Cardiovascular modulation during vagus nerve stimulation therapy in patients with refractory epilepsy.
To evaluate the effects of permanent vagal stimulation on cardiovascular system, 10 patients, affected by drug-resistant epilepsy with no primitive cardiovascular pathologies, were assessed prior to VNS surgery. A complete echocardiographic study [conventional and tissue Doppler imaging (TDI)], 24-h blood pressure (BP) monitoring and HRV evaluation were performed. The above mentioned parameters were investigated without any substantial changes to drug treatment during a check-up subsequent to VNS activation [mean: 7.7 months]. The results obtained show that while the anthropometrical data and both conventional and TDI echocardiography were unvaried compared to baseline, BP showed a significant increase of both systodiastolic values. Moreover, a close scrutiny of the most affected period of the BP increase (zenith between 16:31 and 17:30 pm) (systolic BP 114.7 mmHg vs 95.3 mmHg, P < 0.0001; diastolic BP 70.9 mmHg vs 56.9 mmHg, P < 0.001) showed a significant increase of the high frequencies components (HF) (28.4 ± 2.7 vs 36 ± 5.3, P < 0.05) and a significant reduction in low frequency/HF ratio (2.3 ± 0.3 vs 1.7 ± 0.3, P < 0.0001). The present study confirms the intrinsic cardiovascular safety and reliability of VNS procedures on both BP and HF and LF profiles and suggests that a primitive VNS-mediated central impingement on vagal efferents, independently by the antiepileptic mechanism, correlated to an moderate increase of parasympathetic activity, which in turn might play a protective role in seizure-triggered alterations of cardiovascular dynamic.
Cadeddu
Christian
C
Dept. of Cardiovascular and Neurological Sciences, University of Cagliari, Sardinia, Italy. cadedduc@unica.it
Deidda
Martino
M
Mercuro
Giuseppe
G
Tuveri
Antonella
A
Muroni
Antonella
A
Nocco
Silvio
S
Puligheddu
Monica
M
Maleci
Alberto
A
Marrosu
Francesco
F
D000293:Adolescent; D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D004562:Electrocardiography / Q000379:methods; D004827:Epilepsy / Q000503:physiopathology* / Q000628:therapy*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods; D018709:Statistics, Nonparametric; D055536:Vagus Nerve Stimulation / Q000379:methods*; D055815:Young Adult