P-wave dispersion by 12-lead electrocardiography in carotid artery stenting.

OBJECTIVE: Although carotid artery stenting (CAS) is an effective treatment for severe carotid stenosis, it has been associated with alterations in autonomic functions during or shortly after the procedure. And, autonomic functions influence P-wave durations. In this study, our aim was to investigate P-wave durations on 12-lead surface electrocardiography after CAS. METHODS: Patients (19 male, 8 female) who are suitable for CAS, without a history of hypertension, diabetes mellitus, severe coronary artery or valvular heart disease, were enrolled in our study. 12-lead surface electrocardiography recordings were obtained at the beginning, immediately after and at the 24 h of the procedure. P-wave maximum, minimum and dispersion durations were analyzed by double-blinded observers. Results were statistically analysed using Friedman and Wilcoxon tests. RESULTS: The P maximum and P dispersion values were significantly increased immediately after the procedure and continued with high levels at 24-h recordings, respectively (128 ± 10/19 ± 7, 143 ± 14/37 ± 11, and 137 ± 11/30 ± 7 ms, p value <0.05). The P minimum value was significantly decreased immediately after the procedure (109 ± 11/105 ± 10 ms, p value <0.05). At 24-h recordings, a nonsignificant increase occured in P minimum values (106 ± 8 ms). CONCLUSIONS: P maximum and dispersion durations were significantly increased after the CAS and continued with high levels at 24-h recordings, which may be associated with the alterations in autonomic functions via augmented parasympathetic activity by vagally mediated stimulus. Overall, these findings suggest that decline in cardiovascular activity is prolonged at least 24 h after CAS.

Evaluation of autonomic functions by heart rate variability after stenting in patients with carotid artery stenosis.

OBJECTIVE: Although carotid stenting is an effective treatment for severe carotid stenosis, it has been associated with alterations in autonomic functions during or shortly after the procedure. Heart rate variability (HRV) is an established tool for the asessment of autonumic functions. In this study, our aim was to investigate the relation between the alterations in autonomic functions and HRV by Holter monitoring parameters. METHODS: Patients (19 male, 8 female) that are suitable for carotid artery stenting, without a history of hypertension, diabetes mellitus, severe coronary artery or valvular heart disease, were enrolled to our study. Short-term HRV analysis recordings were obtained at the beginning, and after the procedure. The square root of the mean squared differences of successive NN intervals (RMSSD), total frequency, low frequency (LF), high frequency (HF), normalized units LF (LFnu), normalized units HF (HFnu), LF/HF ratios were analyzed. Results were statistically analysed by using Wilcoxon test. RESULTS: Total frequency did not show any significant changes after the procedure (1101 ± 829, 981 ± 855). While RMSSD and HFnu values significantly increased respectively (23 ± 12/33 ± 22, and 22 ± 10/35 ± 10, p < 0.05) after the procedure, HF values increased nonsignificantly after the procedure (82 ± 92/92 ± 108). LF, LFnu, and LF/HF values were significantly decreased after the procedure. (228 ± 166/112 ± 100, 70 ± 15/55 ± 18, 4 ± 2.5/2.1 ± 2, respectively, p < 0.05) CONCLUSIONS: While RMSSD and HF are used as markers of vagal activity, LF is a marker of sympathetic modulation and LF/HF ratio shows sympathovagal balance. In our study, we showed that carotid artery stenting is associated with increase in parasympathetic activation, and this finding is demonstrated by HRV parameters.