Coronary arterial mapping in hypertrophic cardiomyopathy.

The diameters of the coronary arteries and their peripheral branches were measured on coronary angiograms obtained from 9 patients with hypertrophic obstructive cardiomyopathy (HOCM), 6 patients with hypertrophic non-obstructive cardiomyopathy, and 6 normal controls. There was a marked increase in the diameters of the main coronary arteries in the patients suffering from cardiomyopathy but no significant difference in the peripheral branches between the three groups. This discrepancy between the 'run-in' and 'run-off' components of coronary circulation could explain anginal symptoms during exercise in HOCM, but in the absence of direct coronary flow measurements this theory remains to be tested. HOCM was associated with the widest arteries whereas hypertrophic non-obstructive cardiomyopathy occupied an intermediate position between HOCM and the control group.