Tetralogy of Fallot With Absent Pulmonary Valve Clinical Presentation

Updated: Dec 28, 2020
  • Author: Prema Ramaswamy, MD; Chief Editor: Howard S Weber, MD, FSCAI  more...
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Symptoms are noted soon after birth in patients in whom fetal detection failed to reveal the condition. In early infancy, patients with tetralogy of Fallot (TOF) with absent pulmonary valve fall into two groups: those with severe respiratory problems in whom medical management fails in the first year of life and those with less severe respiratory symptoms.

In a fetus, severe pulmonary regurgitation may cause heart failure, and this may result in fetal hydrops and intrauterine death. It has been suggested that only fetuses in whom the ductus is restrictive or absent are able to survive to term. [1] In fetuses that survive to term, respiratory symptoms develop immediately after birth due to tracheal or bronchial obstruction.

Cyanosis may also present early because of the high pulmonary vascular resistance. Cyanosis usually does not progress as it does in typical tetralogy of Fallot in patients with an intact pulmonary valve. As the pulmonary vascular resistance (PVR) falls, the cyanosis decreases as the left-to-right shunt increases.


Physical Examination

Cyanosis, if present, is mild in most cases. The newborn may demonstrate more significant cyanosis because of both higher hemoglobin concentration and higher pulmonary vascular resistance (PVR). Stenosis can predominate in patients with a significantly hypoplastic pulmonic annulus. Such patients, therefore, demonstrate more cyanosis.

Respiratory distress may be evident with variable auscultatory findings consistent with atelectasis, hyperinflation, or consolidation.

Congestive heart failure (CHF) evidenced by increased heart rate, respiratory rate, hepatomegaly, and cardiomegaly, with an increase in the pulmonary blood flow, is noted after the normal fall in the PVR.

The precordium is hyperactive with a right ventricular lift.

Cardiac auscultation

The first heart sound is normal. The second sound is single because of the absence of the pulmonic component. The aortic component may be accentuated.

The murmur in this condition is characteristic and is a systolic and diastolic (to-and-fro) murmur best heard in the pulmonic area. The murmur is rough in quality and radiates widely over the lung fields. A short pause between the systolic and diastolic components is noted; this helps differentiate this murmur from that of a patent ductus arteriosus.