Myocarditis differential diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Maliha Shakil, M.D. [2] Homa Najafi, M.D.[3]

Overview

Myocarditis must be differentiated from other causes of chest pain such as ST elevation myocardial infarction, pericarditis, and unstable angina. Myocarditis must also be differentiated from pulmonary edema and alcoholic cardiomyopathy.

Differential Diagnosis

Differential Diagnosis	History and Symptoms	Physical Examination	Laboratory Findings	Imaging Findings
ST Segment Elevation Myocardial Infarction	Chest pain with possible radiation to left arm and lower jaw Squeezing, crushing chest pain Sweating Nausea and vomiting	Anxious patient in pain with diaphoresis Signs of heart failure may be present Arrhythmia	ST elevation, new left bundle branch block, and Q wave on EKG Elevated cardiac biomarkers	Either complete or subtotal occlusion of an epicardial coronary artery on coronary angiography Confluent hyperenhancement extending from the endocardium
Non ST Elevation Myocardial Infarction	Crushing, left-sided substernal chest pain or pressure that radiates to the neck or left arm	Same as ST-elevation MI	ST-segment depression or T-wave inversion on EKG Elevated cardiac biomarkers
Pericarditis	Chest pain relieved by sitting up and leaning forward and worsened by lying down Fever, anxiety, difficulty breathing	Pericardial friction rub Signs of cardiac tamponade may be present	PR segment depression and electrical alternans on EKG	A flask-shaped, enlarged cardiac silhouette on CXR Pericardial thickness of more than 4 mm on MRI Pericardial effusion and cardiac chamber indentation or collapse on echo when cardiac tamponade is present
Pulmonary Edema	Hemoptysis Difficulty breathing, wheezing Symptoms of fluid overload if pulmonary edema is chronic	Dyspnea, nasal flaring End-inspiratory crackles Third heart sound (S3)	Low oxygen saturation on ABG	Kerley B lines, increased vascular markings, interstitial edema, and peribronchial cuffing on CXR Patchy alveolar infiltrates on CXR in noncardiogenic edema
Alcoholic Cardiomyopathy	History of alcohol abuse Fatigue, weakness, anorexia, palpitations, and shortness of breath on activity Leg swelling and pedal edema	Signs of heart failure such as presence of S3 and S4 heart sounds, pedal edema, and jugular venous distension Signs of alcoholic liver disease may be present	Elevated MCV and MCHC on CBC Elevated LDH, AST, ALT, creatine kinase, gammaglutamyl transpeptidase, malic dehydrogenase, and alpha-hydroxybutyric dehydrogenase Q waves and non specific ST and T wave changes on EKG	Cardiomegaly, pulmonary congestion, and pleural effusions on CXR Left ventricular dilatation on echo

Differentiating Myocarditis from ST Segment Elevation Myocardial Infarction

Both diseases present with chest pain, elevated cardiac biomarkers, and focal left ventricular dysfunction. There are two studies that can be used to distinguish the two syndromes:

Coronary Angiography

Coronary angiography can be performed to distinguish myocarditis from ST segment elevation myocardial infarction. ST segment elevation myocardial infarction is associated with either complete or subtotal occlusion of an epicardial coronary artery on coronary angiography. When used in conjunction with the findings on coronary angiography, cardiac MRI is useful in establishing the diagnosis of myocarditis.

Cardiac Magnetic Resonance Imaging

Cardiac magnetic resonance imaging is also useful in distinguishing between the two diseases as well. On cardiac MRI, myocarditis is associated with patchy, non-sentimental, hyperenhancement which is confined to the epicardial layer of the myocardium. In contrast, in ST segment elevation myocardial infarction there is confluent hyperenhancement extending from the endocardium in a distribution that mimics the distribution of the epicardial coronary arteries.

Differentiating Myocarditis from Pericarditis

Both diseases present with chest pain and ST segment elevation. The two conditions can be distinguished by the following studies:

Electrocardiogram

While both disorders are associated with ST segment elevation, pericarditis is also associated with PR segment depression.

Cardiac Biomarkers

Myocarditis is associated with elevations of the CK-MB and the troponin, while pericarditis is not. If pericarditis is associated with underlying inflammation of the myocardium, then this is called myopericarditis. If there is concomitant involvement of both the pericardium and myocardium in myopericarditis, then there are elevations of the cardiac biomarkers.

Echocardiography

In patients with myocarditis there will be a focal wall motion abnormalities, while these will be absent in patients with pericarditis. There may be a pericardial effusion in the patient with pericarditis, while myocarditis is not associated with a pericardial effusion.

Overview

[Disease name] must be differentiated from other diseases that cause [clinical feature 1], [clinical feature 2], and [clinical feature 3], such as [differential dx1], [differential dx2], and [differential dx3].

OR

[Disease name] must be differentiated from [[differential dx1], [differential dx2], and [differential dx3].

Differentiating [Disease name] from other Diseases

[Disease name] must be differentiated from other diseases that cause [clinical feature 1], [clinical feature 2], and [clinical feature 3], such as [differential dx1], [differential dx2], and [differential dx3].

OR

[Disease name] must be differentiated from [differential dx1], [differential dx2], and [differential dx3].

OR

As [disease name] manifests in a variety of clinical forms, differentiation must be established in accordance with the particular subtype. [Subtype name 1] must be differentiated from other diseases that cause [clinical feature 1], such as [differential dx1] and [differential dx2]. In contrast, [subtype name 2] must be differentiated from other diseases that cause [clinical feature 2], such as [differential dx3] and [differential dx4].

Differentiating [disease name] from other diseases on the basis of [symptom 1], [symptom 2], and [symptom 3]

On the basis [symptom 1], [symptom 2], and [symptom 3], [disease name] must be differentiated from [disease 1], [disease 2], [disease 3], [disease 4], [disease 5], and [disease 6].

Diseases	Clinical manifestations						Para-clinical findings							Gold standard	Additional findings
	Symptoms			Physical examination
							Lab Findings			Imaging			Histopathology
	Symptom 1	Symptom 2	Symptom 3	Physical exam 1	Physical exam 2	Physical exam 3	Lab 1	Lab 2	Lab 3	Imaging 1	Imaging 2	Imaging 3
Differential Diagnosis 1
Differential Diagnosis 2
Differential Diagnosis 3
Diseases	Symptom 1	Symptom 2	Symptom 3	Physical exam 1	Physical exam 2	Physical exam 3	Lab 1	Lab 2	Lab 3	Imaging 1	Imaging 2	Imaging 3	Histopathology	Gold standard	Additional findings
Differential Diagnosis 4
Differential Diagnosis 5
Differential Diagnosis 6

Diseases	Diagnostic tests			Physical Examination			Symptoms							Past medical history	Other Findings
	CT scan and MRI	EKG	Chest X-ray	Tachypnea	Tachycardia	Fever	Chest Pain	Hemoptysis	Dyspnea on Exertion	Wheezing	Chest Tenderness	Nasalopharyngeal Ulceration	Carotid Bruit
Pulmonary embolism	On CT angiography: Intra-luminal filling defect On MRI: Narrowing of involved vessel No contrast seen distal to obstruction Polo-mint sign (partial filling defect surrounded by contrast)	S1Q3T3 pattern representing acute right heart strain	Fleischner sign (enlarged pulmonary artery), Hampton hump, Westermark's sign	✔	✔	✔ (Low grade)	✔	✔ (In case of massive PE)	✔	-	-	-	-	Hypercoagulating conditions (Factor V Leiden, thrombophilia, deep vein thrombosis, immobilization, malignancy, pregnancy)	May be associated with metabolic alkalosis and syncope
Congestive heart failure	On CT scan: Mediastinal lymphadenopathy Hazy mediastinal fat On MRI: Abnormality of cardiac chambers (hypertrophy, dilation) Delayed enhancement MRI may help characterize the myocardial tissue (fibrosis) Late enhancement of contrast in conditions such as myocarditis, sarcoidosis, amyloidosis, Anderson-Fabry's disease, Chagas disease)	Goldberg's criteria may aid in diagnosis of left ventricular dysfunction: (High specificity) SV1 or SV2 + RV5 or RV6 ≥3.5 mV Total QRS amplitude in each of the limb leads ≤0.8 mV R/S ratio <1 in lead V4	Cardiomegaly	✔	✔	✔	-	-	✔	-	-	-	-	Previous myocardial infarction Hypertension (systemic and pulmonary) Cardiac arrythmias Viral infections (myocarditis) Congenital heart defects	Right heart failure associated with: Hepatomegaly Positive hepato-jugular reflex Increased jugular venous pressure Peripheral edema Left heart failure associated with: Pulmonary edema Eventual right heart failure
Percarditis	On contrast enhanced CT scan: Enhancement of the pericardium (due to inflammation) Pericardial effusion Pericardial calcification On gadolinium-enhanced fat-saturated T1-weighted MRI: Pericardial enhancement (due to inflammation) Pericardial effusion	ST elevation PR depression	Large collection of fluid inside the pericardial sac (pericardial effusion) Calcification of pericardial sac	✔	✔	✔ (Low grade)	✔ (Relieved by sitting up and leaning forward)	-	✔	-	-	-	-	Infections: Viral (Coxsackie virus, Herpes virus, Mumps virus, HIV) Bacteria (Mycobacterium tuberculosis-common in developing countries) Fungal (Histoplasmosis) Idiopathic in a large number of cases Autoimmune Uremia Malignancy Previous myocardial infarction	May be clinically classified into: Acute (< 6 weeks) Sub-acute (6 weeks - 6 months) Chronic (> 6 months)
Pneumonia	On CT scan: (not generally indicated) Consolidation (alveolar/lobar pneumonia) Peribronchial nodules (bronchopneumonia) Ground-glass opacity (GGO) Abscess Pleural effusion On MRI: Not indicated	Prolonged PR interval Transient T wave inversions	Consolidation (alveolar/lobar pneumonia) Peribronchial nodules (bronchopneumonia) Ground-glass opacity (GGO)	✔	✔	✔	✔	-	✔	✔	-	-	-	Ill-contact Travelling Smoking Diabetic Recent hospitalization Chronic obstructive pulmonary disease	Requires sputum stain and culture for diagnosis Empiric management usually started before culture results
Vasculitis	On CT scan: (Takayasu arteritis) Vessel wall thickening Luminal narrowing of pulmonary artery Masses or nodules (ANCA-associated granulomatous vasculitis) On MRI: Homogeneous, circumferential vessel wall swelling	Right or left bundle-branch block (Churg-Strauss syndrome) Atrial fibrillation (Churg-Strauss syndrome) Non-specific ST segment and T wave changes	Nodules Cavitation	✔	✔	✔	✔	✔	✔	-	✔	✔	✔	Takayasu arteritis usually found in persons aged 4-60 years with a mean of 30 Giant-cell arteritis usually occurrs in persons aged > 60 years Churg-Strauss syndrome may present with asthma, sinusitis, transient pulmonary infiltrates and neuropathy alongwith cardiac involvement Granulomatous vasculitides may present with nephritis and upper airway (nasopharyngeal) destruction
Chronic obstructive pulmonary disease (COPD)	On CT scan: Chronic bronchitis may show bronchial wall thickening, scarring with bronchovascular irregularity, fibrosis Emphysema may show alveolar septal destruction and airspace enlargement (Centrilobular- upper lobe, panlobular- lower lobe) Giant bubbles On MRI: Increased diameter of pulmonary arteries Peripheral pulmonary vasculature attentuation Loss of retrosternal airspace due to right ventricular enlargement Hyperpolarized Helium MRI may show progressively poor ventilation and destruction of lung	Multifocal atrial tachycardia (atleast 3 distinct P wave morphologies)	Enlarged lung shadows (emphysema) Flattening of diaphragm (emphysema)	✔	✔	-	-	-	✔	✔	-	-	-	Smoking Alpha-1 antitrypsin deficiency Increased sputum production (chronic bronchitis) Cough	Alpha 1 antitrypsin deficiency may be associated with hepatomegaly

References

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