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Dynamic Assessments of Coronary Flow Reserve after Myocardial Ischemia Reperfusion in Mice
Published on: August 25, 2023
Impaired myocardial perfusion and perfusion reserve associated with increased coronary resistance in persistent
Felix T Range1, Michael Schäfers, Tayfun Acil
1Department of Nuclear Medicine, University of Münster, Albert-Schweitzer-Str. 33, D-48149 Münster, Germany.
European Heart Journal
|July 3, 2007
Summary
Patients with atrial fibrillation (AF) experience reduced myocardial blood flow (MBF) and increased coronary vascular resistance (CVR) due to the arrhythmia. While cardioversion partially restores MBF, hyperemic function remains impaired, suggesting persistent microvascular dysfunction.
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Nuclear Cardiology
Background:
- Patients with atrial fibrillation (AF) often exhibit symptoms of myocardial ischemia.
- Coronary artery disease is typically excluded, suggesting potential small vessel disease.
- Quantifying myocardial perfusion and vascular function in AF is crucial for understanding ischemia.
Purpose of the Study:
- To quantify myocardial perfusion, perfusion reserve, and coronary vascular resistance (CVR) in patients with AF using positron emission tomography (PET).
- To assess the reversibility of these parameters after cardioversion.
Main Methods:
- Utilized H(2)(15)O-PET to quantify myocardial blood flow (MBF) at rest, during hyperemia (adenosine), and cold-pressor testing (CPT).
- Compared 25 male patients with persistent idiopathic AF to 13 age- and risk-matched controls.
- Repeated PET scans in 10 AF patients after electrical cardioversion.
Main Results:
- AF patients showed significantly reduced resting MBF, hyperemic MBF, and MBF under CPT compared to controls.
- Hyperemic CVR was significantly increased in AF patients, while resting and CPT CVR were unchanged.
- After cardioversion, resting MBF and CPT MBF normalized, but hyperemic MBF and CVR did not recover.
Conclusions:
- Atrial fibrillation is associated with reduced myocardial blood flow and increased hyperemic coronary vascular resistance.
- These hemodynamic alterations are partly reversible after cardioversion, indicating they are likely secondary to the arrhythmia.
- Persistent impairment in hyperemic function post-cardioversion suggests potential lasting microvascular dysfunction.
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