Male patients with left anterior descending CAD had a steeper maximal slope of the QT restitution curve during exercise testing compared to controls (1.40 vs 0.84, P=0.002).
Observational (n=26)
Does exercise ECG testing reveal differences in QT restitution properties between male patients with and without left anterior descending CAD?
Exercise ECG testing can noninvasively identify steeper QT restitution curves in male patients with left anterior descending CAD, reflecting altered ventricular electrophysiological properties.
Absolute Event Rate: 1.4% vs 0.84%
p-value: p=0.002
BACKGROUND: The hypothesis of action potential duration restitution (APDR) suggests that wave break is mainly determined by the steepness of APDR curve. The purpose of this study was to investigate the QT restitution properties by a noninvasive method, exercise ECG test, in patients with and without left anterior descending coronary artery disease (CAD). METHODS: Twenty-six male patients were divided into CAD group and control group based on the result of selective coronary angiography (SCA). Exercise tests were performed in each case before the SCA. Sequential QT intervals and preceding TQ intervals were measured, and QT restitution curve (QTRC) was constructed by plotting QT versus TQ intervals. RESULTS: Within the physiological maximal heart rate, the maximal slope of QTRC in the CAD group (1.40 ± 0.41) was greater than that in the control group (0.84 ± 0.20, P = 0.002). The mean slope values of the CAD group was also statistically higher than that in the control group at the same TQ levels when the TQ interval decreased to less than 250 ms (P < 0.05). CAD patients had lower linear correlation coefficients of QT/TQ compared with the control group (0.86 ± 0.04 in the CAD group vs 0.91 ± 0.02 in the control group, P < 0.001). CONCLUSIONS: Male patients with left anterior descending CAD had steeper QTRC than those without CAD. QTRC from exercise test ECG may be an effective noninvasive method for estimating the electrophysiological restitution properties of the ventricle.
Zhao et al. (Tue,) conducted a observational in Coronary Artery Disease (n=26). Left anterior descending coronary artery disease vs. Without coronary artery disease (control group) was evaluated on Maximal slope of QT restitution curve (QTRC) (p=0.002). Male patients with left anterior descending CAD had a steeper maximal slope of the QT restitution curve during exercise testing compared to controls (1.40 vs 0.84, P=0.002).