Angiographic semeiotics and pathophysiology of congenital fistulas of the coronary arteries

: From analysis of the findings of intracardiac examination of 35 patients with congenital fistulas of the coronary arteries the authors discuss the angiographic semeiotics of the anomaly and the mechanism of disorders of coronary circulation. The pathophysiology of the anomaly is determined by the amount of blood shunted through the fistula, the location of the fistula (whether in the proximal or distal segment of the artery), and the perfusion deficit of the distal segment of the involved artery. Fistulas with a large volume of the shunt may be accompanied both with ischemic changes in the basin of the affected coronary artery and with regional disorders of myocardial perfusion in the adjacent basins (intact coronary arteries). The last named is due to the phenomenon of "stealing" the adjacent coronary trunk. The absence of electrocardiographic signs of focal disorders cannot be considered a sign of a hemodynamically insignificant fistula because an ECG of rest does not always reflect the state of the coronary blood flow in the basin of the involved vessel. Evidence of this are asymptomatic coronary insufficiency and disorders of myocardial perfusion which are revealed by exercise tolerance tests and scintigraphy of the myocardium in patients with a normal ECG.