Turk Kardiyol Dern Ars. 1997; 25(4): 215-219
Absence of Frequency dependent Effects of Intravenous Propafenone at High Rates on Ventricular Action Potential and QRS Duration in Humans
, Murat ÖZDEMİR1
Propafenone is an antiarrhythmic agent that blocks sodium channels in a frequency-dependent manner. In this study, frequency-dependent effects of intravenous propafenone on right ventricular action potential duration (APD90), QRS duration and ventricular effective refractory period (VERP)/APD90 ratio were investigated in 10 healthy subjects. Intravenous propafenone caused no significant difference in APD90 at 4 different pacing cycle lengths (600, 500, 400, 300 ms). On the other hand, a 22-24 % increase in QRS duration was seen after propafenone (p<0.05). Decreasing the pacing cycle length from 600 ms to 300 ms caused a 6.4% increase in QRS duration. Compared to baseline, this increase was not statistically significant (p>0.05). VERP/APD90 ratio increased by 4-13 % after propafenone but no frequency-dependent changes were evident in this ratio (p>0.05). In conclusion, intravenous propafenone caused no change in APD90 but led to an increase in QRS duration and VERP/APD90 ratio in 10 healthy subjects. Moreover, these changes were shown not to be frequency-dependent at the pacing cycle lengths used in this study.
How to cite this article
Erdem DİKER, Murat ÖZDEMİR. Absence of Frequency dependent Effects of Intravenous Propafenone at High Rates on Ventricular Action Potential and QRS Duration in Humans. Turk Kardiyol Dern Ars. 1997; 25(4): 215-219