Electrocardiographic abnormalities in COVID-19 patients visiting the emergency department: a multicenter retrospective study.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be associated with myocardial injury. Identification of at-risk patients and mechanisms underlying cardiac involvement in COVID-19 remains unclear. During hospitalization for COVID-19, high troponin level has been found to be an independent variable associated with in-hospital mortality and a greater risk of complications. Electrocardiographic (ECG) abnormalities could be a useful tool to identify patients at risk of poor prognostic. The aim of our study was to assess if specific ECGs patterns could be related with in-hospital mortality in COVID-19 patients presenting to the ED in a European country. METHODS: From February 1st to May 31st, 2020, we conducted a multicenter study in three hospitals in France. We included adult patients (≥ 18 years old) who visited the ED during the study period, with ECG performed at ED admission and diagnosed with COVID-19. Demographic, comorbidities, drug exposures, signs and symptoms presented, and outcome data were extracted from electronic medical records using a standardized data collection form. The relationship between ECG abnormalities and in-hospital mortality was assessed using univariate and multivariable logistic regression analyses. RESULTS: An ECG was performed on 275 patients who presented to the ED. Most of the ECGs were in normal sinus rhythm (87%), and 26 (10%) patients had atrial fibrillation/flutter on ECG at ED admission. Repolarization abnormalities represented the most common findings reported in the population (40%), with negative T waves representing 21% of all abnormalities. We found that abnormal axis (adjusted odds ratio: 3.9 [95% CI, 1.1-11.5], p = 0.02), and left bundle branch block (adjusted odds ratio: 7.1 [95% CI, 1.9-25.1], p = 0.002) were significantly associated with in-hospital mortality. CONCLUSIONS: ECG performed at ED admission may be useful to predict death in COVID-19 patients. Our data suggest that the presence of abnormal axis and left bundle branch block on ECG indicated a higher risk of in-hospital mortality in COVID-19 patients who presented to the ED. We also confirmed that ST segment elevation was rare in COVID-19 patients.

Value of the sodium-channel blocker challenge in Brugada syndrome.

AIMS: Intravenous drug challenge is frequently performed to unmask Brugada syndrome (BrS). However, its true sensitivity has never been assessed. We used the obligate BrS transmitters in families affected by BrS to evaluate the true accuracy of drug challenge. METHODS: All consecutive patients from 2000 to 2014 who underwent drug challenge during familial screening for BrS were included in the study. Obligate BrS transmitters were defined as the presence of a descendant and non-descendant first-degree relative affected by BrS. Two physicians blinded to the clinical and genetic status reviewed the data. RESULTS: Among 705 drug challenges performed in 149 families, 50 were performed in obligate transmitters from 42 different families. SCN5A mutations were identified in 20 families. Two obligate transmitters were not carrier of the familial mutation. Based on obligate transmitters, sensitivity was 100% for Ajmaline vs 77% for Flecainide (P=0.002). Based on the presence of the familial SCN5A mutation in all family relatives, sensitivity and specificity of sodium channel blocker challenge were respectively 78% (95/122) and 46% (68/148). During a median follow-up of 91 (26-136) months, 2 ventricular fibrillations occurred in obligate transmitters. CONCLUSION: We demonstrated that Ajmaline challenge presents an excellent sensitivity that may rule out the diagnosis of BrS when negative. Conversely, a negative Flecainide challenge may not prevent from Brs inheritance and risk of SCD. This may lead to suggest systematic use of Ajmaline during drug challenge.

Sodium-channel blocker challenge in the familial screening of Brugada syndrome: Safety and predictors of positivity.

BACKGROUND: Sodium-channel blocker challenge (SCBC) is frequently performed to unmask Brugada syndrome. OBJECTIVE: We aim to identify predictors of positivity and complications of SCBC in the setting of familial screening of Brugada syndrome. METHODS: All consecutive patients from 2000 to 2014 who benefit from a sodium-channel blocker and belong to a family with at least 2 subjects affected by the syndrome were enrolled and followed prospectively. Data were reviewed by 2 physicians blinded to the clinical and genetic status. RESULTS: Of the 672 SCBCs performed in 137 families, 337 (50%) were positive. Multivariate analysis identified ajmaline (odds ratio [OR] 2.98; 95% CI 1.65-4.91) and a significant S wave in lead DII (OR 3.11; 95% CI 2.12-4.58), DIII (OR 2.75; 95% CI 1.78-4.25), or V5 (OR 3.71; 95% CI 2.54-5.44) as predictors of a positive SCBC (P < .0001). Eleven patients (1.6%) presented complications (10 ventricular arrhythmias and 1 atrial flutter), but no deaths occurred. Familial history of complications (OR 41; lower quartile, upper quartile 10, 203; P < .0001), young age (P = .04), and decreased electrocardiographic conduction parameters at baseline (P = .04) were predictors of complications. QRS enlargement during SCBC was not associated with complications. During a median follow-up of 106 months (lower quartile, upper quartile 54, 143 months), 11 life-threatening arrhythmias occurred. CONCLUSION: SCBC in the screening of familial Brugada syndrome is safe. The risk of complication is considerably increased in the case of familial history of complicated SCBC, in young patients, and in the presence of decreased electrocardiographic conduction parameters. However, QRS enlargement during the test is not directly related to complications and should not be used to prematurely stop the test unless leading to false-negative results.