Value of pressure-strain loop in evaluating the effects of thoracic paravertebral block on left ventricular function before off-pump coronary artery bypass graft / 中华超声影像学杂志

ABSTRACT

Objective:To observe the effects of bilateral thoracic paravertebral block (TPVB) on left ventricular myocardial work using pressure-strain loop(PSL) in patients before off-pump coronary artery bypass graft(OPCABG).Methods:A total of 24 patients with coronary heart disease undergoing selective OPCABG were recruited in the First Affiliated Hospital of Nanjing Medical University from May to August 2021. All patients underwent ultrasound-guided TPVB preoperatively. Left ventricular global work, including global longitudinal strain(GLS), global work index(GWI), global constructive work(GCW), global waste work(GWW), global work efficiency(GWE), and regional work, including myocardial work index(MWI), myocardial work efficiency(MWE) were observed before TPVB and 20 minutes after TPVB.Results:The parameters of heart rate and left ventricular outflow tract blood flow were decreased [(69.13±10.72)bpm vs (65.46±9.66)bpm, P=0.010; (13.86±2.83)ml vs (12.72±2.60)ml, P=0.017]. The MWI in regional segments of hypokinesis and akinesis were significantly improved [hypokinesis (1 175.76±206.64)mmHg% vs (1 349.38±462.35)mmHg%, P=0.004; akinesis (684.94±251.39)mmHg% vs (965.35±384.33)mmHg%, P=0.001] and the MWE in regional segments of hypokinesis and akinesis were improved [hypokinesis (87.79±7.46)% vs (90.35±6.39)%, P=0.029; akinesis (70.24±18.03)% vs (80.15±16.65)%, P=0.021]. There were no significant changes in MWI, MWE, LVEF, GLS, GWI, GCW, GWW and GWE(all P>0.05). Conclusions:Based on PSL, the changes of left ventricular work in patients with OPCABG before and after TPVB show that TPVB can improve the blood supply of the ischemic myocardium, which provides a reliable basis for optimizing the perioperative anesthesia management.