ST elevation without cardio-pulmonary symptoms

1. Case description

A 57-year-old man with no significant past medical history presented to the emergency department (ED) with complaints of dysuria, increased frequency of urination, and subjective fevers since 2 days. The patient denied any other symptoms. He did not have any chest pain, dyspnea, orthopnea, paroxysmal nocturnal dyspnea, dizziness, or palpitations. At the time of presentation, the patient did not have a history of syncope or seizures. He worked in construction and could tolerate exercise without dyspnea. He had no family history of arrhythmias, sudden cardiac death, or coronary artery disease. He smoked 20 cigarettes daily and had no history of alcohol or illicit drug use. Vital signs on presentation were as follows: temperature, 103 F (39.4 °C); blood pressure, 132/80 mmHg; pulse, 116/min; and respiratory rate, 17/min. Oxygen saturation was 100% on room air. Physical examination revealed mild suprapubic tenderness, without any guarding or rigidity. His cardiovascular examination revealed normal heart sounds, and regular rate and rhythm, without any murmurs, rubs, or gallops. There was no jugular venous distention, and the lungs were clear to auscultation bilaterally. He underwent electrocardiography (ECG) in the ED (Fig. 1). What would be the next most appropriate step in the management of this patient?

• –Activate code ST-segment elevation myocardial infarction (STEMI).
• –Genetic testing and electrophysiology study (EPS) after infection resolves.
• –Schedule for Implantable Cardioverter Defibrillator (ICD) once infection resolves.
• –Observation with outpatient follow-up after prompt treatment of fever with antipyretics for urinary tract infection (UTI).

Fig. 1.

Results of ECG performed in the emergency room.

2. Discussion

The answer is D. This patient had a typical Brugada type 1 ECG pattern. Coved ST-segment elevation of more than or equal to 2 mm in at least either lead V1 or V2 with T-wave inversion is considered typical type 1 pattern; this was not STEMI, and hence, option 1 is incorrect. As per the 2015 European Society of Cardiology (ESC) guidelines, prompt treatment of fever with antipyretic drugs is a class I recommendation [1]. The most likely precipitating factor in this patient was the high fever. The loss of sodium channel current (I_Na) with an unopposed action of transient outward current (I_to) is thought to be responsible for the ECG pattern and risk for ventricular arrhythmias [2]. A rise in temperature beyond the physiological range dramatically reduces the charge carried by the sodium channel current (I_Na) and hence can lead to its accelerated inactivation (premature closing). There can also be a failure of the channel to express at higher temperatures [2]. Hence, these patients should be treated promptly with antipyretic drugs. Since this patient had no history or syncope, seizures, or family history of sudden cardiac death, he cannot be classified as having Brugada Syndrome. Rather, he would just be classified as having Brugada type 1 ECG pattern. This distinction is important, as it will affect the management algorithm. The most common genetic abnormality is a mutation in the SCN5A gene. Genetic abnormalities exist in only one-third of Brugada Syndrome patients [3]. Genetic testing is recommended for patients when there is a clinical index of suspicion for Brugada Syndrome based on clinical history, family history, and expressed ECG phenotype. It is recommended that family members and appropriate relatives follow the identification of the Brugada Syndrome causative genetic mutation in the index case [4]. Hence, in this patient, genetic testing is not indicated. The role of EPS is controversial in Brugada Syndrome patients. Brugada et al. reported inducibility of ventricular arrhythmias as an independent predictor of arrhythmic events [5]. In the two subsequent large-scale registries – FINGER France, Italy, Netherlands, GERmany and PRogrammed ELectrical stimUlation preDictive value (PRELUDE), inducibility during EPS did not predict arrhythmic events [6], [7]. These are the two largest registries, which provide the strongest evidence for the use of EPS in asymptomatic patients. Based on the most recent HRS/EHRA/APHRS recommendations, ICD is recommended in Brugada Syndrome patients who meet the following criteria: (i) survivors of cardiac arrest (class I), (ii) documented spontaneous sustained ventricular arrhythmia with or without syncope (class I), and (iii) spontaneous diagnostic type 1 ECG who have syncope judged likely to be caused by ventricular arrhythmias (class IIa). ICD is not indicated in asymptomatic patients with Brugada ECG pattern (class III) [8]. Since our patient was asymptomatic, there is no role of ICD in this patient. He had transthoracic echocardiography done, which revealed normal left ventricular ejection fraction of 60% and no structural or valvular abnormalities. He was on continuous telemonitoring for more than 24 h until discharge, and there was no evidence of premature ventricular contractions, atrioventricular blocks, left axis deviation, paroxysmal atrial fibrillation, or transient left bundle branch block, which are some of the findings supportive of a diagnosis of Brugada Syndrome [8]. Hence, the next best management option for this patient is the prompt treatment of his fever with antipyretic drugs for his UTI with outpatient follow-up. If the ECG pattern persisted after complete resolution of fever, the patient may be reclassified as having spontaneous Brugada Syndrome and then followed-up regularly with a cardiologist. Even in spontaneous ECG type 1 pattern (Brugada Syndrome), the role of EPS is not well defined, and even if there is inducibility of ventricular arrhythmia, ICD implantation is a class IIb recommendation [8].

Conflict of interest

All authors declare no conflict of interest related to this study.