Modulating effect of respiration on atrioventricular conduction time assessed using PR interval variation

Abstract

Respiratory sinus arrhythmia (RSA) is the variation of heart rate (or RR interval) in phase with respiration and has been extensively studied. However, the effect of respiration on atrioventricular conduction delay (and hence PR interval length) has not yet received much attention. This work reports on measurements of respiration and associated RR and PR variability, in 11 subjects, assessed through surface electrocardiogram measurements, for both paced and spontaneous respiration in the supine position. A wavelet-based approach was used to extract RR and PR intervals. The accuracy of RR and PR interval measurement was consistent with previously published work. Respiratory atrioventricular conduction delay variability (RCV) was assessed using three techniques: spectral, peak-to-trough and cosinor methods. All measures showed statistically significant variations in PR interval due to respiration during paced respiration at 6 min(-1). Of the three measures, cosinor analysis was most reliable in highlighting RCV. Using this measure, statistically significant RCV was seen in ten out of the 11 subjects during paced respiration. The magnitude of the variability was estimated as +/- 5.9% of the mean PR interval. In spontaneous respiration, statistically significant RCV was seen in approximately half of the subjects, with an estimated variability of +/- 1.5%. As a control, statistically significant values for RSA were also obtained from the same data, which agreed with previously published measurements. It was concluded that respiration does indeed modulate atrioventricular conduction delay, deep breathing in the supine position accentuates this effect, and cosinor analysis provides a reliable means for quantifying this effect.

Chronodromotropic coordination in cats

“…However, the spectrum analysis of these oscillations was not carried out. The wave structure of AV interval oscillations were examined only in few papers [6][7][8]10]. The nature of these oscillations was not studied in details, and the corresponding data on animals are absent.…”

Autonomic Cardiac Modulation at Sinoatrial and Atrioventricular Nodes: Observations and Models

“…In [20], we showed that the accuracy of automated PP and PR interval estimation was comparable to that of a human expert. To capture the "average" changes provoked by the supine-to-standing transition, Figure 7.2a shows the median PP and PR interval for all 20 subjects on a beat-by-beat basis in a 300-beat window centered around the standing event.…”

“…The PP (P-wave onset to following P-wave onset), PR (P-wave onset to following QRS onset), and RP (QRS onset to following P-wave onset) intervals were extracted using a wavelet-based technique [20]. In [20], we showed that the accuracy of automated PP and PR interval estimation was comparable to that of a human expert.…”

Effect of pentobarbital on spectral characteristics and phase ratios of wave oscillations of cardiac contraction period and time of atrioventricular conduction in cats

“…Similar wave oscillations of atrioventricular (AV) interval were detected [2,9,10,12], spectral analysis thereof was carried out, transmitter nature was investigated, and ratio between the wave structure of AV interval and cardiac contractions period (RR interval) was studied in cats [2]. Here we studied the effect of barbiturate narcosis, one of the most prevalent methods of anesthesia in physiological experiments, on the wave structure of AV interval and its ratio with the RR interval wave structure.…”