Hereditary rhythm disorders

Carried by: CARDIOGEN

References:

Clinician(s): Vincent PROBST, ISabelle DENJOY

Biologist(s): Florence KYNDT, Véronique FRESSART

Presentation

Heart rhythm disorders are one of the leading causes of sudden death in young people.

These electrical disorders in a structurally healthy heart are often genetic in origin, with autosomal dominant transmission being the most common, and more than 30 genes involved.

After targeted panel analysis, more than 50% of families remain without a genetic diagnosis.

Criteria before considering a discussion in MDM-FMG

Long QT syndrome: QTc (QT corrected for heart rate) >440 ms for men and 460 ms for women on ECG. (Schwartz clinical score > 3).
Short QT syndrome: QTc (QT corrected for heart rate) <330 ms or <360 ms (350 ms in men and 365 ms in women) on ECG.
Brugada syndrome: spontaneous type 1 on ECG (J point elevation of more than 0.2 mV with an upward convex ST segment shift followed by a negative T wave in at least one right lead (V1 and V2) or pharmaco-induced after ajmaline test.
Catecholaminergic ventricular tachycardias: polymorphic adrenergic ventricular arrhythmia on ECG (Holter, stress test or pharmacological tests).
Cardiac conduction disorders: major cardiac conduction abnormality on ECG (complete right bundle branch block, complete left bundle branch block, left anterior fascicular block, hemiblock, prolonged PR interval, complete atrioventricular block with wide QRS complexes, complete AV block).
Early repolarisation syndrome: specific ECG appearance (elevation of the J wave peak (positive deflection after the QRS) >0.1mV in at least 2 inferior and/or lateral leads, hook-shaped or blunted) associated with syncope, ventricular fibrillation, recovered sudden death or a family history of sudden death.