What is hypertrophic cardiomyopathy (HCM)?
Hypertrophic cardiomyopathy (HCM) is a genetic condition in which the heart walls are abnormally thick. In HCM, the heart cannot fill with enough blood, and therefore cannot pump enough blood to the body. HCM affects 1 in every 500 people in the general population; however, most patients are unaware that they have this condition. The diagnosis is made via echocardiography (ECG; heart ultrasound).
What is alcohol septal ablation?
In some HCM patients, there is also thickening in the first area where blood leaves the heart to be sent to the body (left ventricular outflow tract; LVOT). This creates a serious obstacle (obstruction) to the outflow of blood. This type of thickening, called obstructive HCM, can be thinned through surgical or non-surgical methods. In the surgery called septal myectomy, a portion of the thickened area is cut and removed. In the non-surgical method called alcohol septal ablation, the aim is to damage the thickened area by injecting pure alcohol directly into it. Due to the toxic effect of the alcohol, the tissues in that area die and begin to thin over time. Thus, the patient’s complaints decrease; their quality of life and lifespan increase. Today, out of every 10 patients requiring a thinning procedure for the thickened area, alcohol septal ablation is performed in 9, while surgery is performed in 1.
Surgery: Septal myectomy (Adapted from the Tufts Medical Center website.)
Non-surgical method: Alcohol septal ablation (Adapted from the Tufts Medical Center website.)
Who is eligible for alcohol septal ablation?
If there is thickening in the heart’s outflow tract, the first treatment option is to partially suppress the heart’s contractile force with medications to prevent narrowing of the outflow tract. As a result, symptoms resolve in most patients. Alcohol septal ablation or surgery is performed on patients with obstructive HKM whose symptoms persist despite medication. In non-obstructive HKM, however, there is no role for alcohol septal ablation or surgery, as there is no narrowing in the heart’s outflow tract to begin with.Is alcohol septal ablation or surgery better?
In the past, surgery was the first choice; alcohol septal ablation was applied to patients for whom surgery was risky. However, according to the results of scientific research conducted over the years, both can now be the first choice. The selection is determined by the patient’s anatomical and clinical data regarding the surgical or non-surgical method. Today, alcohol septal ablation is preferred in 9 out of every 10 patients. In the long term, the benefit provided to the patient by both is the same (See References).
Prof. Dr. Şükrü Akyüz is an interventional cardiologist. His area of expertise is the treatment of heart diseases using non-surgical methods, including alcohol septal ablation.
What tests are performed before the procedure?
- Blood tests: To check for other conditions such as anemia, kidney failure, and infection.
- ECG: To determine whether there is a heart rhythm disorder.
- ECHO (Heart ultrasound): To determine whether there is thickening in the left ventricular outflow tract, and if so, the degree of stenosis, as well as to detect additional problems that can only be resolved through surgery (for example, anatomical abnormalities in the mitral valve).
How is alcohol septal ablation performed?
In this procedure, the artery supplying the thickened area at the heart’s outlet is identified via angiography, and pure alcohol is injected into it. Since alcohol is toxic, it immediately destroys the tissues supplied by that artery. In other words, a heart attack is intentionally induced in that specific region. Because this small area of the heart loses its viability, can no longer contract, and thins out within a few months, the outflow tract widens, and the obstruction in the path of the pumped blood is removed. During the alcohol septal ablation procedure, the heart continues to function; unlike surgery, the heart is not stopped. In the procedure, a long and flexible tube (catheter) is sent to the heart through the groin (leg) artery. Then, a special dye called contrast medium is injected through the catheter to visualize the heart’s own vessels (coronary arteries). Thus, it is determined which of the heart vessels is the artery for the thickened area in the outflow tract. Next, a wire and a balloon are sent via the catheter to this area where the alcohol will be administered. To trap the alcohol in the area intended for thinning and prevent it from leaking into other heart regions, the balloon is inflated, and then the alcohol is slowly administered through the tip of the balloon. After waiting for 10-15 minutes, the balloon is deflated. Subsequently, the dye is injected again to obtain a new image of the vessel. In a successful procedure, it is observed on angiography that the vessel no longer fills with dye, and on ECHO, a positive change in the pressures in the heart’s outflow tract is noted.
How long does the process take?
It usually takes about an hour. Every patient is different, so this time may be shorter or longer.Will there be any pain during or after the procedure?
The patient remains awake throughout the procedure. Since the procedure involves intentionally inducing a heart attack in the heart’s outflow tract, strong painkillers and sedatives are administered intravenously to ensure the patient can complete the procedure without feeling chest pain. However, the patient may experience mild pain at the site of the intravenous access when they wake up. In such cases, the pain can be relieved with over-the-counter painkillers.Who performs the alcohol septal ablation procedure?
This procedure is performed by interventional cardiologists who have received both theoretical and practical training. Septal myectomy, on the other hand, is performed by cardiac surgeons.What are the risks of alcohol septal ablation?
As with any interventional procedure, there are some risks associated with the alcohol septal ablation procedure, and the most important ones are as follows:- 10 out of every 100 patients may require the implantation of a permanent pacemaker. More rarely, a defibrillator (ICD) may be needed. The mechanism underlying the risk of a pacemaker is as follows: As electrical impulses spread through the heart, they use the main conduction pathway, and this pathway is located exactly at the exit of the left ventricle. This is the area where the treatment is applied, i.e., where the alcohol is injected. In 90 out of every 100 people, the conduction pathway is not affected by the alcohol and there is no problem. However, in the remaining cases, this pathway is partially or completely affected, and the heart rate slows down. To prevent this, a temporary pacemaker lead is placed in the heart via the neck or leg vein during the procedure and stays for 24 hours after the procedure. If the heart rate drops and does not return to its normal rate spontaneously within a few days, this temporary pacemaker is replaced with a permanent one.
- Stroke, death, and the development of a heart attack in heart regions other than the problematic area (LVOT) occur in a total of 1 out of every 100 people.
Examples of our alcohol septal ablation cases
