The importance of stress-induced cardiac wall motion abnormalities in the evaluation of drug intervention.

Stress-induced wall motion abnormalities are a sensitive marker of myocardial ischaemia. Stress echocardiography has recently been the subject of increasing interest because of its improved feasibility and compatibility with new and effective alternative stresses. Transoesophageal atrial pacing (TAP) with 2-dimensional echocardiography (2-D echo) is a recently developed echo-cardiographic stress procedure that has been shown to be reliable and effective in both the diagnosis and evaluation of stress-induced myocardial ischaemia. TAP with 2-D echo was performed after treatment with placebo and intravenous gallopamil 0.03 mg/kg in 12 patients with stable, reproducible angina of effort. Compared with placebo, gallopamil treatment increased the time to 1 mm ST-segment depression (6.6 vs 5.3 minutes; p less than 0.05) and improved the ventricular wall motion score at a heart rate of 130 beats/min (17 vs 15; p less than 0.01) and 150 beats/min (13 vs 11; p = 0.07). Three patients who developed angina after placebo administration were symptom-free after gallopamil. Thus, gallopamil exerts a beneficial effect on atrial pacing-induced ischaemia, by increasing the pacing time to the ischaemic threshold and reducing the extent of dysfunctional myocardium during ischaemia.