Introduction

Brugada phenocopy is an electrocardiographic phenomenon characterized by presenting a type 1 or 2 Brugada pattern triggered by various underlying clinical conditions that resemble the Brugada phenotype in an individual not carrying the genetic mutation.¹ This case highlights the fact that the search for Brugada phenocopies triggering factors remains open, and the list continues to grow, confirming the importance of timely recognition of Brugada phenocopies and their clinical approach.

Case presentation

A 23-year-old male patient was admitted due to the intentional ingestion of a Tablet with 1.7 grams of aluminum phosphide and 1.3 grams of excipients. An electrocardiogram (ECG) was performed (Figure 1). The patient was admitted with neurologic deficit and shock; cardiovascular support, mechanical ventilation, and vasopressors were initiated.

Figure 1: Electrocardiogram was taken at the presentation in the emergency room. 

Cardiac biomarkers (troponin I, brain natriuretic peptide) were elevated beyond the 99th percentile values at admission; no electrolyte imbalance was present when the ECG was taken; a transthoracic echocardiogram was performed, documenting a 34% biplane left ventricular ejection fraction (LVEF) with apical dyskinesia. A second ECG was performed 24 hours later, showing sinus tachycardia without evidence of the Brugada pattern (Figure 2). After 72 hours of admission, vasopressors were discontinued, and the patient was weaned from mechanical ventilation. A second transthoracic echocardiogram showed improvement in systolic function (LVEF 48% by biplane) without alterations in apical contractility. In a 24-hour Holter, the Brugada pattern was not documented again. Due to the patient’s age and contractility improvement, the patient was not considered in need of coronary angiography. Acute stress-induced (tako-tsubo) cardiomyopathy was presumed. The patient continued to show clinical improvement until discharged.

Figure 2: Electrocardiogram taken after patient’s recovery. 

Discussion

Aluminum phosphide (Alp) is used to preserve grains worldwide. It is also one of the most dreaded poisons. The poisoning mechanism after ingestion of Alp is thought to be secondary to the release of phosphine gas by a chemical reaction of the phosphide with water and hydrochloric acid in the stomach.² Phosphine is a metabolic poison that noncompetitively blocks cytochrome C oxidase in rat liver preparation.³ It also boosts the extra-mitochondrial release of oxygen free radicals, resulting in lipid peroxidation and protein denaturation of the cell membrane.⁴

A cardinal feature of Alp poisoning is early hypotension (within six hours) with a clear mental state. Features of shock include a thready pulse, cold extremities, sweating, and oliguria present in 70% of patients.⁵ Myocardial injury is common with global hypokinesia of the left ventricle and interventricular septum with decreased LVEF on echocardiography, which occurs during the first 1 to 4 days in up to 50% cases.⁶ Apical dyskinesia was not found in Alp poisoning in previous reports. In this case, it was attributed to tako-tsubo cardiomyopathy.

In Alp intoxication nonsurvivors, examination of myocardial tissue has been reported with focal areas of congestion, necrosis, and edema along with inflammatory cell infiltration; histopathological changes related to left ventricular dysfunction have been reported.

The ECG may show the following:

Asymmetrical T-wave inversion in precordial leads was attributed to the acute stress-induced cardiomyopathy found in the patient.

Previous cases of Brugada phenocopy induced by intoxication by Alp have been reported, none of them in conjunction with acute stress-induced cardiomyopathy.⁸,⁹

The diagnostic criteria for Brugada phenocopy have been established (The first four criteria are mandatory):

Conclusions

This acute stress-induced cardiomyopathy by Aluminum phosphide intoxication met the criteria to be considered a type 1 class B Brugada phenocopy according to the Morphologic classification system from the international registry of Brugada phenocopies.