[Low cardiac output following open heart surgery and catecholamine therapy]

The authors have studied the possible risk factors and complications of low cardiac output (LCO) following open heart operations. A retrospective analysis of 537 consecutive open heart operations has been performed with regards to the patients past medical and perioperative data. For statistical analysis the authors have applied the Chi-square test, T-probe, Mann-Whitney-test and logistical regression analysis by means of the SPSS software. Occurrence of various types of operations was as follows: coronary bypass (CABG): n = 266, 49.5%, combined CABG: n = 62, 11.5%, aortic valve replacement (AVR): n = 73, 13.6%, mitral valve replacement (MVR): n = 59, 11%, multiple valve replacement: n = 39, 7.3%, adult congenital surgery: n = 25, 4.7%. Aortic dissection repair: n = 6, 1.1%, miscellaneous: n = 7, 1.3%. LCO has developed in 7.3% (n = 39) of the patients. The authors have concluded that in the studied group of patients the independent risk factors of postoperative LCO are as follows: atrial fibrillation in the patient history, mitral valve disease, perioperative myocardial infarction, length of anaesthesia, NYHA stage, number of transfused units of blood, and the perioperative LDH value. Beyond these variables the cause of LCO in some cases was surely an intra or perioperative myocardial necrosis. At least a certain part of this perioperative myocardial damage must have been or might have been caused by the catecholamines given under compulsion for the treatment of LCO.