RESUMO
Background: Lamin A/C-associated heart disease is a group of clinical entities characterized by a mutation in the LMNA gene. Multiple cardiac phenotypes have been described, including a higher risk of sudden death. Case summary: A 23-year-old asymptomatic patient with an extensive history of heart disease in the family consulted the clinic. He had a genetic test performed when he was born revealing a new frameshift mutation in the LMNA gene. Numerous cardiac function tests were ordered, which initially were normal. After a year of follow-up, Holter monitoring was positive for episodes of nonsustained ventricular tachycardia (NSVT). Because of the risk factors and higher likelihood of sudden death, a decision was made to offer an implantable cardiac defibrillator (ICD), which was performed without complications. The patient continues the follow-up with cardiology and electrophysiology consisting of yearly cardiac imaging and device recordings. Discussion: Lamins are nuclear proteins involved in various cellular processes in myocardial cells. Therefore, mutations are associated with wide phenotypic alterations. The mutation described here was not previously reported in the literature. In the face of an undescribed mutation, the decision to use an ICD for primary prevention of sudden death is challenging. Because of the episodes of NSVT and a higher likelihood of risk of sudden death due to male sex and first-degree atrioventricular block, the decision to use an ICD was made for this patient, with no complications.
RESUMO
Abstract: The transvenous implantable cardiac defibrillator (T-ICD) is currently considered the standard of care for prevention of sudden cardiac death in patients with structural cardiac disease or channelopathies. However, the use of these devices is associated with a significant increase of short and long-term complications, mostly related to intravascular leads. The subcutaneous implantable cardiac defibrillator (S-ICD) is a novel alternative for high-risk patients susceptible to intravascular lead complications, with a similar efficacy as T-ICD. Multiple ongoing clinical trials involving the S-ICD are expected to provide additional information about safety, use and benefits in the clinical setting.
Resumen: El desfibrilador cardiaco implantable transvenoso (DCI-T) se considera actualmente el tratamiento estándar para la prevención de la muerte súbita cardiaca en pacientes con enfermedad cardiaca estructural o canalopatías. Sin embargo, el uso de estos dispositivos se asocia con un aumento significativo de complicaciones a corto y largo plazo, principalmente relacionadas con derivaciones intravasculares. El desfibrilador cardiaco implantable subcutáneo (DCI-S) es una alternativa novedosa para pacientes de alto riesgo susceptibles a complicaciones intravasculares, con una eficacia similar al DCI-T. Se espera que varios ensayos clínicos en curso que involucran al DCI-S brinden información adicional sobre seguridad, uso y beneficios en el entorno clínico.
RESUMO
BACKGROUND: Myocardial fibrosis (MF) occurs in up to 80% of subjects with asymptomatic or mildly symptomatic hypertrophic cardiomyopathy (HCM) and can constitute an arrhythmogenic substrate for re-entrant, life-threatening ventricular arrhythmias in predisposed persons. OBJECTIVE: The aim was to investigate whether MF detected by delayed enhancement cardiac CT is predictive of ventricular tachycardia (VT) and fibrillation (VF) that require appropriate therapy by an implantable cardioverter defibrillator (ICD) in patients with HCM. METHODS: Twenty-six patients with HCM with previously (for at least 1 year) implanted ICD underwent MF evaluation by cardiac CT. MF was quantified by myocardial delayed enhanced cardiac CT. Data on ICD firing were recorded every 3 months after ICD implantation. Risk factors for sudden cardiac death in patients with HCM were evaluated in all patients. RESULTS: MF was present in 25 of 26 patients (96%) with mean fibrosis mass of 20.5 ± 15.8 g. Patients with appropriate ICD shocks for VF/VT had significantly greater MF mass than patients without (29.10 ± 19.13 g vs 13.57 ± 8.31 g; P = .01). For a MF mass of at least 18 g, sensitivity and specificity for appropriate ICD firing were 73% (95% CI, 49%-88%) and 71% (95% CI, 56%-81%), respectively. Kaplan-Meier curves indicated a significantly greater VF/VT event rate in patients with MF mass ≥18 g than in patients with MF <18 g (P = .02). In the Cox regression analysis, the amount of MF was independently associated with VF/VT in ICD-stored electrograms. CONCLUSION: The mass of MF detected by cardiac CT in patients with HCM at high risk of sudden death was associated with appropriate ICD firings.