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Rao. Vessel Plus 2022;6:22 https://dx.doi.org/10.20517/2574-1209.2021.105 Page 5 of 24

Table 2. Etiology of ejection systolic murmurs. Reproduced from Rao [5]

Common causes
Aortic stenosis
Coarctation of the aorta
Pulmonary stenosis
Atrial septal defect
Functional or innocent murmur
Less common causes
Mitral prolapse syndrome
Acyanotic tetralogy of Fallot
Patent ductus arteriosus

Table 3. Etiology of holosystolic murmurs. Modified from Rao [5]
Ventricular septal defect
Mitral regurgitation
Tricuspid regurgitation

aortic valve level, a systolic ejection click is usually heard immediately before the murmur. This ejection
systolic click is auscultated at the upper right and mid left sternal borders and apex. The click is constant
and does not vary with the respiratory cycle. A normal second sound is usually heard. The arterial pulses are
typically normal. The exceptions are subjects with very severe AS.

The ECG may be normal or may demonstrate LV hypertrophy. Unfortunately, neither a normal ECG or
abnormal ECG findings are indicative of the severity of AS. Nevertheless, inverted T waves in leads V5 and
V6 suggest severe AS. The heart size is usually normal on a chest roentgenogram, but may commonly
disclose an enlarged ascending aorta, secondary to post-stenotic dilatation. Two-dimensional (2D)
echocardiogram may demonstrate thickened leaflets of the aortic valve with doming. The LV fractional
shortening may be increased, largely proportional to the severity of AS. The magnitude of Doppler flow
velocity across the aortic valve indicates the severity of obstruction. The peak instantaneous pressure
gradient across the aortic valve is calculated by using a modified Bernoulli equation:

ΔP = 4V 2

Where, V is the peak Doppler velocity across the aortic valve in meters/sec, and ΔP is peak instantaneous
pressure gradient in mmHg.

Patients with bicuspid aortic valves without significant AS may also have an ejection systolic click and an
ejection systolic murmur. It should be noted that bicuspid aortic valve may not exhibit an audible click in
infancy. At times, bicuspid aortic valve is indistinguishable from mild AS by physical examination.

Other LV outflow tract obstructions
Ejection systolic murmurs are also heard in subvalvar membranous AS, hypertrophic obstructive
cardiomyopathy (HCM), and supravalvar AS. However, ejection systolic clicks are not present in these
disease entities and, therefore, can be differentiated from valvar AS. In addition, the subjects with
supravalvar aortic stenosis may have distinctive features of Williams syndrome such as trigonal faces,
developmental delay, and infantile hypercalcemia. Furthermore, some of these patients may have a pulse or
blood pressure difference between both arms. The murmur of HCM may be better auscultated at left mid
sternal border and may increase in intensity with Valsalva. In patients with subaortic membrane, no clicks