SPC365

24h-Holter monitoring in Myotonic Dystrophy type 1 follow-up: Is it really needed?

Session: Sessão de Posters 16 - Arritmologia
Speaker: Sofia Nogueira Fernandes

Congress: CPC 2024
Topic: C. Arrhythmias and Device Therapy
Theme: 04. Arrhythmias, General
Subtheme: 04.6 Arrhythmias, General – Clinical
Session Type: Cartazes
FP Number: ---
Authors: Sofia Nogueira Fernandes; Mónica Dias; Inês Macedo Conde; Rodrigo Silva; Carla Ferreira; Filipe Silva; Fernando Mané; Ricardo Maré; Jorge Marques; Sérgia Rocha

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt">Introduction:</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt">Myotonic dystrophy (DM1) is a hereditary neuromuscular disease with frequent cardiac involvement. Cardiac conduction tissue involvement is frequent and is often progressive and asymptomatic. Therefore, regular 24h-Holter monitoring is recommended to identify conduction disturbances and arrhythmias. </span></span></span></p>

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<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt">Aims:</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt">In this study, we aimed </span><span style="font-size:10.0pt">to evaluate the clinical effectiveness of 24h-Holter monitoring to screen for <em>de novo</em> conduction disturbances and arrhythmias in patients with genetic diagnosis of DM1 and evaluate its impact in patients&rsquo; treatment. </span></span></span></p>

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<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt">Methods:</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt">A retrospective single-centre study was conducted including all adult patients with DM1 who received a 24h-Holter from January 2013 to September 2023. Holter findings were compared with the results of cardiac screening based on history taking and </span></span></span><span style="font-size:10.0pt"><span style="font-family:&quot;Calibri&quot;,sans-serif">electrocardiography</span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt">. Arrhythmias and/or conduction abnormalities that would have remained otherwise undiagnosed were considered <em>de novo</em> findings. </span></span></span></p>

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<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt">Results:</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt">A total of 46 genetically confirmed DM1 patients were included, 52,2% were male, and mean age was 48,0 &plusmn; 10,0 years. All patients were asymptomatic. A total of 144 Holter recording was analysed. An average of 3,1 &plusmn; 1,7 Holter recordings per patient were&nbsp;performed. </span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt">Abnormal Holter results were found in 31 (67,4%) patients, including first and second-degree atrioventricular block, atrial fibrillation/flutter and non-sustained ventricular tachycardia. Mean follow-up of 70,8 &plusmn; 34,9 months. Abnormalities mainly consisted of conduction disorders (80,6%) such as AV block. Out of the 31 patients with abnormal Holter findings, 23 (74,2%) patients had <em>de novo</em> Holter findings, with clinical treatment consequences in five of them. &nbsp;</span></span></span></p>

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<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt">Conclusion:</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt">These results suggest that 24h-Holter monitoring may improve routine cardiac screening in patients with DM1. <em>De novo</em> Holter findings added value to disease management in 10,9% of our patients. </span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt">Cardiac involvement screening in this population is challenging and DM1-specific recommendations are still needed to improve cardiac care of this population.</span></span></span></p>