VENTRICULAR EXTRASYSTOLIA IN PATIENTS WITH NON-ST ELEVATION ACUTE CORONARY SYNDROME: ASSESSING THE RISK OF LIFE-THREATENING VENTRICULAR ARRHYTHMIAS (CLINICO-EXPERIMENTAL STUDY)

Abstract

The study aimed to assess the risk of life-threatening ventricular arrhythmias (LTVA) in patients with non-ST elevation acute coronary syndrome (ACS) and ventricular extrasystolia (VE) developing in the first 24 hours of ACS. In 46 dogs, VE with early, postponed post-depolarisation, re-entry and ischemic mechanisms was modelled. In total, 168 patients with non-ST elevation ACS and Class II-V Lawn VE were examined. All patients underwent general clinical examination as well as the assessment of late ventricular potentials (LVP), QT interval dispersion (QTd), and heart rate turbulence (HRT). In the experimental study, persistent ventricular tachycardia and/or ventricular fibrillation developed in 100%, 75%, and 85,71% of the animals with early post-depolarisation, re-entry and ischemic VE mechanisms, respectively. In the clinical study, LTVA was observed in 13,76 % of ACS patients, including 69,32 % with arrhythmia development in the first 3 days. Positive predictive value for LVP, QTd>80 ms and pathologic HRT was no more than 42%. LTVA risk could be assessed by the formula: LTVAR = А ÷ В, where LTVAR is LTVA risk in units, A – linear deviation of corrected pre-ectopic interval (ms) for at least 20 ventricular extrasystoles, calculated separately for left and right VE, and B – analysed ventricular extrasystole number (per hour). LTVAR<0,5 could be a marker of high LTVA risk, with positive predictive value of 96,34%, in non-ST elevation ACS patients with VE