Internal Medicine

0521779407-01 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:45

42 Acute Myocarditides

edema (Kerley B lines, perivascular, subpleural effusion), alveo-

lar edema (“butterfly pattern”)

➣Electrocardiogram: non-specific ST/T wave changes, conduc-

tion abnormalities (especially Chagas’)

➣Echocardiogram (2-D with Doppler flow study): single most use-

ful diagnostic test; cardiac function, structure, wall motion and

valvular abnormalities, assess wall thickness, exclude other dis-

ease

■Other Tests as Appropriate

➣Radionuclide ventriculogram (RVG; MUGA): Cardiac function,

wall motion abnormalities

➣Exercise or pharmacologic stress testing: assess myocardial

ischemia risk

➣Cardiac catheterization: define coronary anatomy

➣Endomyocardial biopsy: insensitive and often non-specific; most

useful for monitoring anthracycline cardiotoxicity and detection

and monitoring of myocarditis, especially Giant cell.

➣Machado-Guerreiro complement-fixation test or ELISA (Chagas’

disease); viral culture from body fluids, viral-neutralizing anti-

body titers, complement fixation, PCR of viral genes from biopsy

samples (viral)

differential diagnosis

■Multiple infectious etiologies: partial listing of most common

pathogens

➣Viral: About 24 viruses associated with myocarditis, including

coxsackieviruses (over 50% of cases), HIV, CMV, viral hepatitis,

poliomyelitis

➣Rickettsial: Rocky Mountain spotted fever, scrub typhus, Q fever

(endocarditis most common)

➣Bacterial: diphtheria (about 25% cases and most common cause

of death with diphtheria), brucellosis, Legionnaires disease,

mycoplasma pneumoniae, streptococcal (see Rheumatic fever)

➣Spirochetal: Lyme carditis (tickborne; 10% with cardiac involve-

ment, usually degrees of heart block; ventricular dysfunction rare)

➣Fungal: most frequent in patients with malignancy and/ or

immunosuppressive therapy; aspergillosis (not uncommon in

generalized infection), mucormycosis (about 20% in patients

with disseminated form; invasion of arteries causes infarction),

candidiasis (endocarditis most common), cryptococcosis (most

common in HIV)