Assessment of short-term prognosis by sinus heart rate turbulence in patients with unstable angina

The aim of this study was to explore the correlation between sinus heart rate turbulence (HRT) and short-term prognosis in patients with unstable angina (UA). Seventy-five patients with UA received Holter monitoring for 24 h, within 48 h of hospitalization to obtain parameters of HRT, including turbulence onset (TO) and turbulence slope (TS), as well as parameters of heart rate variability (HRV), including standard deviation of all NN intervals (SDNN) and average R-R interval. The left ventricular ejection fraction (LVEF) was measured with an ultrasound cardiogram. Patients were divided into a stable group and a refractory group based on the prognosis during a 7- to 21-day hospital stay. The correlation between the prognosis and each risk factor was analyzed. Of the 75 patients with UA, the pathogenetic condition was stable in 50 patients (stable group) and cardiac events occurred in 25 patients (refractory group). Univariate analysis indicated that the risk factors of short-term poor prognosis of UA include TS ≤2.5 msec/R-R, age ≥70 years, LVEF <40% and SDNN <70 msec. Logistic multivariate regression analysis revealed that only TS ≤2.5 msec/R-R and LVEF <40% were independent risk factors of short-term poor prognosis. Our study revealed that weakening or disappearance of HRT is an independent predictor of short-term poor prognosis in patients with UA.