Long QT syndrome (LQTS) is a potentially lethal cardiac channelopathy with 1% to 5% annual risk of LQTS-triggered syncope/seizures or sudden arrest/death (SCA/SCD). Despite maximal LQTS-directed therapies, subset patients experience breakthrough events (BCEs). To describe the phenotype “non-responders” defined as LQTS recurrent BCEs despite therapy. Among 1731 evaluated and treated at Mayo Clin...

The long QT syndrome affects predominantly younger people who demonstrate structurally normal hearts. The underlying defect in the long QT syndrome seems to be genetic mutations in the cardiac ionic channels responsible for generating action potentials. Genetic linkage mapping has identified six genes (designated LQT1-6) associated with the Romano-Ward syndrome; two of these genes (LQT1, LQT5) ...

T he long QT interval syndrome (LQTS) has a low incidence in the general population, but, like the Wolff-Parkinson-White (WPW) syndrome , it has a major impact. While the WPW syndrome is the Rosetta stone of reentry, the LQTS may be the Rosetta Stone for ventricular tachyar-rhythmias dependent on sympathetic stimulation. Present Study In a recent issue of Circulation, Schwartz et all provided f...

Nothing is easy for ion channels that assemble with membrane-embedded regulatory subunits. Something as trivial yet as fundamental as counting the number of subunits in an ion channel complex can be challenging and marred with controversy. The most infamous stoichiometric debate in the ion channel field has been over the potassium (K) channel complex that generates the repolarizing cardiac IKsl...

INTRODUCTION Long QT-syndrome (LQTS) is a genetic cardiac channelopathy characterised by a prolonged QT interval on a surface electrocardiogram (ECG), syncope, T-wave abnormalities, ventricular tachycardia of the torsades de pointes (TdPVT) type (Fig. 1) and an increased risk of sudden death [1]. LQTS has variable clinical presentation and is genetically characterised by incomplete penetrance, ...

TRUNIGER, BRUNO, AND BODIL SCHMIDT-NIELSEN. Intrarenal distribution of urea and related compounds: effects of nitrogen intake. Am. J. Physiol. 207(s) : 971-978. rg64.-Nitrogen and NaCl intake influence the excretion of urea. In rats maintained on a low-protein, high-salt intake the urea-to-inulin clearance ratio decreases to 0.01. In antidiuretic “low-protein” rats the urea concentrations in th...

Approximately unbiased tests based on bootstrap probabilities are considered for the exponential family of distributions with unknown expectation parameter vector, where the null hypothesis is represented as an arbitraryshaped region with smooth boundaries. This problem has been discussed previously in Efron and Tibshirani [Ann. Statist. 26 (1998) 1687–1718], and a corrected p-value with second...

cornelia de lange syndrome (cdls) is an uncommon multiple congenital anomaly with unknown cause and recurrent risk and may be the result of an inheritance metabolic error. in classical form of the syndrome there is a recognizable facial appearance at birth although in children with mild disease this may be less obvious at birth but become more noticeable over the first three years of life. in t...