Patent ductus arteriosus physical examination


 * Associate Editor-In-Chief: Priyamvada Singh, M.B.B.S. [mailto:psingh@perfuse.org],, Assistant Editor-In-Chief: Kristin Feeney, B.S. [mailto:kfeeney@perfuse.org]

Overview
The physical examination varies depending on the size of patent ductus arteriosus and the amount of blood mixing across the ductus

Physical Examination
Patients with a small PDA may have no symptoms. A large PDA can cause heart failure, wide pulse pressure, and bounding arterial pulses. An apical heave may be observed, and a thrill may be heard at the second left intercostal space. The characteristic continuous murmur has been described as a machinery or to and fro murmur heard in both systole and diastole. It can be less prominent or not heard at all in diastole in infants or in the patients with increased pulmonary vascular resistance PVR.

Small PDA — Small PDA may be asymptomatic. The physical findings are-
 * No cyanosis
 * Normal pulses or mildly accentuated.
 * Normal precordial activity
 * Normal first and second heart sounds.
 * Normal respiratory examination.
 * Murmur may be present. Its nature may be different for neonates and older patient. This is so because of the relative difference in pulmonary and systemic vascular resistance in them.
 * Newborn - The pressure during systole is greater in aorta compared to pulmonary circulation. However, this gradient between aortic and pulmonary circulation is not so prominent in diastole. Due to this the murmur may only be audible during the systole.
 * The pulmonary artery pressure falls after the newborn period. Due to this the pressure in aorta is higher than pulmonary artery both in systole and in diastole. This in turn leads to the characteristic continuous, machinery murmur or Gibson's murmur (both during systole and diastole.

Features of machinery murmur are-
 * heard best in the left infraclavicular region.
 * The murmur may be 3/6 or less
 * The intensity is maximal immediately before and after the second heart sound (S2)
 * Not vary with changing postures

Moderate PDA The features of murmur are very similar to that seen with small ducts however, they are louder than that associated with small PDA
 * As a result of the runoff from the aorta, there are bounding pulses, and the pulse pressure widens.
 * A continuous thrill may be present in the first or second left intercostal space.
 * Displaced apex (indicating left ventricular overload)
 * Continuous murmur (may be grade 2,3 and occasionally 4)

Large PDA
 * Bounding pulse with wide pulse pressure
 * Dynamic left ventricular impulse
 * Left ventricular thrill
 * Murmur
 * S1 is normal, S2 may be split with an accentuated pulmonary component. The continuous machinery murmurs with similar features as seen in moderate and small sized ducts but with louder intensity(4/6 grade)could be heard
 * An apical diastolic rumble due to increased flow across the mitral valve may be present
 * A third heart sound may be present.

If there is no reduction in the size of ductus, after age 2, progressive obstructive disease develops in these patients


 * Signs of heart failure


 * The JVP may be elevated due to RV failure. Prominent a wave due to diminished RV compliance and RVH.


 * Signs of pulmonary hypertension associated with right-to-left shunt.


 * As the pulmonary hypertension increases, left to right flow across the duct decreases and there is no audible murmur. A murmur of pulmonic insufficiency may be noted Graham Steell's murmur due to dilation of the pulmonic valve ring resulting from pulmonary hypertension. Flow into a dilated pulmonary trunk causes a pulmonic ejection sound and pulmonic ejection murmur. The second pulmonic heart sound is closely split or not split.


 * Eisenmenger syndrome in case of reversal of shunt(cyanosis and clubbing, preferential cyanosis more pronounced in lower extremities than upper)