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]

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]

Patient Presentation An 11-year-old female came to clinic with a hacking cough for the past 4 days. It was bothering her during the day and night. She had no rhinorrhea, fever, nausea, vomiting or shortness of breath. [pediatriceducation.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]

• Death in Infancy

  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]

• 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]

• Pharyngitis

  Discussion Mycoplasma pneumoniae is a frequent cause of pharyngitis, pneumonia and acute bronchitis, but acute otitis media is uncommon. [pediatriceducation.org]

• Rhinorrhea

  She had no rhinorrhea, fever, nausea, vomiting or shortness of breath. Overall she just didn’t feel well but was attending school and doing her sports activities. [pediatriceducation.org]

• 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 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]

  Diagnosis • Personal/family Hx • LongQTS-triggered syncope/seizure/SCD • Provoke like accident/drownings/emotional/sleep/rest • ECG: QTc 450msec(M) & 460msec (F) 22. Schwartz score 3.5:high (P) 23. Bazett’s QTc QT/ RR 24. Rare variants 25. [de.slideshare.net]

  […] disorder should be suspected when the electrocardiogram shows characteristic QT abnormalities, or when there is a family history of long QT syndrome or of an event that raises suspicion of long QT syndrome, such as sudden death, syncope, or ill-defined “seizure [mdedge.com]

  Interestingly an overlap between LQTS and true epileptic seizures is recognized in a small proportion of patients with long QT2. [rarediseases.org]

• Altered Mental Status

  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]

• Hyperactivity

  Cardiovascular monitoring and stimulant drugs for attention-deficit/hyperactivity disorder. Pediatrics. 2008;122:451-453. 14. FDA. [uspharmacist.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

  ICH E14 Step 2: The Clinical Evaluation of QT/QTc Interval Prolongation and Proarrhythmic Potential for Non-Antiarrhythmic Drugs. www.fda.gov/ohrms/dockets/dockets/04d0377/04D-0377-EC7-Attach-1.pdf. Accessed January 30, 2014. 15. [uspharmacist.com]

  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]

• 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]

  QTc 500 ms. 5. 2:1 atrioventricular block. 6. T wave electric alternans. 7. LQTS3 genotype. [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

  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]

  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]

  LQTS manifestations include syncope, ventricular tachyarrhythmias, torsade de pointes and also cardiac arrest or unexplained sudden death. Patients may also be identified through family history or incidental ECG findings. [pediatriceducation.org]

  ICDs do not prevent the occurrence of torsade de pointes and, therefore, are used in conjunction with beta blockers and/or cardiac sympathectomy. [rarediseases.org]

  Okt. 2013 The long QT syndrome (LQTS) is a rare inherited heart condition in which delayed repolarization of the heart following a heartbeat increases the risk of episodes of torsades de pointes (TDP, a form of irregular heartbeat that originates from [de.slideshare.net]

• 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]

  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]

  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]

  Another indicative finding is T-wave alternans (alternating polarity and amplitude), which may be present at rest for brief moments but most commonly appears during emotional or physical stress. [aafp.org]

  B, Alternating T-wave axis and morphology (T-wave alternans) leading to an episode of torsades de pointes (TdP) triggered by a ventricular ectopic beat. [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]

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]

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]

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

The principal treatment is beta-blocker therapy. Appropriate dosing, with ascertainment of efficacy and compliance with administration, are the key elements in therapeutic success. [journals.lww.com]

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

[…] 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]

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]

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]

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 prognosis of the disease is usually good in patients that are correctly diagnosed and treated. [ojrd.biomedcentral.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]

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]

[…] 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]

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]

Etiology Following the identification, in 1995 and 1996, of the first three LQTS genes associated with the most frequently encountered LQTS variants called respectively LQT1, LQT2, and LQT3, there has been a flourishing of identifications of genes proven [ojrd.biomedcentral.com]

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]

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]

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]

Early diagnosis and preventive treatment are instrumental in preventing sudden cardiac deaths in patients with the congenital LQTS. [jtd.amegroups.com]

View Article PubMed Google Scholar Schwartz PJ, Motolese M, Pollavini G, Lotto A, Ruberti U, Trazzi R, Bartorelli C, Zanchetti A, the Italian Sudden Death Prevention Group: Prevention of sudden cardiac death after a first myocardial infarction by pharmacologic [ojrd.biomedcentral.com]