surgical removal was performed. The diagnostic and therapeutic efforts are discussed.

Complications of intra-aortic balloon counterpulsation, with special reference to limb ischemia.

During a 5-year period, intra-aortic balloon pumping (IABP) was performed on 90 patients (3.1% of those undergoing open-heart surgery), using a Percor catheter inserted with Seldinger technique. Overall prognosis was poor; only 46 of the 90 patients were alive at postoperative follow-up averaging 23 months. Limb ischemia arose in 20%, with incidence uninfluenced by catheter insertion technique (percutaneous v. 'open'). Surgical treatment was required for half of the ischemic limbs. Groin hematoma commonly followed percutaneous extraction of IABP catheter, whereas 'open' removal was always hemostatic, with potential for embolectomy. Percutaneous insertion of IABP catheter via the femoral artery is the method of choice in an emergency situation. 'Open' Seldinger technique is preferable in the operating room. For elective IABP catheter removal, the 'open', hemostatic technique is recommended. If limb-threatening ischemia develops, the catheter must be removed. If the patient is IABP-dependent, the contralateral femoral artery or the ascending aorta should be considered as an alternative catheter route.

Intra-aortic balloon counterpulsation with special reference to determinants of survival.

From 1981 through 1985 intra-aortic balloon counterpulsation (IABP) was required by 90 patients on a total of 91 occasions. They included 85 (3.1%) of the 2751 patients undergoing open-heart surgery during that time. IABP was used preoperatively in 13 cases, to assist weaning from cardiopulmonary bypass in 64, postoperatively in nine, and without cardiac surgery in five cases. Complications arose from IABP in 24/90 patients (27%). The overall short-term survival rate following IABP was 61%, and the long-term (mean 23 months) rate was 51%. Early recovery of cardiac function was the main determinant of survival. Female sex, renal failure and postinfarction ventricular septal defect and mitral incompetence were over-represented among the nonsurvivors. IABP therefore is useful in reversible left ventricular dysfunction, whereas inadequate perfusion of vital organs with potential for failure of more than one organ system implies diminished likelihood of survival.