Hyoscyamine helps in A-fib with slow ventricular response

(HealthDay)—Hyoscyamine can prevent pacemaker placement in a patient with symptoms caused by a slow ventricular response during atrial fibrillation, according to a case study published online May 15 in the Annals of Internal Medicine.

Scott A. Helgeson, M.D., from the Mayo Clinic in Jacksonville, Fla., and colleagues describe the case of a 98-year-old man with a chronic indwelling urinary catheter, dementia, atrial fibrillation, and metastatic prostate cancer who presented with recurrent syncope and bradycardia to the emergency department. Electrocardiography documented atrial fibrillation with a slow ventricular response and right bundle branch block; blood pressure was 72/40 mm Hg and heart rate was 35 beats/minute.

The researchers decided to try treatment with medication therapy because of the patient's comorbidities. Intravenous glycopyrrolate was administered, and his heart rate increased to 73 beats/minute. A similar but prolonged response was seen after administration of 0.125 mg sublingual immediate-release hyoscyamine. The patient did not develop tachycardia overnight and was discharged the following day while receiving hyoscyamine four times daily. At routine follow-up four weeks later, the patient had experienced no syncope and had a resting heart rate of 73 beats/minute.

"Clinicians may want to attempt this approach in patients with atrial fibrillation who have a slow ventricular response and would qualify for a pacemaker but have comorbidities that make this intervention less desirable," the authors write.