Page 134 - Clinical Pearls in Cardiology

122 Clinical Pearls in Cardiology

31. What are the indications for surgical intervention in
a patient with chronic aortic regurgitation?
Because of their excellent prognosis in the short- and
medium-term, operative correction should be deferred
in patients with chronic aortic regurgitation who are
asymptomatic. Aortic valve replacement (AVR) is
the treatment of choice for symptomatic patients. In
the absence of obvious contraindications or serious
comorbidity, surgical treatment is advisable for the
following subset of patients:
Indications for AVR
• Symptomatic patients with severe aortic regurgitation
• Asymptomatic patients with an ejection fraction of
55% or less
• Asymptomatic patients with severe left ventricular
dilation (end-diastolic diameter > 75 mm or end-systolic
diameter >55 mm)
• Asymptomatic patients with less severe ventricular
dilation who have evidence of progressive
enlargement on serial echocardiograms.
So the difficult issue is to decide when to operate
on asymptomatic patients to prevent irreversible left
ventricular dysfunction from occurring. Outcomes are
found to be better in patients with a left ventricular ejection
fraction >55% or an end systolic left ventricular diameter
<55 mm. This rule has been termed the ‘rule of 55’.
32. What is cor bovinum?
Because of the enormous volume overload in chronic
aortic regurgitation, there is slow and progressive left
ventricular dilatation and hypertrophy in an attempt to
normalize the ventricular wall stress. The heart may thus
become larger and heavier than in any other form of