Left Ventricular Hypertrophy

Left ventricular hypertrophy (LVH) is an increase in the thickness of the left ventricle's muscular mass. On an electrocardiogram, this may be detected as an increase in the size of the waves recorded. As the muscle gets larger, it may alter the appearance of the ECG further. The shadow of the heart may appear enlarged on a chest X-ray. The most accurate diagnostic test for LVH is an echocardiogram. This test allows for the direct measurement of the muscle thickness and can help determine the cause of LVH.
In many cases, the cause of LVH is hypertension. If high blood pressure is not treated, it can put strain on the heart. In cases of profound hypertension, this strain often manifests as an increase in the size of the muscle of the pumping chamber. Narrowing of the aortic valve, or Aortic Stenosis, also can lead to significant LVH. As the opening to eject blood from the heart becomes smaller over time, the muscle pushes harder, which results in an increase in muscle mass.
A serious and important cause of LVH is hypertrophic cardiomyopathy (HCM). This genetic disorder results in an inappropriate increase in the mass and size of the heart muscle. In particular, the middle portion of the heart of the septum is affected. This creates an asymmetry in the heart between the posterior wall and septal heart segments. The septum contracts vigorously, affecting the mitral valve and increasing the resistance to flow out of the heart. This abnormal proliferation of muscle tissue is prone to life-threatening arrhythmias such as ventricular tachycardia (VT). Many patients with HCM are treated with beta-blockers to reduce the symptoms of chest pains and shortness of breath. An implanted defibrillator is necessary to prevent sudden death in patients with documented VT. In cases of severe symptoms, surgical removal of septal muscle (myomectomy) can be considered. Direct injection of pure alcohol into an artery feeding the enlarged septum (alcohol septal ablation) can cause a controlled heart attack and decrease symptoms as well.
Management is often conservative for patients with HTN and LVH. Wall thickness greater than 1.3 cm is considered mild hypertrophy. When I see a patient with LVH on echo, I consider this a red flag that their blood pressure is poorly controlled. Over time, with adequate treatment, the process often can be stabilized. Even with poor treatment, the growth process is slow. Aggressive medical treatment of blood pressure will not reduce the size of the muscle. When the muscle is very thick, patients often will have shortness of breath with exertion or even chest pains. In many cases, especially women, the arteries will be free of significant obstruction but will have a characteristic pattern of tortuosity and dramatic tapering. LVH is often a marker for more significant disease such as HCM but it can also serve as a sign that poor blood pressure control has been present for an extended period of time.