ST Segment Annotation

All Authors: Kristin Andres BS, Meenakshi Bhalla MD

Case Report

A 28 year old male with no significant past medical history presented with substernal chest pressure of 3 days' duration with associated productive cough, myalgias, chills and fever to 104.6 F. He had visited his PCP 3 days prior and was prescribed amoxicillin for presumed upper respiratory infection without relief. On presentation he was febrile (103 F) and tachycardic. Physical exam was notable for coarse breath sounds and dullness to percussion over the base of the right lung, and tachycardia with normal rhythm and no extra heart sounds. Chest x-ray revealed an opacity in the right lower lobe of the lung concerning for pneumonia. EKG revealed ST elevation in precordial leads V1-3 and an incomplete right bundle branch block (RBBB). Cardiology was consulted due to suspicion of Brugada syndrome. The ST elevation resolved once the patient was afebrile. The patient was scheduled for an outpatient Flecanide drug challenge test for definitive diagnosis of Brugada syndrome and evaluation of need for ICD placement.


When ST segment elevation is seen on EKG a primary concern is ischemia. However, a variety of conditions other than STEMI can result in ST elevation including but not limited to: pericarditis, early repolarization, left bundle branch block (LBBB), left ventricular hypertrophy (LVH), hyperkalemia and Brugada syndrome. In some of these conditions the observed ST changes are normal variants observed in healthy individuals without underlying cardiac disease. However, in others ST changes may indicate maladaptive remodeling of the myocardium, inflammatory processes, or even disturbances of the cardiac conduction system that place the patient at increased risk for sudden cardiac death (SCD). Therefore, it is of upmost importance to accurately identify the cause of a patient's ST elevation. Patient demographics, comorbidities, clinical presentation and physical exam are key in distinguishing between ischemic vs non-ischemic ST elevation. However, features of the EKG itself can also help to distinguish between the potential causes of ST elevation. Attention to ST segment morphology is particularly important in evaluation of ST elevation in asymptomatic otherwise healthy patients since some morphologies are benign and require no further workup (early repolarization) while others are associated with fatal arrhythmias (Brugada). Diagnosis of Brugada syndrome relies on the recognition of classic EKG findings of an incomplete RBBB and coved ST elevation >2mm in one or more of the precordial leads. Patients with this EKG pattern and a family history of SCD or a personal history of ventricular arrhythmias, syncope or agonal nocturnal breathing are at high risk of having Brugada syndrome and warrant further electrophysiology workup to assess for necessity of ICD placement.

Back to the May 2018 issue of ACP IMpact