Electrocardiographic Recognition of the Epicardial Origin of Ventricular Tachycardias

Abstract

Background-Some ventricular tachycardias (VTs) originating from the epicardium are not suitable for endocardial radiofrequency ablation and require an epicardial approach. The aim of this study was to define the ECG characteristics that may identify an epicardial origin of VTs. Methods and Results-We analyzed the 12-lead ECG recordings during epicardial and endocardial left ventricular pacing in 9 patients to verify the hypothesis that the epicardial origin of the ventricular activation widens the initial part of the QRS complex. Then, we analyzed the ECG pattern in 14 VTs successfully ablated from the epicardium after a failed endocardial approach (group A), in 27 VTs successfully ablated from the endocardium (group B), and in 28 additional VTs that could not be ablated from the endocardium (group C). Four distinct intervals of ventricular activation were defined and measured: (1) the pseudodelta wave, (2) the intrinsicoid deflection time in V2, (3) the shortest RS complex, and (4) the QRS complex. VTs from groups A and C showed a significantly longer pseudodelta wave, intrinsicoid deflection time, and RS complex duration compared with VTs of group B. There was no difference between groups A and C. A pseudodelta wave of Ն34 ms has a sensitivity of 83% and a specificity of 95%, an intrinsicoid deflection time of Ն85 ms has a sensitivity of 87% and a specificity of 90%, and an RS complex duration of Ն121 ms has a sensitivity of 76% and a specificity of 85% in identifying an epicardial origin of the VTs. Conclusions-ECG suggests VTs originating from the epicardium and those with an unsuccessful radiofrequency ablation from the endocardium.

2015 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death

“…Dlatego 12-odprowadzeniowe powierzchniowe EKG, w którym zarejestrowano kliniczny epizod VT, może ułatwić mapowanie i zabieg ablacji. U pacjentów z kardiomiopatią o etiologii innej niż niedokrwienna morfologia zespołów QRS może pozwolić na identyfikację tych pacjentów, u których prawdopodobnie wymagana będzie ablacja nasierdziowa [194][195][196][197]. Co więcej, przedzabiegowe obrazowanie za pomocą CMR może ułatwić nieinwazyjną identyfikację substratu arytmicznego u pacjentów z wywiadem zawału serca [198] lub u pacjentów z nasierdziowym VT [199].…”

Ventricular arrhythmias in nonischemic cardiomyopathy

“…The ECG findings should be delicately interpreted and carefully correlated to the clinical symptoms to exclude the possibility of innocent findings or a misdiagnosis. Apart from the abovementioned approach, efforts to identify the VA morphologies may also help to localize the arrhythmogenic substrate and distinguish epicardial from endocardial circuits 14, 15, 16. In spite of the importance of ECG during clinical practice, current evidence does not support the broad application of ECG screening in the general population, owing to the possibility of a misinterpretation.…”

Ablating Premature Ventricular Complexes: Justification, Techniques, and Outcomes

“…21 PVCs originating from epicardial sites have a pseudo-delta wave, with slurring of the initial part of the QRS complex and delayed intrinsicoid deflection in the precordial leads, and can often be accessed through epicardial veins close to the great cardiac veinanterior interventricular vein (GCV-AIV) junction. 22,23 PVCs originating from the fascicular system have a relatively narrow QRS with a sharp initial deflection as the Purkinje system is engaged. PVCs originating in the left posterior fascicle have a typical right BBB morphology with superior frontal plane axis, 18,19 PVCs originating from the LV posterior and anterior papillary muscles are similar to the respective fascicular PVCs.…”