A septal myomectomy is a type of open-heart surgery used to treat severe hypertrophic obstructive cardiomyopathy (HOCM), an inherited heart condition that can cause sudden death in young adults. This condition is characterized by excess septal muscle. The septum is the wall of muscle separating the left and right sides of the heart. When there is excess muscle, it may interfere with the flow of blood through the ventricle.

This condition is called an outflow tract obstruction and may result in a reduced blood flow to the body. In some rare cases, the outflow tract obstruction may also interfere with the functioning of the mitral valve. This valve sits between the left atrium and left ventricle, and the outflow tract obstruction can cause blood to flow backward from the left ventricle into the left atrium (mitral valve regurgitation). Other complications of this condition include atrial fibrillation, syncope, congestive heart failure and cardiac arrest.

There are four options for treating HOCM:

• Septal myomectomy surgery, an open–heart surgery in which a surgeon removes some of the excess muscle. In some cases, the physician may choose to also replace a faulty mitral valve in conjunction with the surgery, depending if the HOCM is causing mitral valve regurgitation.
  
  
• Septal alcohol ablation, a less-invasive catheter-based procedure in which a physician uses ethanol alcohol to create an infarction, or mini heart attack, in the septum and thins the excess muscle. Studies have shown this relatively new procedure has roughly the same long-term outcome as surgery, with the advantage of less surgical trauma for the patient.

The HOCM’s severity and the patient profile dictates which approach the physician will usually choose as treatment. About 95 percent of cases can be handled with either medication or an implanted pacemaker with ICD. Of the remaining 5 percent, septal alcohol ablation is usually recommended for elderly patients and others who cannot withstand the rigors of open-heart surgery. Surgery is often recommended for younger patients who have severe symptoms that are not responding to medication.