Correlation between cardiac resynchronization response and pulmonary artery hemodynamic parameters. / å¿ƒè„å†åŒæ­¥åŒ–æ²»ç–—ååº”æ€§å’Œè‚ºåŠ¨è„‰è¡€æµåŠ¨åŠ›å­¦å‚æ•°çš„ç›¸å ³æ€§.

OBJECTIVES: To evaluate the response to cardiac resynchronization therapy (CRT) and the correlation between CRT and pulmonary artery hemodynamic parameters. METHODS: The patients with chronic heart failure indicator for CRT were enrolled. The left ventricular end-systolic volume (LVESV) was measured by echocardiography and New York Heart Association (NYHA) classification was evaluated between one week before and six months after CRT. Mean pulmonary artery pressure (mPAP), pulmonary artery systolic pressure (PASP) and pulmonary vascular resistance (PVR) were measured by right heart catheterization. Left ventricular reverse remodeling (LVRR) is defined as a decrease of 15% or more in LVESV at the 6th month after CRT; Clinical response is defined as a decrease of NYHA classification at or above grade 1 at the 6th month after CRT. Pulmonary hypertension (PH) was defined as mPAP≥25 mmHg. According to the response, patients were divided into 3 groups: group A (LVRR+clinical response), group B (no LVRR+clinical response) and group C (no LVRR+no clinical response). The changes of NYHA classification, echocardiographic and pulmonary hemodynamic parameters were observed in the 3 groups. The Kaplan-Meier survival curve was used to analyze the differences in all-cause mortality, combined end-point events of death or re-hospitalization due to heart failure among different groups. RESULTS: A total of 45 patients with CRT implantation [aged (63.27±9.55) years, 36 males] were included. The average follow-up period was (33.76±11.50) months. Thirty-one patients (68.89%) were in group A, 9 of whom with PH. Eight patients (17.78%) were in group B, 7 of whom with PH. Six patients were in group C, all with PH. Cardiac function including NYHA classification, echocardiographic and pulmonary hemodynamic parameters had been significantly improved in group A after CRT implantation (P<0.05). In group B, NYHA classification and pulmonary hemodynamic parameters were decreased significantly (P<0.05), but echocardiographic parameters did not change obviously (P>0.05). There were no significant changes in NYHA classification, echocardiographic and pulmonary hemodynamic parameters in group C (P>0.05). Compared with group C, group A and group B had lower all-cause mortality (P=0.005) and lower incidence of composite endpoint events (P=0.001). CONCLUSIONS: Patients with LVRR and clinical response after CRT have a good prognosis. Patients with clinical response but without LVRR have a better prognosis than those without clinical response and LVRR, which may be related to the decrease of pulmonary hemodynamic parameters such as mPAP and TPG.

Crop straw retention influenced crop yield and greenhouse gas emissions under various external conditions.

Crop straw retention is a strongly recommended practice for sustainable agricultural production in China. However, a comprehensive analysis of straw retention effects on crop yield, N2O and CH4 emissions, net greenhouse gas (NGHG), and net greenhouse gas intensity (NGHGI) and their response to various external influence factors, including location/climatic conditions, soil properties, and field management practices, in a national scale were easily ignored. Based on the collected published literatures, we found that straw retention improved crop yield and N2O and CH4 emissions by 4.7% (-4.6 to 25.8%), 18.3% (-26.6 to 57.6%), and 21.0% (-49.0 to 214.5%) in contrast with no-straw retention. For different external conditions, crop yield was increased by 15.9% in temperate zone and 10.7% in upland soils with straw retention. N2O emissions which correspond to the above conditions were enhanced by 42.2% and 18.8%, while CH4 emissions were restrained by 49.0% in temperate zone. Negligible changes in crop yield and N2O emissions were observed for subtropical zone or paddy soils, but with increase in CH4 emissions. Additionally, straw retention enhanced NGHG and NGHGI by 20.7% and 15.4% on average regardless of various external conditions, respectively. However, NGHG was reduced under conditions of straw retention in temperature or mulching to field. Straw retention under appropriate site-specially conditions simultaneously safeguard food security and slightly increase environmental effects.