Hemodynamic,Autonomic, and Vascular Effects of Exposure to Coarse Particulate Matter Air Pollution from a Rural Location

Background: Fine particulate matter (PM) air pollution is associated with numerous adverse health effects, including increased blood pressure (BP) and vascular dysfunction. Coarse PM substantially contributes to global air pollution, yet differs in characteristics from fine particles and is currently not regulated. However, the cardiovascular (CV) impacts of coarse PM exposure remain largely unknown.Objectives: Our goal was to elucidate whether coarse PM, like fine PM, is itself capable of eliciting adverse CV responses.Methods: We performed a randomized double-blind crossover study in which 32 healthy adults (25.9 ± 6.6 years of age) were exposed to concentrated ambient coarse particles (CAP; 76.2 ± 51.5 μg/m³) in a rural location and filtered air (FA) for 2 hr. We measured CV outcomes during, immediately after, and 2 hr postexposures.Results: Both systolic (mean difference = 0.32 mmHg; 95% CI: 0.05, 0.58; p = 0.021) and diastolic BP (0.27 mmHg; 95% CI: 0.003, 0.53; p = 0.05) linearly increased per 10 min of exposure during the inhalation of coarse CAP when compared with changes during FA exposure. Heart rate was on average higher (4.1 bpm; 95% CI: 3.06, 5.12; p < 0.0001) and the ratio of low-to-high frequency heart rate variability increased (0.24; 95% CI: 0.07, 0.41; p = 0.007) during coarse particle versus FA exposure. Other outcomes (brachial flow-mediated dilatation, microvascular reactive hyperemia index, aortic hemodynamics, pulse wave velocity) were not differentially altered by the exposures.Conclusions: Inhalation of coarse PM from a rural location is associated with a rapid elevation in BP and heart rate during exposure, likely due to the triggering of autonomic imbalance. These findings add mechanistic evidence supporting the biological plausibility that coarse particles could contribute to the triggering of acute CV events.Citation: Brook RD, Bard RL, Morishita M, Dvonch JT, Wang L, Yang HY, Spino C, Mukherjee B, Kaplan MJ, Yalavarthi S, Oral EA, Ajluni N, Sun Q, Brook JR, Harkema J, Rajagopalan S. 2014. Hemodynamic, autonomic, and vascular effects of exposure to coarse particulate matter air pollution from a rural location. Environ Health Perspect 122:624–630; http://dx.doi.org/10.1289/ehp.1306595     

Spontaneous rupture of a coronary artery fistula presenting with post-exertional syncope and haemopericardium

An 8-year-old with a known diagnosis of an asymptomatic coronary artery fistula (CAF) presented with exertional syncope and haemopericardium due to contained rupture of CAF. A transcatheter closure was attempted, but the fistula ruptured again prompting emergency surgical repair. Spontaneous rupture is a catastrophic complication of CAF and warrants a high index of suspicion, timely diagnosis and team management.     

Rheumatic Fever and Rheumatic Heart Disease in Children

Indian Journal of Pediatrics - Acute rheumatic fever (ARF) and its sequelae, Rheumatic heart disease (RHD), contribute significantly to the cardiovascular morbidity and mortality in developing...     

Prediabetes

The burden of diabetes is expected to rise from 415 million individuals in 2015 to 642 million individuals by 2040. Most individuals pass through a phase of prediabetes before developing full-blown diabetes. Insulin resistance, impaired incretin action, and insulin hypersecretion are central to the pathophysiology of prediabetes. Individuals older than 40 years of age and other high-risk individuals should be screened for diabetes with fasting plasma glucose and/or hemoglobin A1c. For those diagnosed with prediabetes, the goal of treatment should be restoring euglycemia, because there are data showing that restoring normoglycemia during prediabetes and early diabetes can produce lasting remission. The preferred approach for this is intensive lifestyle intervention, which besides reducing progression to diabetes, has also been shown to reduce all-cause mortality in a long-term follow-up study. The best evidence for a pharmacological approach is with metformin. Other drugs that have shown efficacy include thiazolidinediones, alpha-glucosidase inhibitors, orlistat, basal insulin, and valsartan. However, except for metformin, none of these drugs are currently recommended for this purpose. Newer agents such as glucagon-like peptide-1 agonists and dipeptidyl peptidase 4 (DPP-4) inhibitors also have considerable promise in this area. Bariatric surgery can be offered to patients with metabolic syndrome and body mass index of 30-35.     

Hemin levels in culture medium of Porphyromonas (Bacteroides) gingivalis regulate both hemin binding and trypsinlike protease production.

Washed cells and Sarkosyl-insoluble outer membrane preparations of the black-pigmented bacteroides Porphyromonas gingivalis W50 bound hemin. The amount of hemin removed from a buffered solution by both cells and outer membranes was significantly larger if bacteria had been grown in broths supplemented with 5 mg of hemin per liter rather than none. Conversely, cells grown without supplemental hemin bound relatively little. However, all preparations bound some hemin. In addition, hemin regulated the production of significantly higher levels of trypsinlike protease by P. gingivalis W50. The nonpigmented variant, W50 BE1, showed no such responses to the levels of hemin in the growth medium.     

Utility of B-type natriuretic peptide in predicting medium-term mortality in patients undergoing major non-cardiac surgery

This study was conducted to assess the ability of preoperative B-type natriuretic peptide levels to predict medium-term mortality in patients who undergo major noncardiac surgery. During a median of 654 days of follow-up, 33 patients from a total cohort of 204 patients (16%) died, 17 from cardiovascular causes. The optimal cutoff in this cohort, determined using a receiver-operating characteristic curve, was >35 pg . ml(-1). This was associated with a 3.5-fold increase in the hazard of death (p = 0.001) and a 6.9-fold increase in the hazard of cardiovascular mortality (p = 0.003). In conclusion, these findings extend recent work demonstrating that B-type natriuretic peptide levels obtained before major noncardiac surgery can be used to predict perioperative morbidity and indicate that they also forecast medium-term mortality, particularly cardiovascular death.