antitachycardia

Antitachycardia is a set of medical approaches intended to prevent or terminate tachyarrhythmias, abnormally fast heart rhythms arising from electrical disturbances in the heart. It includes device-based therapies, such as antitachycardia pacing, as well as pharmacologic and procedural strategies used to suppress or interrupt tachycardias. The term is most commonly applied to patients with structural heart disease or implanted devices who experience ventricular or supraventricular tachycardias.

Antitachycardia pacing is delivered by certain pacemakers and implantable cardioverter-defibrillators (ICDs). It works by emitting rapid pacing sequences to overdrive or interrupt a sustaining reentrant circuit. Successful pacing can terminate the arrhythmia without a shock; if ATP fails or the tachycardia is unstable, the device may deliver a shock or switch to another therapy.

Pharmacologic antitachycardia therapies include antiarrhythmic drugs such as amiodarone, lidocaine, procainamide, sotalol, and mexiletine, which can suppress or convert ventricular tachycardia and other tachyarrhythmias. Beta-blockers reduce sympathetic drive and tachycardia burden. Adenosine can terminate certain focal or reentrant supraventricular tachycardias; digoxin is used less often for tachyarrhythmias today.

Procedural options include catheter ablation, which targets and eliminates the arrhythmogenic tissue or circuitry, reducing or preventing recurrence of tachycardia in selected patients. Ablation is commonly considered when medical therapy is ineffective, poorly tolerated, or when device-delivered therapies persist.

Outcomes depend on the underlying mechanism and heart condition. Antitachycardia therapies carry risks such as proarrhythmia, inappropriate shocks, and device complications, and therapy is individualized with ongoing monitoring and follow-up.