Acute arterial hypertension during spontaneous angina in patients with fixed coronary stenosis and exertional angina: an associated rather than a triggering phenomenon.

The role of systemic arterial hypertension as a possible trigger of myocardial ischemia during angina at rest was studied in 13 consecutive patients who also had a history of exertional angina. Significant (greater than or equal to 70%) stenosis of at least one major vessel was present in each of the 10 patients in whom coronary arteriography was carried out. After documentation of the electrocardiographic and arterial blood pressure changes during two or more episodes of resting angina, i.v. methoxamine was infused under continuous monitoring of the ECG, arterial blood pressure and pulmonary artery diastolic pressure. The heart rate was maintained either spontaneously or by atrial pacing to levels similar to those during angina at rest. Despite increases in arterial blood pressure and the double product (systolic blood pressure x heart rate) to levels higher than those during spontaneous angina in all patients, no chest pain or electrocardiographic changes occurred in nine patients. In the other four patients, however, angina supervened. Three of these four patients, but only one of the remaining nine, had a borderline or elevated pulmonary artery diastolic pressure at rest. We conclude that in a considerable number of patients with "nonvariant" resting angina, acute increases in arterial blood pressure during the spontaneous attacks are not likely to be the cause of myocardial ischemia. Nevertheless, in some of these patients, increases in resting pulmonary artery diastolic pressure may favor the development of ischemia during afterload augmentation.