Radiofrequency Ablation for Hypertrophic Cardiomyopathy With Obstruction

Study Questions:

Can percutaneous septal radiofrequency ablation be effective treatment for patients with hypertrophic cardiomyopathy with obstruction (HOCM)?


Fifteen patients with HOCM underwent echocardiography-guided percutaneous intramyocardial septal radiofrequency ablation (PIMSRA). Left ventricular outflow tract (LVOT) gradients, LV thickness, New York Heart Association (NYHA) class, and biochemical laboratory values were assessed pre-ablation and after 6 months.


After 6 months of follow-up, patients showed significant reductions in peak and stress-induced LVOT gradients (resting gradient from 88.00 [66.00] mm Hg to 11.00 [6.00] mm Hg; p = 0.001 and 117.00 [81.00] mm Hg to 25.00 [20.00] mm Hg; p = 0.005). There was also significant reduction in interventricular septum (IVS) thickness (anterior IVS: from 25.00 [21.00] mm to 14.00 [12.00] mm; p = 0.001; posterior IVS: from 24.00 [21.00] mm to 14.00 [11.50] mm; p = 0.001). The reductions in IVS thickness and LVOT gradients were associated with improvement in NYHA functional classification (from 3.00 [2.00] to 1.00 [1.00]; p < 0.001), total exercise time (from 6.00 [5.50] minutes to 9.00 [8.00] minutes; p = 0.007), and pro B-type natriuretic peptide levels (from 924.00 [370.45] pg/ml to 137.45 [75.73] pg/ml; p = 0.028). No patient had bundle branch block or complete heart block.


PIMSRA leads to effective reduction in LVOT gradients and is associated with clinical improvement in exercise capacity among patients with symptomatic HOCM.


This study was designed to assess the safety and efficacy of a novel treatment approach for HCM with obstruction. Authors used ablation energy to induce a localized therapeutic left anterior descending infarct. The results are impressive with respect to reduction in LVOT gradients, septal thickness, and symptomatic improvement in a small group of patients over 6 months. There were no episodes of complete heart block requiring permanent pacemaker; however, one patient did develop a pericardial effusion due to coronary vein perforation (7%). There also appears to be a learning curve in terms of identifying correct areas to ablate. Larger patient studies will be needed to confirm safety followed by comparison to gold standards of treatment (surgical myomectomy and alcohol ablation).

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Diabetes and Cardiometabolic Disease, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Pericardial Disease, Prevention, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure, Heart Failure and Cardiac Biomarkers, Interventions and Imaging, Interventions and Structural Heart Disease, Echocardiography/Ultrasound, Exercise

Keywords: Ablation Techniques, Cardiomyopathy, Hypertrophic, Catheter Ablation, Diagnostic Imaging, Echocardiography, Exercise, Heart Failure, Natriuretic Peptide, Brain, Peptide Fragments, Percutaneous Coronary Intervention, Pericardial Effusion, Treatment Outcome, Ventricular Outflow Obstruction

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