Left ventricular summit ablation for ventricular tachycardia in tetralogy of Fallot

Figures

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  Figure 1. A 12-lead electrocardiogram (ECG) and Holter monitoring. A: A 12-lead ECG that captured ventricular ectopic beats. The premature ventricular contractions have an rS pattern in V1, an early precordial transition (V3), and an inferior axis compatible with an outflow tract origin. The biphasic pattern in lead I suggests an origin close to the midline. B: Holter monitor recorded ventricular bigeminy followed by sustained monomorphic ventricular tachycardia.

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  Figure 2. Mapping in the great cardiac vein (GCV). A: Left anterior oblique view of an electroanatomic voltage map of the right ventricle (RV), with voltages <0.50 mV shown in red and voltages >1.50 mV shown in purple. The scar below the pulmonary annulus is consistent with the subannular patch repair. Note how the ablation catheter in GCV is adjacent to the septal RV outflow tract. The green sphere indicates the site of the premature ventricular contraction (PVC) recorded in (B) and of the pace map displayed in (C). B: Surface electrocardiographic recordings, bipolar intracardiac electrograms from the distal (MAP1-2) and proximal (MAP3-4) mapping catheter and right ventricular apex (RVA), and unipolar recording from the mapping catheter (MAPUNI) during a sinus beat followed by a spontaneous PVC. At this site, the onset of ventricular activation precedes the surface QRS by 37 ms and a Q-wave pattern is noted on the unipolar recording. C: QRS morphology of a spontaneous PVC followed by a paced ventricular beat. The pace mapping algorithm detected a match of 95%. CS = coronary sinus; LPA = left pulmonary artery; MPA = main pulmonary artery; RA = right atrium; SVC = superior vena cava.

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  Figure 3. Assessment of proximity to coronary arteries. Computed tomography (CT) angiographic images of the aorta and proximal coronary arteries in anteroposterior (A) and left anterior oblique (B) views. C: CT imaging is integrated with electroanatomic mapping in a left anterior oblique view with caudal angulation. The site of successful ablation (green sphere) is over the septal left ventricular (LV) summit adjacent to the posteroseptal right ventricle outflow tract (RVOT). Cx = circumflex artery; GCV = great cardiac vein; LAD = left anterior descending artery; RCA = right coronary artery; RV = right ventricle.

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  Figure 4. Catheter ablation in the left ventricular (LV) summit. A: Left anterior oblique view of activation mapping of premature ventricular contractions (PVCs). Local activation at a distal portion of the great cardiac vein (GCV; in red) overlying the LV summit precedes the site of earliest activation in the posteroseptal right ventricle outflow tract (RVOT). The map is tilted caudally to show the relationship between the site of successful ablation and earliest activation in the RVOT. B: Interruption of ventricular bigeminy during irrigated radiofrequency ablation in the GCV. IVC = inferior vena cava; SVC = superior vena cava.