Presentation
The time of presentation varied from 16 to 38 weeks of gestation. [karger.com]
There are several reasons behind this, the main one being not considering that long QT may be present. [radcliffecardiology.com]
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]
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]
Respiratoric
- 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]
Course
- 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]
Jaw & Teeth
- 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]
Ears
- 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]
Urogenital
- 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]
Workup
[…] 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]
Serum
- 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]
QT, RR, ST Intervals
- Prolonged QT Interval
In summary, inhaled anticholinergic agents do not result in prolongation of QT interval and inhaled beta agonists do variably prolong the interval. [aaaai.org]
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]
Syndrome (LQTS) is a rare hereditary disease that is characterized by a prolonged QT-interval on the electrocardiogram (ECG) due to delayed repolarization of the heart. [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]
Discussion These cases highlight the inability of attending physicians to at least suspect long QT interval on ECG. Failure to recognize prolonged QT interval has been described before. [radcliffecardiology.com]
Other ECG Findings
- 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 [ncbi.nlm.nih.gov]
Treatment
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]
Treatment A conventional treatment is the oral administration of beta-blockers, medications that decrease the input from the sympathetic nervous system to the heart. [medical-dictionary.thefreedictionary.com]
Long-term treatment for acquired long QT syndrome No treatment is necessary after removal of the medications causing the syndrome. Long-term treatment for congenital long QT syndrome Beta-blockers are very effective in congenital LQTS. [ecgwaves.com]
Prognosis
[…] 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]
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]
Female patients with a mutation at the LQT2 locus had a more severe prognosis irrespective of the duration of the QTc, whereas in patients with a mutation at the LQT3 locus, the prognosis was mainly influenced by sex: male patients had a higher probability [nejm.org]
Etiology
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]
Epidemiology
Epidemiological studies of SIDS have shown some link to sedative medications, but not yet to ingestion of QT prolonging medications. [adc.bmj.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]
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
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]
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]
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]
Reed Kl: Fetal arrhythmias, etiology, diagnosis, pathophysiology and treatment. Semin Perinatol 1989;13:294–304. [karger.com]
Prevention
For polymorphic VT due to acquired long QT (Torsade de Pointe), isoproterenol is indicated to increase the sinus rate and prevent further torsade. However, this makes CPVT worse. [hqmeded-ecg.blogspot.com]
Long QT Syndrome, Risk Assessment, Secondary Prevention, Torsades de Pointes < Back to Listings [acc.org]
To prevent this stimulus, pretreatment with fentanyl was done during induction of anaesthesia. [ispub.com]
Appropriate therapy will prevent unnecessary deaths in infants, children, and young adults. [omicsonline.org]
Since LCSD is an invasive procedure, it should be used as a secondary prevention modality. [thecardiologyadvisor.com]