Relationship between heart rate variability and posterior circulation cerebral infarction and its value in prognosis prediction

Abstract

Objective To investigate the characteristic of heart rate variability (HRV) changes in patients with posterior circulation cerebral infarction and its value in prognosis prediction. Methods Fifty-four cases continuously diagnosed with acute posterior circulation cerebral infarction from March 2015 to November 2015 in the Department of Neurology of People′s Hospital of Xinjiang Uygur Autonomous Region were prospectively analyzed. At the same time, 96 cases of anterior circulation infarction were chosen as control group. General state of health and results of laboratory examinations and other auxiliary examinations of all patients were recorded. The 24-hour dynamic electrocardiogram was done to calculate the HRV. The characteristics of HRV changes in patients with posterior circulation cerebral infarction were compared with those with anterior circulation infarction. According to modified Rankin Scale (mRS) score at onset of 90 days, posterior circulation infarction cases were divided into good prognosis group (mRS score 0 to 2) and poor prognosis group (mRS score 3 to 6). The correlation between HRV and the prognosis of posterior circulation infarction was analyzed. Results In patients with posterior circulation cerebral infarction, HRV time-domain parameters standard deviation of normal to normal interbeat intervals (SDNN, (93.32±23.51) ms), root mean square of square sum of adjacent NN interval differences (SDANN, (82.57±18.40) ms), root mean square of sussessive differences (rMSSD, (32.89±15.56) ms) were lower than those with anterior circulation infarction ((109.66±52.08) ms, (107.41±61.58) ms, (42.60±23.24) ms; t=2.181, 3.670, 3.059, all P<0.05); and HRV frequency domain parameters total power ((3 373.28±1 928.07) ms), low frequency ((294.00±157.23)ms), low frequency/high frequency(LF/HF, 3.80±2.24) were higher than those with anterior circulation infarction ((2 629.00±1 352.43) ms, (233.61±134.53) ms, 2.68±1.38; t=2.762, 2.481, 3.426, all P<0.05). HRV parameters SDNN (OR=0.915, 95% CI 0.87-0.962, P=0.000), SDANN(OR=0.921, 95% CI 0.869-0.976, P=0.005), rMSSD(OR=0.895, 95% CI 0.831-0.963, P=0.003) and LF/HF (OR=1.564, 95% CI 1.052-2.326, P=0.027) were found associated with poor prognosis of posterior circulation cerebral infarction at onset of 90 days. Conclusions Compared with anterior circulation infarction cases, the HRV is decreased in posterior circulation infarction patients and the increased sympathetic nervous activity is coupled with the sympathetic nerve and vagus nerve regulation imbalance. The decreased SDNN, SDANN, rMSSD and increased LF/HF prompt 90 days poor prognosis in posterior circulation infarction patients. Key words: Cerebral infarction; Heart rate; Autonomic nervous system; Prognosis