Forty patients with coronary artery disease and 15 normal subjects (group C) were studied to assess the influence of the site of stress-induced myocardial ischemia on cardiovascular response after exercise. Patients were divided in 2 groups according to myocardlal thallium-201 scintigraphy: those with an anteroseptal reversible perfusion defect (group A; n = 24), and those with an inferoposterior reversible perfusion defect (group I; n = 16). All patients underwent serial bicycle exercise stress tests. The first 2 stress tests were interrupted when 0.1 mV of ST-segment depression was achieved (2,000 to 2,500 kgm); a third test was stopped before the onset of ischemia (1,500 kg-m). Normal subjects performed stress tests at comparable work loads. At ischemic threshold, there was no difference in ejection fraction between groups A (65.5%) and I (67.3%). Mean values and recovery ratios of heart rate and systolic blood pressure were significantly higher in group A than in C and I during the recovery period of the 2,000 to 2,500 kg-m stress test. In contrast, no significant difference was observed among the groups in the 1,500 kgm stress test, and between groups I and C in any stress test. The data show that in patients with the same degree of stress-induced impairment of ventricular function, the anterior site of ischemia leads to persistently higher values of heart rate and blood pressure after exercise, which are likely due to an enhanced adrenergic discharge.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine