Septal myectomy is an open-heart surgical procedure in which part of the thickened septum of the heart muscle is removed. It can improve symptoms in people with severe HCM, and complications are rare.

Cardiomyopathy is a condition that affects your heart muscle (myocardium). “Hypertrophic” means something is enlarged.

Hypertrophic cardiomyopathy (HCM) is a form of inherited cardiomyopathy in which your heart muscle is thicker than usual. This enlargement usually occurs in your left ventricle.

Sometimes, the heart muscle’s inner wall (septum) becomes so thick that blood has a harder time leaving the heart to reach the rest of the body. This effect is known as left ventricular outflow tract obstruction.

Doctors recommend septal myectomy to correct this complication.

Keep reading to learn more about HCM and how septal myectomy may improve your symptoms.

Experts estimate that 1 in 500 people have HCM. Although rare, the changes in the heart that occur from HCM may cause severe complications, such as congestive heart failure and sudden cardiac death.

A septal myectomy is one of several treatment options for HCM, but doctors don’t recommend it for everyone with HCM. Instead, you must experience significant symptoms and problems, including:

  • shortness of breath
  • chest pain
  • lightheadedness
  • affected activity levels that don’t respond to medications

A doctor is unlikely to recommend septal myectomy. However, they might do so if your HCM is severe and you’re unlikely to have a negative surgical outcome.

Septal myectomy is an invasive procedure. This means a medical specialist, like a cardiac surgeon, will make incisions, cuts, or punctures to open up your chest and directly view the heart to perform the procedure.

To ensure a good outcome, a doctor may have several appointments with you to assess your risk of complications. These may involve tests to determine the severity of your condition. Examples of these tests include:

  • Blood tests: These help determine your overall blood counts and whether you might need a blood transfusion during or after surgery.
  • Echocardiogram: This diagnostic test helps determine how well your heart is currently working, how thick the heart muscle is, and the effect of blood flow through the heart.
  • Electrocardiogram: This helps determine whether you have any abnormal heart rhythms.
  • Cardiac MRI: This type of imaging test allows a medical specialist to view the heart in more detail.

During these consultations, consider asking your doctor about the possible risks, benefits, and expected recovery time for the procedure given your current overall health.

It’s also important to ask them how to prepare for your surgery. They may ask you to stop eating, drinking fluids, and taking certain medications for several hours before the appointment.

A septal myectomy is an open-heart procedure. Before starting, a specialist will give you general anesthesia, which is a medication that puts you completely to sleep.

There are several different approaches to performing septal myectomy for HCM. Here’s a general description of the steps:

  1. The surgeon will make a large incision in your chest. They will also cut through your breastbone, splitting it in two. This allows them to see your heart.
  2. They’ll insert special catheters into the areas where blood flow enters and exits your heart. The catheters connect to a special heart-lung machine known as a cardiac bypass machine. This allows the surgeon to work on your heart while keeping you alive.
  3. The surgeon will remove the thickened part of your heart’s septum. Since HCM can also affect your mitral valve, the surgeon will repair this valve if needed.
  4. They will then reestablish blood flow from the cardiac bypass machine. They will make sure your heart beats again on its own.
  5. The surgeon will put your breastbone back together before closing the incision with sutures.

How long does a septal myectomy take?

The amount of time septal myectomy takes depends on how complicated your surgical case is. On average, surgery will take 3 to 6 hours, though this may vary.

Preparation and recovery will add even more time. Your surgeon can advise you on how long your procedure may take based on your medical history and specific circumstances.

Because the procedure is invasive, you can expect to stay in the hospital for a few days. You’ll likely be in an intensive care unit at first before moving to an inpatient room.

According to a 2020 study from a referral center for septal myectomy, the average hospital stay after the procedure was 4.9 days.

You may need to stay longer if you experience any complications. Researchers of the same study found that the average hospital stay for those who experienced atrial fibrillation (AFib) was 5.8 days.

Healing after a septal myectomy will take time. You’ll likely need to limit your activities for 6 to 8 weeks (sometimes more) following surgery.

Your doctor will continue to monitor your heart rhythms and recovery to determine whether your HCM symptoms are resolving after surgery.

Complications from a septal myectomy are not common. In fact, the complication rate for the procedure is one of the lowest for any open heart procedure at 0.6% at experienced centers.

The most common complication following surgery is AFib, which is an irregular heart rhythm. Some other complications may include:

  • incision infection
  • bleeding
  • new-onset heart block, a type of arrhythmia that may require a pacemaker
  • mitral regurgitation, a type of heart valve disease
  • mitral valve replacement within 1 year

A history of certain comorbidities (coexisting health conditions) may reduce your chances of a successful septal myectomy. Such conditions include pulmonary hypertension and obesity.

In a 2022 multicenter study with people who underwent a septal myectomy, 4% of them required a pacemaker after surgery.

Some research suggests that septal myectomy helps improve HCM symptoms in more than 90% of people who undergo the procedure. Around 75% of people find that their symptoms resolve completely following surgery.

Still, 5% of people may continue to experience problems with daily functioning related to HCM after the procedure.

If your HCM doesn’t respond to the surgery, a doctor may recommend other interventions. These can range from a pacemaker to a heart transplant.

What is the survival rate for septal myectomy?

The survival rate for people with HCM who undergo septal myectomy is very high. In fact, researchers suggest it’s similar to people who don’t have the condition.

According to a 2019 study in 2,956 people with HCM who had septal myectomy between 1961 and 2017, the 1-, 10-, and 20-year survival rates were approximately:

  • 1 year: 98%
  • 10 years: 85%
  • 20 years: 52%

A healthcare professional can help you better understand your individual outlook.

Septal myectomy has been the “gold standard” of treatment for HCM since the 1950s. But surgeons developed a new approach in the 1990s called alcohol septal ablation (ASA).

ASA is a catheter-based approach, and it’s not an open-heart surgery. It’s less invasive than septal myectomy and carries less risk of bleeding or infection. A doctor may recommend ASA if you have frailty or certain comorbidities.

That said, according to 2022 research, ASA has a higher long-term death rate, though this may be due to patients’ individual factors more than the procedure itself. It also has a slightly higher risk of heart block.

Several other treatments are available for HCM. These may include:

  • medications, such as beta-blockers, calcium channel blockers, disopyramide, and mavacamten (Camzyos) for obstructive, symptomatic HCM
  • heart implants, such as an implantable cardiac defibrillator (ICD)
  • other surgeries, such as the Maze procedure, radiofrequency ablation, and heart transplant

Experts estimate the average cost of hospitalization for septal myectomy to be $41,715. This number may not include other related costs, such as fees for anesthesia.

It’s important to note that this cost doesn’t reflect what insurance or Medicare might cover. If you have insurance, check with your provider to see what your out-of-pocket cost will be.

It’s unclear what the lifetime cost of managing HCM without surgery is.

If you have HCM and experience symptoms that affect your daily life, you might be a candidate for septal myectomy. Although it’s an invasive procedure, the success rate is very high. The complication rate is low when performed at experienced centers.

Keep in mind that certain underlying conditions may reduce your risk of success. You and a doctor will discuss the pros and cons of this surgery for your unique case.

If you’re not a candidate for septal myectomy, talk with a doctor about alternatives, such as ASA.