Catheter ablation of premature ventricular contractions in a case of obstructive hypertrophic cardiomyopathy

Introduction: Obstructive hypertrophic cardiomyopathy (HOCM) is a heterogeneous disease where ventricular arrhythmias play an important role in the evolution and prognosis of the disease. Taking into consideration the limited efficacy of antiarrhythmic agents, radiofrequency (RF) catheter ablation is being increasingly used due to its superior long-term outcome.
Case presentation: We present the case of a 47 year old patient with HOCM with surgical septal myomectomy and mitral annuloplasty, frequent PVCs and poor anti-arrhythmic treatment response, who underwent a RF ablation procedure. The patient performed an electro-physiological procedure at the Rehabilitation Hospital in Cluj-Napoca. The procedure was guided by the 3D mapping system CARTO (Biosense-Webster). At first, the anatomical and activation maps of the left ventricle were performed by retrograde transaortic approach. The left ventricle activation map revealed an early acti-vation site located on the LV’s lateral wall. Afterwards, voltage mapping revealed a large endocardial scar, whe-re the septal myomectomy was performed and smaller fibrosis islets.
Results: The activation map, performed with the help of bipolar electrograms, pinpointed the VT’s origin on the lateral wall of the left ventricle. The application of RF energy at this specific site resulted in the supression of the PVCs. No intraoperative or postprocedural com-plications were noted. A 24h Holter-ECG Monitoring was performed after the procedure, which revealed few PVCs, though with a different morphology than the initial ones, sugesting a different origin. Six weeks later, the patient was in sinus rhythm and asymptomatic.
Conclusion: Radiofrequency ablation, guided by a 3D mapping system is increasingly being used in mana-ging drug-resistant ventricular arrhythmias, due to its capacity of identifying the arrhythmic substrate whi-ch subsequently enables the guidance of the definitive treatment. The success rate of the procedure is inversely correlated with the degree of the endocardial structural involvement.

ISSN – online: 2734 – 6382
ISSN-L 1220-658X
ISSN – print: 1220-658X
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CODE: 379
CME Credits: 10 (Romanian College of Physicians)