Heart rate variability: a practical review for the beginner

Heart rate variability (HRV) refers to beat-to-beat interval changes on the electrocardiogram (ECG) and is considered a noninvasive measure of the autonomic balance. Although classical ECG is a well-known and standardized clinical method, HRV developed abruptly due to the evolution of computerized data acquisition systems in cardiology (digital electrocardiographs) and their software programs. HRV can be evaluated by visual methods (the beat-to-beat tachogram, the histogram and the Poincaré diagram) or by statistically computed parameters. Its applications include sympathovagal balance evaluation, monitoring of different neuropathies and contribution to survival prediction after cardiac acute events. Studies state that HRV can also be used as a method for rapid screening of some autonomic and cardiac diseases, along with other diagnostic procedures. Mirescu et al (PDF

Acute effects of electronic cigarette smoking on heart rate variability

Heart rate variability (HRV) refers to a temporal variation between consecutive heart beats and is considered a measure of the balance between the sympathetic and the parasympathetic nervous system. HRV is also one of the few methods which can evaluate the acute effects of smoking on the autonomous nervous system. The aim of our study was to evaluate and compare HRV parameters during regular cigarette and electronic cigarette smoking. The study was performed on 15 regular cigarette smokers and 15 electronic cigarette smokers, and time-domain, frequency-domain and nonlinear parameters of HRV were recorded. When smoking regular cigarettes, the subjects had lower values of HRV parameters than before smoking, whereas electronic cigarette smokers described higher HRV parameters values for all HRV parameters. Our results regarding the behavior of HRV parameters during regular cigarette smoking are consistent with the literature, but the evaluation of the sympathovagal balance during electronic cigarette smoking was performed for the first time in our study. Mirescu et al sc (PDF