Carcinoid Syndrome-Induced Ventricular Tachycardia

Abstract

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.

Carcinoid Heart Disease: Review of Current Knowledge

“…Arrhythmias have rarely been reported in the presence of carcinoid HD. In a patient without ischemic HD, carcinoid-induced ventricular tachycardia was controlled with the use of metoprolol 35 ; 2 other cases involved associated atrial arrhythmias. 36,37 In canine studies, serotonin was implicated in paroxysmal ventricular tachycardias and atrial arrhythmias.…”

“…38,39 The underlying mechanism is thought to be increased sympathetic discharge induced by a vasoactive substance, leading to cardiac excitation and tachyarrhythmias. 35 Direct Myocardial Involvement. A fourth manifestation of carcinoid HD is tumor metastasis directly to the cardiac muscle.…”

Carcinoid Heart Disease: Pathophysiology, Pathology, Clinical Manifestations, and Management

“…While arrythmias are a rare presenting feature of CHD, it is necessary to consider them in patients with CHD. As a vasoactive substance, serotonin may increase sympathetic discharge and thereby cardiac excitation, resulting in multiple tachyarrhythmias [27]. This concept was supported by experimental studies, as sudden release of serotonin was associated with paroxysmal ventricular tachycardias and atrial arrhythmias [28].…”

Carcinoid-syndrome: recent advances, current status and controversies

“…Carcinoid crises are often precipitated by various procedures(surgery, anesthesia, endoscopy, chemotherapy, PRRT, radiological procedures [such as biopsies, embolization], but can also be precipitated by stress or abdominal palpation of the tumor area during examination of the patient[2,192–195]. The symptoms/signs characteristically include marked changes in blood pressure(usually hypotension, frequently with shock: however, hypertension can occur also[196]), CNS symptoms(stupor, confusion), flushing, diarrhea, bronchospasm, hyperthermia and cardiac arrhythmias[2,192–194,197,198]. This is serious complication in carcinoid-syndrome patients and needs to be treated, because it can result in death[2,193,194,197,199,200].…”