[Myocardial blood flow in patients with different forms of supraventricular arrhythmia].

The authors studied the status and changes in the myocardial blood flow volume in 25 patients with supraventricular cardiac arrhythmias in the presence of coronary heart disease and without organic abnormalities on the part of the cardiovascular system. As regards the status of the sinus rhythm, the total myocardial blood flow in patients with idiopathic rhythm disturbances versus coronary heart disease showed no significant differences. In conditions of electrostimulation-induced tachyarrhythmia, patients with idiopathic arrhythmias exhibited a linear increase in the blood flow in the basin of both coronary arteries while in the coronary heart disease patients there were heterogeneous alterations of the myocardial blood flow with a general downward trend. In patients with the idiopathic form of continuous fibrillations with the comparable heart rate the values of the myocardial blood flow are significantly lower than in patients with idiopathic paroxysmal tachyarrhythmia. The decrease of the coronary blood flow observed in tachycardia is believed to result from an increased coronary vascular resistance which points to a reduction of the reserve capabilities of the coronary bed in relation to its dilatation.