Percutaneous radiofrequency ablation of the left bundle branch: an alternative modality of treatment for patients with hypertrophic obstructive cardiomyopathy.
Hypertrophic obstructive cardiomyopathy (HOCM), which is characterized by asymmetric septal and ventricular obstructive hypertrophy, is currently palliated with a number of pharmacological, electrical and surgical interventions. Although none of the methods have been successful in reducing the incidence of sudden death, most of the patients have shown significant symptomatic improvement. Currently, pacemaker implantation and surgical procedures have been offered only to those patients who do not respond to a medical line of treatment. Since obstructive pressure gradients correlate fairly well with the clinical condition of a patient, the principal aim of surgical or pacemaker therapy has been to reduce the left ventricular pressure gradient. Surgical procedure achieves this objective by septal myotomy and myectomy whereas pacemakers attain it by altering the sequence of electrical stimulation of the ventricles. A right ventricular pacing, which behaves like a left bundle branch block, is known to alter the pattern of interventricular septal contraction and hence delay the onset of mitral leaflet-septal contact. The latter has been implicated in the pathogenesis of subvalvar dynamic left ventricular outflow tract obstruction, which is the hallmark of this condition. Currently, radiofrequency ablation of the left bundle branch has been successfully carried out for patients with resistant macrore-entry ventricular tachycardia, I, therefore, propose that radiofrequency ablation of the left bundle branch be used as a palliative procedure of choice for patients with HOCM who are resistant to a medical line of treatment. This would result in left bundle branch block which in turn would cause an altered pattern of septal contraction resulting in the reduction or elimination of left ventricular outflow tract obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)
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Department of Cardiology, King Edward VII Memorial Hospital, Parel, Bombay, India.
D002036:Bundle of His / Q000601:surgery*; D002037:Bundle-Branch Block / Q000601:surgery*; D002312:Cardiomyopathy, Hypertrophic / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation; D006801:Humans; D016277:Ventricular Function, Left / Q000502:physiology