[Clinico-morphological features and mechanisms of arrhythmogenesis in idiopathic prolonged QT interval syndrome].

: The paper deals with the idiopathic prolonged QT interval syndrome, a rare and highly malignant cardiac disease, which is characterized by ECG changes, episodes of polymorphic torsades de pointes ventricular tachycardia, and high family history mortality due to sudden cardiac arrest. The causes and optimum treatments of the disease remain less studied. The authors propose noninvasive techniques for investigating the functional characteristics of the cardiac conduction system, whose use is highly important both for the understanding of the nature of the available changes and the diagnosis of asymptomatic types of the disease course. The examination of biopsy specimens of the sinus node and perinodal area in patients undergone surgical treatment has revealed changes in all the components of the cardiac conduction system and working myocardium, the greatest changes being found in the structure of the nervous system. In this group patients, the rather specific changes are also impaired intercellular membranous contacts. These two mechanisms may play the leading role in the occurrence of arrhythmias in the prolonged QT interval syndrome and the proposed noninvasive techniques (including superficial mapping) are highly sensitive in detecting the existing functional disorders in the cardiac conduction system in this disease.