title: Physiologic--angiographic correlates of coronary arterial stenoses in resting and intensely vasodilated states.
abstract: The treatment of ischemic heart disease is dependent upon defining the physiologic significance of coronary arterial stenoses demonstrated on coronary arteriograms. Accordingly, physiologic--angiographic correlates were studied in 12 anesthetized dogs prepared with an electromagnetic flowmeter and micrometer-controlled occluder on the circumflex coronary artery, a pair of sonic crystals in the myocardium within the distribution of the circumflex artery, and a catheter in the thoracic aorta. Measurement of arterial diameters on coronary arteriograms was made to define the minimum percent stenosis that caused: (1) decrease in resting coronary blood flow (CBFr); decline in the peak level of coronary blood flow (CBF) produced by intense vasodilatation induced by intracoronary infusion of ATP (CBFATP); and (3) segmental left ventricular (LV) dysfunction. CBFR decreased at an average stenosis of 80.45 +/- 9.13% (SD) (percent reduction in luminal diameter), while CBFATP declined at a stenosis of 31.83 +/- 5.64%. Segmental LV dysfunction was observed at a stenosis of 85.92 +/- 9.83%. In all dogs, the initial stenosis causing decline in CBFATP was a less than or equal to 40% reduction in luminal diameter. The results of this study indicate that coronary arterial stenoses of 40% or less may be hemodynamically significant under situations of augmented CBF. On the other hand, regional contractile function at rest is preserved up to stenosis in excess of 80%.
mesh_terms: D000255:Adenosine Triphosphate; D000792:Angiography; D000818:Animals; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging / Q000503:physiopathology; D003326:Coronary Circulation / Q000187:drug effects; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004285:Dogs; D009200:Myocardial Contraction / Q000187:drug effects; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents; D000255:Adenosine Triphosphate