Ebstein’s anomaly is a congenital heart defect in which the septal and posterior leaflets of the tricuspid valve are displaced towards the apex of the right ventricle of the heart. It’s classified as a critical congenital heart defect accounting for <1% of all congenital heart defects presenting in ≈1 per 200,000 live births.
Ebstein’s cardiophysiology typically presents as an (antidromic) AV reentrant tachycardia with associated pre-excitation. In this setting, the preferred medication treatment agent is procainamide. Since AV-blockade may promote conduction over the accessory pathway, drugs such as beta blockers, calcium channel blockers, and digoxin are contraindicated.
If atrial fibrillation with pre-excitation occurs, treatment options include procainamide, flecainide, propafenone, dofetilide, and ibutilide, since these medications slow conduction in the accessory pathway causing the tachycardia and should be administered before considering electrical cardioversion. Intravenous amiodarone may also convert atrial fibrillation and/or slow the ventricular response.
The Canadian Cardiovascular Society (CCS) recommends surgical intervention for these indications.
Limited exercise capacity (NYHA III-IV)
Increasing heart size (cardiothoracic ratio greater than 65%)
Important cyanosis (resting oxygen saturation less than 90% – level B)
Severe tricuspid regurgitation with symptoms
Transient ischemic attack or stroke
The CCS further recommends patients who require operation for Ebstein’s anomaly should be operated on by congenital heart surgeons who have substantial specific experience and success with this operation. Every effort should be made to preserve the native tricuspid valve.