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.     

Functional renal insufficiency during long-term therapy with captopril and enalapril in severe chronic heart failure

Renal function was evaluated in 104 patients with severe chronic heart failure whom we treated with captopril or enalapril. Seventy patients showed no change or an improvement in renal function (group A), and 34 patients developed functional renal insufficiency (group B). Before converting-enzyme inhibition, group B patients received higher doses of furosemide (p less than 0.02) and had lower central venous pressures (p less than 0.05) than group A patients. After 1 to 3 months of converting-enzyme inhibition, an excessive reduction in left ventricular filling pressure (to less than 15 mm Hg) or mean arterial pressure (to less than 60 mm Hg) was noted in 28 of 34 (82%) patients in group B but in only 22 of 70 patients in group A (31%) (p less than 0.001). At the end of the study, drug-induced azotemia resolved after a reduction in the dosage of diuretics, despite unaltered treatment with captopril and enalapril. Hence, the deterioration of renal function after converting-enzyme inhibition in heart failure is not a toxic or immunologic reaction to therapy but results from specific hemodynamic events that can be ameliorated by sodium repletion.     

Porphyria cutanea tarda associated with autoimmune hypothyroidism, vitiligo and alopecia universalis.

The aetiology of porphyria cutanea tarda (PCT) has not been elucidated, but the possibility of an autoimmune mechanism has been proposed. We report a case of an unknown clinical combination of PCT with autoimmune hypothyroidism, alopecia universalis and vitiligo with thyroid and parietal cell circulating antibodies. This is highly suggestive of underlying autoimmune damage in this patient.     

Age- and Sex-Related Variation in Sensitivity to the Pyrethroid Cypermethrin in the Marine Copepod Acartia tonsa Dana

Acute effects of cypermethrin, a pesticide used to treat ectoparasite infestations of salmon, were assessed using the calanoid copepod Acartia tonsa. A. tonsa has been widely used for hazard assessment of chemicals in the marine environment using acute toxicity tests, but only with randomly selected adults, assuming a sex ratio of 1:1. The present study assesses the environmental hazard of cypermethrin by exposing nauplii and adult males and females, separately. Our results showed that the naupliar stages were 28 times more sensitive to cypermethrin than adults after 96 h of exposure, with LC₅₀s of 0.005 μg L⁻¹ and 0.142 μg L⁻¹, respectively. Significant differences in sensitivity between sexes were only found during the first 24 h of exposure, with males being approximately twice as sensitive as females. The results of age-related variation in sensitivity are supported by studies with other species of copepods and toxicants, where the increased capacity of the adults for detoxification, the allometric differences in weight and size, and the molting process are given as explanations. Variation in sensitivity between sexes is discussed in terms of faster depuration rates in females through egg production and implications of feeding rate changes after 24 h of exposure. Our results suggested that standard toxicity test methods using A. tonsa are unsatisfactory because the most sensitive life stage is not included and sex-related differences in tolerance are not taken into account. We also found that cypermethrin caused significant mortality in Acartia at exposures concentrations from one to three orders of magnitudes lower than the recommended field treatment concentration for copepodic infestations. Received: 27 April 2001/Accepted: 1 July 2001     

Coronary permeability and left ventricular function following thrombolytic therapy

We study 40 patients, 55 +/- 7 years old with acute myocardial infarction treated early by thrombolytic therapy (20 STK and 20 rt-PA). All patients were angiographically studied in the following conditions: 1) baseline, before initiating therapy. 2) Three hours after treatment. 3) Twenty four hours later. 4) Before discharge. The infarct related artery was patent 24 hours after treatment in 31 patients (78%); five of them were patent before treatment, and we observed an early reperfusion in 20 patients (57%) and late reperfusion in 6 patients (17%). The number of patients with angiographic evidence of intraluminal thrombus decreased progressively through conditions while the grade TIMI of coronary perfusion increased in the absence of reocclusion. Final regional wall motion of infarct related myocardial zones and their degree of recovery were significantly higher in recanalized patients, as compared with non-reperfused patients. Similarly, left ventricular functional recovery was higher in patients with antegrade of collateral flow to the infarct area, as compared with totally occluded patients.     

Linitis plástica primaria rectal

Primary linitis plastica of the rectum is an infrequent and unusual rectal carcinoma. We report a new case that presented clinically as a haemorrhoidal syndrome. We comment on the characteristics--clinical picture and histopathology--of this uncommon presentation of rectal tumour, as well as its clinical history and prognosis taking into account that the literature consulted indicated the unusualness of primary linitis plastica of the rectum.