Key result
Constant or rate-dependent left bundle branch block in patients with syndrome X was associated with significant deterioration of left ventricular ejection fraction during exercise over 4 years.
Why the study?
Does the presence of left bundle branch block versus stress-induced ST-segment depression predict deterioration of left ventricular function in patients with syndrome X?
Cohort (n=40)
Does the presence of left bundle branch block versus stress-induced ST-segment depression predict deterioration of left ventricular function in patients with syndrome X?
p-value: p=<0.05
Patients with syndrome X and left bundle branch block are at risk for significant deterioration of left ventricular function over 4 years, whereas those with stress-induced ST-segment depression have a benign prognosis.
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LBBB may warrant closer LVEF surveillance in syndrome X; leaves open prospective validation and management implications.
Opherk et al. (1989) conducted a cohort in Syndrome X (angina pectoris and normal coronary arteriograms) (n=40). Constant or rate-dependent left bundle branch block vs. Stress-induced ST-segment depression was evaluated on Left ventricular performance (pulmonary artery mean pressure and left ventricular ejection fraction) during rest and exercise (p=<0.05). Constant or rate-dependent left bundle branch block in patients with syndrome X was associated with significant deterioration of left ventricular ejection fraction during exercise over 4 years.
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