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Cardiovascular autonomic control in patients with left ventricular assistance continous flow devices
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Abstracts / Autonomic Neuroscience: Basic and Clinical 192 (2015) 56–141
b
Oppenheimer Center for the Neurobiology of Stress, UCLA, Los Angeles, CA, USA c Laureate Institute for Brain Research, Tulsa, OK, USA Background: Cardiac sympathetic denervation (CSD) is an effective therapy for ventricular arrhythmias (VAs); however, no physiologic probes exist to quantify denervation. Aim: To quantify physiologic impact of cardiac sympathetic denervation. Methods: Non-invasive neurophysiologic measures [galvanic skin resistance (GSR), finger pulse volumetry (FPV), heart rate variability (HRV), noninvasive beat-to-beat blood pressure (NIBP), and respiratory rate (RR)] were measured at baseline and during psychophysiologic stressors [Valsalva, posture change, handgrip, and mental arithmetic] in patients before and 4-6 weeks after bilateral CSD (BCSD). Clinical outcomes were also collected during follow up (3-21 months). Results: Eight patients with recalcitrant VAs (48 ± 15 yrs, 6 male, 7 NICM, 3 PMVT, LV EF 40 ± 15%) completed testing protocol before and after BCSD. Surgery was successful in all patients, and no complications occurred. At baseline, GSR and FPV responses to maximal stressors were 2.8 ± 1.5 μS and 0.5 ± 0.29 au, respectively. Following BCSD, no significant changes in resting HR, NIBP, or RR were observed. During maximal stress, responses to GSR and GPV following BCSD decreased by 97 ± 21% (p = 0.007 for GSR) and from 45.2 ± 10au to 23.7 ± 5au (p = 0.042 for FPV) (figure), without significant impact on blood pressure and heart rate (in non-paced patients) responses. During follow up, two patients developed recurrent VAs, with the remaining patients arrhythmia free. Conclusion: Blunted GSR and FPV responses to psychophysiologic stressors identify patients who have undergone BCSD, and identify favorable responses to BCSD.
doi:10.1016/j.autneu.2015.07.072
P5.21 Modulation of cardiac vagal tone during breathing at 0.1 Hz in fully conscious human volunteers Mussadiq Shaha,b, Jean Monroa, Peter O.O. Julua,b a Neuroscience Department, Breakspear Medical Group, Hemel Hempstead UK b William Harvey Heart Centre, Queen Mary University of London UK Introduction and aim: Respiratory sinus arrhythmia is used to indicate functional integrity of cardiac vagal nerve and heart rate variability during deep breathing (DB) and is widely used in clinics to test autonomic function. We wanted to compare cardiac vagal tone (CVT) during DB at 0.1 Hz with CVT at rest. Methods: Noninvasive, real-time and continuous measurement of CVT was carried out in 6 subjects (5 M, 1 F) aged 24–40 years using the NeuroScope (Little et al. 1999). Investigation carried out in supine position with 6 cycles of 4 s inspiration and 6 s expiration respectively. Study was
approved by the local ethics committee. Results: Average CVT for each subject during 1 min of DB was used to derive the mean CVT during DB. Peak CVT during DB was 25.1 ± 4.0, significantly higher than baseline CVT (P b 0.01). Maximum CVT occurred at 19.5 ± 3.7 s. CVT at last cycle of DB was 18.1 ± 2.4, lower than the peak (P b 0.03), but higher than baseline value (P b 0.01). Conclusion: DB at 0.1 Hz increased the mean CVT by 95 % above the baseline level, but peak rises more than twice baseline levels. CVT showed a decrease during DB period suggesting brainstem habituation. The amplitude of respiration sinus arrhythmia peaks at 0.1 Hz of DB (Hirsch & Bishop, 1981). Hirsch, J.A. & Bishop, B. (1981). Am. J. Physiol. 241, H620–629. Little, C.J., Julu, P.O.O., Hansen, S. & Reid, S.W.J. (1999). Am. J.Physiol. 276, H758–765. doi:10.1016/j.autneu.2015.07.073
P5.22 Cardiovascular autonomic control in patients with left ventricular assistance continous flow devices G. Colombob, E. Tobaldinia,b, M. Del Medicob, L. Angaronib, M. Bulgheronib, M. Frigerioc, N. Montanoa,b a Department of Internal Medicine, Fondazione IRCSS Ca' Granda, Ospedale Maggiore Policlinico, Milano b Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Italy c Department of Cardiology-Heart Failure and Transplants, Ospedale Niguarda Ca’ Granda, Milano Left ventricular assistance devices (LVAD) have proven effective in reducing mortality in patients on the waiting list for heart transplantation, also making them superior to medical therapy as "destination therapy" in case of inaccessibility to the list. In the last few years it appeared on the market continuos flow devices leading to better results than pulsed one; an unexpected event since the absence of pulsatile flow would be able to alter the physiological homeostatic mechanism of cardiovascular system. Aim of the study was to assess whether the implantation of LVAD can alter autonomic control in these patients. We enrolled five patients with endstage heart failure waiting for LVAD implantation and we recorded ECG and respiration for ten minutes at T0 (before) and T1 (after implantation). Cardiovascular autonomic control was assessed by spectral analysis of heart rate variability, which identifies two different components: low frequency (LF), marker of sympathetic modulation and high frequency (HF), marker of vagal activity. Results showed that heart rate and LFnu were higher at T1 compared to T0 (80 vs 60, 25 vs 17, HR and LFnu respectively). These preliminary results suggest an improvement of autonomic cardiac modulation in patients with end stage heart failure implanted with LVAD. doi:10.1016/j.autneu.2015.07.074
P5.23 The dynamics of cardiac autonomic control in sleeping preterm neonates exposed in utero to smoking E. Stéphan-Blancharda, K. Chardona, A. Lékéa,b, S. Delanauda, V. Bacha, F. Tellieza a PériTox (UMR-I-01), University of Picardy Jules Verne, Amiens b Neonatal and Paediatric Intensive Care Unit, University Medical Center, Amiens, France Aims: Fetal smoking exposure is a risk factor for preterm birth. Both smoking exposure and preterm birth are associated with an elevated incidence of early and long-term cardiovascular dysfunction.
Abstracts / Autonomic Neuroscience: Basic and Clinical 192 (2015) 56–141
b
Oppenheimer Center for the Neurobiology of Stress, UCLA, Los Angeles, CA, USA c Laureate Institute for Brain Research, Tulsa, OK, USA Background: Cardiac sympathetic denervation (CSD) is an effective therapy for ventricular arrhythmias (VAs); however, no physiologic probes exist to quantify denervation. Aim: To quantify physiologic impact of cardiac sympathetic denervation. Methods: Non-invasive neurophysiologic measures [galvanic skin resistance (GSR), finger pulse volumetry (FPV), heart rate variability (HRV), noninvasive beat-to-beat blood pressure (NIBP), and respiratory rate (RR)] were measured at baseline and during psychophysiologic stressors [Valsalva, posture change, handgrip, and mental arithmetic] in patients before and 4-6 weeks after bilateral CSD (BCSD). Clinical outcomes were also collected during follow up (3-21 months). Results: Eight patients with recalcitrant VAs (48 ± 15 yrs, 6 male, 7 NICM, 3 PMVT, LV EF 40 ± 15%) completed testing protocol before and after BCSD. Surgery was successful in all patients, and no complications occurred. At baseline, GSR and FPV responses to maximal stressors were 2.8 ± 1.5 μS and 0.5 ± 0.29 au, respectively. Following BCSD, no significant changes in resting HR, NIBP, or RR were observed. During maximal stress, responses to GSR and GPV following BCSD decreased by 97 ± 21% (p = 0.007 for GSR) and from 45.2 ± 10au to 23.7 ± 5au (p = 0.042 for FPV) (figure), without significant impact on blood pressure and heart rate (in non-paced patients) responses. During follow up, two patients developed recurrent VAs, with the remaining patients arrhythmia free. Conclusion: Blunted GSR and FPV responses to psychophysiologic stressors identify patients who have undergone BCSD, and identify favorable responses to BCSD.
doi:10.1016/j.autneu.2015.07.072
P5.21 Modulation of cardiac vagal tone during breathing at 0.1 Hz in fully conscious human volunteers Mussadiq Shaha,b, Jean Monroa, Peter O.O. Julua,b a Neuroscience Department, Breakspear Medical Group, Hemel Hempstead UK b William Harvey Heart Centre, Queen Mary University of London UK Introduction and aim: Respiratory sinus arrhythmia is used to indicate functional integrity of cardiac vagal nerve and heart rate variability during deep breathing (DB) and is widely used in clinics to test autonomic function. We wanted to compare cardiac vagal tone (CVT) during DB at 0.1 Hz with CVT at rest. Methods: Noninvasive, real-time and continuous measurement of CVT was carried out in 6 subjects (5 M, 1 F) aged 24–40 years using the NeuroScope (Little et al. 1999). Investigation carried out in supine position with 6 cycles of 4 s inspiration and 6 s expiration respectively. Study was
approved by the local ethics committee. Results: Average CVT for each subject during 1 min of DB was used to derive the mean CVT during DB. Peak CVT during DB was 25.1 ± 4.0, significantly higher than baseline CVT (P b 0.01). Maximum CVT occurred at 19.5 ± 3.7 s. CVT at last cycle of DB was 18.1 ± 2.4, lower than the peak (P b 0.03), but higher than baseline value (P b 0.01). Conclusion: DB at 0.1 Hz increased the mean CVT by 95 % above the baseline level, but peak rises more than twice baseline levels. CVT showed a decrease during DB period suggesting brainstem habituation. The amplitude of respiration sinus arrhythmia peaks at 0.1 Hz of DB (Hirsch & Bishop, 1981). Hirsch, J.A. & Bishop, B. (1981). Am. J. Physiol. 241, H620–629. Little, C.J., Julu, P.O.O., Hansen, S. & Reid, S.W.J. (1999). Am. J.Physiol. 276, H758–765. doi:10.1016/j.autneu.2015.07.073
P5.22 Cardiovascular autonomic control in patients with left ventricular assistance continous flow devices G. Colombob, E. Tobaldinia,b, M. Del Medicob, L. Angaronib, M. Bulgheronib, M. Frigerioc, N. Montanoa,b a Department of Internal Medicine, Fondazione IRCSS Ca' Granda, Ospedale Maggiore Policlinico, Milano b Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Italy c Department of Cardiology-Heart Failure and Transplants, Ospedale Niguarda Ca’ Granda, Milano Left ventricular assistance devices (LVAD) have proven effective in reducing mortality in patients on the waiting list for heart transplantation, also making them superior to medical therapy as "destination therapy" in case of inaccessibility to the list. In the last few years it appeared on the market continuos flow devices leading to better results than pulsed one; an unexpected event since the absence of pulsatile flow would be able to alter the physiological homeostatic mechanism of cardiovascular system. Aim of the study was to assess whether the implantation of LVAD can alter autonomic control in these patients. We enrolled five patients with endstage heart failure waiting for LVAD implantation and we recorded ECG and respiration for ten minutes at T0 (before) and T1 (after implantation). Cardiovascular autonomic control was assessed by spectral analysis of heart rate variability, which identifies two different components: low frequency (LF), marker of sympathetic modulation and high frequency (HF), marker of vagal activity. Results showed that heart rate and LFnu were higher at T1 compared to T0 (80 vs 60, 25 vs 17, HR and LFnu respectively). These preliminary results suggest an improvement of autonomic cardiac modulation in patients with end stage heart failure implanted with LVAD. doi:10.1016/j.autneu.2015.07.074
P5.23 The dynamics of cardiac autonomic control in sleeping preterm neonates exposed in utero to smoking E. Stéphan-Blancharda, K. Chardona, A. Lékéa,b, S. Delanauda, V. Bacha, F. Tellieza a PériTox (UMR-I-01), University of Picardy Jules Verne, Amiens b Neonatal and Paediatric Intensive Care Unit, University Medical Center, Amiens, France Aims: Fetal smoking exposure is a risk factor for preterm birth. Both smoking exposure and preterm birth are associated with an elevated incidence of early and long-term cardiovascular dysfunction.