Related Experiment Videos
Ischemia on effort is not a determinant of stunned myocardium in man: a radioisotopic study based on quantitative
A Gimelli1, P Marzullo, M Bartoli
1CNR Institute of Clinical Physiology, Pisa, Italy.
Insights
Brief episodes of effort ischemia in patients with coronary artery disease did not cause myocardial stunning. Ventricular function remained largely unchanged during recovery, despite transient dysfunction during ischemia.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Background:
- Myocardial stunning is a phenomenon of post-ischemic ventricular dysfunction.
- Animal studies suggest brief ischemia can cause stunning, but clinical evidence in humans is less clear.
Purpose of the Study:
- To investigate if brief episodes of effort-induced ischemia cause myocardial stunning in patients with coronary artery disease.
- To compare ventricular function recovery after ischemia in patients with single-vessel versus multi-vessel coronary artery disease.
Main Methods:
- Radionuclide angiography was used to assess ventricular function in 29 patients with coronary artery disease.
- Patients were divided into single-vessel and multi-vessel disease groups.
- Ejection fraction, peak filling rate, and wall motion index were measured at baseline, peak exercise, and during recovery.
Main Results:
- No significant differences in global or regional ventricular function were observed between groups during recovery.
- While transient ventricular dysfunction occurred during ischemia, it did not lead to the phenomenon of systolic and diastolic stunning post-ischemia.
- Patients with multi-vessel disease showed a more impaired wall motion index during ischemia compared to single-vessel disease patients.
Conclusions:
- Brief episodes of effort-induced ischemia in patients with coronary artery disease do not appear to cause myocardial stunning.
- Ventricular function recovers adequately after transient ischemia, even when it induces temporary dysfunction.
Abstract:
To assess whether myocardial stunning occurs following brief episodes of effort ischemia, ventricular function was assessed by radionuclide angiography in 29 patients with coronary artery disease. No patient had evidence of previous myocardial infarction. Patients were divided into two groups according to presence of single (14 patients, Group 1) or multi-vessel (15 patients, Group 2) coronary artery disease. Equilibrium radionuclide angiocardiography was performed in the left anterior oblique projection by a small field-of-view gamma-camera. Acquisition were performed at baseline, at peak exercise, then again at 1 and 5 minutes of the recovery phase. For each acquisition, ejection fraction, peak filling rate and wall motion index were measured and compared. No difference in baseline and stress measurements was found between Group 1 and Group 2, except for the wall motion index that was more impaired during ischemia in patients of Group 2. Global and regional indexes of ventricular function did not show significant differences also in the two recovery periods when compared to the relative baseline values. Transient ischemia caused by an increase of oxygen demand did not reproduce the phenomenon of systolic and diastolic stunning observed in animal experiments, although in all patients the ischemia was of sufficient duration and severity to induce transient ventricular dysfunction.