Hypertrophic cardiomyopathy is a genetic disease of the heart muscles that reduces the heart’s ability to pump blood around the body effectively.
In the majority of cases, the condition does not cause any symptoms or affect the individual’s daily life. However, significant symptoms do sometimes develop including shortness of breath, chest pain (angina), palpitations, lightheadedness and loss of consciousness.
The condition affects around one in 500 individuals in the UK and men and women are affected equally.
It is caused by at least one gene mutation that affects the proteins in heart muscle cells. This causes the heart muscle (myocardium) to thicken (hypertrophy), stiffen and in some cases, become scarred. This can disrupt the heart’s electrical signaling system, which can in turn lead to the development of abnormal heart rhythms that may endanger the individual’s life or result in sudden cardiac arrest.
There is currently no cure for the condition, but various therapies are available that can alleviate symptoms and help to prevent complications. Providing patients have their symptoms treated and are appropriately monitored, people with hypertrophic cardiomyopathy can lead a normal life. The choice of treatment depends on what the symptoms are and how the condition has affected heart function. Current therapies are described in more detail below.
Medication may be prescribed to relax the heart muscles, reduce heart rate and enable the organ to pump more effectively. Examples of such medications include beta-blockers, calcium channel blockers and heat rhythm regulators. Patients with atrial fibrillation may be prescribed anticoagulants to decrease the risk of blood clot formation.
If medications are not effective at relieving symptoms, open heart surgery may be performed. The surgeries used are described below.
A surgeon removes thickened areas of the ventricular septum – the wall that separates the two ventricles in the lower portion of the heart. This increases the blood volume pumped from the heart. While the myectomy is being conducted, a surgeon may also correct the mitral valves if they are failing to fully close and are allowing blood to move up into the atria from the ventricles.
Overgrown muscle at the apex of the left ventricle is removed. This improves heart function by increasing the size of the cavity, lowering blood pressure in the ventricle and improving ventricular filling. Patients who undergo an apical or septal myectomy do not usually experience any further symptoms.
Using a catheter, alcohol is injected into the artery that provides an area of thickened muscle with blood. This destroys the abnormal muscle, which can alleviate the symptoms of this condition. The procedure may, however, interfere with the heart’s electrical signaling system, in which case an artificial pacemaker needs to be implanted to control heart rate.
Implantable Cardioverter-Defibrillator (ICD)
If a patient is experiencing dangerous arrhythmias, they may be offered an ICD. This tracks the heart rate at all times and delivers electric shocks to regularize the heart if such an arrhythmia does arise. The shocks stabilizes the heart rhythm, which reduces the risk of sudden cardiac arrest occurring.