Ventricular repolarization alterations in women with angina pectoris and suspected coronary microvascular dysfunction

Abstract

Objectives: CMD could be the explanation of angina pectoris with no obstructive CAD and may cause ventricular repolarization changes. We compared T-wave morphology and QTc interval in women with angina pectoris with a control group as well as the associations with CMD.

Methods: Women with angina pectoris and no obstructive coronary artery disease (n=138) and age-matched controls were compared in regard to QTc interval and morphology combination score (MCS) based on T-wave asymmetry, flatness and presence of T-wave notch. CMD was assessed as a coronary flow velocity reserve (CFVR) by transthoracic echocardiography.

Results: Women with angina pectoris had significantly longer QTc intervals (429±20ms) and increased MCS (IQR) (0.73 [0.64-0.80]) compared with the controls (419±20ms) and (0.63 [(0.53-0.73]), respectively (both p<0.001). CFVR was associated with longer QTc interval (p=0.02), but the association was attenuated after multivariable adjustment (p=0.08).

Conclusion: This study suggests that women with angina pectoris have alterations in T-wave morphology as well as longer QTc interval compared with a reference population. CMD might be an explanation.

Keywords: Angina pectoris; Coronary microvascular dysfunction; Non-obstructive coronary artery disease; QT interval prolongation; T wave morphology.