Recent studies have shown that premature ventricular contractions （PVCs） could enlarge the heart, but its risk factors are incompletely understood as a single 24-hour recording cannot reflect the true PVC burden due...Recent studies have shown that premature ventricular contractions （PVCs） could enlarge the heart, but its risk factors are incompletely understood as a single 24-hour recording cannot reflect the true PVC burden due to day-to-day variability. Our purpose was to investigate the effect of burden and origin sites on left ventricular （LV） function in patients with PVCs by 7-day Holter electrocardiography （ECG）. From May 2012 to August 2013, 112 consecutive patients with PVCs were recruited from the authors＇ affiliated hospital. All patients received 2-dimensional transthoracic echocardiography, 12-lead routing ECG and 7-days Holter ECG. Serum N-terminal pro- brain natriuretic peptide （NT-proBNP） levels were measured. A total of 102 participants with PVCs were included in the final analysis. Origin of PVCs from the tricuspid annulus had the highest burden and NT-proBNP level. LV papillary muscle had a higher LV ejection fraction （EF） level and a lower LV end-systolic dimension （ESD） than other PVC foci （P〈0.05）. The high burden group had a higher LV end-diastolic dimension （EDD） and LVESD but lower LVEF than the other two groups （P〈0.05）. Female, older age, physical work, and history of PVCs had a significantly positive correlation with symptoms. Male, older age, physical work, and high burden were positive predictors of enlarged LVEDD, LVESD and higher serum NT-proBNP level, but lower LVEF. Seven-day dynamic ECG Holter monitor showed the true PVC burden on patients with PVCs. PVCs with a lower burden or origin from the LV papillary muscle and the fascicle were relatively benign, while PVCs with a higher burden or origin from the tricuspid annulus may lead to cardiac dysfunction.展开更多
We consider the problem of structure and functions of the first forms of living matter and present a hypothe-sis that they were formed through a physico-chemical process known as dendritic crystallization. According t...We consider the problem of structure and functions of the first forms of living matter and present a hypothe-sis that they were formed through a physico-chemical process known as dendritic crystallization. According to this hypothesis the branching, dendritic structures helped build living systems by lending them functions so that organic chemical evolution is just one natural consequence of the evolution of matter in the universe. We conclude that a self-replicating biological system with adaptation emerged from simple molecules using completely abiotic mechanism of formation, which acted simultaneously or intermittently at different places on the early Earth and created similar structures everywhere. The dendritic hypothesis of origin of the func-tions explains similarities in the living systems and supports the assumption of a ‘second genesis of life’. The dendritic scenario does not need carbon/phosphorus-based solutes in water-based solutions, which may have important implications for exobiology and extraterrestrial origin-of-life scenarios. An experiment to test the hypothesis is suggested.展开更多
基金supported by the innovation project in Jiangsu province,Chinathe Program for Development of Innovative Research Team in the First Affiliated Hospital of NJMU(IRT-004)
文摘Recent studies have shown that premature ventricular contractions （PVCs） could enlarge the heart, but its risk factors are incompletely understood as a single 24-hour recording cannot reflect the true PVC burden due to day-to-day variability. Our purpose was to investigate the effect of burden and origin sites on left ventricular （LV） function in patients with PVCs by 7-day Holter electrocardiography （ECG）. From May 2012 to August 2013, 112 consecutive patients with PVCs were recruited from the authors＇ affiliated hospital. All patients received 2-dimensional transthoracic echocardiography, 12-lead routing ECG and 7-days Holter ECG. Serum N-terminal pro- brain natriuretic peptide （NT-proBNP） levels were measured. A total of 102 participants with PVCs were included in the final analysis. Origin of PVCs from the tricuspid annulus had the highest burden and NT-proBNP level. LV papillary muscle had a higher LV ejection fraction （EF） level and a lower LV end-systolic dimension （ESD） than other PVC foci （P〈0.05）. The high burden group had a higher LV end-diastolic dimension （EDD） and LVESD but lower LVEF than the other two groups （P〈0.05）. Female, older age, physical work, and history of PVCs had a significantly positive correlation with symptoms. Male, older age, physical work, and high burden were positive predictors of enlarged LVEDD, LVESD and higher serum NT-proBNP level, but lower LVEF. Seven-day dynamic ECG Holter monitor showed the true PVC burden on patients with PVCs. PVCs with a lower burden or origin from the LV papillary muscle and the fascicle were relatively benign, while PVCs with a higher burden or origin from the tricuspid annulus may lead to cardiac dysfunction.
文摘We consider the problem of structure and functions of the first forms of living matter and present a hypothe-sis that they were formed through a physico-chemical process known as dendritic crystallization. According to this hypothesis the branching, dendritic structures helped build living systems by lending them functions so that organic chemical evolution is just one natural consequence of the evolution of matter in the universe. We conclude that a self-replicating biological system with adaptation emerged from simple molecules using completely abiotic mechanism of formation, which acted simultaneously or intermittently at different places on the early Earth and created similar structures everywhere. The dendritic hypothesis of origin of the func-tions explains similarities in the living systems and supports the assumption of a ‘second genesis of life’. The dendritic scenario does not need carbon/phosphorus-based solutes in water-based solutions, which may have important implications for exobiology and extraterrestrial origin-of-life scenarios. An experiment to test the hypothesis is suggested.
