Examine this patient's heart.

Examine this patient's cardiovascular system.



· Asymptomatic.

· Bronchitis or dyspnoea on exertion in severe cases.

· Take a maternal history of rubella, particularly in the first trimester.

· Determine whether the patient was a premature baby or had a low birth weight. Remember, the

frequency of PDA in infants weighing 501-1500 g was 31% (Pediatrics 1993; 91:540 5).

· Determine whether the patient was born in a place at high altitude.


· Collapsing pulse (due to an aortic diastolic run-off).

· Heaving apex beat.

· Systolic and/or diastolic thrill in the left second interspace.

· Loud, continuous 'machinery' murmur, i.e. pansystolic and extending into early diastole - known

Gibson murmur - is heard along the left upper sternal border and outer border of the clavicle. The

begins after the first heart sound, peaks with the second sound, and trails off in diastole (Edinb

8: 1).

· The second sound is not heard.


This patient has a patent ductus arteriosus (lesion) which is probably congenital ill origin (aetiology);

patient is not in heart failure (functional status).


Mention a few causes of a collapsing pulse.

Hyperdynamic circulation due to:

· Aortic regurgitation.

· Thyrotoxicosis.

· Severe anaemia.

· Paget's disease.

· Complete heart block.


Mention a few causes of continuous murmurs.

· Venous hum.

· Mitral regurgitation murmur with aortic regurgitant murmur.

· VSD with aortic regurgitation.

· Pulmonary arteriovenous fistula.

· Rupture of the sinus of Valsalva.

· Coronary arteriovenous fistula.

· Arteriovenous anastomosis of intercostal vessels following a fractured rib.

What happens to the continuous murmur of patent ductus arteriosus (PDA) in pulmonary

hypertension ?

First the diastolic murmur, then the systolic murmur, becomes softer and shorter, and P2 increases


How would you investigate this patient?

· ECG may be normal or shows left ventricular hypertrophy.

· Chest X-ray (CXR) may be normal, or there may be left ventricular and left atrial enlargement.

chest film shows pulmonary plethora, proximal pulmonary arterial dilatation, and a prominent

ascending aorta. The ductus arteriosus may be visualized as an opacity at the confluence of

descending aorta and the aortic knob. If pulmonary hypertension develops, right ventricular

hypertrophy is noted.

· Echocardiogram: the ductus arteriosus can usually be visualized, and Doppler studies demonstrate

continuous flow in the pulmonary trunk.

· Cardiac catheterization is useful to determine the presence and severity of the shunt; it also

determines pulmonary vascular resistance. Angiography defines the anatomy.

Mention a few associated lesions.

· Ventricular septal defect.

· Pulmonary stenosis.

· Coarctation of aorta.

What are the complications?

· Congestive cardiac failure is the commonest complication.

· Infective endocarditis or endarteritis (involves the pulmonary side of the ductus arteriosus or the

pulmonary artery opposite the duct orifice, from which septic pulmonary emboli may arise).

· Pulmonary hypertension and reversal of shunt (causes differential cyanosis and clubbing, i.e. toes,

not fingers, are clubbed and cyanosed).

· Substantial left-to-right shunting through the ductus in infants may increase the risk of

intraventricular haemorrhage, necrotizing enterocolitis, broncho-pulmonary dysplasia and death.

· The ductus may become aneurysmal and calcified, which may lead to its rupture.

Remember. One third of patients with a patent ductus arteriosus that is not surgically repaired die of

heart failure, pulmonary hypertension, or endarteritis by the age of 40 years, and two thirds die by the age

of 60 years.

How would you manage such patients?

· Within 1-3 weeks of birth: administer a prostaglandin E synthesis inhibitor such as indometacin or

ibuprofen. Ibuprofen is as effective as indometacin but is associated with a lower incidence of renal toxic

effects (N Engl J Med 2000; 343: 674-81 ).

· A Rashkind PDA occluder can be inserted percutaneously without the need for a thoracotomy. It

consists of a series of miniature back-to-back umbrellas which are positioned across the duct.

· In children or adults with large shunts: perform surgery, i.e. ligation or division of the PDA.


· Because of the risk of endarteritis associated with unrepaired patent ductus arteriosus (estimated at

0.45% annually alter the second decade of life) and the low risk associated with ligation (mortality of

less than 0.5%), it is recommended that even a small patent ductus arteriosus be ligated surgically or

occluded with a percutaneously placed closure device.

· Once severe pulmonary vascular obstructive disease develops, surgical ligation or percutaneous

closure is contraindicated.

Which congenital cardiac lesions are dependent on a PDA?

Hypoplastic left heart syndrome, complex coarctations of aorta and critical congenital aortic stenosis.

Collapsing pulse is also called Corrigan's pulse after Sir Dominic J. Corrigan (1802-1880), a Dublin-born

physician who graduated from Edinburgh. R.E. Gross was the first to report surgical closure of the PDA

in 1939.