A chasing dead-end case report: a fatal lead intoxication following an attempted homicide

Forensic Toxicology - In developed countries, lead intoxication is decreasing in adults as sources of contamination were considerably reduced. Hence, cases of lead encephalopathy have become...     

Effects of heart rate on experimentally produced mitral regurgitation in dogs

The effects of increasing heart rate (HR) on the hemodynamics of acute mitral regurgitation (MR) were studied in 8 open-chest dogs. Filling volume, regurgitant volume and stroke volume were calculated from electromagnetic probe measurements of mitral and aortic flows. The left atrial-left ventricular systolic pressure gradient was measured with micromanometers. The calculated effective mitral regurgitant orifice area varied from 10 to 128 mm², with a consequent regurgitant fraction (regurgitant volume/filling volume) of 24 to 62%. After crushing the sinus node, HR was increased stepwise from 90 to 180 beats/min by atrial pacing while maintaining aortic pressure constant. With increasing HR, filling volume, stroke volume, regurgitant volume and regurgitant time decreased; total cardiac output, forward cardiac output, regurgitant output, systolic pressure gradient, regurgitant fraction and the regurgitant orifice did not change; left ventricular end-diastolic pressure decreased; and left atrial v-wave amplitude increased. These results indicate that in acute experimental MR with a wide spectrum of incompetence, the relative distribution of forward and regurgitant flows did not change with large increases in HR. At rates >150 beats/min the atrial contraction occurs early and increases the amplitude of the left atrial v wave. This may contribute to the severity of pulmonary congestion in patients with MR.     

What have we learned about heart failure with mid‐range ejection fraction one year after its introduction?

The 2016 European Society of Cardiology heart failure guidelines introduced the term ‘heart failure with mid‐range ejection fraction’ (HFmrEF) to refer to patients with heart failure and a mildly reduced ejection fraction of 40–49%. About 20% of heart failure patients fall in this category. One of the main reasons for the introduction of this category was to stimulate research into this grey area. This review aims to highlight the key findings that have been published so far. Firstly, HFmrEF more closely resembles heart failure with reduced (HFrEF) than preserved ejection fraction (HFpEF) with regard to ischaemic aetiology, which is more frequent in both HFmrEF and HFrEF compared to HFpEF. Secondly, changes in ejection fraction over time are common, and seem to be more important than baseline ejection fraction alone. Patients who progress from HFmrEF to HFrEF have a worse prognosis than those who remain stable or transition to HFpEF. Lastly, and perhaps most importantly, retrospective analyses from a randomized trial suggest that patients with HFmrEF seem to benefit from therapies that have shown to improve outcome in HFrEF, whereas no such benefit was seen in patients with HFpEF.