Holter monitoring in neuromuscular disorders: frequency and importance in clinical management

Abstract Introduction Cardiac involvement is a common manifestation in a variety of neuromuscular disorders (NMD) and initial cardiac manifestations in these patients are often asymptomatic. Hence, regular 24h-Holter monitoring is recommended to identify conduction disturbances and rhythm disturbances. Purpose In this study, we aimed to assess abnormal findings in 24h-Holter monitoring to screen for conduction disturbances and arrhythmias in patients with NMD and evaluate its impact in patients’ treatment. Methods A retrospective single-centre study was conducted including all adult patients with NMD who received a 24h-Holter from January 2013 to September 2023. Results A total of 76 patients with NMD were included, 39 (51.3%) were male, and mean age was 46,3 ± 11,5 years. Most patients were asymptomatic. A total of 220 Holter recording was analysed. An average of 2,9 ± 1,6 Holter recordings per patient was performed. Abnormal Holter results were found in 47 (61,8%) patients, and mainly consisted of conduction disorders such as atrioventricular block in 31 (65,9%) patients. Other abnormalities included atrial fibrillation/flutter in 6 (12,8%) patients, supraventricular tachycardia in 4 (8,5%) patients, and non-sustained ventricular tachycardia in 6 (12,8) patients. Out of the group of the patients with abnormal Holter findings, ten patients had direct clinical treatment consequences, namely implantation of cardiac electronic devices or initiation of anticoagulation therapy. Conclusion In this study, holter findings resulted in relevant clinical treatment consequences in 10 out of 76 patients (13,2%). These results suggest that 24h-Holter monitoring may improve routine cardiac screening in patients with NMD.