Left Ventricular Summit Ventricular Tachycardia Identified by Electrocardiographic Pattern Recognition and Managed With Radiofrequency Ablation.

A 66-year-old man with left ventricular summit ventricular tachycardia (LVSVT) presented with dizziness and palpitations and was hemodynamically stable.

• Patient age was 66 years with 24 hours of dizziness and palpitations at presentation
• He was hemodynamically stable at the time of initial evaluation
• LVSVT originates in the epicardium of the superior left ventricular wall, between the origins of the main coronary arteries

The initial 12-lead ECG showed frequent premature ventricular complexes with left bundle branch block-like morphology, inferior axis, and early precordial transition characteristic of LVSVT.

• ECG demonstrated left bundle branch block-like morphology
• Inferior axis was present on the ECG
• Early precordial transition was identified as a characteristic finding
• These ECG features are described as able to guide ablation targeting

Continuous monitoring and 24-hour Holter recording documented a high ventricular ectopic burden with both sustained and nonsustained ventricular tachycardia.

• Ventricular ectopic burden was approximately 65%
• Episodes of both sustained and nonsustained monomorphic ventricular tachycardia were recorded
• All tachycardia episodes were of identical morphology
• Monitoring confirmed the arrhythmia burden that warranted further intervention

Echocardiography, coronary angiography, and cardiac magnetic resonance imaging excluded structural and ischemic etiologies for the arrhythmia.

• Echocardiography showed preserved left ventricular systolic function
• Coronary angiography excluded obstructive coronary disease
• Cardiac magnetic resonance imaging excluded myocardial fibrosis and scar
• Absence of structural heart disease supported an idiopathic origin of the LVSVT

Electrophysiological study performed on day 4 localized the arrhythmia origin to the left ventricular summit using activation mapping.

• Electrophysiological study was performed on day 4 after presentation
• Isoproterenol infusion was used to induce ventricular tachycardia
• Activation mapping localized the earliest ventricular activation to the left ventricular summit
• The mapping findings confirmed the ECG-based localization of the arrhythmia origin

Radiofrequency ablation targeting multiple sites successfully suppressed ventricular ectopy immediately after the procedure.

• Ablation was performed from the great cardiac vein and adjacent left ventricular outflow tract and left coronary cusp sites
• Coronary angiography was performed prior to ablation to confirm a safe distance from the coronary arteries
• Ventricular ectopy was immediately suppressed after ablation
• No arrhythmia was inducible after ablation during the electrophysiological study

At 30-day follow-up, the patient remained asymptomatic with no recurrent ventricular arrhythmia on Holter monitoring.

• Follow-up duration was 30 days
• Patient was asymptomatic at follow-up
• No recurrent ventricular arrhythmia was detected on Holter monitoring at 30 days
• The outcome demonstrates short-term efficacy of the radiofrequency ablation approach