Defibrillation Threshold Testing: Current Status

Abstract

When the transvenous ICD initially came into use for primary and secondary prevention of sudden cardiac death, defibrillation threshold (DFT) testing was universally performed. However, DFT testing is no longer routinely recommended for transvenous ICD implantation except in certain situations. Risk scores can help guide the decision to perform DFT testing. The subcutaneous ICD represents an area of uncertainty, with limited data available regarding the role of DFT testing in these devices. Current guidelines give a class I recommendation for performing DFT testing at the time of implant. Further studies are needed before this recommendation can be safely dismissed.

Teste de Limiar de Desfibrilação e Seguimento a Longo Prazo de Pacientes com Cardiopatia Crônica da Doença de Chagas

“…Nosso protocolo para o teste de LDF evoluiu ao longo de duas décadas, refletindo os avanços na tecnologia dos CDIs, conforme relatado anteriormente. 18 Identificamos que apenas 3% da nossa amostra apresentava LDF elevado, resultado próximo ao dos valores mais baixos encontrados na literatura, entre 2,2 e 12%. 10 Esse achado original indica que, embora apresentem miocárdio com fibrose extensa, os pacientes com CCDC podem não representar uma população que necessite de muitos ajustes durante um procedimento de implante de CDI.…”

Omdlenie i elektrokardiograficzne podejrzenie zawału serca z uniesieniem odcinka ST nad ścianą przednią – pomyśl o zespole Brugadów!

“…Due to possible significant adverse events, routine DT testing is no longer recommended in all patients at the time of ICD implantation [6]. However, it is reasonable to perform the test, if there are risk factors for high DT, like young age, high body mass index, non-ischemic cardiomyopathy or congenital heart diseases [6,7].…”

“…According to a recommendation, this symptomatic patient was qualified for ICD implantation [5] and additionally, he was advised prompt treatment of any fever with antipyretic drugs [3,5]. Routine DT testing is no longer recommended in all patients with ICD and subcutaneous electrode implantation may be a useful method of lowering DT [6][7][8].…”

Perioperative considerations during implantation of the subcutaneous defibrillator: State‐of‐the‐art review

“…Antiplatelets may be held if there is no history of recent coronary intervention, myocardial infarction, or stroke. Class 1B sodium channel blockers and amiodarone tend to increase defibrillation thresholds 26 and may need to be adjusted.…”