[Characteristics of lactate metabolism in the myocardium of patients with auricular fibrillation].

Coronary arteriovenous difference in lactate was measured in 20 patients with permanent atrial fibrillation and coronaroangiographic evidence of unchanged coronary arteries before and after the recovery of sinus rhythm by electric-pulse treatment (EPT); and in 15 patients with neurocirculatory dystonia (NCD) and intact cardiac rhythm, subjected to the atrial stimulation test (AST). Before EPT, the majority of atrial fibrillation patients exhibited myocardial lactate production, which was particularly pronounced in patients with prolonged (over 6 months) duration of fibrillation. After the sinus rhythm was recovered, lactate production was replaced by lactate extraction. None of the NCD patients showed lactate production in spite of high AST-induced heart rates. Both the heart rate and the pattern of intracardiac and coronary hemodynamics may be involved in disrupted lactate metabolism in patients with permanent atrial fibrillation and intact coronary arteries.