Cardiomegaly - Causes and Symptoms

Definition

Cardiomegaly is the increase in cardiac muscle volume, which may depend on myocardial hypertrophy (increase in thickness of the walls of the heart) and / or dilation of atrial and / or ventricular cavities. Within certain limits, these changes represent compensation mechanisms that the heart puts in place to adapt to more demanding working conditions.

Cardiomegaly can be congenital (present from birth) or develop over time due to different pathological conditions affecting the heart, but not only. The cardiac problems at the base of the enlarged heart are heart attacks, abnormal heart rhythms (chronic tachycardia, uncontrolled atrial fibrillation), valve insufficiencies, cardiac infections (acute or chronic) and inflammations of the heart (myocarditis). Other causes include: arterial hypertension, coronary heart disease and metabolic alterations (eg glycogen storage disease).

The enlarged heart is a symptom that can be found even in the case of Chagas disease (it is the most common infectious cause of cardiomegaly), toxoplasmosis, nutritional disorders (eg beriberi, selenium and carnitine deficiency), anemia, hemochromatosis, insufficiency renal, Down syndrome, fetal-fetal transfusion syndrome, collagenopathies and granulomatous diseases (sarcoidosis and Wegener's granulomatosis).

Furthermore, cardiomegaly can be a consequence of morbid obesity, thyrotoxicosis, hyperthyroidism, hypothyroidism, diabetes mellitus and secreting endocrine tumors (eg pheochromocytoma, adrenal and thyroid tumors). There are also cases of idiopathic cardiomegaly (for which a real cause is not found) or reversible, such as in the case of pregnancy, stress, hyperadrenergic states, intense and prolonged training ("athlete's heart").

Various toxic substances, especially alcohol, organic solvents, drugs and some drugs (eg doxorubicin and trastuzumab) damage the heart muscle.

The most characteristic symptoms of the enlarged heart are dyspnea, palpitations, asthenia, peripheral edema, arrhythmias and chest pain. Cardiomegaly always procures a state of circulatory decompensation; if this is severe and progressive a heart transplant may be necessary.