Cardiomegaly
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Cardiomegaly Microchapters |
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Cardiomegaly On the Web |
Template:DiseaseDisorder infobox
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor in Chief: Cafer Zorkun, M.D., Ph.D. [2]
Overview
Pathophysiology
Epidemiology and demographics
Risk factors
Screening
Natural History, Complications & Prognosis
Causes
Differential diagnosis of cardiomegaly
Diagnosis
History and Symptoms | Physical examination | Lab tests | Electrocardiogram |
Chest X Ray
- Cardiomgaly is traditionally defined as an increase in the cardiothoracic ratio to be > 0.5 on a PA film. To calculate the thoracic ratio, the width of the cardiac silhouette is divided by the width of the entire thoracic cage.
- If the heart is viewed on an AP film, the heart can appear to be artificially enlarged because the X ray beam moves from anterior to posterior direction and therefore the heart which lies anterior is magnified.
- Postero Anterior (PA) Projection: adult heart is 12 cm from base to apex and 8-9 cm in transverse direction
- Lateral Projection: The adult heart is 6 cm in the Antero Posterior (AP) direction
X-ray findings for left ventricular enlargement
- Left heart border is displaced leftward, inferiorly, or posteriorly.
- Rounding of the cardiac apex
Image courtesy of C. Michael Gibson MS. MD
X-ray findings for left atrial enlargement
- Double density sign: Occur when the right side of the left atrium pushes into the adjacent lung.
- Convex left atria appendage: usually reflect prior rheumatic heart disease
- Splaying of the carina
- Posterior displacement of the left main stem bronchus on lateral radiograph
- Superior displacement of the left main stem bronchus on frontal view
- Posterior displacement of a barium filled esophagus
X-ray findings for right ventricular enlargement
- Frontal view
- Rounded left heart border
- Uplifted apex
- Lateral view
- Filling of the retrosternal space
- Rotation of the heart posteriorly
X-ray findings for right atrial enlargement
- On a frontal view, the right atrium is visible because of its interface with the right middle lobe.
- Subtle and moderate right atrial enlargement is not accurately determined on plain films because there is normal variability in the shape of the right atrium.
Echocardiography or Ultrasound
- Echocardiogram recommended for those patients presenting suspected valvular disease, chamber size, ventricular function, and wall motion abnormalities
Other Diagnostic Studies
- Exercise or pharmacologic stress testing may be indicated in those patients suspected of having coronary artery disease
- Patients suspected of having valvular disease or coronary artery disease may need a cardiac catheterization for full evaluation following echocardiography
Pathological Findings
Treatment
Pharmacotherapy
Acute Pharmacotherapies
- Administration of digoxin, diuretics, antiarrhythmics and/or preload and afterload reducers per clinical indication
Chronic Pharmacotherapies
A combination of diuretics and angiotensin converting enzyme (ACE) inhibition is currently the standard of care. Digoxin may reduce the frequency of rehospitalization, but does not improve mortality.
Surgery and Device Based Therapy
- In patients who are awaiting a transplant for end-stage symptomatic heart failure, implantable ventricular assist devices may serve as a temporary aid for compensation.
Transplantation
- In patients who are in end-stage symptomatic heart failure, a heart transplant my be necessary.
Future or Investigational Therapies
Mechanical strategies currently under investigation include:
- Development of devices to reduce the size of the heart
- Development of a device to exclude that portion of the apex where clots may form.
Pathological Findings
