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Acute coronary hemodynamic response to cigarette smoking in patients with coronary artery disease
Insights
Cigarette smoking increases coronary resistance in patients with coronary artery disease, particularly those with severe proximal lesions. This impacts coronary blood flow, highlighting smoking
Area of Science:
- Cardiology
- Vascular Physiology
Background:
- Acute effects of cigarette smoking on coronary hemodynamics are not well-defined.
- Understanding these changes is crucial for patients with coronary artery disease.
Purpose of the Study:
- To determine the acute effects of cigarette smoking on coronary blood flow and resistance.
- To investigate factors influencing these responses in patients with and without coronary artery disease.
Main Methods:
- Coronary sinus blood flow was measured in patients with (Group I) and without (Group II) coronary artery disease.
- Group I was further divided based on lesion severity and location (proximal vs. distal).
Main Results:
- Patients with coronary artery disease showed a smaller increase in coronary blood flow and an increase in coronary resistance post-smoking compared to healthy individuals.
- Severe proximal lesions (Group IA) resulted in a significant increase in coronary resistance and a tendency for decreased coronary flow, unlike distal lesions (Group IB).
Conclusions:
- Smoking increases coronary resistance in patients with coronary artery disease.
- The severity and location of coronary artery stenosis significantly influence the hemodynamic response to smoking.
- Smoking may increase coronary artery tone at stenotic sites, impairing coronary flow proportionally.
Abstract:
The acute changes in coronary blood flow and coronary resistance that occur in response to cigarette smoking have not been accurately determined. To define the factors that affect this response, coronary sinus blood flow was measured in 16 patients (group I) with coronary artery disease and in 6 patients (group II) without angiographically detectable coronary disease. Seven patients (group IA) had severe (greater than or equal to 75%) proximal left coronary lesions and nine patients (group IB) had significant distal lesions with 50% or less proximal stenoses. Group I had a smaller overall increase (increases 1.6 +/- 5.3%) in coronary sinus blood flow than did group II (increases 7.7 +/- 6.1%) (p less than 0.05). Coronary resistance increased overall (increases 2.7 +/- 5.3%) in group I but decreased (decreases 2.4 +/- 3.4%) in group II (p less than 0.05). Patients in group IA had a highly significant increase in coronary resistance as compared with group IB (increases 7.0 +/- 4.2% versus decreases 0.9 +/- 2.6%) (p less than 0.001). Coronary sinus flow tended to decrease (decreases 1.2 +/- 4.6%) in group IA but to increase (increases 3.8 +/- 5.1%) in group IB (p = 0.06). It is concluded that smoking increases coronary resistance in patients with coronary artery disease. A greater impact is observed in patients with a severe proximal stenosis than in those with a distal stenosis. It is proposed that smoking increases coronary artery tone at the site of the stenosis, limiting the coronary flow response proportionally to the size of the affected vascular bed.