Pulmonary valve stenosis obstructs right
ventricu-lar outflow and causes concentric right ventricular hypertrophy.
Severe obstruction presents in the neonatal period, whereas lesser degrees of
obstruc-tion may go undetected until adulthood. The valve is usually deformed
and is either bicuspid or tricus-pid. Valve leaflets are often partially fused
and dis-play systolic doming on echocardiography. The right ventricle undergoes
hypertrophy, and poststenotic dilatation of the pulmonary artery is often
present. Symptoms are those of right ventricular heart fail-ure. Symptomatic
patients readily develop fatigue, dyspnea, and peripheral cyanosis with
exertion as a result of the limited pulmonary blood flow and increased oxygen
extraction by tissues. With severe stenosis, the pulmonic valve gradient
Hg, depending on the age of the patient.
Right-to-left shunting may also occur in the presence of a patent foramen ovale
or atrial septal defect. Cardiac output is very dependent on an elevated heart
rate, but excessive increases in the latter can compromise ventricular filling.
Percutaneous balloon valvulo-plasty is generally considered the initial
treatment of choice in most patients with symptomatic pul-monic stenosis.
Anesthetic management for patients undergoing surgery should maintain a normal
or slightly high heart rate, augment preload, and avoid factors that increase