A case of atenolol-induced sinus node dysfunction presenting as escape-capture bigeminy

Area of Science:

• Cardiology
• Clinical Pharmacology

Background:

• Hypertension medications, including beta blockers and non-dihydropyridine calcium channel blockers, are known to potentially depress sinus node function.
• This can lead to symptoms and electrocardiographic findings suggestive of sinus node dysfunction.

Observation:

• A patient with hypertension, treated with atenolol, presented with recurrent near-syncopal episodes.
• The patient's symptoms were attributed to medication-induced sinus node dysfunction.

Findings:

• The electrocardiogram revealed an unusual arrhythmia: escape-capture bigeminy.
• This specific arrhythmia was a manifestation of atenolol-induced sinus node dysfunction.

Implications:

• Medication-induced sinus node dysfunction is a potentially reversible cause of syncope and arrhythmias.
• Clinicians should consider drug effects when evaluating patients with apparent sinus node dysfunction and arrhythmias like escape-capture bigeminy.