Cardiology

Question 1

A 28/F patient with mitral valve prolapse and moderate to severe mitral regurgitation was admitted for fever of 38.5 deg C, Osler’s node, and Janeway lesions. Two separate blood cultures drawn 12 hours apart have grown Staphylococcus epidermidis. Based on the available information, your patient has: (H20 C123 P925)
A.	Definite IE
B.	Positive IE
C.	Possible IE
D.	Probable IE
E.	Rejected IE

Answer 1

The answer is A. Definite endocarditis is defined by documentation of two major criteria, of one major criterion and three minor criteria, or of five minor criteria. Major criteria are positive blood culture and evidence of endocardial involvement. Minor criteria include predisposition, fever ≥38.0°C (≥100.4°F), vascular phenomena, immunologic phenomena, and microbiologic evidence. The diagno- 925 sis of endocarditis is rejected if an alternative diagnosis is established, if symptoms resolve and do not recur with ≤4 days of antibiotic therapy,
or if surgery or autopsy after ≤4 days of antimicrobial therapy yields no histologic evidence of endocarditis. Illnesses not classified as definite endocarditis or rejected as such are considered cases of possible infective endocarditis when either one major and one minor criterion or three minor criteria are fulfilled.

Question 2

Which of the following is true about rate control in atrial fibrillation? (H20 C246 P1747-8)
A. Acute rate control can be achieved with beta blockers and/or non-dihydropyridine calcium channel blockers.
B. For patients with difficult to control ventricular rates, catheter ablation of the AV junction obviates the need for pacemaker implantation.
C. The goal of acute rate control, if permitted by the clinical status of the patient, is a ventricular rate less than 100/min.
D. The goal of chronic rate control is a resting heart rate of 50-60/min.

Answer 2

The answer is C.

Acute rate control can be achieved with beta blockers and/or the calcium channel blockers verapamil and diltiazem administered either intravenously or orally, as warranted by the urgency of the clinical situation. Typically, the goal of acute rate control is to reduce the ventricular rate to less than 100/min, but the goal must be guided by the clinical situation and the adverse effects of rate control medications. For patients who remain in AF chronically, the goal of rate control is to alleviate and prevent deterioration of ventricular function from excessive rates. The initial goal is a resting heart rate of <80 beats/min that increases to <100 beats/min with light exertion, such as walking.