The effect of nitroglycerin on cardiac extrasystoles and heart rate variability in patients with ­stable angina pectoris class 1 and 2

Aim. To study the effect of nitroglycerin on the heart rate and its variability in patients with stable angina pectoris class 1 and 2. Methods. 85 men with stable angina pectoris class 1 and 2 pathologies were examined between 2007 and 2012 in the City Clinical Hospital No. 8 of Chelyabinsk (mean age 53.1±5.66 years). In addition to common methods, a rhythmocardiographic study was performed, which allows you to calculate heart rate variability. An electrocardiogram was recorded simultaneously with the rhythmocardiogram. Results. After sublingual nitroglycerin, the number of ventricular extrasystoles decreased in the background test and during Valsalva maneuver, increased in the Ashner's test and an exercise stress tests and did not change in the orthostatic test. An increase in supraventricular extrasystoles after nitroglycerin administration occurred in 10.6% of patients. Nitroglycerin administration resulted in a decrease in the inter-systolic intervals, an increased in the proportion of slow low-frequency waves— statistically significant in the background and an exercise stress test. Spectral indicators of cardiac sympathetic modulation significantly increased in the Ashner’s test and decreased in the background test, while spectral indicators of cardiac parasympathetic modulation decreased in all samples except in exercise stress tests. Conclusion. Under the influence of nitroglycerin, supraventricular arrhythmias increased in all vegetative tests except for orthostatic, the number/severity of ventricular extrasystoles ambiguously changed: decreased in Valsalva manoeuvre the background test, did not change in orthostatic and increased in Aschner's and an exercise stress tests; after nitroglycerin, the proportions of sympathetic influence (in Ashner's test) and slow low-frequency waves in the spectrum of the vegetative modulation increased with a decrease in parasympathetic.