0071643192.pdf

MYOCARDITIS

Myocarditis is characterized by inflammation of the myocardium.

A number of infectious agentshave been implicated (see Table 2.14).

■ Viral agents are the most common etiology in the United States.
■ Trypanasoma cruziis the most common etiology worldwide.
■ Chagas disease, from the bite of the kissing bug
■ Common in Latin America

Myocarditis may also result from autoimmune diseases, chemical exposure,
or drugs.

■ Kawasaki’s, sarcoidosis, SLE
■ Penicillins, sulfonamides, cocaine

PATHOPHYSIOLOGY

■ Direct invasion or inflammatory response to agent →myocardial damage.
■ Often associated with pericarditis.

SYMPTOMS

■ Flu-like symptoms: Fever, fatigue, myalgias, vomiting, diarrhea
■ Retrosternal chest pain
■ Dyspnea
■ Palpitations
■ Syncope or near syncope

EXAM

■ Sinus tachycardia beyond what would be expected from fever
■ Rales
■ Peripheral edema
■ Jugular venous distention

DIAGNOSIS

■ Suspect in any patient presenting with flu-like symptoms and CHF
■ ECG
■ Tachycardia
■ Nonspecific ST-T changes
■ AV block or other conduction abnormalities
■ Low QRS voltages

CARDIOVASCULAR EMERGENCIES

TABLE 2.14. Infectious Agents Implicated in Myocarditis

VIRAL BACTERIAL PARASITIC

Coxsackie B virus β-Hemolytic strep Trypanasoma cruzi

Adenovirus (rheumatic fever) (Chagas disease)

Echovirus Mycoplasma pneumoniae Trichinella spiralis

Corynebacterium diphtheria (trichonosis)

(diphtheria)

Borrelia burgdorferi

(Lyme disease)

Flu-like symptoms and new

CHF? Suspect myocarditis.