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Objective:To analyze the relationship between the left atrioventricular (AR) interval of patients with coronary heart disease (CHD) measured by electrocardiogram and the patients′ condition, cardiac color Doppler ultrasound and coronary artery lesions.Methods:The CHD patients undergoing esophageal ECG examination in Yantai Mountain Hospital from June 2018 to April 2020 are divided into three groups according to the AR interval: AR interval <100ms, AR interval 100 to 150 ms, and AR interval>150 ms; The general data, condition, cardiac color Doppler ultrasound and coronary artery lesions indicators of the three groups were compared. Disorderly multiple Logistic regression was used to analyze the relationship between coronary heart disease AR interval and condition, cardiac color Doppler ultrasound and coronary artery lesions indicators.Results:There were no statistical difference in gender, age, diabetes, smoking history, blood lipids, blood uric acid (UA) and diastolic blood pressure (DBP) among 3 groups ( P>0.05); but there were statistical differences in proportion of hypertension, systolic blood pressure (SBP), CHADS2 score, CHADS2 -VASc score and Gensini score among 3 groups: 54.72% (29/53), 31.25% (20/64) and 46.81% (35/72); (138.84 ± 4.97), (122.47 ± 7.45) and (139.23 ± 7.05) mmHg (1 mmHg = 0.133 kPa); (1.47 ± 0.08), (1.02 ± 0.15) and (1.67 ± 0.10) scores; (1.49 ± 0.28), (1.00 ± 0.24) and (1.74 ± 0.22) scores; (38.27 ± 5.84), (24.45 ± 6.08) and (39.42 ± 5.71) scores, P<0.05. There was no statistical difference in stroke volume (SV) among 3 groups ( P>0.05), but there were statistical differences in the incidence of AP, incidence of AMI, left ventricular end -diastolic volume (LVEDV), left ventricular end -systolic volume (LVESV), left ventricular ejection fraction (LVEF), the ratio of early diastolic mitral valve blood flow velocity to late diastolic mitral valve blood flow velocity (E/A) and single branch/ double branches/ ≥3 branches lesions of coronary artery: 41.51% (22/53), 65.62% (42/64) and 37.50% (27/72); 58.49% (31/53), 34.38% (22/64) and 62.50% (45/72); (150.73 ± 15.09), (141.49 ± 28.68) and (151.49 ± 14.47) ml; (42.15 ± 10.49), (39.82 ± 8.37) and (40.94 ± 11.02) ml; (56.27 ± 4.94)%, (62.20 ± 3.69)% and (57.64 ± 4.99)%; 0.98 ± 0.29, 1.22 ± 0.35 and 0.97 ± 0.34); 14/18/21, 37/13/14 and 9/22/41, P<0.05. Disorderly multiple Logistic regression analysis showed hypertension, AMI, LVEDV, LVESV, LVEF, Gensini score, coronary artery double branches lesions and ≥3 branches lesions of coronary artery were significantly associated with the AR interval of coronary heart lesions ( OR = 2.349, 1.893, 2.754, 2.872, 0.414, 2.201, 4.336 and 3.401; P<0.05). Conclusions:The AR interval of coronary heart disease is closely related to the condition, cardiac color Doppler ultrasound and coronary artery lesions indicators, which deserves clinical attention.
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Objective To study the hardness properties of pig esophageal at the nanoscale using atomic force microscope (AFM). Methods The porcine esophagus was chosen as experimental sample to study the hardness properties of esophageal tissues at different loading rates, deflection and dwell time with AFM. Results The hardness of esophageal tissues at the nanoscale was strongly correlated with the loading rate and the deflection, which increased with the increasing loading rate and decreased with the increasing deflection of cantilever. The difference in the hardness was associated with the viscoelasticity and viscoplasticity of esophageal tissues, including contact stress, energy transition and strain plastic gradient. Conclusions The experimental results have important significance for clinical diagnosis, surgical operation and artificial material development, and reveal the changing patterns for mechanical properties of the esophageal tissues at the microscale.