Heart rate variability and catecholamines during hypoglycemia and orthostasis Export

@article{citeulike:3574534, abstract = {The low frequency component of heart rate variability (HRV) is believed to be affected by sympathetic activity, but an evidence for this suggestion remains controversial. This study analyzed association between HRV and plasma catecholamines in response to two distinct conditions activating sympathetic nervous system. Changes in HRV were analysed from ECG recording and plasma norepinephrine and epinephrine levels were measured in response to head-up tilt (60\&\#xb0;, 10\&\#xa0;min) in 14 healthy volunteers (6 males, mean age 27.2 \&\#xb1; 0.8) and in response to insulin-induced hypoglycemia (0.1\&\#xa0;IU per kg, i.v. bolus) in 11 healthy volunteers (5 males, mean age 26.6 \&\#xb1; 0.9\&\#xa0;yr). Normalized low frequency power, low/high frequency ratio, plasma catecholamines increased, whereas normalized high frequency power decreased in response to head-up tilt or hypoglycemia. When analyzed individual time points of orthostatic test, plasma epinephrine correlated positively with low/high frequency ratio and negatively with normalized high frequency at the 3rd min of the head-up tilt. When all data at different time points were pooled significant correlations were found between catecholamines and normalized low frequency power and low/high frequency ratio. In insulin-induced hypoglycemia test plasma epinephrine correlated negatively with normalized high frequency power at the 30th minute. When all data measured at different time points were pooled no significant correlation was found between plasma catecholamines and HRV parameters. In conclusion, the present study shows an increase in low frequency component of HRV in response to orthostasis or hypoglycemia with significant, however inconsistent association to changes in plasma catecholamines.}, author = {Vlcek, M. and Radikova, Z. and Penesova, A. and Kvetnansky, R. and Imrich, R.}, citeulike-article-id = {3574534}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.autneu.2008.08.001}, citeulike-linkout-1 = {http://linkinghub.elsevier.com/retrieve/pii/S1566070208001380}, comment = {"The HRV is often used and misused as a measure of cardiac autonomic outflow, however available data are not unequivocal in support for the above assumption (Eckberg,1997). Rather than absolute marker of autonomic activities HRV should be considered a marker of cardiac autonomic modulation (Pagani et al., 1997; Parati et al., 2006). Moreover, some recent data suggest that HRV ismore related to arterial baroreflex function than cardiac autonomic activity itself (Moak et al., 2007) and that HRV has no direct relationship to directly recorded cardiac sympathetic nerve activity (Jardine et al., 2002). It seems that especially for the measurement of cardiac sympathetic activity other methods than HRV should be used (Grassi and Esler, 1999)."}, day = {14}, doi = {10.1016/j.autneu.2008.08.001}, issn = {15660702}, journal = {Autonomic Neuroscience}, keywords = {autonomic\_ns, catecholamines, clinical\_study, epinephrine, hrv, hypoglycaemia, sympathovagal\_balance, vfc}, month = {September}, posted-at = {2008-11-18 16:14:36}, priority = {2}, title = {Heart rate variability and catecholamines during hypoglycemia and orthostasis}, url = {http://dx.doi.org/10.1016/j.autneu.2008.08.001}, volume = {(Article in Press)}, year = {2008} }

TY - JOUR ID - citeulike:3574534 L3 - citeulike-article-id:3574534 N2 - The low frequency component of heart rate variability (HRV) is believed to be affected by sympathetic activity, but an evidence for this suggestion remains controversial. This study analyzed association between HRV and plasma catecholamines in response to two distinct conditions activating sympathetic nervous system. Changes in HRV were analysed from ECG recording and plasma norepinephrine and epinephrine levels were measured in response to head-up tilt (60°, 10 min) in 14 healthy volunteers (6 males, mean age 27.2 ± 0.8) and in response to insulin-induced hypoglycemia (0.1 IU per kg, i.v. bolus) in 11 healthy volunteers (5 males, mean age 26.6 ± 0.9 yr). Normalized low frequency power, low/high frequency ratio, plasma catecholamines increased, whereas normalized high frequency power decreased in response to head-up tilt or hypoglycemia. When analyzed individual time points of orthostatic test, plasma epinephrine correlated positively with low/high frequency ratio and negatively with normalized high frequency at the 3rd min of the head-up tilt. When all data at different time points were pooled significant correlations were found between catecholamines and normalized low frequency power and low/high frequency ratio. In insulin-induced hypoglycemia test plasma epinephrine correlated negatively with normalized high frequency power at the 30th minute. When all data measured at different time points were pooled no significant correlation was found between plasma catecholamines and HRV parameters. In conclusion, the present study shows an increase in low frequency component of HRV in response to orthostasis or hypoglycemia with significant, however inconsistent association to changes in plasma catecholamines. JF - Autonomic Neuroscience SN - 15660702 TI - Heart rate variability and catecholamines during hypoglycemia and orthostasis VL - (Article in Press) KW - autonomic_ns KW - catecholamines KW - clinical_study KW - epinephrine KW - hrv KW - hypoglycaemia KW - sympathovagal_balance KW - vfc N1 - "The HRV is often used and misused as a measure of cardiac autonomic outflow, however available data are not unequivocal in support for the above assumption (Eckberg,1997). Rather than absolute marker of autonomic activities HRV should be considered a marker of cardiac autonomic modulation (Pagani et al., 1997; Parati et al., 2006). Moreover, some recent data suggest that HRV ismore related to arterial baroreflex function than cardiac autonomic activity itself (Moak et al., 2007) and that HRV has no direct relationship to directly recorded cardiac sympathetic nerve activity (Jardine et al., 2002). It seems that especially for the measurement of cardiac sympathetic activity other methods than HRV should be used (Grassi and Esler, 1999)." AU - Vlcek, M AU - Radikova, Z AU - Penesova, A AU - Kvetnansky, R AU - Imrich, R PY - 2008/09/14/ UR - http://dx.doi.org/10.1016/j.autneu.2008.08.001 ER -