Correlations between the Poincaré plot and conventional heart rate variability parameters assessed during paced breathing.
OBJECTIVE
To analyze the correlation of the Poincaré plot descriptors of RR intervals with standard measures of heart rate variability (HRV) and spontaneous baroreflex sensitivity (BRS). A physiological model of changing respiratory rates from 6 to 15 breaths/min provided a wide range of RR intervals for analysis.


METHODS
Beat-to-beat finger blood pressure, ECG, and respiratory curves were recorded noninvasively in 15 young healthy volunteers (19-25 years old; 7 females) breathing for 5 min at 4 different respiratory rates of 6, 9, 12, and 15 breaths/min. Four descriptors of the Poincaré plot (SD1, SD2, S, and SD2/SD1), time and frequency domain HRV, and spontaneous BRS (cross-correlation method) were calculated for each 5-min recording.


RESULTS
The values of SD1 characterizing short-term HRV, SD2 describing long-term HRV, and S measuring total HRV were significantly correlated with BRS and time and frequency domain measures of short, long, and total HRV. The LF/HF significantly correlated with SD2 and SD2/SD1 representing the balance between long- and short-term HRV. None of the Poincaré plot descriptors was correlated with the mean RR interval. The increased respiratory rate caused a significant reduction of BRS, measures of total and long-term HRV, and an increase of HF that peaked at 12 breaths/min.


CONCLUSIONS
The descriptors of the Poincaré plot of RR intervals are significantly correlated with measures of BRS and time and frequency domain HRV, but not with heart rate. A faster respiratory rate reduces long-term HRV measures and temporarily increases HF.
Guzik
Przemysław
P
Department of Cardiology-Intensive Therapy, University of Medical Sciences in Poznań, Przybyszewskiego 49, 60-355 Poznan, Poland. pguzik@ptkardio.pl.
Piskorski
Jarosław
J
Krauze
Tomasz
T
Schneider
Raphael
R
Wesseling
Karel H
KH
Wykretowicz
Andrzej
A
Wysocki
Henryk
H
D000328:Adult; D017704:Baroreflex; D001794:Blood Pressure; D002320:Cardiovascular Physiological Phenomena; D004562:Electrocardiography; D005260:Female; D005385:Fingers / Q000098:blood supply; D006339:Heart Rate; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular; D012016:Reference Values; D015203:Reproducibility of Results; D012107:Research Design; D015656:Respiratory Mechanics; D012143:Respiratory Physiological Phenomena; D013997:Time Factors