Answer: A. Prompt squatting leads to a transient increase in venous return,
which moves the click later in systole. Such an increase in preload increases
ventricular size and results in prolapse of the valve later in the cycle (and with a later
murmur). Likewise, isometric exercise (handgrip) moves the click earlier in systole
(i.e., increases afterload primarily but also increases preload to some degree).
Administration of amyl nitrite causes systemic vasodilatation and a decline in
preload, which moves the click earlier in systole. Similarly, during the strain phase of
the Valsalva maneuver, decreased filling of the left ventricle moves the click earlier
in systole.
Q.5. A 65-year-old man with a history of rheumatic fever as a child underwent a root
canal four weeks ago. Two weeks ago, he presented to the emergency department
with fever, myalgias, and fatigue. Admission creatinine was 1.8 with microscopic
hematuria. An echocardiogram revealed mitral valve vegetation, and he was started
on intravenous antibiotics for presumed endocarditis. Blood cultures subsequently
grow Stetococcus viridans. He responds well, with resolution of his fever and return
of his creatinine to normal. However, on the day of discharge, you are called
urgently to his room because of sudden shortness of breath. His examination is
notable for labored breathing, a blood pressure of 90/55, crackles in the bases of the
lungs, and II/VI systolic murmur. An ECG is notable for sinus tachycardia at 110 bpm
but no ischemic changes. What is the best course of action?
A. Urgent echocardiogram followed by intra-aortic balloon pump insertion
B. Urgent echocardiogram and surgical consultation
C. Urgent Swan-Ganz catheter with pulmonary capillary wedge measurement
D. Urgent transesophageal echocardiogram
E. Fluid challenge, repeat blood cultures, and addition of vancomycin treatment
Answer: B. This patient has been treated for infective encarditis involving the
mitral valve. While he has had a microbiologic response, the inflammation to the
valve has resulted in acute regurgitation (despite initial clinical improvement). He
now has acute shortness of breath, hypotension, and pulmonary edema. He requires
urgent echocardiography to confirm regurgitation, followed by emergent surgery.
Neither a transesophageal echocardiography nor a Swan-Ganz catheter is necessary
for confirmation or diagnosis. An intra-aortic balloon pump would be temporizing