Page 123 - Clinical Pearls in Cardiology

Valvular Heart Diseases 111

feature that helps differentiate the holosystolic murmur
of tricuspid regurgitation from that due to a ventricular
septal defect. In general, it has to be remembered that all
right-sided cardiac sounds increase in intensity during
inspiration, except the pulmonary ejection click sound.
17. What are the causes of tricuspid regurgitation (TR)?
The most common cause of tricuspid regurgitation
is functional tricuspid regurgitation. This occurs due
to dilatation of the annulus of the tricuspid valve
secondary to gross dilatation of the right ventricle in
severe pulmonary hypertension. The common causes
of primary tricuspid regurgitation are rheumatic fever
and infective endocarditis (common in intravenous drug
addicts). Apart from the holosystolic murmur, primary
TR may be associated with large ‘V’ waves in JVP, left
parasternal heave and systolic pulsations of the liver. In
functional TR secondary to pulmonary hypertension,
there may be loud P2 and high pitched decrescendo
murmur of pulmonary regurgitation, in addition to the
findings of primary TR.
18. What are the common causes of aortic stenosis?
Valvular aortic stenosis is the most common type of left
ventricular outflow tract obstruction. It is usually caused
by either degenerative calcification of a trileaflet aortic
valve or progressive stenosis of a congenital bicuspid
valve. It has to be remembered that bicuspid aortic valve
is the most common congenital cardiac abnormality
(occurs in about 2% of general population).
The risk factors for the development of degenerative
calcific AS are diabetes, hypertension, smoking and
elevated levels of low-density lipoprotein cholesterol and
lipoprotein-a. Obstruction to left ventricular outflow can