Postoperative arrhythmias after surgery for congenital heart disease (CHD) is usually associated with inadequate repair. Electrograms using the pacing wires are useful in arriving at a diagnosis.
Sick sinus syndrome in post op CHD occurs most often in Fontan and Glenn. Fontan patients tolerate junctional rhythm poorly.
Atrial flutter can be diagnosed by demonstrating the flutter waves. If the flutter waves are not obvious, adenosine or recording from the atrial pacing wire may be useful.
Ectopic atrial tachycardia can also be identified by giving adenosine to demonstrate the P waves.
Sinus node reentrant tachycardia is a long RP tachycardia and resemble ectopic atrial tachycardia (EAT). It is adenosine responsive and exquisitely sensitive to digoxin.
Junctional ectopic tachycardia (JET) is a major problem in post op period of CHD. It is a narrow QRS tachycardia with AV dissociation. In those with intact retrograde conduction, AV dissociation will not be there and diagnosis becomes difficult. Fever worsens the rate. JET can be associated with severe hemodynamic consequences and can be lethal. This rhythm does not respond to DC shock. Mechanism of post op JET is supposed to be irritation due to local hematoma. Hypothermia is useful in managing this tachycardia. The most useful drugs are amiodarone, procainamide and esmolol.
Ventricular tachycardia is associated with electrolyte abnormalities, inotropes, bad ventricular function or scar based, especially if monomorphic. Overdrive pacing, cardioversion, lignocaine, procainamide or amiodarone may be used.
Ventricular fibrillation needs thought of electrolytes as well as coronary compromise. Inadvertent inclusion of coronary arteries in the suture line has to be thought of.
Alarms due to artefacts are also common in the ICU setting.