Is Long QT Syndrome A Genetic Disorder?
Congenital long QT syndrome or LQTS is a hereditary cardiovascular condition in which there is lengthiness of QT musical interval on ECG put the individual at risk for potentially life threatening form of rhythm disorderliness or arrhythmia . This consideration is believed to occur in 1 out of every 2000 citizenry . The primary presenting feature article of long QT syndrome admit episode of syncope which can ultimately cause a severe cardiac arrest and sudden end .
It is possible to record the electrical signal produced by the ions by an cardiograph . This machine makes touch of sign , which is called “ wave shape ” and whose unlike component are represented by the letters P , Q , R , S , and T.
Observing the waveform can determine how long it takes for the electrical signal to set off and inactivate the scurvy enclosed space of the heart ( the ventricle ) , which is called the QT time interval . A problem in one of the ion channel tends to prolong this interval and this , in turn , can increase the peril of suffering a character of arrhythmia know in French as torsade de pointes ( twisting of the tips ) . When the “ tips twist ” , the heart can not pump enough O - deep rakehell to the eternal sleep of the body , especially the brain , and could lead to ventricular fibrillation : a dangerous type of arrhythmia , which causes rapid and uncoordinated condensation of the essence .
All affected role with sustain QT syndrome may experience arrhythmic cardiac disorderliness , disregardless of the value they face in the QTc interval and the subsist chromosomal revision ; however , in a small number of families , a peculiarly malignant evolution has been described , with sudden expiry in the new members of several propagation . The longsighted QT syndrome affects hoi polloi who seem to be very healthy , especially for children and immature grownup .
About The Genetic Origin
The genetic origin of long QT syndrome disease was let on at in the middle period of the ‘ 90s and the genes responsible for for this condition are think to code for cardiac ion epithelial duct subunits or the proteins involved in modulation of ion currents . Mutations in these genes namely KCNQ1 , KCNE1 , CACNA1c , and SCN5A result in prolongation of the QT separation resulting in Long QT Syndrome .
The most coarse variant of foresighted QT syndrome disease is the QTL1 which result due to sport in KCNQ1 factor and approximately 50 % of patients are believed to be carriers of these mutations . Due to the specificity of the clinical symptoms of long QT syndrome , distinctive shell do not award any difficultness in diagnosing this term for most of the doc who are intimate with the condition . However , some cases are a lot more complex as there is very footling in the form of symptoms fix a diagnosis unmanageable . Such case require thorough evaluation with multiple electrocardiographic studies along with clinical and family chronicle to make an precise diagnosis .
Molecular masking is yet another gain for a timely and accurate diagnosis of Long QT Syndrome . The direction of the disease in bulk of the cases always begins with administration of beta - blocker the patient is not a desirable candidate for this course of medications . If , despite a maximum dose of beta - blockers , the patient role gift episodes of faint , a unexpended cardiac sympathetic denervation should be performed and should be count a treatment with implantable cardioverter - defibrillator ( ICD ) , taking into score the characteristic of the patient ( age , sexual urge , clinical history and genetic subgroup , with specific characteristics depending on the sport in some cases , as well as the front of ECG signs -including Holter recordings of 24 hours- indicators of high electrical instability ) .
In general , for patients diagnosed and treated correctly , the prospect of long QT syndrome is salutary . However , there are some serious exception for patients with long QT syndrome variants : patients with Timothy syndrome ( characterize by marked prolongation of the QT interval , auriculoventricular occlusion 2 : 1 and syndactyly ) , patients with Lange - Nielsen syndrome and Jervell carriers of KCNQ1 mutation ( stark form of prospicient QT syndrome associated with innate deafness and a very former onset of cardiac arrhythmias ) and patient role with QTL3 with atrioventricular auction block 2 : 1 and very early attack of cardiac arrhythmias .
Conclusion
The transmission of long QT syndrome disease is autosomal dominant . It is one of several room in which a trait or upset can be conduct from parents to children .
foresighted QT syndrome is an autosomal dominant trait mean that only one copy of the bad cistron from either parent is undecomposed enough to lead to the development of this circumstance . ordinarily , it is observed that at least one parent of the patient has had farsighted QT Syndrome .
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