Third degree atrioventricular block associated with treatment with rivastigmine transdermal patch
Seventy-one year old male admitted to the coronary care unit with shortness of breath. The patient had a prior history of stroke, but no history of cardiac disease and had no chest pain. ECG at admission revealed a 3rd degree atrioventricular block with a heart rate of 25–35 beats/min. The patient had been diagnosed with PD eight months earlier by a neurologist and started rivastigmine transdermal patch titrated to 9.6 mg/d, as well as mirtazapine, levodopa and quetiapin with good response. ECG before the initiation of rivastigmine therapy showed sinus rhythm, with a heart rate of 68 beats/min. There were no signs of ischemia and no atrioventricular conduction delay. The patient was followed in a geriatric outpatient clinic and had no known co-morbidities. The patient had normal red and white blood counts, slightly increased creatinine 108 µg/L and normal CRP. Electrolytes and thyroid stimulating hormone were normal. Troponin T was normal at admission, but increased slightly to 64 ng/L after 12 h. Echocardiography was normal. Rivastigmine was discontinued and intravenous isoprenaline was initiated. The patient reverted to a normal sinus rhythm. The patient started low-dose aspirin, but was not a candidate for invasive coronary angiography due to his general and mental state. Following consultations with the patient's family and caregivers, rivastigmine was reinitiated under continuous electrocardiographic monitoring. Atrioventricular block did not reappear and the patient was discharged with rivastigmine treatment. Cardiac follow-up after three months, including echocardiography, was normal. Eighteen months later, the patient was admitted to the medical ward after dizziness and fall, ECG showed 1st degree atrioventricular block. The patient was tested positive for orthostatic hypotension, and discharged after seven days. One week following the discharge, the patient was re-admitted to the coronary care unit due to syncope and bradycardia. The ECG revealed a 3rd degree atrioventricular block with a heart rate of 30-32 beats/min. The patient had no chest pain, and consecutive measurements of Troponin T were within normal range. The patient received a permanent atrioventricular pacemaker later that day and was discharged the following day.