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Patients with long‐lasting hypertension often suffer from atrial or ventricular arrhythmias. Evidence suggests that mechanical stimulation can change the refractory period and dispersion of the ventricular myocyte action potential through stretch‐activated ion channels (SACs) and influence cellular calcium transients, thus increasing susceptibility to ventricular arrhythmias. However, the specific pathogenesis of hypertension‐induced arrhythmias is unknown. In this study, through clinical data, we found that a short‐term increase in blood pressure leads to a rise in tachyarrhythmias in patients with clinical hypertension. We investigated the mechanism of this phenomenon using a combined imaging system(AC) of atomic force microscopy (AFM) and laser scanning confocal microscopy. After mechanical distraction to stimulate ventricular myocytes isolated from Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR), we synchronously monitored cardiomyocyte stiffness and intracellular calcium changes. This method can reasonably simulate cardiomyocytes' mechanics and ion changes when blood pressure rises rapidly. Our results indicated that the stiffness value of cardiomyocytes in SHR was significantly more extensive than that of normal controls, and cardiomyocytes were more sensitive to mechanical stress; In addition, intracellular calcium increased rapidly and briefly in rats with spontaneous hypertension. After intervention with streptomycin, a SAC blocker, ventricular myocytes are significantly less sensitive to mechanical stimuli. Thus, SAC is involved in developing and maintaining ventricular arrhythmias induced by hypertension. The increased stiffness of ventricular myocytes caused by hypertension leads to hypersensitivity of cellular calcium flow to mechanical stimuli is one of the mechanisms that cause arrhythmias. The AC system is a new research method to study the mechanical properties of cardiomyocytes. This study provides new techniques and ideas for developing new anti‐arrhythmic drugs. Highlight: The mechanism of hypertension‐induced tachyarrhythmia is not precise. Through this study, it is found that the biophysical properties of myocardial abnormalities, the myocardium is excessively sensitive to mechanical stimulation, and the calcium flow appears to transient explosive changes, leading to tachyarrhythmia. [ABSTRACT FROM AUTHOR]

Pregnant women are a group of people in a special period, once sudden cardiac arrest (CA) occurs, it will threaten the life of both mother and child. It has become a great challenge for hospital, doctors and nurses to minimize maternal mortality during pregnancy. All the efforts should ensure the safety of both mother and child throughout the perinatal period. Because difference of the cardiopulmonary resuscitation strategies for common CA patients of the same age, the resuscitation strategies for CA patients during pregnancy need consider the patient's gestational age and fetal condition. Different resuscitation techniques, such as manual left uterine displacement (MLUD), will involve perimortem cesarean delivery (PMCD). At the same time, drugs should be reasonably used for different causes of CA during pregnancy, such as hypoxemia, hypovolemia, hyperkalemia or hypokalemia and other electrolyte disorders and hypothermia in 4Hs, as well as thrombosis, pericardial tamponade, tension pneumothorax and toxicosis in 4Ts. In view of the fact that many causes of CA in pregnancy are preventable, it is more necessary to introduce guidelines for CA in pregnancy in line with our national conditions for clinical guidance. This paper systematically reviewed the pathophysiological characteristics of CA during pregnancy, the high-risk factors of CA during pregnancy, and identified the correct resuscitation methods and prevention and treatment strategies of CA during pregnancy.

Objective: To explore the clinical efficacies of bilevel positive airway pressure (BiPAP) ventilation in uremic patients with acute heart failure., Methods: Fifty uremic patients with acute heart failure on dialysis were recruited from February 2008 to October 2012 at our center. All of them received angiectasis, heart strengthening and continuous renal replacement therapy (CRRT), but their clinical symptoms had no relief 30 min later. Non-invasive ventilation was administered immediately. And the parametric changes of systolic pressure (SBP), diastolic pressure (DBP), heart rate (HR), breathing rate (R), partial pressure of oxygen (PaO2) and carbon dioxide (PaCO2) were observed at 30 min after conventional therapy and 1, 2 h later after non-invasive ventilation. And the levels of blood brain natriuretic peptide (BNP), left ventricular ejection fraction (LVEF) and clinical manifestations were observed at 2 h after non-invasive ventilation., Results: Their clinical symptoms improved after BiPAP ventilation. And SBP, DBP, P, R and BNP showed a declining tendency, but PaO2 and LVEF showed a rising trend. Compared to conventional therapy, SBP ((160 ± 17), (147 ± 18) vs (172 ± 20) mmHg) (1 mmHg = 0.133 kPa), DBP ((90 ± 9), (85 ± 10) vs (98 ± 10) mmHg), HR ((95 ± 8), (88 ± 9) vs (102 ± 12) times/min), R ((20 ± 3), (17 ± 4) vs (26 ± 3) times/min) declined while PaO2 ((87 ± 9), (94 ± 12) vs (81 ± 9) mmHg) increased significantly, 1, 2 h later after noninvasive ventilator treatment (all P < 0.05); the blood level of BNP decreased ((1084 ± 398) vs (2686 ± 576) µg/L), LVEF elevated (52% ± 7% vs 39% ± 9%) significantly, 2 h later after noninvasive ventilator treatment (both P < 0.01)., Conclusion: As a safe and effective intervention, early use of BiPAP ventilator-assisted breathing in uremic patients with acute heart failure effectively ameliorates their clinical manifestations and improve heart function.

Objective: To investigate the correlation of asthma incidence with environmental pollution., Methods: We performed stratified-cluster-disproportional-random-sampling survey in the occupational populations from 10 professional systems by using an uniform protocol, questionnaire and procedure in this multicenter study. Original data were processed and statistically analyzed with SPSS 8.0 for windows. Prevalence rates were compared by chi(2) test., Results: A total of 50,558 people supposed to cover more than 200,000 staff and workers were sampled. Six hundred and thirty asthmatics were identified and the overall prevalence rate in Beijing area was 1.25%. The incidence of asthma in occupational populations from urban commercial and trade circles, common chemical plants, and a certain petrochemical works was 0.51%, 1.06% and 2.81% respectively. The morbidity of asthma in the latter two populations was significantly higher than that in peasants (0.43%) in the remote outskirts of Beijing city (P < 0.01). The relative risk (RR) of asthma incidence in occupational populations from the commercial and trade circles, common chemical plants, the petrochemical works and the students in elementary and middle schools was 1.88, 2.79, 5.19 and 3.05 respectively as compared to peasants, the differences being statistically significant., Conclusion: The results suggest that the difference in asthma incidence in occupational populations may be attributable to environmental pollution.