In cardiac surgery hemofiltration can be used: 1. to balance fluids during ECC, especially in long-term perfusion; 2. to carry out open heart procedures in patients with terminal renal insufficiency; 3. to treat acute hyperkalemia. The model of the 12.5 by 4.5 cm DIAFILTER TM and the model of operation are described. The compounds of the ultrafiltrate (UF) are identical with that of plasma water. Particles with a molecular weight of less than 50,000 can pass freely across the filtration membrane. The filtration capacity is 100 cc/min UF (Q blood: 300 cc/min, pressure across the membrane 600 mm Hg and hematokrit (Hkt) 25%). The technical details of operation are explained. Its general use as well as its simplicity is demonstrated in 10 patients.

One hundred twenty-eight patients underwent left ventricular aneurysmectomy; in 78 cases the procedure was combined with either aortocoronary bypass or valve replacement. In 7 patients undergoing isolated aneurysmectomy the influence of atrial pacing on various hemodynamic parameters was studied immediately postoperatively and on the first, second and third postoperative days. Until a certain point, increase in heart rate resulted in decrease of left ventricular filling pressure and increase of cardiac output, while systemic pressure changed only slightly. For each patient and each day the optimal heart rate as well as the optimal point of the Starling curve in these patients was found at extremely low filling pressures Kirklin's scheme of therapy may be limited in these patients. Therefore, in low cardiac output syndrome, left ventricular filling pressure should only be increased after the optimal heart rate is selected by atrial stimulation.

Urgent coronary surgery is used to prevent or to clear life threatening complications of myocardial infarction. The methods are: aortocoronary vein bypass for impending infarction or following thrombolysis, resection of ventricular aneurysm, closure of ventricular septum perforation or correction of mitral regurgitation. In 1975 -1982 hospital mortality in elective coronary surgery was 2.4 % out of 1,108 patients. From the group of 105 emergency cases 16 died (= 15.2 %). In 48 % of the patients the indication for surgery was impending infarction, in 10 % intractable congestive heart failure. In 24 % emergency ACB-surgery was performed after successful thrombolysis.

Post myocardial infarction recurrent ventricular arrhythmias are usually coupled with depressed left ventricular function. We have until recently employed the most widely used surgical techniques such as endocardial resection, cryosurgery and isolation. After these methods had failed in a patient with an extensive septal focus, it finally became possible to effectively ablate the arrhythmogenic area by injection of 10 ml 95% alcohol subendocardially. The following experimental studies were carried out to investigate the effect of direct injection of alcohol on the myocardicytes. 95% alcohol, injected into the apex of the left ventricle of Wistar rats weighing between 150 and 200 g caused extensive coagulation necrosis 5 minutes after injection, as was revealed by histological examination. The site of injection showed marked scar formation after 6 months. On the basis of these findings, 4 more patients were treated successfully with alcohol, which was directly injected subendocardially without endocardial resection using a long needle. The advantage of this procedure is that resection can be avoided, particularly in critical areas such as the septum and regions around papillary muscles.