Epicardial, endocardial ablation feasible option for monomorphic VT in HCM patients

Dukkipati S. Circ Arrhythm Electrophysiol. 2011;doi:10.1161/CIRCEP.110.957290.

Issue: April 2011

More than three-quarters of selected patients with hypertrophic cardiomyopathy who underwent epicardial and endocardial catheter ablation were free of implantable cardioverter defibrillator shocks after the procedure, new data suggested.

The cohort study included 10 patients (mean age, 59 ± 9 years) with hypertrophic cardiomyopathy (HCM) and documented monomorphic ventricular tachycardia (VT). Physicians performed a combined epicardial and endocardial approach at four centers between December 2003 and December 2009.

Among the five patients with inducible, stable monomorphic VT, physicians successfully terminated three with ablation from the epicardium and one from the endocardium. One patient failed catheter ablation, however, and underwent surgical cryoablation to abolish the incessant VT. In the five patients who remained, physicians performed ablation at epicardial and endocardial sites.

After a mean follow-up of 37 (± 17) months, seven patients (78%) who underwent ablation were free from recurrent ICD shocks.

Although monomorphic VT is uncommon in patients with HCM, when it occurs, the mechanism appears to be scar-related reentry that is similar to VT occurring in other substrates, the researchers wrote.

“Targeting this tissue using a combination of voltage-based substrate mapping and activation-, entrainment-, late/fractionated potential-mapping is effective in eliminating VT. However, standard endocardial mapping and ablation alone are likely insufficient to target the relevant VT circuits,” they said. “In this highly selected population, a combined epicardial and endocardial approach to catheter ablation is feasible and of reasonable efficacy to consider if aggressive trials of anti-arrhythmic medications and trials of anti-tachycardia pacing fail to control VT.”

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