Symptomatic Long Pauses and Bradycardia due to Massive Multinodular Goiter

Received Apr 26, 2017; Accepted Jul 3, 2017

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1. Introduction

Permanent pacemaker implantation is generally indicated in patients with symptomatic sinus node dysfunction. Such sinus node dysfunction may be the result of age related degeneration or secondary to ischemic, infiltrative, endocrinologic, or autonomic diseases [1]. Mass lesions of the head and neck, including multinodular goiters, have been reported to cause bradycardia, pauses, or syncope [2, 3]. Carotid sinus syndrome or autonomic dysfunction may occur when mass effect involves the carotid sinus baroreceptor, airway, or recurrent laryngeal nerve [2]. With surgical decompression or denervation, the cardioinhibitory and vasodepressor response to compression can be reversed [2, 3]. We present the case of a 55-year-old woman with recurrent sinus pauses and syncope who was found to have carotid sinus and airway compression from a massive multinodular goiter.

2. Case Presentation

A 55-year-old woman with history of bipolar disorder, obstructive sleep apnea (OSA), and multinodular goiter presented with recurrent syncope. The patient also endorsed nocturnal palpitations and several syncopal events associated with voiding. There was no previous history of arrhythmia, conduction disease, or known cardiac structural or functional abnormality. Electrocardiogram demonstrated sinus rhythm with normal atrioventricular nodal and ventricular conduction intervals including PR, QRS, and QTc at baseline. Her sinus rate was 70 to 80 beats per minute at rest. Laboratory analyses including electrolytes and thyroid function were unremarkable. However, inpatient telemetry monitoring demonstrated frequent episodes of sinus bradycardia which were asymptomatic and intermittent long sinus pauses of up to 9 seconds (Figure 1). These bradycardic events were most frequent and prolonged during sleep and when the patient was noncompliant with continuous positive airway pressure ventilation. Few episodes of sinus tachycardia were also recorded; however no other arrhythmias were present. She was not on any medication to suppress the sinus or atrioventricular nodes. Transthoracic echocardiogram...