Журнал «Здоровье ребенка» 2 (45) 2013

Sudden cardiac death (SCD) is the sudden death from cardiac causes, which occurred within 1 hour from onset of the patients` symptoms with the known heart disease or not.

Dysplastic changes in the muscle-valve structures of the heart, with a risk of SCD, include congenital morphofunctional disorders of connective tissue formations with increase of elasticity and formation of pathological syndromes.

Marfan syndrome is a hereditary disease of the connective tissue inherited in the autosomal dominant pattern. By Marfan's syndrome SCD is caused by acute aortic dissection with rupture of it.

Ehlers-Danlos syndrome comprises a group of diseases that differ in the primary gene defect and the type of inheritance, the characteristics and severity of clinical symptoms. Characteristically an aortic aneurysm is formed.

Mitral valve prolapse (MVP) is a systolic sagging of one or both mitral cusps into the cavity of the left atrium. Clinical and anatomical MVP is not a disease but a syndrome various nosological forms have. The maximum risk of SCD have the patients with cases of sudden death in the family history, previous syncope, ECG abnormalities at rest, an extended interval QT, the presence of complex ventricular tachyarrhythmias, elongated and myxomatously degenerated cusps of the mitral valve.

The acquired pathology of the cardiovascular system, underlying the development of SIDS, involves inflammation of the myocardium, endocardium with possible formation of valvular defects, cardiomyopathy. They believe that in 20-40% of cases the cause of SCD is myocarditis. Heart disease by myocarditis ranges from conducting system with the emergence of blockades of various levels and degree to actually myocardium with the development of ventricular tachycardia. In this case, clinical signs of heart failure may be absent.

Primary and secondary cardiac arrhythmia of children is a major cause of sudden death of children and adolescents. The prevalence of severe, life-threatening forms of arrhythmia of children reaches 1:50 000. There are several distinct syndromes that are associated with the development of life-threatening arrhythmias: the syndrome WPW; syndrome of extended interval QT; sick sinus syndrome, the Brugada syndrome.

The anatomic substratum of WPW syndrome is additional atrioventricular ways, existing besides the atrioventricular node. Patients with WPW-syndrome are at risk of sudden death, which may occur as a result of the rapid pulse through additional routes with the development of atrial or ventricular fibrillation.

Syndrome of extended interval QT (LQT) is a family disease in which the pathology is detected in the genes which encode the transport of sodium and potassium ions through the cell membrane. In the classification they distinguish: congenital LQT – genetic (Romano – Ward and Jervell – Lange – Nielsen syndromes) and sporadic forms, acquired LQT – a result of taking drugs, metabolic disorders, low-calorie diet, the presence of central and autonomic nervous system diseases. The disease manifests itself with interval QT prolongation of more than 440 ms. Syncope or SCD may occur during swimming (15%), other inadequate physical activity, sharp acoustic signals (8%), cases of pain expectation, emotional overstrain.

One of the reasons for children`s SCD may be sick sinus syndrome. Diagnosis is made by ECG, based on the results of the daily or long-term monitoring of heart rate, additional methods of examination (non-invasive electrophysiological investigation).

The main symptom of congenital heart blockade, syncope, is due to bradycardia. With long-term follow-up, attacks of Morgani – Adams – Stokes and SCD caused by bradycardia, prolongation QT, tachycardia Torsades de pointes were observed in a significant percentage of these patients.

SCD diagnosis is based on the presence of symptoms of natural death, detected during a physical examination prior to the events of cardio-pulmonary resuscitation (CPR): lack of consciousness, lack of breath or a very rare breath of agonistic type, lack of pulse in the carotid arteries, absence of heart sounds while auscultation, absence of corneal and pupillary reflexes, lack of blood pressure, pale gray skin, abnormal ECG changes.

Following the success of CPR diagnosis of diseases, which were the cause of sudden cardiac death, is required. Identification and dynamic control of risk factors for the development of children`s SCD is a difficult clinical challenge that requires a clear sequence of actions at all stages, from the anamnesis and ending up with the use of modern diagnostic algorithms.

Preventive measures of sudden cardiac death should be aimed at the prevention, timely diagnosis and appropriate therapy of diseases that can cause its development. Children are recommended: systematic preventive medical examinations; reducing the impact of stress factors; adapted, individually tailored physical activity, healthy lifestyle; prevention of smoking which increases the risk of coronary artery disease, arrhythmia.

Now the problem of SCD is far from its final solution, which is caused by a whole complex of theoretical, methodological and practical factors. Numerous calls to standardization of autopsies and the full implementation of pathomorphological research of SCD cases, analysis of morphological substratum and all the possible trigger factors remain unfulfilled. With the accumulation of data, appear a number of new issues that need solution or correction of the answers, which, seemed, have been already found.