Abstract
Preexcitation syndromes are becoming a more often detected disease in the pediatric population. Their essential feature is the presence of additional paths / pathways in the heart, through which the impulse is conducted faster than physiologically. This leads to faster ventricular excitation and may lead to creating dangerous arrhythmias. The most common preexcitation syndrome is Wolff - Parkinson-White syndrome, which affects 2/ 1000 people. The presence of an accessory pathway could result in serious consequences, ranging from supraventricular tachycardia to sudden cardiac death. There are both invasive and non-invasive methods of diagnosing preexcitation syndromes. Therapeutic treatment includes pharmacotherapy and ablation, which makes it possible to permanently remove the cause of the arrhythmia.