Continuous perioperative heart rate variability monitoring in video-assisted thoracoscopic surgery lobectomy-a pilot study

Abstract

Heart rate variability (HRV) is a measure of cardiac autonomic modulation and is potentially related to hypotension, postoperative atrial fibrillation, and orthostatic intolerance. However, there is a lack of knowledge on which specific time points and indices to measure. To improve future study design, there is a need for procedure-specific studies in an enhanced recovery after surgery (ERAS) video-assisted thoracic surgery (VATS) lobectomy setting, and for continuous measurement of perioperative HRV. HRV was measured continuously from 2 days before until 9 days after VATS lobectomy in 28 patients. After VATS lobectomy, with median length of stay = 4 days, the standard deviation between normal-to-normal beats and the total power of HRV were reduced for 8 days during the night and day times, while low-to-high frequency variation and detrended fluctuation analysis were stable. This is the first detailed study to show that HRV measures of total variability were reduced following ERAS VATS lobectomy, while other measures were more stable. Further, preoperative HRV measures showed circadian variation. The patch was well tolerated among participants, but actions should be taken to ensure proper mounting of the measuring device. These results demonstrate a valid design platform for future HRV studies in relation to postoperative outcomes.

Keywords: Enhanced recovery after surgery; Heart rate variability; Orthostatic intolerance; Postoperative atrial fibrillation; Surgical risk stratification; VATS.

Fig. 1

Patient flow with reasons for exclusion. Four patients had partially usable recordings and were therefore included in analyses

Fig. 2

Course of Standard deviation of normal-to-normal beats (SDNN) in the perioperative period during the night, day, and evening. *p < 0.05, **p < 0.01, ***p < 0.001, **** p < 0.0001. One-way ANOVA followed by post-hoc paired t-test between time points adjusted for mass significance. Data presented as mean (dot) ± SE (error bars)

Fig. 3

Course of Total Power (TP) in the perioperative period during night, day, and evening periods. One-way ANOVA fol lowed by post-hoc paired t-test between time points adjusted for mass significance. **p < 0.01, ***p < 0.001. To improve readability of the graph, only p < 0.01 are shown in the night and day periods. Subjects 9, 35 and 36 were removed from TP analysis due to being an extreme outlier. Data presented as mean (dot) ± SE (error bars)

Fig. 4

Course of low-frequency power divided by high-frequency power (LF/HF) in the perioperative period during night, day, and evening periods. One-way ANOVA showing significant fluctuations in evening period. Subjects 15 and 16 were removed from LF/HF analysis due to being extreme outliers. Data presented as mean (dot) ± SE (error bars)

Fig. 5

Course of detrended fluctuation analysis alpha-1 (DFA1) in the perioperative period during night, day, and evening periods. One-way ANOVA showing s ignificant fluctuations in NIGHT and EVENING periods. Data presented as mean (dot) ± SE (error bars)

Fig. 6

Preoperative time course of A SDNN showing significant circadian variation with increases from EVENING to NIGHT to DAY periods, and then a drop to EVENING again, B TP showing significant circadian variation, C LF/HF and D) DFA1 with no significant development during the preoperative period. Subjects 9, 35 and 26 were removed from TP analysis and subjects 14 and 16 were removed from LF/HF analysis because they were extreme outliers. Data presented as mean (dot) ± SE (error bars), **p < 0.01