TY - JOUR
T1 - The role of local voltage potentials in outflow tract ectopy
AU - Bloch Thomsen, Poul Erik
AU - Johannessen, Arne
AU - Jons, Christian
AU - Hansen, Thomas Fritz
AU - Kanters, Jørgen K.
AU - Haarbo, Jens
AU - Hansen, Jim
AU - Christiansen, Liselotte Klint
AU - Sogaard, Peter
AU - Saermark, Knud
AU - Antzelevitch, Charles
PY - 2010/6/1
Y1 - 2010/6/1
N2 - Aims: Discrete, fragmented, local voltage potentials (LVPs) have been observed in electrograms recorded at the ablation site in patients undergoing radiofrequency ablation for arrhythmias originating in both the right and left ventricular outflow tract; however, the incidence and the significance of the LVP with respect to arrhythmogenesis is uncertain. Methods and results: We studied 25 patients with outflow tract arrhythmias referred for radiofrequency catheter ablation and recorded high-amplified intracardiac electrograms close to the site of origin of the arrhythmia. Ten patients undergoing ablation for supraventricular arrhythmias served as controls. During sinus rhythm, LVPs were recorded in 24 of the 25 patients, 10-85 ms (41 ± 19 ms) after the onset of the QRS complex, duration 33 ± 11 ms, voltage 2.0 ± 1.5 mV. The same potential was recorded 10-52 ms (mean 37 ± 11 ms) prior to the V potential in the ventricular premature beats. In 10 patients, ventricular parasystole was suggested by varying coupling intervals >100 ms, and fusion beats allowing for the estimation of the least common denominator of R-R intervals. In 23 of the 25 patients, the 12-lead electrocardiogram (ECG) and intracardiac contact mapping located the arrhythmias to an area of 3-4 cm 2 in the septal region of the right ventricular outflow tract; in two patients, the site of origin was in the left coronary cusp. Radiofrequency ablation carried out in 24 of the 25 patients was successful in 21 patients, and after successful ablation, the LVP could still be recorded in all these 21 patients. The LVP was not present in 10 controls. Conclusion: Local potentials are recorded close to the site of origin of ventricular ectopy in >90 of patients with idiopathic outflow tract ectopy and imply successful ablation. The potentials may reflect an area of depressed conductivity known to be a prerequisite for experimental ventricular ectopy including parasystole.
AB - Aims: Discrete, fragmented, local voltage potentials (LVPs) have been observed in electrograms recorded at the ablation site in patients undergoing radiofrequency ablation for arrhythmias originating in both the right and left ventricular outflow tract; however, the incidence and the significance of the LVP with respect to arrhythmogenesis is uncertain. Methods and results: We studied 25 patients with outflow tract arrhythmias referred for radiofrequency catheter ablation and recorded high-amplified intracardiac electrograms close to the site of origin of the arrhythmia. Ten patients undergoing ablation for supraventricular arrhythmias served as controls. During sinus rhythm, LVPs were recorded in 24 of the 25 patients, 10-85 ms (41 ± 19 ms) after the onset of the QRS complex, duration 33 ± 11 ms, voltage 2.0 ± 1.5 mV. The same potential was recorded 10-52 ms (mean 37 ± 11 ms) prior to the V potential in the ventricular premature beats. In 10 patients, ventricular parasystole was suggested by varying coupling intervals >100 ms, and fusion beats allowing for the estimation of the least common denominator of R-R intervals. In 23 of the 25 patients, the 12-lead electrocardiogram (ECG) and intracardiac contact mapping located the arrhythmias to an area of 3-4 cm 2 in the septal region of the right ventricular outflow tract; in two patients, the site of origin was in the left coronary cusp. Radiofrequency ablation carried out in 24 of the 25 patients was successful in 21 patients, and after successful ablation, the LVP could still be recorded in all these 21 patients. The LVP was not present in 10 controls. Conclusion: Local potentials are recorded close to the site of origin of ventricular ectopy in >90 of patients with idiopathic outflow tract ectopy and imply successful ablation. The potentials may reflect an area of depressed conductivity known to be a prerequisite for experimental ventricular ectopy including parasystole.
KW - Action Potentials
KW - Adult
KW - Aged
KW - Catheter Ablation
KW - Electrocardiography
KW - Female
KW - Heart Conduction System
KW - Humans
KW - Male
KW - Middle Aged
KW - Parasystole
KW - Tachycardia, Supraventricular
KW - Tachycardia, Ventricular
KW - Ventricular Premature Complexes
U2 - 10.1093/europace/euq090
DO - 10.1093/europace/euq090
M3 - Journal article
C2 - 20413613
SN - 1099-5129
VL - 12
SP - 850
EP - 860
JO - Europace
JF - Europace
IS - 6
ER -