Arrhythmias & electrophysiology
Electrocardiogram vs Electrophysiological Study and Major Conduction Delays in Myotonic Dystrophy Type 1
Authors' conclusion
In this cohort of patients with DM1, the HV interval outperformed ECG criteria in predicting MBAEs.
Study context
- Population
- Adults with genetically confirmed myotonic dystrophy type 1 (DM1 Heart Registry, 2000–2020), first electrophysiological study (EPS) after 1999, no history of advanced AV block or sustained VTof 1778 registry adults
- Participants
- 706 adults
- Exposure
- EPS-based (His-ventricular (HV) interval) vs electrocardiogram (ECG)-based criteria for predicting major bradyarrhythmic events
- EPS criterionn = 273
- ECG criterian = 232reference
- Outcome
- Major bradyarrhythmic events:
- SCD
- Resuscitated cardiac arrest
- Second-degree type II or complete AV block
- Follow-up
- Median 5.9 years
Methodological detailsmulticentre, 6 French university hospitals, registry-based, Data analysed January to July 2025
- Multicentre
- 6 French university hospitals
- Registry-based
- Data analysed January to July 2025
Main finding
As reported in the abstract
MBAE · median (IQR) follow-up 5.9 (2.3-9.7) years
EPS criterion
68.35%
6.24%
performance index (sensitivity) [SE]
ECG criteria
34.76%
6.47%
performance index (sensitivity) [SE]
Hazard ratio (95% CI)P value
EPS criterionvs ECG criteriaEPS criterion as predictor of MBAE
2.89(1.92–4.34)
ECG criteriaECG criteria as predictor of MBAE
1.95(1.31–2.89)
HV intervalmultivariable Cox model; only variable significantly associated
1.77(1.46–2.16)
P < 0.001HV intervaljoint model with time-varying PR and QRS
1.78(1.40–2.22)
P = 0.001- MBAE incidence, all patients
- 99 patients (14%)
- EPS criterion accurately reclassified patients with an MBAE
- 28.8%
Observational data: associations, not effects.
Further findings
| Outcome | Values | Net reclassification improvement (95% CI) |
|---|---|---|
| MBAE prediction with lowered HV threshold (HV greater than or equal to 65 milliseconds) | HV greater than or equal to 65 milliseconds performance index 90.18% (SE 3.85%) | 33.7% (19.6%–48.2%) |
MBAE prediction with lowered HV threshold (HV greater than or equal to 65 milliseconds)
- Lowering the threshold to HV greater than or equal to 65 milliseconds further improved sensitivity and net reclassification improvement for MBAE prediction
Original publication
Electrocardiogram vs Electrophysiological Study and Major Conduction Delays in Myotonic Dystrophy Type 1. JAMA Cardiol. Published 1 November 2025. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →