Cardiomegaly –Diagnosis
Cardiovascular
Context
Cardiomegaly is suggested via ECG criteria or imaging findings:
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Cardiothoracic ratio >50 % on a posterior-anterior chest x-ray or CT.
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- Cardiomegaly etiology is numerous and complex with both genetic and non-genetic components.
- Cardiomegaly is associated with a spectrum of clinical heart failure syndromes.
- The critical pathophysiological changes include dilated hypertrophy, fibrosis, and contractile malfunction leading to heart failure.
- Heart failure has a 5-year 50% mortality rate.
Etiologies
- Numerous etiologies of dilated or hypertrophic cardiomyopathy:
- Coronary artery disease.
- myocardial infarction.
- ischemia.
- Hypertensive heart disease.
- Valvular heart disease.
- Congenital heart disorders:
- Atrial septal defect.
- Ventricular septal defect.
- Patent ductus arteriosus.
- Tetralogy of Fallot.
- Coarctation of the aorta.
- Pulmonary disease:
- Primary pulmonary hypertension.
- COPD.
- Obstructive sleep apnea.
- Pulmonary embolism.
- Infection: viral, HIV, Chaga disease.
- Infiltrative disease: amyloidosis, sarcoidosis, acromegaly, and hemochromatosis.
- Toxins: alcohol, cocaine, chemotherapeutic agents.
- Arrhythmia: atrial fibrillation and flutter.
- Systemic disease: anemia, hypo/hyperthyroidism, vitamin B1 deficiency, AV fistula.
- Physiologic: stress cardiomyopathy, exercise-induced cardiomegaly, and pregnancy.
- Familial cardiomyopathy.
- Idiopathic.
- Coronary artery disease.
Clinical Presentation
History
- Many are asymptomatic.
- Symptoms:
- Dyspnea on exertion/rest, orthopnea, and paroxysmal nocturnal dyspnea.
- Peripheral edema and abdominal distension.
- Fatigue and poor exercise tolerance.
- Palpitations, light-headedness, and/or syncope.
- Angina.
- Anorexia, nausea, and early satiety.
- Family history of cardiomyopathy or cardiovascular disease.
Physical exam:
- Sinus tachycardia.
- Diminished pulse pressure.
- Respiratory distress.
- Cool, cyanotic extremities.
- Jugular venous distension.
- Ascites, hepatomegaly and peripheral edema.
- Pulmonary crackles.
- Murmur.
- S3 gallop in early diastole (systolic dysfunction).
- S4 gallop in late diastole (diastolic dysfunction).
- Displaced point of maximal impulse indicating LV hypertrophy.
- Sustained and prolonged left parasternal heave indicating RV hypertrophy.
Risk factors:
- Family history.
- Smoking.
- Hypertension.
- Diabetes.
- Obesity.
- History of alcohol or drug use.
- Sedentary lifestyle.
- Coronary artery disease.
- Male gender.
- Age > 65.
- African-American.
Diagnostic Process
The diagnosis of cardiomegaly is based on imaging and suggested by ECG.
If heart failure present:
Visit The New York Heart Association based on symptoms:
https://www.heart.org/en/health-topics/heart-failure/what-is-heart-failure/classes-of-heart-failure .
Imaging
- Chest X-ray.
- Enlarged cardiac silhouette with a cardiothoracic ratio > 50%.
- Heart failure:
- Interstitial edema.
- Pleural effusion.
- Alveolar edema.
- LV enlargement.
- Leftward displacement of left heart border.
- RV enlargement.
- Upward deviation of the left apical margin.
- LA enlargement.
- Double density sign.
- RA enlargement.
- Increased convexity of the right heart border.
- Transthoracic echocardiogram.
- Assess size, function and possibly etiology.
- Coronary angiography.
- Cardiac computerized tomography (CT) scan.
- Cardiac magnetic resonance imaging (MRI).
- Emerging diagnostic modality for accurate evaluation of LV and RV mass, size and function. It can characterize ischemic and non-ischemic causes such as myocarditis.
Investigations
- Electrocardiogram (ECG).
- Reveals non-specific changes including LV/RV hypertrophy, arrhythmias, fibrosis or cardiomyopathy.
- See Acute Heart Failure for specific ECG findings.
- Lab work:
- CBC, electrolytes, urea, creatinine, liver function tests, TSH, glucose.
- Cardiac enzyme serum levels (used in setting of heart failure).
- Troponin.
- Elevation = worse prognosis.
- N-terminal pro-B-type natriuretic peptide (NT-proBNP).
- Useful to monitor ongoing management and has prognostic value.
- BNP <100 nanograms/L or NT-proBNP <300 nanograms/L strong negative predictors of heart failure.
- BNP >400 nanograms/L or NT-proBNP >900 (>1800 if age 75+) nanograms/L make heart failure more likely.
- Troponin.
Related Information
Reference List
Cardiomegaly.
Amin, H., & Siddiqui, W. J. (2020). StatPearls [internet].
-PubmedHeart failure: clinical manifestations and diagnostic in adults.
Colucci, W. S., Borlaug, B.A. (2021). [cited 2021 Apr 26].
– UpToDateEffect of heart-size parameters computed from digital chest radiographs on detection of cardiomegaly. Potential usefulness for computer-aided diagnosis.
Nakamori, N., MacMahon, H., Sasaki, Y., & Montner, S. (1991). Investigative radiology, 26(6), 546-550.
-Pubmed
Relevant Resources
RELEVANT RESEARCH IN BC
Cardiovascular EmergenciesRESOURCE AUTHOR(S)
DISCLAIMER
The purpose of this document is to provide health care professionals with key facts and recommendations for the diagnosis and treatment of patients in the emergency department. This summary was produced by Emergency Care BC (formerly the BC Emergency Medicine Network) and uses the best available knowledge at the time of publication. However, healthcare professionals should continue to use their own judgment and take into consideration context, resources and other relevant factors. Emergency Care BC is not liable for any damages, claims, liabilities, costs or obligations arising from the use of this document including loss or damages arising from any claims made by a third party. Emergency Care BC also assumes no responsibility or liability for changes made to this document without its consent.
Last Updated May 07, 2021
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