Myocardial hypertrophy is a thickening of the heart muscle (myocardium) in response to a constant overload. Most often it is the wall of the left ventricle that thickens — then it is called left ventricular hypertrophy.
The main cause is the heart working against elevated pressure in arterial hypertension. Over time the “over-pumped” muscle relaxes worse and is supplied with blood worse.
What myocardial hypertrophy is
Like any muscle, the heart builds up mass in response to load. But unlike the biceps, the thickened myocardium has a harder time: the coronary vessels do not keep up with the growth of the muscle, so blood supply and the chamber’s ability to relax and fill with blood worsen.
A distinction is drawn between concentric hypertrophy (the wall thickens under pressure overload) and eccentric (the chamber dilates under volume overload). The “athlete’s heart” is set apart — a moderate adaptive hypertrophy in trained people, which is usually reversible.
Why the heart thickens
The most common cause is long-standing high blood pressure: the heart has to push blood with effort. Other causes are narrowing of the aortic valve (aortic stenosis), chronic kidney disease, obesity and diabetes.
A separate group is hypertrophic cardiomyopathy, a genetic disease with thickening of the myocardium (often the interventricular septum) unrelated to blood pressure. It requires special monitoring because of the risk of dangerous arrhythmias.
Why it is dangerous and what to do
Myocardial hypertrophy is an independent cardiovascular risk factor: it raises the likelihood of arrhythmias (including atrial fibrillation), heart failure, ischemia and sudden cardiac death.
Thickening is detected by echocardiography (more precisely) and by indirect signs on the ECG. The good news: with blood-pressure control the hypertrophy often shrinks and the risk of complications falls. The approach is chosen by a cardiologist.
Calculate using this marker
Calculators where Myocardial hypertrophy is used directly:
Frequently asked questions
Is myocardial hypertrophy reversible?
Adaptive hypertrophy (the “athlete’s heart”) and thickening due to hypertension often shrink — when the load is reduced or blood pressure is controlled. Genetic hypertrophic cardiomyopathy does not “go away” like that and requires separate monitoring.
How is hypertrophy different from cardiomegaly?
Hypertrophy is a thickening of the wall muscle itself. Cardiomegaly is a general enlargement of the heart, which can be due either to thickened walls or to dilated chambers. They are distinguished on echocardiography.
Related terms
Sources
- StatPearls (NCBI) — Left Ventricular Hypertrophy
- American Heart Association — Hypertrophic Cardiomyopathy