Evaluation of beta-adrenergic reactivity in paroxysmal atrial fibrillation patients administered with sotalol in the presence of sympathicotonic and vagotonic disorders

We examined 23 patients with paroxysmal form of atrial fibrillation in the presence of coronary heart disease and hypertension to study в-adrenergic receptor reactivity and tone of the autonomic nervous system (ANS). The evaluation of β-adrenergic reactivity of the cell membranes was performed; sinus rhythm variability was determined; and sympatheticotonic and vagotonic disorders in patients with paroxysmal form of atrial fibrillation were studied before and during treatment with sotalol. Using a quantitative biochemical method of adrenergic reactivity of the organism, individual sensitivity to β-adrenergic blocking agent (sotalol) was determined based on measuring the β-APM values of red blood cells. Effect of sotalol on ANS manifested through greater augmentation of the high-frequency spectral component of heart rate variability compared with the low frequency component. Long-term sotalol administration significantly reduced β-APM and increased the sensitivity of adrenergic receptors while maintaining the achieved target heart rate.