Microvascular angina in systemic hypertension: diagnosis and treatment with enalapril.

The causes of hypertensive microvascular ischemia are reviewed along with diagnostic factors. Stress/rest thallium-201 scintigraphy is shown to have a predictive value of 78% for a diagnosis of microvascular disease in hypertensive patients with exertional angina and left ventricular hypertrophy. Lack of isotope uptake at peak stress correlates well with the decrease in coronary flow reserve in ischemic segments, which is 2-3 times lower than in normal subjects. Treatment with enalapril produces regression of left ventricular hypertrophy, normalization of thallium-201 uptake, and an increase in exercise capacity in patients with microvascular angina.