QuestionSBA
QuestionChoice
The most likely diagnosis here is infective endocarditis. Intravenous drug use is a risk factor for this. Splinter haemorrhages and janeway lesions are cardinal signs too. First-line imaging investigation in endocarditis is transthoracic echo and it should be performed as soon the diagnosis of endocarditis is suspected. It is required as part of the major Duke criteria for diagnosis. Vegetation, abscess, partial dehiscence of prosthetic valve or new valvular regurgitation may be identified. Transoesophageal echocardiogram has a higher sensitivity of 90% but is much more invasive and often not available as promptly as required.
10005256
a
Transthoracic echocardiogram
QuestionChoice
This test should be performed at admission and throughout to check for new changes but again does not form part of the diagnostic Duke criteria and is therefore not as appropriate as an echocardiogram. A new AV block is suggestive of abscess formation.
10005259
d
Resting 12-lead ECG
QuestionChoice
This is a scan which images the pulmonary arteries, often reserved to diagnose or exclude pulmonary emboli - an unlikely diagnosis here.
10005260
e
CT Pulmonary Angiogram
QuestionChoice
Chest x-ray does not form part of the diagnostic Duke criteria and is therefore not as appropriate as an echocardiogram. A chest x-ray in infective endocarditis may show evidence of heart failure and cardiomegaly in extreme cases though. A combination of sepsis and pulmonary infiltrates on a chest x-ray is highly suggestive of right-sided endocarditis.
10005257
b
Chest X-ray
QuestionChoice
CT Chest also does not form part of the diagnostic Duke criteria and is therefore not as appropriate as an echocardiogram. It may have value in identifying septic emboli or if a chest x-ray shows pathology which is not certain.
10005258
c
CT Chest
Concept
Chapter
2693
3710
Infective Endocarditis
Topic
134
Cardiology
13598
A 45-year-old male is reviewed in the infectious diseases ward. He is a known intravenous drug user and has been injecting heroin daily for the last five years. He reports feeling feverish and having extreme malaise over the last 5 days. On examination, he has numerous splinter haemorrhages and janeway lesions on his hands. The rest of his examination is unremarkable, and he has no audible murmur.

Which of the following is the most appropriate first-line diagnostic investigation?
a