Myocardial transit times from intracoronary dye-dilution curves in normal subjects and patients with coronary artery disease

Myocardial transit times were derived from analysis of indicator-dilution curves obtained selectively from coronary artery to coronary sinus in a series of patients with and without significantly occlusive coronary artery disease. Appearance, buildup, disappearance, passage and mean transit times were measured from curves in eight patients with angiographically normal right coronary arteries and compared with data from eight patients with coronary artery disease. Similar comparisons of data were made between eight patients with no disease in the left coronary arterial system and nine patients with coronary artery disease. In both groups of patients with coronary artery disease, significant prolongations in transit time values were observed. This difference in time course of intracoronary dye curves between normal patients and patients with coronary artery disease suggests a difference in regional coronary flow patterns. Similar prolongation of all transit time values was observed in response to sublingual administration of nitroglycerin in a composite group of nine patients with and without coronary artery disease in either the right or left coronary artery. Possible mechanisms are discussed. This method may serve as a useful adjunct in studying the changes in coronary blood flow that occur with coronary artery disease and use of vasoactive drugs.