Essential arterial hypertension is associated with increased risk for the development of atrial and ventricular arrhythmias. Their nature and expression influence disease severity, death rate and quality of life. The heart morphological remodelling – the development of left ventricular hypertrophy and its diastolic dysfunction, the increase of left atrial sizes are the significant substratum for arrhythmias development in hypertensive patients. Electrical inhomogeneity of the heart, as a rule, precedes arrhythmias manifestation that have defined the need for development of noninvasive electrocardiographic parameters (ECG high resolution, dispersion of the interval QT, heart rate variability, morphological analysis the T wave) and study of their prognostic value. Long-term antihypertensive therapy leading to left ventricular hypertrophy regression is accompanied by increasing of its electric stability – a reduction of markers of myocardium electrical inhomogeneity, numbers and gravity of extrasystoles.