The role of local voltage potentials in outflow tract ectopy

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 -