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Essentials in the Post-operative Evaluation of Congenital Heart Disease
or desaturation is a residual right-to-left shunt, particularly after Electrolyte abnormalities secondary to renal failure can make
repair of ventricular septal defects, tetralogy of Fallot, and transposition post-operative management difficult. Dialysis should be considered in
of the great arteries. In these lesions, cyanosis occurs only if there is any patient for whom renal compromise is affecting cardiac output,
right-to-left shunting due to elevated right ventricular pressures. In respiratory status, caloric intake, or fluid balance.
2,24
Peritoneal dialysis is
these patients,  right ventricular outflow tract obstruction, branch most often used in neonatal patients, whereas hemodialysis or
pulmonary artery obstruction, and causes of elevated pulmonary continuous arteriovenous ultrafiltration can be used in older patients.
vascular resistance should be investigated.
Cardiac Arrhythmia 
Cyanosis following Glenn or Fontan operations largely occurs due to Overall, arrhythmias occur in more than 25% of patients following
abnormal right-to-left shunts that allow blood to unexpectedly bypass cardiopulmonary bypass. They typically occur within 48 hours after
the pulmonary arterial bed and thus avoid oxygenation. Examples of this surgery.
2
Intra- or post-operative electrolyte abnormalities can increase the
include veno-venous fistulae, pulmonary arteriovenous malformations, risk of arrhythmia presentation. Additionally, any history of ventriculotomy,
or an anomalous source of systemic venous return. After a Glenn ischemia, or ventricular hypertrophy can increase arrhythmia risk.
operation, if the azygous vein is not ligated the superior vena cava can
decompress through the azygous to the inferior vena cava circulation, Complete heart block most commonly occurs when there is significant
with resulting cyanosis. Cyanosis can similarly occur after a fenestrated manipulation of the area near or around the atrioventricular (AV) node.
Fontan operation if the fenestration from the inferior vena cava pathway This may occur during repair of AV septal defects or ventricular septal
to the right atrium is too large.
2
defects (VSD), during the Rastelli procedure for transposition of the great
arteries and in patients with congenitally corrected transposition of
In lesions where myocardial resection has been performed the great arteries.
25,26
Heart block can also occur after cardiac
(hypertrophic cardiomyopathy or tetralogy of Fallot), coronary fistulae catheterization in susceptible patients, typically on manipulation of
can occur that do not cause cyanosis. These are typically left-to-right catheters around the ventricular septum and in those with underlying
shunts. Coronary steal phenomenon rarely occurs. These problems are bundle branch block. While usually transient in nature, pacing may be
easily identified during post-operative echocardiography.
15
When a required if the heart block is persistent.
27
A permanent pacemaker is
residual defect or unexpected cyanosis is present post-operatively, typically placed for patients in whom complete heart block persists
further imaging including echocardiography and/or cardiac beyond one week after surgery.
catheterization is indicated, with subsequent interventions performed
depending on imaging results.
16
Supraventricular tachycardia (SVT) is common in many different types of
intracardiac surgery and is typically responsive to anti-arrhythmic
Thrombosis/Perfusion medications, including amiodarone. Surgeries involving significant
The risk of cerebral embolism or cerebral ischemia during repair or suturing of atrial tissue (Ebstein’s anomaly, atrial switch, anomalous
palliation of congenital heart disease is low. Nearly 20% of neonatal pulmonary veins) are at increased risk for developing SVT.
28
These risks
patients may experience seizures
17
post-operatively, either clinical or can be minimized by concurrent surgical Maze procedures
29
if indicated.
subclinical. Risk factors for seizure activity include young age at Development of atrial flutter or atrial fibrillation occurs in a similar
surgery, prolonged period of circulatory arrest, and concurrent fashion and is usually responsive to medication or cardioversion. The
cerebral structural abnormalities.
18
Use of cerebral oxygen saturation majority of older patients undergoing valve replacement surgery may
monitoring has become increasingly valuable in predicting those experience transient post-operative atrial arrhythmias. Adolescent or
patients at risk for poor outcomes.
19,20
Prompt referral to neurology as adult patients who have had a classic Fontan procedure (atriopulmonary
well as rehabilitation services on suspicion of cerebrovascular insult connections) are at particular risk for atrial arrhythmias in short-term
can be crucial for long-term outcome. and long-term follow-up due to severely enlarged right atria.
30
Patient nutrition is extremely important following cardiac surgery. It Post-operative ventricular tachycardia is rare in congenital heart
can be stunted by complications including chylothorax, infection, and disease. Most commonly this occurs in patients with a history of
respiratory issues that interfere with enteric feeding.
21
Total parenteral ventricular dysfunction and systemic or pulmonary hypertension and
nutrition should be used whenever possible to augment the slow after prolonged cardiopulmonary bypass.
31
Additionally, patients with a
advancement of oral feedings in post-operative patients. Liver enzyme history of myocardial ischemia and ventricular hypertrophy and those
abnormalities following cardiopulmonary bypass are not uncommon but who have had a ventriculotomy or ventricular plication may be at
rarely progress to fulminant liver failure.
22
Necrotizing enterocolitis can increased risk.
32
Differentiation between ventricular tachycardia and SVT
occur in infants with congenital heart disease, particularly those lesions with aberrant conduction can be difficult. Treatment may include
with compromised aortic outflow or wide pulse pressure due to cardioversion, ablation, and anti-arrhythmic medications, including
diastolic run-off (truncus arteriosus, hypoplastic left heart syndrome, amiodarone or lidocaine.
aortopulmonary window).
23
Junctional ectopic tachycardia (JET) is a common post-operative
Renal failure following cardiopulmonary bypass is more common in tachyarrhythmia thought to arise from tissue damage adjacent to the AV
patients who have had prolonged bypass times, low cardiac output, junction of the conduction system.
33
It occurs particularly after surgery
left-sided obstructive lesions, or pre-operative renal dysfunction.
2
that involves suturing on the ventricular septum, including ventricular
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