The management of
syncope is clinically important for
heart failure (HF) patients. We herein describe a case on the efficacy of
disopyramide for refractory
syncope in HF with preserved ejection fraction (HFpEF). An 82-year-old man was hospitalized for respiratory distress and lower limb
edema and was subsequently diagnosed with HFpEF. The use of
diuretics improved HF symptoms; however, on day 10 after hospitalization, a rapid decrease in blood pressure and transient
loss of consciousness developed. After neurologic examination, he was diagnosed with
pure autonomic failure. Although he was administered
midodrine 8 mg/d,
fludrocortisone 0.1 mg/d, and
droxidopa 300 mg/d,
syncope was observed once a day on average. According to the Holter electrocardiogram, the patient's heart rate and coefficient of variation of R-R intervals (CVRR) during the day were unstable. In addition, high frequency power (parasympathetic nerve activity) was significantly higher than low frequency power (both sympathetic and parasympathetic nerves activity), suggesting that the parasympathetic nerves may have been highly active while the sympathetic nerves would have been blocked. On day 29, a pharmacist proposed
disopyramide 300 mg/d, which blocks parasympathetic nerves and improves neural-mediated
syncope, to the attending doctor. After the initiation of
disopyramide, transient
loss of consciousness was not observed. Furthermore, the diurnal variation in the heart rate and CVRR completely disappeared. In conclusion,
disopyramide would be effective for refractory
syncope in patients with HFpEF, and the Holter electrocardiogram may be a useful tool for the assessment of
drug efficacy by pharmacists.