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Coronary sinus occlusion enhances coronary collateral flow and reduces subendocardial ischemia
A Ido1, N Hasebe, H Matsuhashi
1First Department of Internal Medicine, Asahikawa Medical College, Asahikawa 078-8510, Japan.
Insights
Coronary sinus occlusion (CSO) enhances blood flow to the heart muscle during ischemia. This intervention improves blood supply to the subendocardium, potentially preserving ischemic heart tissue.
Area of Science:
- Cardiovascular Physiology
- Myocardial Ischemia Research
Background:
- Myocardial ischemia poses a significant threat to cardiac function.
- Coronary collateral blood flow is crucial for mitigating ischemic damage.
Purpose of the Study:
- To investigate the effects of coronary sinus occlusion (CSO) on coronary collateral blood flow.
- To determine the impact of CSO on regional myocardial blood flow (RMBF) distribution during ischemia.
Main Methods:
- Utilized a canine model with left anterior descending coronary artery occlusion.
- Measured RMBF and intramyocardial pressure (IMP) in subendocardial and subepicardial layers.
- Assessed the effects of CSO with intact vasomotor tone and after adenosine administration.
Main Results:
- CSO significantly increased RMBF in the ischemic region, particularly in the subendocardium.
- The subendocardial to subepicardial ratio of RMBF (Endo/Epi) was significantly elevated by CSO.
- These beneficial effects were partially attenuated by adenosine but remained significant.
Conclusions:
- Coronary sinus occlusion demonstrates potential in enhancing coronary collateral flow.
- CSO may play a role in preserving ischemic myocardium, with a notable benefit to the subendocardium.
Abstract:
On the hypothesis that coronary sinus occlusion (CSO) may reduce myocardial ischemia, we examined the effects of CSO on coronary collateral blood flow and on the distribution of regional myocardial blood flow (RMBF) in dogs. Thirty-eight anesthetized dogs underwent occlusion of the left anterior descending coronary artery with or without CSO and intact vasomotor tone. We measured RMBF and intramyocardial pressure (IMP) in the subendocardium (Endo) and subepicardium (Epi) separately. With intact vasomotor tone, CSO during ischemia significantly increased RMBF in the ischemic region (IR), particularly in Endo from 0.17 +/- 0.03 to 0.33 +/- 0.05 ml x min(-1) x g(-1) (P < 0.05), and increased the Endo/Epi from 0.59 +/- 0.10 to 1.15 +/- 0.15 (P < 0.01). These effects of CSO were partially abolished by adenosine. However, the Endo/Epi was still increased from 0.90 +/- 0.13 to 2.09 +/- 0.30 (P < 0.01). The changes in RMBF in IR were significantly correlated with the peak CS pressure during CSO. The Endo/Epi of IMP in IR was significantly decreased during CSO. In conclusion, CSO potentially enhances coronary collateral flow, and preserves the ischemic myocardium, especially in Endo.