SPC365

Ajmaline provocative test in the diagnosis of Brugada syndrome - what to expect?

Session: Posters (Sessão 3 - Écran 4) - Morte súbita cardíaca
Speaker: ANGELA MARGARIDA MARTINS DE CASTRO

Congress: CPC 2023
Topic: C. Arrhythmias and Device Therapy
Theme: 08. Ventricular Arrhythmias and Sudden Cardiac Death (SCD)
Subtheme: 08.7 Ventricular Arrhythmias and SCD - Other
Session Type: Pósters Electrónicos
FP Number: ---
Authors: Margarida De Castro; Filipa Cardoso; Tamara Pereira; Mariana Tinoco; Luísa Pinheiro; Margarida Oliveira; Bebiana Faria; Lucy Calvo; João Português; Sílvia Ribeiro; Victor Sanfins; António Lourenço

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="font-size:12pt"><strong><span style="font-size:10.0pt">Introduction</span></strong><span style="font-size:10.0pt">: The diagnostic type 1 ECG pattern in Brugada syndrome (BrS) is often concealed and may occur either spontaneously or induced by sodium channel blocking drugs or fever. </span></span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="font-size:12pt"><strong><span style="font-size:10.0pt">Purpose</span></strong><span style="font-size:10.0pt">: The aim of this study was to describe and identify predictors of a positive ajmaline test.</span></span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="font-size:12pt"><strong><span style="font-size:10.0pt">Methods:</span></strong><span style="font-size:10.0pt"> Retrospective single-center study of 192 individuals with suspected BrS</span> <span style="font-size:10.0pt">that underwent ajmaline test between June 2017 and May 2022. Differences in positive and negative groups regarding clinical and electrocardiographic variables were analysed. Binary logistic regression was conducted to identify predictors of a positive response. </span></span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="font-size:12pt"><strong><span style="font-size:10.0pt">Results:</span></strong><span style="font-size:10.0pt"> From our 192 patients (pts), 87% (N=167) underwent testing in the context of familial screening for BrS and 13% (N=25) for initial assessment of a suspicious pattern. Mean follow-up (FU) was 21&plusmn;15 months.</span></span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="font-size:12pt"><span style="font-size:10.0pt">Ajmaline test was positive in 58,3% of all cases and in 52,7% of the pts with family history. </span></span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="font-size:12pt"><span style="font-size:10.0pt">Of the 25 <em>index</em> cases who underwent ajmaline test, 12 were asymptomatic and all of them had a positive ajmaline test.</span></span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="font-size:12pt"><span style="font-size:10.0pt">Pts with a positive ajmaline test were 45,5% male with a mean age of 45&plusmn;15 years old; 33,9% had previous symptoms. On basal ECG, 34,8% had a type 2 or 3 ECG pattern, 2,7% complete and 20,5% incomplete right bundle branch block. Genetic test was positive in 17%. Because they had suspicious symptoms or had developed spontaneous type 1 pattern during FU, 11 pts underwent electrophysiological study of which 2 had ventricular arrhythmias (VA). &nbsp;An implantable cardiac defibrillator was implanted in 5 pts of which 3 had VA during FU. </span></span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="font-size:12pt"><span style="font-size:10.0pt">In univariate analysis, a positive test was associated with the presence of previous symptoms (<em>p</em>=0,038). No differences in other clinical variables were found. Regarding electrocardiogram, positive ajmaline test was related to non-type 1 ECG pattern (<em>p</em>&lt;0,001), positive R-wave sign in aVR (<em>p</em>=0,011) and QRS fragmentation (<em>p</em>=0,001). </span></span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="font-size:11pt"><span style="font-size:10.0pt">Positive R-wave sign (OR= 9,14; <em>p</em>=0,001) and previous symptoms including syncope, nocturnal agonic breathing and/or palpitations (OR = 2,22; <em>p</em>=0,20) were identified as predictors for a positive ajmaline test.&nbsp; </span></span></span></p>

<p style="text-align:justify"><span style="font-family:Arial,Helvetica,sans-serif"><span style="font-size:12pt"><strong><span style="font-size:10.0pt">Conclusions: </span></strong><span style="font-size:10.0pt">Although the ajmaline test is no longer recommended in asymptomatic pts with no family history of BrS, the number of positive tests in this population was high. The meaning of its prognostic impact requires longer FU. In addition, there are electrocardiographic criteria that can guide the selection of pts for this exam.</span></span></span></p>