TEST CHARACTERISTICS 2.1 Analytical sensitivity (proportion of positive tests if the genotype is present) Close to 100% if complete Sanger sequencing and MLPA of the affected gene is performed. [nature.com]

D85N is a polymorphism in the KCNE1 gene, present in 0.7–1% of the general population ( 41 ). [frontiersin.org]

The age at presentation of patients with c-LQTS varies from in utero to adulthood. [anesthesiology.pubs.asahq.org]

Given the characteristic features of LQTS, the typical cases present no diagnostic difficulties for physicians aware of the disease. [ojrd.biomedcentral.com]

• Pertussis

  Despite the FDA’s warning, azithromycin obviously continues to have an important role in treating certain infections (especially pertussis) in the pediatric population. [uspharmacist.com]

• Severe Clinical Course

  Even though the clinical diagnosis of J-LN is rather straightforward, it is important to genotype all these patients because it has been shown by Schwartz et al. [ 3 ] that the smaller group with KCNE1 mutations has a markedly less severe clinical course [ojrd.biomedcentral.com]

• Small Teeth

  LQTS8 Also known as Timothy syndrome (TS), patients show severe QT prolongation on their ECGs, which is combined with syndactyly, baldness at birth, and small teeth in 100% of cases and less penetrant cardiac structural malformations, mental retardation [frontiersin.org]

• Normal Hearing

  Subsequent descriptions of an almost identical condition aside from normal hearing were made in 1963 by Romano (2) and 1964 by Ward (3), who described multiple individuals from two distinct families affected by recurrent ventricular fibrillation, a condition [rarediseases.org]

  hearing, later called Romano-Ward syndrome. [en.wikipedia.org]

• Phenylketonuria

  Issues in newborn screening for phenylketonuria. Am Fam Physician. 1999;60:1462-1466. 12. Leslie LK, Rodday AM, Saunders TS, et al. Cardiac screening prior to stimulant treatment of ADHD: a survey of US-based pediatricians. [uspharmacist.com]

[…] the systemic circulation. [1] Clinically, the syndrome is characterized by rapid development of hyperuricemia,hyperkalemia, hyperphosphatemia, hypocalcemia, and acute kidney injury. [2, 3] (See Pathophysiology, Etiology, Prognosis, Presentation, and Workup [emedicine.medscape.com]

• Hypercapnia

  […] could theoretically prolong the QT interval through prolonged recovery of inactivated sodium channels. 39 No matter what anesthetic technique is used, light or insufficient anesthesia, hypertension, bradycardia, tachycardia, hypoxemia, and hypocapnia or hypercapnia [anesthesiology.pubs.asahq.org]

• Hypocapnia

  […] hypothermia could theoretically prolong the QT interval through prolonged recovery of inactivated sodium channels. 39 No matter what anesthetic technique is used, light or insufficient anesthesia, hypertension, bradycardia, tachycardia, hypoxemia, and hypocapnia [anesthesiology.pubs.asahq.org]

• Prolonged QT Interval

  Both of these agents, in this investigation, were given by infusion to sixteen patients with congenitally prolonged QT intervals and9 healthy controls. [aaaai.org]

  Without a standardized screening program for LQTS in the U.S., pharmacists might be expected to presuppose that any given patient could be the estimated one in 2,500 who is predisposed to a prolonged QT interval. [uspharmacist.com]

  Complications Most of the time, prolonged QT intervals in people with long QT syndrome never cause problems. However, physical or emotional stress might "trip up" a heart that is sensitive to prolonged QT intervals. [mayoclinic.org]

  However, the diagnosis of LQTS can be challenging since around 2.5% of the healthy population have prolonged QT-interval while some of LQTS patients do not exhibit abnormal ECG findings. [asperbio.com]

  Overview People with LQTS have prolonged QT intervals on their ECGs. The QT interval represents repolarization, or "recharge," of a cardiac cell. [verywell.com]

• Early Repolarization

  "ST-segment elevation in the early repolarization syndrome, idiopathic ventricular fibrillation, and the Brugada syndrome: cellular and clinical linkage". J Electrocardiol. vol. 38. 2005. pp. 26-32. [thecardiologyadvisor.com]

  Long QT syndrome (LQTS), short QT syndrome (SQTS), sick sinus syndrome (SSS), cardiac conduction defect (CCD), BrS, catecholaminergic polymorphic ventricular tachycardia (CPVT), early repolarization syndrome (ERS), and familial Atrial Fibrillation (AF [frontiersin.org]

• Ventricular Repolarization Abnormalities

  RESULTS: Compared with the analysis of the healthy group (n 8), age- and sex-matched pair analysis revealed that the mutation carriers (n 8) had ventricular repolarization abnormality results in the prolongation of corrected QT and QTpeak intervals (P [ncbi.nlm.nih.gov]

Recent studies suggest feasibility of genotype specific treatment of LQTS and, in near future, mutation specific treatment will probably become a novel approach to this potentially fatal syndrome. [jtd.amegroups.com]

The ICD is the remaining treatment option. A device is implanted that includes a computer, battery, and leads that are attached to the heart. [athletesheart.org]

With this innovative discovery of a new treatment in long QT syndrome 2, it marks a big step towards personalised medicine. "Currently, we have been successful in providing a medicine to treat long QT syndrome 2. [news-medical.net]

Standard Therapies Treatment is aimed at preventing symptoms such as syncope or cardiac arrest. [rarediseases.org]

Treatment and Management LQTS treatment may include medications, medical devices or surgery, or simple lifestyle changes. [uspharmacist.com]

[…] and metabolic byproducts into the systemic circulation. [1] Clinically, the syndrome is characterized by rapid development of hyperuricemia,hyperkalemia, hyperphosphatemia, hypocalcemia, and acute kidney injury. [2, 3] (See Pathophysiology, Etiology, Prognosis [emedicine.medscape.com]

[…] may experience symptoms from as early as the first months of life to as late as middle age. 2 LQTS can be detected in children through ECG, although widespread routine screening in asymptomatic patients is not currently recommended in the U.S. 7 The prognosis [uspharmacist.com]

Prognosis of LQTS in Children Previous reports showed that males with LQTS before the age of 15 years have a significant increased risk of syncope, aborted cardiac arrest, and sudden cardiac death. 12 However, the risk of these cardiac events is inverted [jstage.jst.go.jp]

Prognosis LQTS is a life-long condition. Individuals who are not diagnosed and treated are at an increased risk of syncope and sudden death. Adequate treatment can decrease this risk. There is no cure. [medical-dictionary.thefreedictionary.com]

In addition to an improved prognosis, we can better prepare for changes in a patient’s condition and triage them to more appropriate receiving facilities. How Do I Detect LQTS? As the name implies, simply measure the QT/QTc interval. [emsworld.com]

Etiology Tumor lysis syndrome occurs most often in patients with acute leukemia with high white blood cell (WBC) counts and in those with high-grade lymphomas in response to aggressive treatment. [emedicine.medscape.com]

Physicians must remain vigilant and consider LQTS as a possible etiology in patients with a history of syncope. [radcliffecardiology.com]

Management of Polymorphic VT (PMVT) Non-Torsades Etiologies of PMVT (normal QT) Most commonly due to ischemia. These will almost always be overt, severe episodes of ischemia, with chest pain and/or unequivocal ischemic ECG abnormalities. [hqmeded-ecg.blogspot.com]

[…] taught in most EMS curricula and may be overlooked. 1 This condition is identified by a long QT interval on an electrocardiogram (ECG) and may be congenital or medication-induced. 2 An increasing number of sudden cardiac arrests with previously unknown etiology [emsworld.com]

Reed Kl: Fetal arrhythmias, etiology, diagnosis, pathophysiology and treatment. Semin Perinatol 1989;13:294–304. [karger.com]

and 3) patients with implantable cardioverter-defibrillators (ICD)s. 2 On the other hand, for European athletes with LQTS, sports participation is still regarded as taboo irrespective of their genotype/phenotype relationship or clinical history. 3 Epidemiology [acc.org]

Epidemiological studies of SIDS have shown some link to sedative medications, but not yet to ingestion of QT prolonging medications. [adc.bmj.com]

Epidemiology International occurrence The incidence of tumor lysis syndrome is unknown. The prevalence varies among different malignancies; bulky, aggressive, treatment-sensitive tumors are associated with higher frequencies of tumor lysis syndrome. [emedicine.medscape.com]

American Journal of Epidemiology, 170, 739-746. doi:10.1093/aje/kwp191 Van Noord, C., Sturkenboom, M.C., Straus, S.M., Hofman, A., Kors, J.A., Witteman, J.C. and Stricker, B.H. (2010). [file.scirp.org]

Sudden infant death syndrome and long QT syndrome: an epidemiological and genetic study. Int J Legal Med. 2006; 120 :129–37. [ PubMed : 16012827 ] Westenskow P, Splawski I, Timothy KW, Keating MT, Sanguinetti MC. [ncbi.nlm.nih.gov]

Pathophysiology Rapid tumor cell turnover results in release of intracellular contents into the circulation. This release can inundate renal elimination and cellular buffering mechanisms, leading to numerous metabolic derangements. [emedicine.medscape.com]

In this review, we will describe exclusively on LQTS linked arrhythmias, its pathophysiology and presently available clinical management. [frontiersin.org]

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test Long QT syndrome (LQTS) is a genetic cardiac disorder characterized by QT prolongation and T-wave abnormalities on electrocardiogram [mayomedicallaboratories.com]

The pathophysiology of CPVT is very different from Long QT syndrome. CPVT, unlike Torsade, is worsened with tachycardia. See this post for management of Torsade. [hqmeded-ecg.blogspot.com]

Reed Kl: Fetal arrhythmias, etiology, diagnosis, pathophysiology and treatment. Semin Perinatol 1989;13:294–304. [karger.com]

Prophylactic β-blocker therapy was started in these two patients to prevent sudden death. In conclusion, this syndrome should be sought in children with syncope or a family history of it, especially those with congenital deafness. [link.springer.com]

Atrial Fibrillation/Supraventricular Arrhythmias, Congenital Heart Disease, CHD and Pediatrics and Arrhythmias, CHD and Pediatrics and Prevention, CHD and Pediatrics and Quality Improvement, Exercise, Sports and Exercise and Congenital Heart Disease [acc.org]

Prevention is key. And that's especially hard for a family in Franklin to hear because if only the Mother had gotten the right diagnosis, she could have taken steps to save her children. [wthr.com]

Precautionary measures as described above are not needed. 3.2.2 Which options in view of lifestyle and prevention does a person at-risk have if no genetic test has been done (please describe)? Same as described above. [nature.com]

Although β-blockade helps reduce the incidence of cardiac events, it is not entirely effective in preventing TdP and sudden death in c-LQTS. [anesthesiology.pubs.asahq.org]