Objective: To determine whether isometric exercise increases collateral flow in remote ischaemic myocardium in acute coronary occlusion models of patients with coronary artery disease.
Design: A randomized controlled study.
Subjects: Sixty-five patients with 1-vessel coronary artery disease.
Methods: Subjects were randomly assigned to either the isometric exercise group or non-exercise group. Patients in the exercise group performed isometric handgrip exercises (50% maximal voluntary contraction) during 1 min coronary balloon occlusion, while patients in the non-exercise group remained sedentary. The collateral flow index, heart rate, systolic blood pressure and diastolic blood pressure were determined prior to and following 1 min of coronary occlusion.
Results: In the exercise group, difference values for collateral flow index (after coronary occlusion before coronary occlusion) were significantly higher than those in the non-exercise group (0.04 standard deviation (SD) 0.05 vs 0.01 (SD 0.03), p < 0.01). Differences in heart rate, systolic blood pressure and diastolic blood pressure were also significantly higher than controls (heart rate 7.84 (SD 8.20) vs 0.88 (SD 3.96), p < 0.01; systolic blood pressure: 3.25 (SD 7.17) vs 1.88 (SD 6.21), p < 0.01; diastolic blood pressure 5.88 (SD 6.40) vs 1.5 (SD 6.22), p < 0.01).
Conclusion: Isometric exercise in patients with coronary artery disease induced an increase in coronary collateral flow during acute vessel occlusion, which was significantly different from control occlusion.