Research Progress on Echocardiographic First-Phase Ejection Fraction in Assessing Early Left Ventricular Systolic Dysfunction / 中山大学学报(医学科学版)

First-phase ejection fraction （EF1） is the volume change rate of left ventricle （LV） from end-diastole to the time of peak aortic velocity. This article reviewed the research progress of EF1 in detecting early left ventricular systolic dysfunction （LVSD） of patients with aortic stenosis （AS）， stable coronary artery disease （SCAD）， Coronavirus Disease 2019 （COVID-19） and so on， analyzed the advantages and limitations of EF1 in clinical application， and envisioned the future development of EF1 as a novel predictor of early LVSD in clinical use.

Effects of electroacupuncture pretreatment on cardiac function and immune inflammatory response in mice with acute myocardial ischemia / 中国针灸

OBJECTIVE@#To observe the effects of electroacupuncture (EA) pretreatment on the cardiac ejection fraction (EF), the number of macrophages in spleen and heart, and the expression of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and interleukin-1β (IL-1β) in myocardium in mice with acute myocardial ischemia, and to explore the possible mechanism of EA pretreatment on promoting myocardial protection.@*METHODS@#A total of 30 male C57BL/6J mice were randomly divided into a control group, a model group and an EA pretreatment group, 10 rats in each group. The acute myocardial ischemia model was established by ligating the left anterior descending branch of the coronary artery in the model group and EA pretreatment group, while threading but no ligating at left anterior descending branch of the coronary artery was applied in the control group. In the EA pretreatment group, mice were intervented with EA at bilateral "Neiguan" (PC 6), disperse-dense wave, frequency of 2 Hz/15 Hz, intensity of 2 mA; each EA treatment last for 20 min, once a day, and 3-day treatment was given before model establishment. The EF value was evaluated by ultrasonic cardiogram; the number of macrophages in spleen and heart was measured by flow cytometry; the expression level of NLRP3 and IL-1β in myocardium was measured by Western blot.@*RESULTS@#Compared with the control group, the EF value was decreased in the model group (<0.001), the number of macrophages in the heart and spleen was increased (<0.001), and the expression level of NLRP3 and IL-1β in the myocardium was increased (<0.001, <0.01). Compared with the model group, the EF value was increased in the EA pretreatment group (<0.01), the number of macrophages in the heart and spleen was decreased (<0.01), and the expression level of NLRP3 and IL-1β in the myocardium was decreased (<0.01, <0.05).@*CONCLUSION@#EA pretreatment could reduce the number of macrophages in spleen and heart, down-regulate the expression of NLRP3 and IL-1β in myocardial tissue in mice with acute myocardial ischemia, which could relieve the local inflammatory response and achieve the myocardial protective effect.

Quantitative Evaluation of the First Order Creatine-Kinase Reaction Rate Constant in in vivo Shunted Ovine Heart Treated with Oxandrolone Using Magnetization Transfer 31P Magnetic Resonance Spectroscopy (MT-31P-MRS) and 1H/31P Double-Tuned Surface Coil: a Preliminary Study

PURPOSE: Children born with single ventricle physiology demonstrate poor growth rate and suffer from malnutrition, which lead to increased morbidity and mortality in this population. We assume that an anabolic steroid, oxandrolone, will promote growth in these infants by improving myocardial energy utilization. The purpose of this paper is to study the efficacy of oxandrolone on myocardial energy consumption in these infants. MATERIALS AND METHODS: We modeled single ventricle physiology in a lamb by prenatally shunting the aorta to the pulmonary artery and then postnatally, we monitored cardiac energy utilization by quantitatively measuring the first order reaction rate constant, kf of the creatine-kinase reaction in the heart using magnetization transfer 31P magnetic resonance spectroscopy, home built 1H/31P transmit/receive double tuned coil, and transmit/receive switch. We also performed cine MRI to study the structure and dynamic function of the myocardium and the left ventricular chamber. The spectroscopy data were processed using home-developed python software, while cine data were analyzed using Argus software. RESULTS: We quantitatively measured both the first order reaction rate constant and ejection fraction in the control, shunted, and the oxandrolone-treated lambs. Both kf and ejection fraction were found to be more significantly reduced in the shunted lambs compared to the control lambs, and they are increased in oxandrolone-treated lambs. CONCLUSION: Some improvement was observed in both the first order reaction rate constant and ejection fraction for the lamb treated with oxandrolone in our preliminary study.

Effectiveness of 99mTc-tetrofosmin for assessment of heart functions in micropigs

This study examined the suitability of a nuclear imagingtechnique using 99mTc-tetrofosmin as an agent to assess theheart functions of healthy micropigs. The mean age of thepigs was 360 days (male), and the mean body weight was35.3kg ranging from 34.5-36kg. There were no significantperfusion defects in any of the reconstructed images.Gated single-photon emission computed tomographyimaging can be used to calculate the ventricular volumeand ejection fraction (EF). In this case, an EF of 79% wascalculated from the ventricular volume of the end-systolicimage (10 ml) subtracted from that of the end-diastolicvolume (49 ml). A perfusion defect (particularly the apex,lateral wall) is unlikely because of the presence of apreserved wall motion in a segment with a defect. It isconcluded that quantitative cardiac scintigraphy, using99mTc-tetrofosmin is an adequate technique for estimatingthe heart functions of healthy micropigs.