What Is Cardiomegaly? - Definition, Causes & Symptoms

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  • 0:03 Definition of Cardiomegaly
  • 0:35 Causes of Cardiomegaly
  • 1:59 Symptoms of Cardiomegaly
  • 2:17 Treatment Options
  • 3:20 Lesson Summary
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Instructor: Danielle Haak

Danielle has a PhD in Natural Resource Sciences and a MSc in Biological Sciences

Cardiomegaly occurs when the heart is larger than normal due to some underlying condition. In this lesson, you'll learn about the causes, symptoms, and treatment options for cardiomegaly.

Definition of Cardiomegaly

Have you ever seen How the Grinch Stole Christmas? If so, you know the Grinch had a problem where his heart was 'two sizes too small.' Well, cardiomegaly is the opposite of that - it's a condition that occurs when the heart is larger than normal! This condition usually occurs as a symptom of another condition rather than as a disease in itself (as a result of some type of damage), and it's problematic because as the heart gets larger, it loses its ability to pump blood, which can lead to congestive heart failure.

Causes of Cardiomegaly

High blood pressure (hypertension) and coronary artery disease are the most common causes of cardiomegaly, though there are many other causes as well. Others include viral infections of the heart, malfunctioning heart valves (your heart has four), serious kidney disease, HIV, genetic conditions, and longstanding low red blood cells (anemia). You may also see cardiomegaly in those with thyroid disorders, elevated iron levels (hemochromatosis), fluid around the heart (pericardial effusion), rare diseases, or that abuse alcohol and drugs. Temporary causes of cardiomegaly include pregnancy and stress.

The more common causes and their effects are listed here:

  • In dilated cardiomyopathy (a disease of the heart muscle), both the right and left ventricles (sides) of the heart become thin and stretched. This is the most common form of cardiomegaly.

  • Pulmonary disease causes the right ventricle to become thickened and enlarged

  • Hypertension causes the left ventricle to become thickened and enlarged (hypertrophy)

  • Hypertrophic cardiomyopathy is an inherited condition causing part of the myocardium (the heart's muscle) to become thickened and enlarged

  • Idiopathic dilated cardiomyopathy has no cause of cardiomegaly that has been identified

Symptoms of Cardiomegaly

Cardiomegaly may not produce any symptoms at all. If symptoms are present, they typically include shortness of breath or difficulty breathing; swelling or weight gain, especially in the abdominal region; and fatigue. Other symptoms include abnormal heart rhythms (arrhythmia) or chest pains.

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