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

Table 4

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

Index	Normal control ()	Negative CAG ()	Positive CAG ()
Initial heart rate (before exercise)
RR interval				0.906	0.407
QT interval			^b	3.686	0.028
QTc value			^ab	4.475	0.014
90 beats/minute during exercise
RR interval				0.768	0.466
QT interval			^ab	5.241	0.007
QTc value			^ab	4.690	0.011
120 beats/minute during exercise
RR interval				1.434	0.243
QT interval		^a	^b	10.580	0.000
QTc value		^a	^b	11.450	0.000
Maximum heart rate during exercise
RR interval		^a		2.308	0.104
QT interval		^a		5.809	0.004
QTc value		^a	^b	8.651	0.000
During the recovery period (1 minute after exercise)
RR interval				0.073	0.930
QT interval		^a		2.452	0.091
QTc value		^a	^b	9.983	0.000
During the recovery period (3 minute after exercise)
RR interval				0.013	0.987
QT interval		^a	^b	4.911	0.009
QTc value		^a	^b	7.694	0.000

Note: ^acomparison with the normal control, ; ^bcomparison with negative CAG, .