| Abstract: | patients with severe congestive heart failure (CHF) were underwent digoxin therapy of one week to evaluate the relationship between autonomous nervous function and heart rate variability (HRV),and effect of digoxin on it.Plasma levels of norepinephrine (NE) and HRV were determined before and after digoxin therapy.The results showed that basic NE levels had significant negative correlation with all the time domain variables of HRV.Digoxin therapy improved cardiac function by a mean of 1.52±0.51 NYHA functional class;NE levels decreased significantly from a mean of 291±80 pg/ml to 213±82 pg/ml( P <0.001) with concomitant increase in variables of HRV.Among them,mean normal RR interval and SDNN increased significantly from 727±123 ms and 67.7±21.8 ms to 777±122 ms and 87.4±29.2 ms respectively;variables reflecting cardiac vagal activity such as RMSSD,PNN 50 and HF increased significantly from 36.3±30.6 ms,5.3±5.5% and 37.1±21.2 ms 2 to 56.1± 43.7 ms ,10.8±10.6% and 79.9±58.2 ms 2 respectively.A significant positive correlation was found between the changes in plasma NE levels and the changes in all the time domain variables of HRV after digoxin therapy;in addition,the changes in most of the time domain variables of HRV and their post treatment levels,especially variables reflecting cardiac vagal activity,eg,RMSSD and PNN 50 were strongly correlated with serum digoxin levels.It was concluded that the increased sympathetic nerve activity paralleled to decreased HRV in patients with severe CHF,Digoxin therapy could increase cardiac vagal tone and improve HRV and cardiac function in patients with severe CHF. |
