Title: Bidirectional ventricular tachycardia - the present state of knowledge
- Janusz Kudlicki, Teresa Widomska-Czekajska
- Review articles
- Polish Journal of Cardiology
- Start page:
- Final page:
- bidirectional ventricular tachycardia - BiVT, familial polymorphic ventricular tachycardia - FPVT, catecholaminergic polymorphic ventricular tachycardia, calsequestrin, ryanodine receptor 2 - RYR2
Bidirectional ventricular tachycardia (VT) is a rare arrhythmia, the pathogenesis of which remains unclear till now. It is characterized by changing frontal electric heart axis up to 180 degrees in every alternate QRS com-plex.
Usually it is familial (familial polymorphic VT-FPVT), but could be also due to digitalis toxicity. Polymorphic VT is induced by catecholaminergic stimulation, like physical exertion or emotional stress (catecholaminergic polymorphic VT, stress-induced polymorphic VT).
The underlying cause of the disease is ryanodine 2 receptor (RYR2) gene mutation (1q42-q43), with auto-somal dominant inheritance or calsequestrin 2 gene mutation (1 p13.3-p11) with autosomal recessive inhe-ritance. Uncontrolled calcium leakage from sarcoplasmatic reticulum to cytosol causes pathological activi-tytriggered by delayed afterdepolarisations.
Sudden death is the most dramatic complication of the disease. Cumulated mortality ratę up to the age of 30 is about 31 %.
Our own experience consists of one family where 2 brothers died suddenly in their age of 6 months and 12 years and 4 sisters have multiple ventricular arrhythmias with bidirectional tachycardia and MAS-syndrome episodes.
The treatment of choice are p-adrenergic blocking agents and in case of their ineffectiveness - implantation of cardioverter-defibrillator (ICD).