[Concentration of endogenous prostanoids and cyclic nucleotides in patients with atrial fibrillation]. / Soderzhanie éndogennykh prostanoidov i tsiklicheskikh nukleotidov u bol'nykh s mertsatel'noi aritmiei.

The variations in the content of endogenic prostanoids and cyclic nucleotides in the blood plasma of the coronary sinus and ascending aorta were studied in patients with the idiopathic stable form of atrial fibrillation before and after sinus rhythm recovery effected by electroimpulse therapy. Changes in the levels and ratios of these compounds in the coronary venous and arterial blood were found to be opposite in their trends. A significant elevation in TxB2 levels and the TxB2/6-keto-PGF1 ratio as well as increased cGMP concentrations in the plasma of the coronary venous blood appear to be suggestive of an unfavourable prognosis because patients with such changes developed atrial fibrillation recurrences soon after electroimpulse therapy.

[Characteristics of lactate metabolism in the myocardium of patients with auricular fibrillation]. / Osobennosti metabolizma laktata v miokarde bol'nykh s mertsatel'noi aritmiei.

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.