Discussion on Repolarization Reserve between Patients with Coronary Heart Disease and Normal Controls

Table 3

Comparison of RR interval, QT interval, and QTc value between patients with positive and negative coronary angiography ().

Index	Negative CAG ()	Positive CAG ()
Initial heart rate (before exercise)
RR interval			0.035	0.973
QT interval			2.665	0.011
QTc value			2.535	0.014
90 beats/minute during exercise
RR interval			1.235	0.223
QT interval			4.132	0.000
QTc value			3.699	0.001
120 beats/minute during exercise
RR interval			0.999	0.323
QT interval			3.937	0.000
QTc value			4.061	0.000
Maximum heart rate during exercise
RR interval			0.405	0.687
QT interval			1.812	0.076
QTc value			3.560	0.001
During the recovery period (1 minute after exercise)
RR interval			0.373	0.711
QT interval			1.282	0.206
QTc value			2.615	0.012
During the recovery period (3 minute after exercise)
RR interval			0.022	0.983
QT interval			2.485	0.017
QTc value			3.022	0.004

There were significant differences in QTc values among the three groups ().