Effect of amiodarone on sinus node function in patients with sick sinus syndrome

Area of Science:

• Cardiology
• Electrophysiology

Background:

• Sick sinus syndrome (SSS) presents with symptomatic tachyarrhythmias.
• Dual-chamber pacemakers are often used in managing SSS.
• Amiodarone is an antiarrhythmic drug used for tachyarrhythmias.

Purpose of the Study:

• To investigate the impact of oral amiodarone on sinus node function in patients with documented sick sinus syndrome.
• To determine if amiodarone affects sinus node recovery time and intrinsic heart rate.

Main Methods:

• Nine patients with symptomatic sick sinus syndrome and pacemakers underwent Holter-ECG monitoring.
• Pacemaker inhibition assessed sinus node activity before and after four weeks of oral amiodarone.
• Sinus node function was evaluated by measuring recovery time and heart rate.

Main Results:

• Amiodarone did not alter sinus node function in 5 out of 9 patients.
• Severe depression of sinus node function was observed in 4 patients after amiodarone treatment.
• The drug's effect on sinus node function was variable among patients.

Conclusions:

• Amiodarone's safety in sick sinus syndrome patients with tachyarrhythmias is not universal.
• Concomitant pacemaker use is crucial for patients with sick sinus syndrome treated with amiodarone.
• Risk stratification is necessary to identify patients who may experience adverse effects on sinus node function.