How Serious Is Long QT Syndrome?
Long QT syndrome is a serious problem. LQTS is primarily responsible for claiming the lives of otherwise healthy infants, toddlers, teenagers, and young adults at an alarming rate, althou8gh with the advancement of technology and better treatment options, Long Q-T syndrome can be diagnosed in its initial stages and sudden premature death can be avoided.
Currently, this condition still goes unnoticed until sudden death occurs and may even not be diagnosed as the primary cause of death. The relatives of individuals who have experienced sudden death need to be studied to rule out long QT syndrome and other arrhythmias of genetic origin. Long QT syndrome is a treatable condition and by prompt diagnosis and treatment, most deaths from this cause can be prevented.
The doctor needs to know:
-When should LQTS be considered as a possible diagnosis.
-When to send the patient for accurate diagnosis and prompt treatment.
-About the genetic study of LQTS and certain other conditions that determine Sudden Death Syndrome (SMS).
-How to build a family tree and approach family members with suspected LQTS.
What Is Long QT Syndrome?
Long Q-T syndrome also known as LQTS can be defined as an alteration of the conduction system of the heart´s which affects repolarization, a process when the heart’s electrical charge is restored after each beat. Congenital LQTS syndrome is a very rare disorder, and as the name suggests is normally inherited (it is transmitted from one generation to the next).
Occasionally, long QT syndrome may be originated by the intake of specific medicines. Among the best-known drugs that prolong the QT interval are the antiarrhythmics. However, it has been observed that there are more drugs that produce this side effect such as some antidepressants, antipsychotics, antibiotics, antivirals, antifungals, and antiemetics, among others.
Stroke or any other neurological disorder can be a probable cause of this condition. Long QT syndrome provokes arrhythmia, name given to abnormal heart rhythms, syncopal spells, or sudden death.
What Is The Cause Of Long QT Syndrome?
When the heart contracts, an electrical signal is transmitted; the signal originates due to the flow of potassium, calcium, and sodium ions present within the cardiac cells. Ions enter and leave cardiac cells through channels.
It is possible to observe the electrical signal produced by the ions by means of an electrocardiograph. This machine gives a graphical representation of the signal, which is called “waveform.” The different parts of the waveform are defined by alphabets P, Q, R, S, and T.
By observing the waveform on the ECG, it is possible to determine how long it takes for activation and deactivation of the electrical signals to lower cavities of the heart which are the ventricles. It is defined as Q-T interval. An alteration in any of the ion channels can make the Q-T interval prolonged, which in turn can increase the risk of suffering from a type of arrhythmia named torsade de pointes (twisting of the tips). When there is this type of arrhythmia, the heart is not able to pump enough oxygenated blood to other parts of the body, especially the brain. This type of arrhythmia can also cause ventricular fibrillation which is extremely serious and life t threatening. It produces rapid and uncoordinated contractions, which can result in death.
Long QT syndrome can affect people who are relatively healthy. It generally affects children and young adults. There is also increased vulnerability to developing LQTS in case other members of the family also have this condition.
People suffering from long QT syndrome do not always have symptoms. When there are symptoms, the most frequent are syncopal spells and arrhythmia. People suffering from LQTS have prolonged Q-T interval during activity, when in distress, or as a reaction to sudden loud sound.
Patients with LQTS have had at least one syncopal episode by the time they are 10 years old. In other cases, there may be more than 1 episode of fainting in childhood, and curiously never have any such occurrences again.