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Left ventricular dysfunction in patients with angina pectoris, normal epicardial coronary arteries, and abnormal
Insights
Patients with chest pain and normal coronary arteries show impaired coronary flow and left ventricular function. Abnormal vasodilator reserve indicates myocardial ischemia, affecting systolic and diastolic function.
Area of Science:
- Cardiology
- Diagnostic Imaging
- Physiology
Background:
- Chest pain in patients with angiographically normal coronary arteries is a clinical challenge.
- Coronary artery disease (CAD) can manifest as microvascular dysfunction, not just epicardial stenosis.
- Understanding the mechanisms behind chest pain in these patients is crucial for diagnosis and management.
Purpose of the Study:
- To investigate the relationship between coronary flow, left ventricular function, and chest pain in patients with normal coronary arteries.
- To evaluate the diagnostic utility of coronary flow studies and gated blood pool scintigraphy in this population.
- To identify physiological abnormalities indicative of myocardial ischemia in patients with normal epicardial coronary arteries.
Main Methods:
- Coronary flow studies during pacing and ergonovine administration were performed in 33 patients.
- Resting and exercise gated blood pool scintigraphy was utilized to assess left ventricular function.
- Comparison was made between patients experiencing chest pain and those without, as well as with a control group.
Main Results:
- Patients with chest pain showed significantly lower great cardiac vein flow, higher coronary resistance, and reduced lactate consumption during pacing.
- Abnormal vasodilator reserve was associated with reduced left ventricular ejection fraction during exercise compared to controls.
- Impaired left ventricular diastolic filling and exercise-induced regional wall motion abnormalities were observed in patients with abnormal vasodilator reserve.
Conclusions:
- Abnormal vasodilator reserve in patients with chest pain and normal coronary arteries is linked to myocardial ischemia.
- These findings suggest significant abnormalities in left ventricular systolic and diastolic function.
- Coronary flow studies and scintigraphy can help identify underlying ischemia in patients with non-obstructive coronary artery disease.
Abstract:
Thirty-three patients with chest pain despite angiographically normal coronary arteries underwent both coronary flow studies during pacing and resting and exercise gated blood pool scintigraphy. During atrial pacing after administration of ergonovine, those patients developing their typical chest pain demonstrated significantly lower great cardiac vein flow (97 +/- 31 vs 150 +/- 33 ml/min, p less than .001), higher coronary resistance (1.27 +/- 0.43 vs 0.77 +/- 0.18 mm Hg/ml/min, p less than .005), and less lactate consumption (30.5 +/- 22.0 vs 69.7 +/- 41.1 mM . ml/min, p less than .005) and a higher left ventricular end-diastolic pressure after pacing (20 +/- 4 vs 12 +/- 1, p less than .001) compared with those without pain and in the absence of significant luminal narrowing of the epicardial coronary arteries. The 26 patients with abnormal vasodilator reserve demonstrated reduced left ventricular ejection fraction during exercise (58 +/- 8%) compared with the seven patients with appropriate vasodilator reserve (66 +/- 4%, p less than .05) and with a group of 52 control patients of similar age and sex distribution and free of known heart disease (66 +/- 10%, p less than .001). In addition, 12 of the 26 patients with abnormal vasodilator reserve demonstrated exercise-induced regional wall motion abnormalities. Many of these patients also manifested impaired left ventricular diastolic filling at rest compared with the control subjects (peak filling rate 2.6 +/- 0.7 vs 3.2 +/- 0.7 end-diastolic volume/sec, p less than .005). Thus, patients with chest pain resulting from abnormal vasodilator reserve demonstrate abnormalities of left ventricular systolic and diastolic function suggestive of myocardial ischemia.