Who Are the Long-QT Syndrome Patients Who Receive an Implantable Cardioverter-Defibrillator and What Happens to Them?

Abstract

Background-A rapidly growing number of long-QT syndrome (LQTS) patients are being treated with an implantable cardioverter-defibrillator (ICD). ICDs may pose problems, especially in the young. We sought to determine the characteristics of the LQTS patients receiving an ICD, the indications, and the aftermath. Methods and Results-The study population included 233 patients. Beginning in 2002, data were collected prospectively.Female patients (77%) and LQT3 patients (22% of genotype positive) were overrepresented; mean QTc was 516Ϯ65 milliseconds; mean age at implantation was 30Ϯ17 years; and genotype was known in 59% of patients. Unexpectedly, 9% of patients were asymptomatic before implantation. Asymptomatic patients, almost absent among LQT1 and LQT2 patients, represented 45% of LQT3 patients. Patients with cardiac symptoms made up 91% of all study participants, but only 44% had cardiac arrest before ICD implantation. In addition, 41% of patients received an ICD without having first been on LQTS therapy. During follow-up, 4.6Ϯ3.2 years, at least 1 appropriate shock was received by 28% of patients, and adverse events occurred in 25%. Appropriate ICD therapies were predicted by age Ͻ20 years at implantation, a QTc Ͼ500 milliseconds, prior cardiac arrest, and cardiac events despite therapy; within 7 years, appropriate shocks occurred in no patients with none of these factors and in 70% of those with all factors. Conclusions-Reflecting previous concepts, ICDs were implanted in some LQTS patients whose high risk now appears questionable. Refined criteria for implantation, reassessment of pros and cons, ICD reprogramming, and consideration for other existing therapeutic options are necessary. (Circulation. 2010;122:1272-1282.)

A 26-Year-Old Woman with Recurrent Loss of Consciousness

“…A third treatment option is the ICD, for which small studies suggest excellent protective benefit 30,31 . ICDs are best reserved for the highest risk patients, including females with LQT2 32,33 . Risk factors for increased mortality have been identified, and differ according to age group.…”

The role of sympathectomy in long QT syndrome

“…With this in mind, data from the European Long-QT syndrome implantable cardioverter-defibrillator (LQTS ICD) registry were gathered and a novel scoring system was proposed to properly select the patients who may benefit from an ICD implantation (11).…”

El síndrome de QT largo en anestesia. Una revisión a partir de un caso clínico

“…Teórica-mente, estos pacientes pudieran beneficiarse con el uso de antiarrítmicos de clase I como flecainida y mexiletina, que bloquean los canales de sodio, aunque la evidencia aún es limitada 37,38 . Por último, en los pacientes de mayor riesgo, que no responden bien al betabloqueo o que ya han tenido un episodio de paro cardiocirculatorio recuperado, se indican procedimientos más invasivos como la denervación cardiaca izquierda vía toracotomía, que consiste en la extirpación de los primeros cuatro ganglios torácicos 39 , y/o la implantación de un cardiodesfibrilador [40][41][42] . Estos procedimientos se realizan excepcionalmente en pacientes muy seleccionados…”