slow heart rhythms associated with AV block and inadequate escape rhythm.
The diagnosis is usually made with outpatient Holter monitoring.
(b)Myocarditis results from inflammatory damage to the myocardium. The
etiology may be infectious. Bacteria and enteroviruses, especially Coxsackie B
virus and adenovirus, predominate as causative agents. Worldwide, Chagas
disease is the leading cause, especially in South America. Often myocarditis
presents with flu-like complaints, including fever, fatigue, and myalgias.
Tachycardia out of proportion to the temperature or clinical picture may be
present. Vasculitis lesions, Janeway lesions, and retinal hemorrhages are not
expected.(c)Pericarditis is caused by inflammation of the pericardial sac.
The etiology is broad, including infection, trauma, metabolic diseases
(eg, uremia), medications, systemic autoimmune diseases, and most often
the cause is idiopathic. (d)Cardiac tamponade is a large pericardial effusion
that restricts ventricular filling and eventually stroke volume. The classic
findings are hypotension, JVD, and muffled heart sounds (Beck triad).
186.The answer is d.(Cook, 2007.) Malignant or necrotizing otitis
externa is a complication of otitis externa that occurs primarily in adult dia-
betics and debilitated and immunocompromised individuals. It is associ-
ated with a high mortality rate. The condition is better described as an
osteitis of the underlying bone of the external auditory canal caused by
P aeruginosa.It is distinguished by fever, intense ear pain, erythema, edema,
and granulation tissue in the external canal. Cranial nerve palsies and tris-
mus can also occur. These patients require hospitalization and treatment
with IV antipseudomonal antibiotics and possible surgical debridement.
CT and MRI are appropriate studies to evaluate for osteomyelitis. Patients
also require immediate ENT consultation.
(a)Patients are usually diabetics, debilitated, or immunocompro-
mised.(b)Owing to its high morbidity and mortality, this condition
requires in-patient management. (c)Fever and ear pain are common.
(e)Although hearing loss is a possibility, the most common cranial nerve
involved is the facial nerve (cranial nerve VII).
187.The answer is c.(Rosen, pp 2123-2128.)Recommended treatment
for early Lyme diseaseincludesdoxycycline,amoxicillin (for children
younger than 8 years or for pregnant or lactating women), or cefuroxime.
Erythromycin and azithromycin can be used, but are less effective. The
same drugs can be used for the second stage of disease, but their course of
therapy needs to be longer.
204 Emergency Medicine