Résumé :
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Mutations in LMNA gene, encoding lamin A/C, have been associated with a high risk of sudden death. The implant of a cardioverter defibrillator (ICD) is to date the only effective intervention, but no specific guidelines are available. To define a risk stratification protocol for ICD implant, we designed a clinical trial that may in the future involve other italian centers. Patients bearing LMNA alterations are subjected to extensive cardiological examination, including ECG, Holter monitoring, electro-physiological study (EPS), echocardiogram and heart MRI. In addition, neurological evaluation and cutaneous biopsy are performed and family history collected. Patients are advised to undergo ICD or Reveal implant according to proposed indications and are re-evaluated every six months for at least 5 years. Major arrhythmic events (MAE: arrhythmic syncope, cardiac arrest, appropriate ICD shock) occurring during follow-up will be compared in the two groups to evaluate the effectiveness of risk stratification performed. Moreover, the efficacy of different clinical variables as predictors of MAE and the benefits/ adverse events ratio among ICD patients will be evaluated. To date, 9 patients were enrolled (age 39±13), six displaying cardiac symptoms. Four patients were given the indication to implant ICD. Interestingly, exams performed in these patients highlighted some common features, revealing underlying defects in initial stages of cardiac disease. Indeed, while none of our patients developed sustained ventricular tachycardia during EPS, two showed a prolongation of the AH interval after injection with Verapamil, a calcium antagonist able to reveal intranodal conduction defects. In one case this result was associated with alterations at heart MRI, revealing initial features of DCM with areoles of fibrotic substitution in the conduction tissue. Notably, this patient was asymptomatic except for bradicardia. Follow-up will allow to correlate these results with increased risk of MAE, therefore better addressing the use of ICD in LMNA mutated patients.
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