Adverse hemodynamic and clinical effects of encainide in severe chronic heart failure

STUDY OBJECTIVE: To evaluate the hemodynamic effects of the antiarrhythmic drug, encainide, in patients with severe chronic heart failure. DESIGN: Unblinded, before-after study. SETTING: Referral center for patients with heart failure. PATIENTS: Thirty patients with severe chronic heart failure and a left ventricular ejection fraction less than 40%. INTERVENTIONS: Invasive hemodynamic measurements were done (using a balloon-tipped thermodilution catheter) before and for 3 hours after a single oral dose of 50 mg of encainide. MEASUREMENTS AND MAIN RESULTS: Ninety to one hundred and twenty minutes after its administration, encainide produced a significant deterioration in cardiac performance, as reflected by a fall in cardiac index from 2.3 to 1.8 L/min.m2 body surface (mean change 0.5 +/- 0.1; P less than 0.001), a fall in stroke work index from 26 to 18 g.m/m2 (mean change 8 +/- 2; P less than 0.001), and an increase in left ventricular filling pressure from 19 to 22 mm Hg (mean change 3 +/- 2; P less than 0.05). These deleterious hemodynamic effects were accompanied by worsening symptoms of heart failure in 8 of the 30 patients. Serum levels of encainide and its metabolites, O-desmethylencainide and 3-methoxy-O-desmethylencainide, were within the therapeutic range in most patients. CONCLUSIONS: Encainide can cause adverse hemodynamic and clinical effects in patients with severe chronic heart failure.     

Preliminary evidence for a role of apolipoprotein E alleles in identifying haemodialysis patients at high vascular risk

Conventional risk factors have very low predictive power in identifying haemodialysis patients at high risk of vascular accidents. A role for apolipoprotein E isotypes was looked for in a small, but rigorously defined, cohort of longterm haemodialysis patients. In individuals with high vascular risk, as identified by higher common carotid intima/media thickness, we found an excess of apolipoprotein E4 alleles. This preliminary result requires confirmation in large patient cohorts.      

Pectus excavatum defect on liver-spleen scintigraphy

A 58-year-old man with a pectus excavatum demonstrated a photon-deficient defect within the left lobe of the liver on liver-spleen scintigraphy using Tc-99m SCOL. Computed tomography of the liver clearly revealed the abnormal defect seen on the liver-spleen scan to be due to the pectus excavatum. This case confirms the impression that these skeletal aberrations may cause false-positive hepatic defects.The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense     

心房颤动：心率与心律同等重要

两项新的研究显示，在心房颤动的药物治疗方面控制心率不仅与控制心律的疗效及操作相当，而且更加经济、安全。因而我们可以推测由于药物控制心率副作用较少，可能会降低心房颤动患者的住院率。