Case Presentation: 21-year-old male patient was referred for muscle biopsy after experiencing severe rhabdomyolysis following exercise. He underwent this outpatient procedure uneventfully, but post-procedure, experienced four episodes of syncope and pre-syncope.Patient was orthostatic, and improved some with fluids.
Baseline pre-operative electrocardiogram (EKG) showed sinus rhythm with no evidence of PR prolongation, ventricular pre-excitation, interventricular conduction delay, ST or T wave abnormality, or QT prolongation. An EKG performed the morning of the procedure showed new T wave inversion with subtle ST elevation in leads V1 and V2. EKG was repeated post-operatively with leads V1 and V2 shifted cranially one intercostal space, and revealed >2 mm coved ST elevation with T wave inversion in leads V1, V2, and V3.

The patient reported he had had multiple syncopal and pre-syncopal episodes since 9 months of age. Many of these episodes were preceded by vagal, prodromal symptoms with stereotypical precipitants: the sight of blood, skin biopsy, or after bowel movement. However, there was one episode that occurred while swimming. Episodes lasted a few seconds, usually while standing, no seizure-like activity, often preceded by lightheadedness, and followed by nausea, emesis, or bowel movement.

Family history was notable for an uncle with seizures, and paternal grandfather and great grandfather who had passed from suspected myocardial infarction at age 70-80 years without known history of coronary artery disease, perhaps representing sudden cardiac deaths.

The patient had been able to run for 2-3 miles in recent months without symptoms. While the patient had not sought medical attention for most of these episodes, he had previously undergone tilt table testing and echocardiography that were unremarkable, and he had been told these episodes were vasovagal.

Discussion: Based on diagnostic EKG findings, personal history of recurrent syncope, and concerning family history, patient was diagnosed with Brugada syndrome (BrS). Pathology from his muscle biopsy is pending but will be important as there is overlap between BrS and myotonic dystrophy through a common genetic and pathophysiological mechanism. Cardiac MRI ruled out arrhythmogenic right ventricular cardiomyopathy, a disorder that can be otherwise phenotypically identical to BrS. Genetic screening and a subcutaneous implantable cardioverter-defibrillator (ICD) were recommended.

Prevalence of BrS ranges from 1 in 2000 to 5000, and may be responsible for 4-12% of all sudden deaths. It is much more prevalent in men. Mean age of presentation is 41 ± 15 years. Patients can present with syncope, seizures, and nocturnal agonal breathing due to ventricular tachycardia or ventricular fibrillation. Lethal arrhythmias usually occur during resting or sleeping, suggesting an association with bradycardia or vagal events.

Diagnosis of BrS can be made without further testing when a type 1 EKG pattern is present. Type 1 Brugada pattern consists of ≥2 mm ST elevation in V1 and/or V2 positioned in the 2nd-4th intercostal space, a concave or straight ST segment that crosses the isoelectric line, followed by a negative and symmetric T wave. Placement of right precordial leads in more cranial positions may increase sensitivity due to the variable anatomical correlation between right ventricular outflow tract and V1-V2 in the standard position.

Conclusions: Diagnosis of BrS requires a high degree of clinical suspicion, especially in patients with recurrent syncope.

IMAGE 1: Preprocedure electrocardiograms

IMAGE 2: Postprocedure electrocardiogram with V1/V2 in third intercostal space