Sotalol associated polymorphic ventricular tachycardia and coronary spasm

Area of Science:

• Cardiology
• Pharmacology

Background:

• Sotalol is known to prolong cardiac action potentials, potentially causing Torsade de Pointes.
• A proarrhythmic effect of sotalol secondary to its beta-blocking action has not been previously reported.

Observation:

• A 54-year-old male patient experienced angina and presyncope due to coronary spasm.
• Sotalol treatment worsened his symptoms, leading to recurrent polymorphic ventricular tachycardia.

Findings:

• The observed polymorphic ventricular tachycardia was indistinguishable from that caused by Class III antiarrhythmic agents.
• Resolution of symptoms and tachycardia occurred upon sotalol withdrawal.

Implications:

• Polymorphic ventricular tachycardia in patients on sotalol may arise from beta-adrenoceptor blockade, not solely from delayed repolarization.
• This finding broadens the understanding of sotalol's proarrhythmic mechanisms.