Vasodilators which induce a sustained increase in coronary blood flow may have little, if any, beneficial effect in patients with ischemic heart disease, a Canadian investigator reports.
Maurice McGregor, MD, contends that such drugs must act by interfering with an autoregulatory mechanism at the arteriole level in the heart, and that such interference may result in decreased blood flow to the potentially ischemic areas of the heart while, paradoxically, overall coronary flow is increased.
"In the search for better coronary vasodilators, I think we should stop looking for drugs which increase coronary flow in the normal heart," said Dr. McGregor, associate professor of medicine, McGill University, Montreal. "We should search rather for drugs which confine their vasodilator action to the large conductive vessels and leave the autoregulatory function intact."Speaking at the New York Heart Association Conference on Metabolic Aspects of Circulatory Disease, Dr. McGregor added:"It is