Presentation
Patients with this syndrome may present with syncopal or near-syncopal events that may be mistaken for seizures. Milder presentations may include palpitations or lightheadedness. [ahcmedia.com]
Children, who present with LQTS and seizures, generally have a precipitating event causing seizures, and they respond well to drug therapy. [springermedizin.de]
The initial case was in a patient who presented with seizures, ventricular fibrillation, and syncope. After a trial of conventional modalities of treatment including left stellate ganglionectomy, primidone (Mysoline) therapy was initiated. [annals.org]
There are several reasons behind this, the main one being not considering that long QT may be present. [radcliffecardiology.com]
Among patients enrolled in The International Long-QT registry, the average age of presentation is 21±15 years. Presentation most often is with a syncopal episode. Males often present during pre-adolescence while females present later [9]. [geneticheartdisease.org]
Cardiovascular
- Hypertension
Syncope Slow Onset Abrupt Onset Abrupt Onset Slow Offset Abrupt Offset Slow Offset Seizure disorder Hyperventilation Hypoglycemia Obstructive Arrhythmic Vascular Aortic Stenosis, HCM, Myxoma Brady Tachy Vasovagal, Orthostatic Hypertension 11. [de.slideshare.net]
Case You are asked to admit a 63-year-old male with a history of hypertension and osteoarthritis. The patient, who fell at home, is scheduled for open repair of his femoral neck fracture the following day. [the-hospitalist.org]
She has a past medical history of hypertension and paroxysmal atrial fibrillation. Her medications include tramadol hydrochloride, hydrochlorthiazide, and aspirin. [radcliffecardiology.com]
The family history was negative for sudden cardiac arrest (SCA) but significant for hypertension and hyperlipidemia. She denied tobacco or illicit drug use and consumed occasional alcohol. [innovationsincrm.com]
The presence of arterial hypertension, diabetic cardiovascular complications and electrocardiographic abnormalities of left ventricular hypertrophy and conduction disturbances were associated with increased QT dispersion in diabetes mellitus [3,12,13] [file.scirp.org]
Neurologic
- Hyperactivity
Cardiovascular monitoring and stimulant drugs for attention-deficit/hyperactivity disorder. Pediatrics. 2008;122:451-453. 14. FDA. [uspharmacist.com]
Recent Issues of LQTS in Children Attention deficit/hyperactivity disorder (ADHD) is a relatively common disease and is prevalent in approximately 11% of children. [jstage.jst.go.jp]
- Febrile Seizures
Fever is a trigger for LQTS type 2 and the first presentation may be a febrile “seizure” in a toddler. Startling noises, fright, and exertion are all LQTS torsades triggers and they vary in the different QT syndromes. [epmonthly.com]
Workup
The patient tolerated the surgery and post-operative period without complication and was scheduled for an outpatient workup and management for his prolonged QT interval. [the-hospitalist.org]
QT, RR, ST Intervals
- Prolonged QT Interval
[…] syndrome ( I45.81 ) Diagnosis Index entries containing back-references to I45.81 : Jervell-Lange-Nielsen syndrome I45.81 Long QT syndrome I45.81 Prolonged, prolongation (of) QT interval I45.81 Romano-Ward I45.81 (prolonged QT interval) Syndrome - see [icd10data.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]
Get Update Overview Congenital long QT syndrome is electrocardiographically characterized by a prolonged QT interval and polymorphic ventricular arrhythmias (torsade de pointes). [diseaseinfosearch.org]
An electrocardiogram (ECG) reveals a QTc (QT) interval of 480 ms. How should this hospitalized patient’s prolonged QT interval be managed? Overview Patients with a prolonged QT interval on routine ECG present an interesting dilemma for clinicians. [the-hospitalist.org]
Since long QT syndrome does not always create longer than normal QT intervals all the time, there's a chance your EKG may be normal even though you have prolonged QT intervals at other times. [drugs.com]
Rhythm
- Sinus Arrhythmia
Sinus pauses Several LQTS patients have sudden pauses in sinus rhythm exceeding 1.2 seconds that are not related to sinus arrhythmia [ 11 ] and may contribute to the initiation of arrhythmias in LQTS patients. [ojrd.biomedcentral.com]
Treatment
CLOSE Medical Disclaimer The medical information on this site is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes. [diseaseinfosearch.org]
You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments. [rarediseases.info.nih.gov]
After a trial of conventional modalities of treatment including left stellate ganglionectomy, primidone (Mysoline) therapy was initiated. [annals.org]
Treatment and Lifestyle Modifications There is currently no treatment to “cure” the disease. Medications known as beta-blockers are used in most patients as they have been shown to reduce the risk of fainting episodes and cardiac arrest due. [heartrhythm.com.au]
Prognosis
Prognosis The scary thing about long QT syndrome is that it can cause sudden death in otherwise healthy people. [drugs.com]
LQT2 Gene T wave tends to be bifid and notched Additional Triger factors are sleep, auditory stimulation Respond to B-Blockers LQT3 Gene Poorest prognosis amongst all T wave is asymmetrical or Late biphasic Trigger factor : Bradycardia ( sleep ) B-Blockers [slideshare.net]
[…] patients received a comprehensive 2- to 3-day clinical and genetic evaluation, including a 1- to 2-hour consultation with an LQTS specialist (M.J.A.) and additional consultations as needed. 3 - 5 Extensive counseling was provided to discuss individual prognosis [jamanetwork.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]
関連する報告書 [学会発表] Clinical Phenotype and Prognosis of Probands With Brugada Syndrome in Relation to SCN5A Mutation. [kaken.nii.ac.jp]
Etiology
Physicians must remain vigilant and consider LQTS as a possible etiology in patients with a history of syncope. [radcliffecardiology.com]
Either mutation etiology can lead to fatal arrhythmias, most notably secondary to TdP. [innovationsincrm.com]
LQTS Subtypes: Jervell and Lange-Nielson and Romano-Ward Syndromes When LQTS was initially described, the genetic etiologies and electrophysiologic mechanisms underlying the disorder were not known. [lqts.research.chop.edu]
[…] abnormal repolarization, usually lengthening the QT interval and thus predisposing to ventricular dysrhythmias.2 It is estimated that as many as 85% of these syndromes are inherited, and up to 15% are acquired or sporadic.3 Depending on the underlying etiology [the-hospitalist.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]
Epidemiology
Epidemiological studies of SIDS have shown some link to sedative medications, but not yet to ingestion of QT prolonging medications. [adc.bmj.com]
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]
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]
Epidemiology: In the United States, the incidence of congenital LQTS is estimated to be one in 7,000-10,000 [5] [6]. There is a female preponderance, ranging from 1.6-2.0:1 [7] [8]. [geneticheartdisease.org]
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]
Pathophysiology
Pathophysiology: The ventricular myocyte activation cycle, or action potential, is dependent on ion channels (Figure 2). [geneticheartdisease.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]
In this review, we will describe exclusively on LQTS linked arrhythmias, its pathophysiology and presently available clinical management. [frontiersin.org]
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]
"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]
Prevention
Appropriate therapy will prevent unnecessary deaths in infants, children, and young adults. [omicsonline.org]
Prevention There's no way to prevent inherited long QT syndrome. However, people with the inherited syndrome want to avoid taking medications that can make the QT even longer than it is naturally. [drugs.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]
This medication is typically used to prevent recurrence of TdP in acquired LQTS. [annalspc.com]
If the patient is on a beta blocker, it should be continued, and the anesthesiologist should be made aware of the diagnosis so that the anesthethic plan can be optimized to prevent arrhythmic complications. TH Dr. [the-hospitalist.org]