Table 3.

 Electrocardiographic and electrophysiologic data from 89 dogs with accessory atrioventricular pathways

OAVRT measurements	Mean ± SD or median (range)	P value
OAVRT cycle length (HR) prior to medication	180 ms (140‐240 ms)*	*<.0001
OAVRT cycle length during EPS	219 ms (146‐290 ms)*
Surface ECG RP′ interval during OAVRT prior to EPS	77.6 ± 9.4 ms**	**.0033
Surface ECG RP′ interval during OAVRT at EPS	75.7 ± 8.2 ms**
Surface ECG P′R interval during OAVRT prior to EPS	107 ± 19 ms***	***<.0001
Surface ECG P′R interval during OAVRT at EPS	141 ± 22 ms***
VA interval to distal ablation dipole at site of success	51 ms (32‐80 ms)
Shortest VA interval to standard catheter dipole	61.5 ± 15.5 ms
Shortest cycle length at which retrograde AP conducts 1:1 during decremental RV pacing	190 ms (150‐290 ms)
AH in OAVRT	112 ms (48‐206 ms)^	^<.0001
AH in sinus rhythm	70 ms (40‐125 ms)^
HV in OAVRT	34.5 ms (24‐49 ms)#	#<0.0001
HV in sinus rhythm (includes ventricular preexcitation)	31 ms (−26 to 49 ms)#
Ventricular preexcitation measurements
PR interval on preexcited complexes prior to EPS	60 ms (40‐90 ms)##	##0.7058
PR interval on preexcited complexes at EPS	60 ± 15 ms##
PR interval on nonpreexcited complexes prior to EPS	110 ms (80‐140 ms)
Shortest cycle length at which antegrade AP conducts 1:1 during decremental HRA pacing	303.6 ± 127.5 ms
Antegrade AP effective refractory period	243.1 ± 65.0 ms