Inclusion Criteria:  HOCM refractory to medical treatment with symptoms like syncope, angina or NYHA functional classes III and IV, with a resting gradient or provocable gradient equal or greater than 50 mmHg, requiring surgical intervention. Absence of other cardiac or systemic diseases capable of producing hypertrophy. Sinus rhythm.  Exclusion Criteria:  Patient refusal. Patient unable to give consent. TEE contraindication. Different rhythm than sinus. Other systemic diseases capable of producing hypertrophy. Severe Aortic or coronary artery pathology.