Inter- and intraindividual variations in shortening of ventricular effective refractory period after an abrupt decrease in pacing cycle length.
After an abrupt decrease in pacing cycle length (PCL), the ventricular effective refractory period (VERP) shortens. The pacing protocol needed to determine accurate and reproducible values for the VERP during this process is elaborate and time consuming. In this study, steady-state values of VERP at 800 and 350 msec PCL and dynamic values of VERP due to an abrupt change in PCL from 800 to 350 msec were determined. This was done for 11 different dogs to test the interindividual variation and repetitively in the same dog to test the intraindividual variation. The results for steady-state and dynamic values of the VERP show a wide range for both groups. This means that accurate prediction of steady-state and dynamic values of VERP based on previous measurements is not possible.
Department of Cardiology, Cardiovascular Research Institute Maastricht, University Hospital Maastricht, The Netherlands.
H M
HM
Leerssen
M A
MA
Vos
K
K
den Dulk
J
J
van der Zande
M J
MJ
Begemann
H J
HJ
Wellens
D000818:Animals; D002304:Cardiac Pacing, Artificial; D004285:Dogs; D005260:Female; D006339:Heart Rate; D008297:Male; D012032:Refractory Period, Electrophysiological; D016276:Ventricular Function