Introduction: The failure of medications and the unsuitability of myectomy and alchol septal ablation for some hypertrophic obstructive cardiomyopathy (HOCM) patients call for a novel treatment. A mini-invasive treatment of HOCM, the echocardiography-guided percutaneous trans-apex intra-septal RF ablation (PTAISRA) of inter-ventricular septum (IVS), was described and evaluated in mid-term.
Methods: PTAISRA was performed for 10 HOCM patients with pressure gradient (PG) of left ventricular tract (LVOT) higher than 50mmHg. Under the guidance of the echocardiography (EPIQ 7C, Phillips Medical Systems), a RF needle electrode (17G, Cool-tip™ RF Ablation System and Switching Controller, Medtronic Minimally Invasive Therapies) was pierced along the long axis of IVS into the hypertrophic segment of the anterior IVS (Fig1.a) from the apex in parasternal intercostal region at a non-standard apical four chamber or five chamber view. Each ablation lasted for 12 minutes at 60/80W (Fig1.b). Then RF needle electrode was adjusted to ablate the posterior IVS in a similar manner till the . The patients was followed up for mean7.4±1.8 months.
Results: No death or malignant arrhythmia occurred during the perioperative period. The patients felt mild pain and recovered quickly after the operation due to the mini-invasive trauma and few bleeding. The symptoms of the patients were greatly improved from the follow-up observations. Their averaged NYHA class improved from level III-VI to level I-II. The wall thickness of anterior IVS decreased from 24.8 ± 6.3mm to 15.7 ± 2.9mm (t=5.156, P=0.004), LVOT PG from 125.2±18.2mmHg to 28±16.3mmHg (t=15.096, P < 0.001), mitral regurgitation from 4.6 ± 1.7ml to 1.8 ± 1.3ml (t=4.735, P=0.005). SAM signs improved or disappeared.
Conclusions: Echocardiography-guided PTAISRA is a safe and feasible treatment for HOCM. It can effectively reduce the LVOT obstruction and improve the symptoms of patients. The long term outcome warrants further study.