Bradycardia during therapy for multiple myeloma with thalidomide.

We studied the medical records of 96 patients who received thalidomide and 104 patients who made up a control group. We found that 53% of patients (52 patients) using thalidomide had a heart rate of <60 beats/min at some point during follow-up and 19% of thalidomide patients (10 patients) developed symptom-related bradycardia. Reducing the thalidomide dose appeared to alleviate symptoms in most patients.