RCSIsmjcase report Table 1: Comparison of pre-ductal and post-ductal CoA. Comparative qualities
Pre-ductal/ductal CoA
Post-ductal CoA
Age
Neonatal presentation
Adolescent/adult presentation
Symptoms/signs
Cyanosis when DA closes Dyspnoea, tachypnoea Loss of consciousness Absent femoral pulses Plethora of upper extremity Upper extremity hypertension Decreased lower extremity perfusion Cardiogenic shock
Cyanosis during exercise/stress Dyspnoea, tachypnoea Loss of consciousness Rib notching and pulsations Upper extremity hypertension Possible cardiogenic shock
Investigations
Pulse oximetry of four limbs Blood pressure of four limbs VBG – metabolic acidosis CXR – cardiomegaly ECG – arrhythmia ECHO – RVH
Pulse oximetry of four limbs Blood pressure of four limbs ABG – metabolic acidosis CXR – cardiomegaly ECG – arrhythmia and RVH/LVH ECHO – RVH and LVH CT or MRI angiography
Management
Alprostadil/Prostin Dobutamine CPAP and intubation (if needed) Diuretics – if fluid overloaded NPO prep. for surgery Anti-hypertensive medication
Dobutamine High flow oxygen Diuretics – if fluid overloaded NPO prep. for surgery Anti-hypertensive medication
Abbreviations: CoA – coarctation of the aorta; DA – ductus arteriosus; VBG – venous blood gas; ABG – arterial blood gas; CXR – chest x-ray; ECG – electrocardiogram; ECHO – echocardiogram; RVH – right ventricular hypertrophy; LVH – left ventricular hypertrophy; CPAP – continuous positive airway pressure; NPO – nil per os. This presentation is associated with a mortality rate of approximately 13.6%.1 Post-ductal CoA patients typically have the classic sign of rib notching and pulsations due to intercostal collateral circulation. Non-duct-dependent children may never experience symptoms until adulthood due to collateral circulation through intercostal arteries, but eventually experience cardiac decompensation.3 Management of a duct-dependent coarctation requires immediate administration of prostaglandin E1 to maintain the ductus arteriosus. The ductus arteriosus is the primary means of perfusion to the lower extremities, especially in very narrow coarctations.3 If prostaglandin E1 is not FIGURE 1: Comparison between pre-ductal (left) and post-ductal (right) coarctation of the aorta. Image courtesy of Catherine Tennant, RCSI medical student.
administered, death is nearly certain from cardiogenic shock. Dobutamine must also be given to maintain cardiac output in heart failure. Management of post-ductal coarctation presentation is
the junction with the ductus arteriosus (pre-ductal/ductal) or distal
dependent on the severity of narrowing and symptoms. Surgery is
to the ductus arteriosus (post-ductal), as shown in Figure 1.
always required for pre-ductal CoA, while patients with post-ductal
Pre-ductal and ductal coarctations are duct dependent and have a
CoA should have surgery prior to decompensation to increase life
worse prognosis due to ductus arteriosus closure at about seven
expectancy.5 The common types of surgical intervention in
days postnatally, leading to cardiac decompensation.3 Postnatally
pre-ductal and post-ductal CoA repair include stent placement,
diagnosed pre-ductal CoA typically presents at approximately seven
end-to-end anastomosis, and catheter balloon aortoplasty with
1
days postnatally with cardiogenic shock or signs of heart failure,
concurrent patent ductus arteriosus (PDA) ligation.5 A comparison of
typically central cyanosis, breathlessness, and systemic oedema.2
both classifications based on presentation age, signs and
Page 24 | Volume 9: Number 1. 2016