[Cardiac arrhythmias in adults with congenital heart disease]. / Herzrhythmusstörungen bei Erwachsenen mit angeborenen Herzfehlern.

In patients with congenital heart disease, cardiac arrhythmias are complex and require a thorough understanding of the anatomy, past surgical and interventional procedures, and the specific electric processes. Supraventricular tachycardias commonly present as emergency situations and should be treated immediately, particularly when there is an underlying complex malformation. Establishing sinus rhythm is usually superior to pure frequency control for hemodynamic reasons. Catheter ablation should be preferred over medical treatment, even though several procedures are often necessary. In addition, bradycardia is seen more frequently in congenital heart defects; this could be aggravated by antiarrhythmic drugs. There are significant differences between the indications and techniques used for pacemaker implantation in patients with congenital heart defects and those without. Patients with complex congenital heart diseases have an increased risk of thromboembolism; therefore, an individual and early indication for low-threshold oral anticoagulation is necessary; direct oral anticoagulants can also be used for this purpose. In risk stratification for sudden cardiac death, the principles of general guidelines are often not applicable, and individualized decisions are required. Recently, a new general risk score for congenital heart disease has been developed. The treatment of cardiac arrhythmias in patients with congenital heart disease should always be performed in close cooperation with specialized centers.

[Reversible severe cardiomyopathy caused by a slow permanent tachycardia]. / Reversible, schwere Kardiomyopathie als Folge einer langsamen, permanenten Schmalkomplextachykardie.

Incessant narrow QRS complex tachycardias may result in severe tachycardia-induced cardiomyopathy even if the heart rate during tachycardia is only moderately elevated. The risk of ventricular deterioration is particularly increased in patients with underlying congenital heart disease. In these patients, drug treatment is often insufficient. Thus, catheter ablation of the arrhythmogenic substrate is required in the majority of patients. After successful ablation, ventricular function may recover completely.

Diagnosis of tachycardia mechanism with cryomapping in a toddler with complex congenital heart disease.

A 2.5-year-old patient with complex congenital heart disease involving dextrocardia, atrioventricular and ventriculoarterial discordance, pulmonary stenosis, ventricular septal defect (VSD), atrial septal defect (ASD), and paroxysmal supraventricular tachycardia (SVT) underwent electrophysiological study. The tachycardia mechanism was diagnosed with cryomapping. The ability of cryomapping to have transient and reversible effect on the tissue, unlike radiofrequency (RF) ablation, helped in the establishment of diagnosis in this toddler with typical atrioventricular nodal reentrant tachycardia. Cryomapping can be an additional safe diagnostic utility in young patients with complex congenital heart disease.