Elias Simiat O, Ajayi Reina E
Department of Physiology, Lagos State University College of Medicine, Ikeja, Lagos, Nigeria.
Physiol Rep. 2019 Jan;7(2):e13985. doi: 10.14814/phy2.13985.
There is a dearth of studies investigating the effect of sympathetic activation on left ventricular function. This study aimed to investigate the effect of sympathetic autonomic stress on left ventricular function in young healthy adults. Fifty-six normotensive healthy participants (age 23.55 ± 3.82 years) took part in the study after giving informed consent. After obtaining baseline measurements, heart rate (HR), blood pressure (BP), peripheral saturation of oxygen (SpO2) and left ventricular function (assessed by means of ejection fraction (EF) obtained by transthoracic 2-D echocardiography) were determined before and following sympathetic activation using cold pressor test (CPT). Exposure to CPT led to significant increase (P < 0.0001) in HR (70.4 ± 10.7 bpm to 91.6 ± 14.8 bpm), SBP (118 ± 8 mmHg to 138 ± 14 mmHg) and DBP (71 ± 7 mmHg to 91 ± 11 mmHg). Participants' EDV (101.1 ± 15.8 ml to 104.2 ± 19.3 mL), ESV (38.7 ± 9.1 mL to 40.3 ± 11.6 mL), SpO2 (99.5 ± 0.79% to 99.5 ± 0.77%) and EF (61.9 ± 5.9% to 60.9 ± 6.4%) were only slightly changed (P > 0.05). However, cardiac output (4.3 ± 0.9 L/min to 5.4 ± 1.4 L/min) and cardiac index (3.7 ± 0.8 L/min per m to 4.5 ± 1.4 L/min per m ) increased significantly (P < 0.0001). We conclude that sympathetic stress induced by cold pressor test has marginal effect on ejection fraction and fractional shortening while increasing cardiac output and cardiac index in young healthy adults.
目前对于交感神经激活对左心室功能影响的研究匮乏。本研究旨在探讨交感自主神经应激对年轻健康成年人左心室功能的影响。56名血压正常的健康参与者（年龄23.55±3.82岁）在签署知情同意书后参与了本研究。在获得基线测量值后，使用冷加压试验（CPT）在交感神经激活前后测定心率（HR）、血压（BP）、外周血氧饱和度（SpO2）和左心室功能（通过经胸二维超声心动图获得的射血分数（EF）进行评估）。暴露于CPT导致HR（从70.4±10.7次/分钟显著增加至91.6±14.8次/分钟，P<0.0001）、收缩压（SBP，从118±8mmHg增加至138±14mmHg）和舒张压（DBP，从71±7mmHg增加至91±11mmHg）。参与者的舒张末期容积（EDV，从101.1±15.8ml至104.2±19.3mL）、收缩末期容积（ESV，从38.7±9.1mL至40.3±11.6mL）、SpO2（从99.5±0.79%至99.5±0.77%）和EF（从61.9±5.9%至60.9±6.4%）仅有轻微变化（P>0.05）。然而，心输出量（从4.3±0.9L/分钟增加至5.4±1.4L/分钟）和心脏指数（从3.7±0.8L/分钟每平方米增加至4.5±1.4L/分钟每平方米）显著增加（P<0.0001）。我们得出结论，冷加压试验诱导的交感神经应激对年轻健康成年人的射血分数和缩短分数影响较小，同时增加了心输出量和心脏指数。
