Carcinoid Syndrome-Induced Ventricular Tachycardia.

Introduction. Carcinoid tumors are rare neuroendocrine malignancies that secrete multiple bioactive substances. These bioactive substances are responsible for the carcinoid syndrome characterized by diarrhea, flushing, syncope, and right-sided valvular heart disease. Previous case reports have described carcinoid syndrome associated with coronary vasospasm and the well-characterized carcinoid heart disease. Case. Our patient is a 73-year-old female with complex past medical history most notable for metastatic carcinoid tumors diagnosed in 2013-05. She initially presented in 2014-09 with syncope and dizziness associated with sinus pause on an event monitor. She received a pacemaker given normal left ventricular function and was discharged. However, she was readmitted with similar symptoms corresponding to multiple episodes of ventricular tachycardia. She was started on high-dose beta blockade and has had no recurrence of arrhythmia over a follow-up period of 12 months. Conclusion. We hypothesize that the patient's ventricular tachycardia was mediated by the multiple bioactive substances secreted by her carcinoid tumors. Her carcinoid tumor biomarkers were elevated and other explanations for arrhythmia were investigated and ruled out. To our knowledge, this is the first case of ventricular tachycardia mediated by carcinoid syndrome and suppressed by beta-blocker. Further investigation into this relationship is needed.