They cause syncope and sudden death in response to exercise or emotional stress, and can present with a sentinel event of sudden cardiac death in infancy. [uniprot.org]

Long QT syndrome (LQTS) should be suspected in individuals on the basis of ECG characteristics, clinical presentation, and family history. [centogene.com]

This is likely an underestimate as sudden death with a normal autopsy may be the first and only presentation. There are 12 genes responsible for 3 main types of c-LQTS. The presentation is one of aborted sudden death or brief arrhythmia. [epmonthly.com]

Key words Long QT syndrome Neonatal presentation Syncope Ventricular arrhythmias This is a preview of subscription content, log in to check access. Preview Unable to display preview. Download preview PDF. References 1. [link.springer.com]

Case presentation: We describe a 14-year-old boy with hypopituitarism after trans-sphenoidal surgery (TSS) due to suprasellar mass who manifested bradycardia and QT prolongation on electrocardiogram. [abstracts.eurospe.org]

• Pertussis

  Pertussis was circulating in the community, but not influenza. The past and family medical history showed a history of long QT syndrome that was diagnosed after the paternal grandfather had a syncopal incident. [pediatriceducation.org]

  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]

• Hemianopsia

  This subject complained of blurred vision and bilateral temporal hemianopsia for 1 month. Brain magnetic resonance image (MRI) revealed 3 cm sized suprasellar mass and TSS was performed. [abstracts.eurospe.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]

• Seizure

  Case Studies SK is a 12-year-old girl who was diagnosed 1 year ago with a generalized seizure disorder. Both her mother and maternal uncle had histories of seizures. [pedsinreview.aappublications.org]

  Case report A 29 year-old Caucasian male, recently diagnosed with seizure disorder, was brought to emergency room for altered mental status with combative behavior. [jtd.amegroups.com]

  Other testing may include: Exercise stress test Ambulatory monitor Your doctor will also ask you if you have a: Family history of LQTS Family history of unexplained fainting, seizures, or cardiac arrest History of fainting, seizures or cardiac arrest, [my.clevelandclinic.org]

  Seizures. If the heart continues to beat erratically, the brain will eventually not get enough oxygen, which can cause seizures. Sudden death. Generally, the heart returns to its normal rhythm. [mayoclinic.org]

  This usually manifests as sudden, without warning syncope, near syncope or prolonged syncope with seizures. Many are misdiagnosed with seizure disorder or vasovagal syncope. [epmonthly.com]

The Mayo Clinic cases analyzed were anonymous samples derived from fetuses referred to the Mayo Clinic for chromosomal analysis as part of a workup for unexplained fetal death and were noted to be nonanomalous and found to be karyotypically normal. [jamanetwork.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]

• QTc Interval Prolonged

  Hypokalemia, hypocalcemia, and use of loop diuretics are risk factors for QTc interval prolongation. [4] LQTS has been recognized as mainly Romano-Ward syndrome (ie, familial occurrence with autosomal dominant inheritance, QT prolongation, and ventricular [emedicine.medscape.com]

  Most clinicians consider a corrected QT interval (QTc) of >440 msec for males and >450 msec for females to be prolonged. As the heart rate increases, the QT interval shortens. [uspharmacist.com]

• 2:1 Atrioventricular Block

  There is 2:1 atrioventricular block because the t wave has not even started when the next p wave appears; since ventricular repolarisation has not yet occurred, the ventricle cannot yet be depolarised again. [adc.bmj.com]

  […] strip showing 2:1 atrioventricular block secondary to prolongation of the QT interval. ( C ) A rhythm strip demonstrating polymorphic ventricular tachycardia. [pnas.org]

  B: atrioventricular block 2:1. C: self-limited torsade de pointes. [revespcardiol.org]

  Timothy syndrome may include a functional 2/1 atrioventricular block, due to an exceedingly long QT interval5,19,48. [romanianjournalcardiology.ro]

• Torsades De Pointes

  Torsade de pointes In LQTS, QT prolongation can lead to polymorphic ventricular tachycardia, or torsade de pointes, which itself may lead to ventricular fibrillation and sudden cardiac death. [emedicine.medscape.com]

  The delayed recovery predisposes individuals to the development of early afterdepolarizations and initiation of torsade de pointes arrhythmias. The torsade produces the syncope and sudden death. [journals.lww.com]

  The long QT syndrome and torsade de pointes. Pacing and Clinical Electrophysiology 22(1), Pt 1:91-110, 1999. 9. Kirchhof P, Eckardt L, Franz MR, et al. [emsworld.com]

  Electrocardiogram showing torsades de pointes. Note the more or less symmetric variation in the ventricular tachycardia waves. Torsades de pointes may resolve into sinus rhythm or progress into ventricular fibrillation. [ corrected ] FIGURE 3. [aafp.org]

  Drugs That Prolong the QT Interval and/or Induce Torsades de Pointes Table 1. Drugs That Prolong the QT Interval and/or Induce Torsades de Pointes × [anesthesiology.pubs.asahq.org]

• T Wave Alternans

  A 24-hour ambulatory ECG tracing was obtained in each individual. 5/14 patients with LQTS had pathological findings during ambulatory ECG monitoring (2 patients with episodes of torsade de pointes tachycardia, 2 patients with T-wave alternans and 1 patient [karger.com]

  Follow-up electrocardiograms and Holter records show persistent QT prolongation, bizarre T waves, and intermittent episodes of T wave alternans. On propranolol monotherapy the boy is thriving and completely free of ventricular arrhythmias. [link.springer.com]

  The severity of T-wave alternans tends to correlate with the risk of cardiac events. 10 View/Print Figure FIGURE 3. Electrocardiogram showing torsades de pointes. Note the more or less symmetric variation in the ventricular tachycardia waves. [aafp.org]

  T wave alternans Beat-to-beat alternation of the T wave, in polarity or amplitude, may be present at rest for brief moments but most commonly appears during emotional or physical stresses and may precede TdP (Fig. 2 ). [ojrd.biomedcentral.com]

  […] morphological abnormalities and T-wave alternans ( Figure 1 ). [circ.ahajournals.org]

• Biphasic T Wave

  In addition to the diagnostic criteria just mentioned, T wave morphology may help differentiate LQT1–3. 27 Typically, a broad T wave is observed in LQT1 ( Figure A ), a biphasic T wave in LQT2 ( Figure B ) and a late-appearing T wave in LQT3, which has [jstage.jst.go.jp]

• Peaking T Wave

  ECGs of LQTS types 1–3, with the typical T wave of each subtype. ( A ) LQTS type 1 with typical broad-based T wave pattern. ( B ) LQTS type 2 with typical bifid T wave. ( C ) LQTS type 3 with late-onset peaked T wave. [jstage.jst.go.jp]

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]

Additionally, candidacy for cochlear implantation, currently the only medical treatment available for the treatment of profound sensorineural hearing loss, cannot be established without a comprehensive medical examination. [californiaearinstitute.com]

It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Our staff consists of biologists and biochemists that are not trained to give medical advice . [uniprot.org]

Treatment includes beta-blockers and implantation of an implantable cardioverter defibrillator (ICD). [healio.com]

LTQTS subtypes influence the arrhythmia risk and also the choice of treatment including no specific treatment for some patients. [pediatriceducation.org]

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]

[…] 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]

Large-scale epidemiologic studies have demonstrated an association between QTc prolongation and cardiac prognosis in patients with heart disease, though many studies lack appropriate adjustment for prior conditions. [nature.com]

The relationship of heart rate variability with severity and prognosis of cirrhosis. Dig Dis Sci. 2006; 51 :1614–1618. [ PubMed ] [ Google Scholar ] 15. Hendrickse MT, Thuluvath PJ, Triger DR. [ncbi.nlm.nih.gov]

Two-to-one AV block is an infrequent manifestation with a poor prognosis that can be present since the fetal stage in the form of persistent bradycardia. [revespcardiol.org]

[…] 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]

Clinical features and etiology of hepatocellular carcinoma arising in patients with membranous obstruction of the inferior vena cava: in reference to hepatitis viral infection. [ncbi.nlm.nih.gov]

Advances in molecular and genetic cardiology over the past 20 years, coupled with increasing awareness of inherited conditions in the etiology of sudden cardiac death, have moved LQTS from the periphery to mainstream clinical medicine. [circ.ahajournals.org]

It presents when the QT interval is prolonged, regardless of the etiology. It is a polymorphic ventricular tachycardia due to reentry, characterized electrocardiographically by continuous twisting of the QRS axis around an imaginary line. [revespcardiol.org]

[…] patients, and aborted cardiac arrest/sudden cardiac death (ACA/SCD) is rare (1–3%). 6 Of the patients who eventually become symptomatic, 50% experience their first cardiac event by the age of 12, and 90% by the age of 40. 7 LQTS is also known as an etiology [jstage.jst.go.jp]

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

Investigative teams have published comprehensive clinical-epidemiologic reviews of both long QT syndrome as a family and several of the other channelopathies under Human Genome Epidemiology (HuGE) reviews (e.g., long QT syndrome 21 ) and GeneReviews [currents.plos.org]

The genetic epidemiology of both forms can vary with subpopulation depending on the allele, but as a whole, LQTS appears in every corner of the globe. [nature.com]

Pathophysiology of hepatic dysfunction and intrahepatic cholestasis in heart failure and after left ventricular assist device support. J Heart Lung Transplant. 2005; 24 :361–370. [ PubMed ] [ Google Scholar ] 122. [ncbi.nlm.nih.gov]

The pathophysiological basis of long-QT syndrome (LQTS) is prolongation of cardiac ventricular repolarization by acquired factors such as drug exposure or genetic variation in the proteins controlling transmembrane ion-concentration gradients ( 8, 9 ) [pnas.org]

The role of the sympathetic nervous system in the long QT syndrome: the long road from pathophysiology to therapy. Long QT syndrome. Cardiac Electrophysiology Clinics, volume 4, number 1. Editors: Priori SG, Thakur RK, Natale A. [romanianjournalcardiology.ro]

"Molecular Pathophysiology of Congenital Long QT Syndrome". Physiological Reviews. 97 (1): 89–134. doi : 10.1152/physrev.00008.2016. PMC 5539372. PMID 27807201. ^ a b Giudicessi JR, Ackerman MJ (October 2013). [en.wikipedia.org]

Appropriate therapy will prevent unnecessary deaths in infants, children, and young adults. [omicsonline.org]

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]

Conclusion: This case highlights that hormonal disorders should be considered as a cause of arrhythmia or prolongation of QT intervals and this can be prevented and cured by appropriate hormone replacement therapy. [abstracts.eurospe.org]

June 13, 2017 WIRED: A Radical Proposal For Preventing Rare Genetic Diseases Read More April 14, 2017 Parent of a Medically Complex Child, “I am Always Choosing Between the Lesser… Read More November 23, 2013 Martial Arts Expert Suffers From Andersen-Tawil [globalgenes.org]

This information is important because it supports the need to consider implanting an ICD for secondary prevention of CA even in young SQTS patients. Anttonen O, Junttila J, Giustetto C, et al. T-Wave morphology in short QT syndrome. [e-cardiogram.com]