The Long QT Controversy
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The QT interval is the distance from the beginning of the QRS complex to the end of the T wave on an electrocardiogram
Electrophysiologically, QT is defined as the result of alternating depolarization and repolarization of the ventricular myocardium
The QT interval is often called the electrical systole of the heart
There are concepts of prolonged QT and long QT syndrome (hereinafter LQT), and here it is a mess
In practice, QTc and LQTc normalized to the ventricular rate are assessed
Some include all cases of prolonged QT in LQT, postulating the associated risk of potential development of life-threatening arrhythmias
Others add mandatory episodes of syncope with a high risk of death due to polymorphic ventricular tachycardia to the definition of LQT.
QT reflects not only electrical, but also electro-chemical-mechanical systole of the ventricles of the heart and should be considered not only in terms of the risk of life-threatening arrhythmias, but also the impact on the biomechanics of the ventricles of the heart
Elongated ventricular systole of the heart should be the subject of a special study
LQT criteria were established largely before the introduction of evidence-based medicine and require revision
LQT criteria should take into account not only gender differences, but also the nature, primarily congenital and acquired conditions, LQTc, age, daily fluctuations and general cardiovascular (somatic) risk
The possible influence of the frequency of LQTc in the circadian (daily) measurement on the state and sources of the patient's health should be studied
The established importance of stress factors in the implementation of life-threatening conditions in conditions of excited neurohumoral regulation and the possibility of their detection using VSS technology raises the question of developing a protocol standard
Dispensary observation of individuals with certain genetic mutations characteristic of LQTc should be followed regardless of their established QT length
Restrictions on drug interventions in individuals with acquired LQTc can be reduced by taking into account the results of preliminary pharmacological tests, when they are used in cases of their positive results
Individuals with genetic mutations determined characteristic of congenital LQTc should be given special attention regardless of its duration, in the context of registered life-threatening events (pirouette-type arrhythmia, syncope, etc.).