Reciprocated tachycardias in cardiac laminopathy: a clinical case report.

Background: Cardiac laminopathies, associated with mutations in the LMNA gene, are a rare inherited disorder characterized by a broad range of clinical manifestations. There are currently no data on the association between supraventricular re-entrant tachycardias and LMNA-related cardiomyopathy.

Case summary: A 26-year-old male presented with either wide-QRS tachycardia with a left bundle branch block (LBBB) pattern or narrow QRS tachycardia, as well as a history of palpitations since age 15. Echocardiography showed no overt structural heart disease. Electrophysiological studies confirmed the diagnosis of orthodromic atrioventricular re-entrant tachycardia mediated by a concealed left posterolateral accessory pathway (AP), with transient LBBB and dual AV-node physiology, characterized by single echo beats. A short-run, asymptomatic episode of atrial fibrillation was induced. Cardiac magnetic resonance (CMR) imaging demonstrated myocardial hyperaemia, subepicardial late gadolinium enhancement, and a small pericardial effusion, initially interpreted as myocarditis according to the modified Lake Louise criteria. A family history of pacemaker implantation and cardiac death at age 65 of the patient's grandfather, a history of re-entrant arrhythmia recurrence following ablation, and further CMR deteriorations led to genetic counselling. Genetic testing identified a heterozygous pathogenic variant in the LMNA gene (NM_170707.3.456_457insTCTC, NP_733821.1.Glu154GlnfsX2), classified as likely pathogenic and associated with laminopathy.

Discussion: This case raises the question of whether the combination of re-entrant arrhythmias is coincidental or an early indicator of LMNA-related cardiomyopathy.