Some normal-hearing carriers of heterozygous missense variants of KCNE1 and KCNQ1 have prolonged QT intervals, a dominantly inherited phenotype designated Romano-Ward syndrome (RWS), which is also associated with arrhythmias and elevated risk of sudden death.
Transient myocardial ischemia may have exaggerated the instability from the arrhythmic substrate, even though KCNE1-D85N abnormalities alone are not thought to cause fatal arrhythmias.
Patients with KCNE1(G38S) had a rate-dependent repolarization abnormality similar to patients with LQT2 and, therefore, may have a potential risk to develop lethal arrhythmias.
We have created a novel transgenic LQT5 rabbit model with increased susceptibility to drug-induced arrhythmias that may represent a useful model for testing proarrhythmic potential and for investigations of the mechanisms underlying arrhythmias and sudden cardiac death due to repolarization disturbances.
Mutations in either KCNQ1 or KCNE1 genes lead to life-threatening cardiac arrhythmias causing long QT syndrome, short QT syndrome, sinus bradycardia and atrial fibrillation.
KCNE1, a membrane protein that spans the membrane once is responsible for modulating potassium channel functions and plays an important role in the etiology of arrhythmia.
Rate-dependent facilitation of K(+) conductance, a key property of I(Ks) that enables action potential shortening at higher heart rates, was defective for both KCNE1 C-terminal mutations, and may contribute to the clinical phenotype of arrhythmias triggered by heart rate elevations during exercise in LQTS mutations.
We demonstrate that each additional copy of the KCNE1D85N minor allele is associated with a considerable 10.5 ms prolongation of the age-, gender- and heart rate-adjusted QT interval and could thus modulate repolarization-related arrhythmia susceptibility at the population level.
KCNE1 encodes the beta-subunit of cardiac voltage-gated K(+) channels and causes LQTS, which is characterized by the prolongation of the QT interval and torsades de pointes, a lethal arrhythmia.
To detect single nucleotide polymorphisms (SNP) in SCN5A, KCNQ1 and KCNE1 of post-MI patients, and to assess whether they are related to electrophysiological markers of cardiac arrhythmia (QT interval) and the clinical course.
Because KVLQT1 mutations cause arrhythmia susceptibility in the long QT syndrome (LQT), we hypothesized that mutations in KCNE1 also cause this disorder.