Does flecainide regain its antiarrhythmic activity after electrical cardioversion of persistent atrial fibrillation?

OBJECTIVES: The purpose of this study was to evaluate the hypothesis that presumed reversion of electrical remodeling after cardioversion of atrial fibrillation (AF) restores the efficacy of flecainide. BACKGROUND: Flecainide loses its efficacy to cardiovert when AF has been present for more than 24 hours. Most probably, the loss is caused by atrial electrical remodeling. Studies suggest electrical remodeling is completely reversible within 4 days after restoration of sinus rhythm (SR). METHODS: One hundred eighty-one patients with persistent AF (median duration 3 months) were included in this prospective study. After failure of pharmacologic cardioversion by flecainide 2 mg/kg IV (maximum 150 mg in 10 minutes) and subsequent successful electrical cardioversion, we performed intense transtelephonic rhythm monitoring three times daily for 1 month. In case of AF recurrence, a second cardioversion by flecainide was attempted as soon as possible. RESULTS: AF recurred in 123 patients (68%). Successful cardioversion by flecainide occurred only when SR had been maintained for more than 4 days (7/51 patients [14%]). Failure to cardiovert was associated with a prolonged duration of the recurrent AF episode and concurrent digoxin use. Multivariate logistic regression confirmed that successful cardioversion was determined by digoxin use (odds ratio [OR] 0.093, P = .047) and by the interaction between the duration of SR and the (inverse) duration of recurrent AF (OR 6.499, P < .001). When flecainide was administered within 10 hours after AF onset and the duration of SR was greater than 4 days, the success rate was 58%. CONCLUSIONS: Flecainide recovers its antiarrhythmic action after cardioversion of AF. However, successful pharmacologic cardioversion occurs only after SR has lasted at least 4 days and is expected only for recurrences having duration of a few hours. Immediate pharmacologic cardioversion of AF recurrence may be a worthwhile strategy for management of persistent AF.     

Cost-effectiveness of ceftazidime or imipenem/cilastatin versus ceftriaxone+aminoglycoside in the treatment of febrile episodes in neutropenic cancer patients in Germany

Summary A three-pronged cost-effectivess analysis of the treatment of febrile episodes in neutropenic cancer patients was conducted. It included a review of 37 randomized, controlled studies in the MEDLINE and EMBASE databases (1980–1996). Clinical outcomes as well as costs of treatment with imipenem/cilastatin, ceftazidime and ceftriaxone+aminoglycoside were compared. Primary therapy and modification, respectively, were successful in 62 and 27% of patients treated with imipenem/cilastatin, in 56 and 31% with ceftazidime and in 41 and 13% with ceftriaxone+aminoglycoside. From the perspective of a 1,800-bed teaching hospital, the average overall cost per successfully treated patient was DM 7,475 with imipenem/cilastatin, DM 7,810 with ceftazidime and DM 8,963 with ceftriaxone+netilmicin (DM 1=USD 0.56; 7/97). The costs for the German national economy were imipenem/cilastatin DM 23,828, ceftazidime DM 24,985 and ceftriaxone+netilmicin DM 29,838.     

Effects of disulfiram on the metabolism of nitrosodiethylamine during liver carcinogenesis

Summary We have studied the effects of disulfiram (DSF) administration on the metabolism of nitrosodiethylamine (NDEA) in rats during acute and chronic administration. DSF was found to have the following effects during the course of carcinogenesis: (a) marked decrease in the exhalation of ¹⁴CO₂ derived from ¹⁴C-NDEA; (b) reduction of the total levels of DNA and RNA ethylation in the liver. In acute experiments DSF caused an incrase in the amount of NDEA in organs and in the urine. We suggest that inhibition of NDEA biotransformation and the subsequent decrease in the total level of DNA ethylation may prevent specific chemical interactions relevant to carcinogenesis.Abbreviations DSF disulfiram - NDEA N-nitrosodiethylamine     

Departments of medicine and international health

There is an emerging role in international health for departments of medicine that care to accept the challenge. Supervised medical rotations in the developing world and the care of culturally distinct immigrant populations provide unique opportunities to expand the scope of medical education while emphasizing a sensitive and humanistic approach to health care. The restraints imposed by diminished laboratory support and limited availability of drugs can foster reliance on diagnostic skills and the essential elements of therapy. Medical schools may elect to become involved in international health, but they must do so without becoming exploitative. Rotations of students, residents, and faculty in both directions should lead to productive interaction at both the clinical and research levels, for all participants.     

Single or multiple dose ursodeoxycholic acid for cholestatic liver disease: biliary enrichment and biochemical response

Background: Ursodeoxycholic acid (UDCA) improves liver biochemistry in primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). Since UDCA acts partly by reducing the intestinal absorption of hydrophobic endogenous bile salts and is poorly absorbed from the intestine, a multiple dose regimen has been advocated. Single dose treatment, on the other hand, may improve compliance.Aim: The effects of a single or multiple dose regimen on liver enzymes and serum and biliary bile salts composition were evaluated.Methods: Twenty-seven patients (19 PSC, 8 PBC), most with early stage disease, received UDCA (10 mg kg⁻¹ day⁻¹) in a single dose at bed time (n=13) or in three divided gifts with meals (n=14) over 3 months. Five patients had both treatment regimens in random order with a 1-month wash-out period in between.Results: Liver biochemistry equally improved in both groups. Biliary enrichment (% UDCA of total bile salts, mean±SEM) was 40.1±2.4 in the single dose group vs 40.8±2.8 in the multiple dose group (p=NS) and was positively correlated with biochemical improvement (AP: r=0.47, p=0.02; GGT: r=0.58, p=0.002; ASAT: r=0.67, p=0.002; ALAT: r=0.52, p=0.01). Biochemical improvement was not correlated with the concentration or %UDCA in serum. Patients participating in the cross-over design had comparable biochemical response and biliary %UDCA during both regimens.Conclusion: Single and multiple dose UDCA have similar effects on liver biochemistry and biliary enrichment in cholestatic liver disease. Biochemical improvement appears to be related to biliary (but not serum) enrichment with UDCA.     

Trends in Alcohol-Related Mortality among New Mexico's American Indians, Hispanics, and Non-Hispanic Whites

Reduction of alcohol-related mortality is a national goal for health promotion and disease prevention. We conducted this analysis to determine whether trends in New Mexico's Hispanics, non-Hispanic Whites, and American Indians were consistent with national trends in alcohol-related mortality, and whether differences in drinking patterns could account for racial and ethnic differences in rates. Age-adjusted, race-specific, and ethnic-specific alcohol-related mortality rates and 95% confidence intervals were calculated for 5-year periods for 1958–1991 using New Mexico vital statistics data. We estimated the prevalence of acute and chronic at-risk drinking behaviors and abstinence from data collected by the Behavioral Risk Factor Surveillance System (BRFSS) for the period 1986–1992. We found that alcohol-related mortality rates varied substantially by race, ethnicity, sex, age, and calendar period. American Indians had the highest rates for both sexes. Rates increased sharply from the period 1958–1962 until the late 1970s and the early 1980s, and then began to decrease rapidly. However, during the most recent decade, the rates have followed contrasting trends in the three ethnic and racial groups. Although rates have continued to decline among non-Hispanic Whites, rates for Hispanics and American Indians have not declined, and still remain substantially higher than rates during the 1958–1962 period. Differences in at-risk drinking behaviors reported to the BRFSS do not explain the contrast in race-specific and ethnic-specific mortality rates. Although progress has been made in reducing national per capita alcohol consumption and alcohol-related mortality, certain high-risk racial and ethnic groups may not be sharing in the progress.     

Definitive management of rectal cancer by contact (endocavitary) irradiation

In a retrospective review, 62 patients treated for rectal cancer by contact (endocavitary) irradiation at The Cleveland Clinic Foundation were analyzed. This treatment modality delivers high dose, low penetration irradiation to a rectal cancer by direct contact of a 50 KV x-ray source through a special proctoscope. Cancers selected for this treatment include small (3 cm or less), mobile tumors without presacral lymphadenopathy that are within reach of digital examination and are well- or moderately well-differentiated adenocarcinomas. Between 1973 and 1984, 62 patients (37 males, 25 females) were treated—46 by contact irradiation alone and 16 by contact irradiation after excisional biopsy. The median tumor dose was 12,000 rads administered in four fractions at monthly intervals. Mean follow-up was 31 months. Fiftysix patients (90 percent) were disease-free at the time of review or death (ten died from unrelated causes). Eleven patients (18 percent) developed local recurrence but eight of these without distant metastases were rendered disease-free by other treatment—six by surgical resection and two by further radiotherapy. Mean time since secondary treatment is 20 months. Three patients are alive with incurable disease and three have died from cancer—in three of these six patients there was no evidence of local disease. Ulcerated tumors developed local recurrence in five of 17 cases (29 percent) while polypoid tumors recurred locally in six cases (14 percent). Morbidity from the treatment was minor in nature. It is suggested that contact (endocavitary) irradiation is effective treatment for carefully selected cases of rectal cancer Read at the meeting of the American Society of Colon and Rectal Surgeons, Washington, D.C., April 5 to 10, 1987.     

Pathophysiology and management of unstable angina

Significant progress has been made in recent years in unraveling the dynamic mechanisms involved in the production of unstable angina. This knowledge, and advances in medical and interventional therapy allow the formulation of treatment strategies aimed at specific pathogenic mechanisms and promise to reduce mortality and morbidity. This review covers the diagnosis, pathogenesis, risk stratification, and therapy of unstable angina.     

Adverse effects of direct current cardioversion on cardiac pacemakers and electrodes Is external cardioversion contraindicated in patients with permanent pacing systems?

Use of pacing in sick sinus syndrome and recent developments in pacemaker therapy for intermittent atrial fibrillation raise the question of whether external electrical cardioversion should be used for termination of atrial fibrillation. This paper analyzes three cases of pacemaker and/or electrode dysfunction appearing after direct current (DC) cardioversion for termination of atrial fibrillation. Despite similar conditions during cardioversion in all cases, different dysfunctions reflecting damage to the pulse generator and/or a rise of the stimulation threshold in both, atrial and ventricular leads, have been observed. The possible mechanisms for these effects are discussed and recommendations for the management of cardioversion in patients with permanent pacemaker systems are given.     

High levels of complement-activation capacity in sera from patients with cystic fibrosis correlate with high levels of IgG3 antibodies to Pseudomonas aeruginosa antigens and poor lung function

Heat-stable opsonins from sera of cystic fibrosis (CF) patients were investigated for their ability to activate complement. Complement activation by Pseudomonas aeruginosa after opsonization with patient serum was examined in a complement-consumption assay. Absorption of patients' sera with formalin-treated and boiled bacteria removed specific antibodies and the complement activation decreased. We found a positive correlation between serum complement-activation ability and IgG3 antibody levels to lipopolysaccharide (LPS), alginate, and a crude mixture of P. aeruginosa antigens (sonicate) in a group of patients with high levels of anti-Pseudomonas precipitins. In the same group of patients a significant negative correlation was found between complement activation and lung function. Eighteen patients have been followed longitudinally with serum samples covering the pre-infection, the early, and the late stages of chronic infection. Patients with poor lung function showed significantly higher levels of complement-activation capacity. We conclude that patients with high levels of specific IgG3 antibodies are able to induce a high level of complement activation and then develop more aggressive pulmonary tissue damage, probably secondary to local immune complex formation. Pediatr Pulmonol. 1995; 20:71–77 . © 1995 Wiley-Liss, Inc.