Sick Sinus Syndrome As First Manifestation of Pheochromocytoma : A Case Report

Presentation Number: SUN-0784
Date of Presentation: June 22nd, 2014

Jin Kyeong Shin*, Yeong Bok Lee, Hee Sun Kwon, Jang Won Son, Seong Su Lee, Sung Rae Kim and Soon Jib Yoo
The Catholic University of Korea, Bucheon St. Mary’s Hospital, Bucheon, Korea, Republic of (South)


Background: Pheochromocytoma is accompanied with cardiac manifestations due to catecholamine secretion. Most of the cardiac manifestations such as hypertension, cardiomyopathy, and tachycardia result from a rapid and massive release of catecholamines. More rarely, patients with pheochromocytoma present with bradycardia or hypotension. We report pheochromocytoma with sick sinus syndrome.

Clinical Case: A 33-year-old, previous healthy Asian male visited our hospital to evaluation of adrenal incidentaloma. Preoperative diagnosis of pheochromocytoma was based on positive biochemical test and I-131 MIBG scan. 24 hours ambulatory BP and ECG monitoring was performed before operation. The patients diagnosed with hypertension. He had sinus pause (5.2 sec) with mild dizziness in 24 hours ECG monitoring. There were no abnormal findings in echocardiography and electrophysiology study.  We started doxazocin and temporary pacemaker was inserted before laparoscopic adrenalectomy. After removal of the tumor, the results of biochemical test were normal ranges and the sinus pause resolved in 24 hours ECG monitoring.

Conclusion: Bradycardia without any atrial electrical activity is a feature of the sick sinus syndrome. Bradycardia was due to transient autonomic dysregulation caused by intermittent excess secretion of catecholamines in pheochromocytoma. In conclusion, it should be preceded that exist of life threatening complications existed before pheochromcytoma operation.


Nothing to Disclose: JKS, YBL, HSK, JWS, SSL, SRK, SJY