Related Experiment Videos
Angiotensin-converting enzyme and coronary haemodynamics in coronary artery disease
Insights
Cardiac angiotensin-converting enzyme activity in coronary circulation was studied in patients with and without coronary artery disease. No significant changes were observed, suggesting it does not regulate coronary vascular resistance.
Area of Science:
- Cardiovascular Physiology
- Enzymology
- Coronary Circulation Research
Background:
- The role of cardiac angiotensin-converting enzyme (ACE) in regulating coronary circulation is not fully understood.
- Investigating ACE activity in the heart could reveal mechanisms influencing coronary blood flow and vascular resistance.
Purpose of the Study:
- To investigate the link between cardiac exchange of angiotensin-converting enzyme and coronary circulation.
- To determine if cardiac ACE activity changes during pacing in patients with and without coronary artery disease.
Main Methods:
- Coronary sinus and arterial blood were sampled from 12 patients with and 12 patients without significant coronary artery disease (verified by angiography).
- Enzyme activity was measured at rest and during coronary sinus pacing.
- Coronary vascular resistance and oxygen consumption were monitored.
Main Results:
- Coronary sinus and arterial angiotensin-converting enzyme activity remained unchanged and were similar in both patient groups.
- Enzyme activity showed no correlation with pacing-induced changes in oxygen consumption or coronary vascular resistance.
Conclusions:
- Global cardiac formation or depletion of angiotensin-converting enzyme does not appear to be of regulatory importance in the coronary vascular bed.
- These findings apply to patients with and without coronary artery disease under the studied conditions.
Abstract:
Coronary sinus pacing was performed in 12 patients with and 12 patients without significant coronary artery disease as verified by angiography in order to elucidate a possible link between cardiac exchange of angiotensin-converting enzyme and the coronary circulation. The coronary sinus and arterial blood enzyme activity remained unchanged and were similar in the two groups, both at rest and during pacing, and the activity was not related to pacing-induced changes in oxygen consumption or coronary vascular resistance. Therefore it does not seem that global cardiac formation or depletion of angiotensin-converting enzyme is of regulatory importance in the coronary vascular bed in patients with and without coronary artery disease under these circumstances.