Twisting until it breaks: A rare cause of ICD lead failure

We describe a rare case of Twiddler’s syndrome that resulted in a complex ICD lead fracture involving both the insulation and the conductor. The conductor fracture resulted in noise artefact that was interpreted by the device as ventricular fibrillation, but the patient had not received any shocks because the "episodes" were non-sustained. The patient did not have traditional risk factors for Twiddler’s syndrome

Pęknięcie na skutek skręcenia: rzadki przypadek uszkodzenia elektrody defibrylującej kardiowertera-defibrylatora serca

W niniejszej pracy opisano rzadki przypadek wystąpienia twiddler syndrome, który był przyczyną złożonego uszkodzenia elektrody kardiowertera-defibrylatora serca dotyczącego zarówno izolacji, jak i przewodnika. Pęknięcie przewodnika spowodowało wytworzenie szumu, który został zinterpretowany przez urządzenie jako migotanie komór, ale nie wystąpiło żadne wyładowanie, ponieważ epizody trwały krótko. U pacjenta nie stwierdzono czynników ryzyka typowych dla twiddler syndrome

A common single nucleotide polymorphism can exacerbate long-QT type 2 syndrome leading to sudden infant death

BACKGROUND: Identification of infants at risk for sudden arrhythmic death remains one of the leading challenges of modern medicine. We present a family in which a common polymorphism (SNP) inherited from the father combined with a stop codon mutation inherited from the mother, both asymptomatic, leads to two cases of sudden infant death. METHODS AND RESULTS: KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2, CACNA1c, CACNB2b, and KCNJ2 genes were amplified and analyzed by direct sequencing. Functional electrophysiological studies were performed with the SNP and mutation expressed singly and in combination in Chinese ovary (CHO-K1) and COS-1 cells. An asymptomatic female presenting after death of her 2 day old infant and spontaneous abortion of a second baby in the first trimester was referred for genetic analysis. The newborn had nearly incessant had nearly incessant ventricular tachycardia while inn-utero and prolonged QTc (560ms) The mother was asymptomatic but displayed a prolonged QTc. Genetic screening of the mother revealed a heterozygous nonsense mutation (P926AfsX14) in KCNH2, predicting a stop codon. The father was asymptomatic with a normal QTc, but had a heterozygous polymorphism (K897T) in KCNH2. The baby who died at 2 days of age and the aborted fetus inherited both K897T and P926AfsX14. Heterologous co-expression of K897T and P926AfsX14 led to loss of function of HERG current much greater than expression of K897T or P926AfsX14 alone. CONCLUSIONS: Our data suggest that a common polymorphism (K897T) can markedly accentuate the loss of function of mildly defective HERG channels leading to long QT syndrome-mediated arrhythmias and sudden infant death