Objective: The aim was to compare subjectively experienced load with cardiovascular load in patients undergoing a medical intervention by either carotid endarterectomy (CEA) or carotid artery stenting (CAS). Heart rate variability (HRV), including parameters of the pNNxx family, and perceived medical intervention load (PMIL) were investigated and compared in a prospective study.Methods: In a sample of 52 patients (CEA: n = 28; CAS: n = 24) aged 69 ± 10 years, electrocardiogram was recorded throughout the perioperative period and questionnaires on pre-and postoperative state (STAI X1) and trait anxiety (STAI X2) as well as the PMIL were filled in. Preoperative (15 minutes before surgery) HRV parameter values of time and frequency domain were compared to postoperative values (15 minutes lasting epoch 5 hours after surgery).
Results:A 2 (Time: pre vs. post) × 2 (Intervention: CEA vs. CAS) repeated measures ANOVA revealed increased HRV after CAS compared to CEA, with the most pronounced effect size for SDNN. Effect sizes for the pNNxx family around 25ms namely pNN20, pNN25, and pNN30 were also pronounced and greater than the effect size for the traditional pNN50. In both groups state anxiety was preoperatively (M = 40.03 ± 11.00) higher than postoperatively (M = 32.74 ± 7.36) but no group differences were observed for anxiety or for the subjective measure of the PMIL.Conclusion: Cardiovascular load as indicated by HRV is less for CAS compared to CEA whereas subjective measures displayed no differences. In addition, HRV assessed by pNNxx (with xx 20 -30 ms) beside global parameters like SDNN and Total Power seems to be in particular sensitive for load.