Quantitative VCG and BSPM Repolarization Parameters Evidence Increased Sympathetic Activation of the Ventricular Myocardium in Different Adrenergic Situations

Participation of the sympathetic nervous system (SNS) in normal or pathological regulations of the heart is in present studies documented mainly by blood pressure (BP) and heart rate (HR) derived indexes. The previously proposed parameters characterizing ventricular repolarization were used in this study to detect the presumed effect of SNS hyperactivity on the ventricular myocardium in prehypertensive subjects and in sympathergic situations. In 75 healthy boys and men, aged 15 – 35 years with optimal, normal and high normal BP and normal or increased body fat proportion (BF), the BP, HR, QTc index, rate pressure product (RPP), magnitude of the maximal spatial repolarization vector (sTmax) and amplitude of the isointegral repolarization map (RIMampl) were evaluated. Compared to subjects with optimal casual BP 120/80 mmHg, already in the class defined as normal and high normal BP (ESH/ESC 2013), the differences in repolarization parameters point to significantly higher sympathetic outflow to the ventricular myocardium at rest, similar to changes due to psycho-emotional or postural reactions. An additional factor – higher proportion of BF amplified the sTmax and RIMampl signs of the direct myocardial SNS effects.