Severe bradycardia and syncope due to topical ophthalmic timolol

Excerpt

A 60-year-old male patient presented to our emergency room complaining of dizziness and syncope. His medical history included mitral valve replacement 5 years previously, atrial fibrillation for 4 years, and glaucoma for 10 days. Medication consisted of warfarin (5 mg/day; for 5 years) and latanoprost/timolol 50 mcg/ml + 5 mg/ml eye drops (Xalacom®, Pfizer, Belgium) once for each eye for 10 days. He had no history of taking digoxin or other atrioventricular node-blocking agents and herbal agents. Examination revealed a blood pressure of 85/50 mmHg, a pulse of 30 bpm, and a metallic heart sound at the apex; the other systemic findings were unremarkable. Electrocardiography on admission demonstrated atrial fibrillation with a low atrial rate (35 bpm) (Fig. 1). Previous ECG records at regular check-up visits revealed atrial fibrillation with a normal ventricular rate approximately between 85 and 95 bpm. The patient’s latest ECG had been recorded was 1 month earlier (Fig. 2) Echocardiography showed normal left ventricular systolic function, a normal mitral prosthetic valve, and a dilated left atrium (61 mm). Because of the hemodynamic instability of the patient, temporary transvenous pacemaker implantation was performed through the jugular venous approach and ECG revealed a ventricular pacemaker rhythm of 60 bpm (Fig. 3). Afterwards, the patient’s hemodynamics improved and he was asymptomatic. Use of the ophthalmic solution timolol was discontinued. He was hospitalized for 5 days to observe the underlying rhythm. There was persistence of atrial fibrillation with a low ventricular response during the hospital stay. Therefore, permanent pacemaker implantation (VVI) was performed successfully with no complications. The remaining hospital stay was uneventful. The patient was asymptomatic at the 1-month and 6-month follow-up visits, and a check-up of the pacemaker revealed 89% right ventricular pacing with a baseline rate of 60 bpm. …