Prediction of Arrhythmic Events After Acute Myocardial Infarction Using Two Methods for Late Potentials Recording

One hundred consecutive patients recovering from an acute myocardiai infarction underwent, prior to home discharge, signal-averaged electrocardiography (ECG), left ventriculography. and 24-hour Holter ECG recording. The signal-averaged ECG was recorded and analyzed using two procedures: the orthogonal bipolar XYZ lead configuration with a bidirectional filter: and a precordial unipolar lead configuration with a uonrecursive digital filter. An abnormal signal-averaged ECG was seen in 40% of patients with the XYZ system and in 30% of patients in the precordial method, abnormal ejection fraction (< 40%) in 24% of patients and high grade ectopy activity in 22%. During the 24-month follow-up period, 12 patients (12%) had an arrhythmic event defined as either sudden death (11 patients) or sustained ventricular tachycardia (1 patient). Neither the signal-averaged ECG with the XYZ configuration, the abnormal ejection fraction, nor the high grade ectopy were able to statistically predict a higher arrhythmic event rate. The signal-averaged ECG with the precordial configuration was able to statistically predict a higher arrhythmic event rate, P < 0.03; odds ratio = 3.96. The combination of the orthogonal XYZ configuration signal-averaged ECG with the ejection fraction (P < 0.01, odds ralio = 7.33), or with ejection fraction and Holter monitoring (P < 0.06. odds ratio = 6.17) was able to predict a higher arrhythmic event rate. The combination of the precordial configuration signal-averaged ECG with the ejection fraction (P < 0.002, odds ratio = 14.4), or with ejection fraction and Holter monitoring (P < 0.06. odds ratio =10) was able to better predict a higher arrhythmic event rate. The combination of a normal or abnormal signal-averaged ECG and ejection fraction gave a sensitivity, specificity, positive, or negative value prediction of arrhythmic events of 60%, 90.6%, 37.5%, and 96%, respectively. It must be emphasized that the number of arrhythmic events during the 2-year follow-up was small and further study is required to determine the true predictive value of each method for arrhythmic events.     

THE INCIDENCE OF BIRTHMARKS IN ISRAELI NEONATES

Background. Several studies have documented cutaneous findings in neonates of various racial groups. Our purpose was to determine the frequency of birthmarks in Israeli neonates of Jewish and Arabic origin. Methods. A cohort of 1672 newborn infants under 96 hours of age were examined for the presence of birthmarks. Of these 841 (50·3%) were Jewish and 831 (49·7%) were Arab. The Jewish group was further subdivided into various ethnic groups according to parental ancestry. Results. Melanocytic brown lesions (Mongolian spots, congenital nevi, and cafe-au-lait spots), were more common in Arab infants. The vast majority of Jewish infants with Mongolian spots were of Asian or African ancestry. On the other hand, congenital melanocytic nevi were found only in Jewish infants of European ancestry. Vascular lesions (salmon patch and port-wine stain) in Arab neonates exhibited a female preponderance. Conclusions. Our data suggest that the prevalence of birthmarks in Israeli neonates is similar to the prevalence reported by others in white neonates.     

A convenient general method for synthesis of Nα- or Nω-dithiasuccinoyl (Dts) amino acids and dipeptides: application of polyethylene glycol as a carrier for functional purification*

N ^α-Dithiasuccinoyl (Dts) amino acids ( 1 ) needed for solid-phase peptide synthesis have been prepared in good yields and excellent purities by a new method that exploits the solubility properties of polyethylene glycol (PEG; bifunctional with average molecular weight 2000 was found to be optimal). Suitably side-chain protected amino acid derivatives are first reacted with a polymeric xanthate ( 11 ), following which the free α-carboxyl is blocked by silylation and the Dts heterocycle is elaborated in the same pot by reaction with chlorocarbonylsulfenyl chloride ( 4 ). Upon aqueous workup, the polymeric carrier removes any urethane blocked amino acids which arise during the process. Exaggerated conditions were explored to prove the power of this functional purification approach, and mechanisms of formation of polymer-bound urethanes are proposed and supported by solution model studies. The preparation and characterization of the companion N-(iso-propyldithio)carbonyl derivative of proline is also presented.     

Regression Equation Predicts Dietary Phosphorus Intake from Estimate of Dietary Protein Intake

Objective To develop a predictive equation for dietary phosphorus intake.

Design In this clinic-based, cross-sectional study, a dietitian-administered food frequency questionnaire provided dietary intake estimates for a population of patients with chronic renal failure. A prediction equation for dietary phosphorus intake was developed and was validated on another sample of patients with CRF from the same clinic.

Subjects Outpatients treated for chronic renal failure at the E. Wolfson Medical Center Institute of Nephrology in Holon, Israel, participated in the study (N=104, 73 men and 31 women, mean AGE=65.6 years). The validation sample consisted of 53 outpatients with chronic renal failure (38 men and 15 women, mean AGE=64.2 years) from the same clinic.

Main outcome measures Dietary variables (ie, energy, protein, carbohydrate, fat, phosphorus) were examined in terms of crude intake, as percentage of total energy intake, and per kilogram of body weight.

Statistical analyses performed Stepwise linear regression analysis and Student's t tests were used to examine relationships between dietary phosphorus and other variables. Results Dietary phosphorus (milligrams)=128+14 (protein intake [grams]) was the best-fitting equation and explained 84% of the variance in dietary phosphorus intake.

Applications The prediction equation for dietary phosphorus intake is especially useful for renal dietitians who calculate patient diets by hand. J Am Diet Assoc. 1996; 96:1268-1270.     

Suppressive Effect of Pregnancy on the Development of Experimental Allergic Encephalomyelitis in Rabbits

ABSTRACT: In the present study we have investigated the influence of pregnancy on the induction and development of experimental autoimmune encephalomyelitis (EAE) in rabbits in relation to the time of gestation. Randomly bred rabbits were immunized with encephalitogenic bovine brain homogenate in complete Freund's adjuvant before or during pregnancy. The appearance of EAE was delayed and occurred only after delivery, abortion, or fetal resorption. The incidence of the disease was lower and the duration longer. The levels of antibodies to myelin basic protein, an autoantigen of EAE, as measured by solid phase radioimmunoassay, were lower in the pregnant rabbits as compared to the nonpregnant animals. The suppressive influence of pregnancy on the induction and the development of EAE confirms previous reports demonstrating amelioration of autoimmune diseases and other immunological reactions during the second half of human pregnancy. This effect might be partially attributed to the increased level of alpha-fetoprotein (AFP) and/or other pregnancy-associated factors in maternal serum.     

Local Electrogram Changes in Response to a High-Voltage Intracardiac Shock in Humans

Electrogram Changes Following ICD Shocks. Introduction: Transvenous defibrillators may have difficulty sensing ventricular fibrillation following an unsuccessful shock. This study was undertaken to characterize the changes that occur in intracardiac electrograms following a defibrillator shock that may contribute to the failure to redetect arrhythmias.
Methods and Results: Unipolar and bipolar electrogram recordings were made during sinus rhythm before and following monophasic and biphasic test shocks delivered in random order through a single lead defibrillator system in 15 patients. An additional 14 patients received only a biphasic shock. Electrogram amplitude, dV/dt, and activation recovery time were determined. Following biphasic shocks, unipolar electrogram amplitude decreased by a mean of 19.6% and the bipolar amplitude by a mean of 20.8% (P = NS). The mean dV/dt in the unipolar recordings decreased by 30.7% and in the bipolar recordings decreased by 33.0% (P = NS). Time constants for recovery were approximately 60 seconds. Reduction in dV/dt was greater when the shocking coil was closer to the distal sensing electrode. There was no significant influence of shock waveform (monophasic vs biphasic), recording type (unipolar vs bipolar), or clinical variables on the change in electrogram characteristics.
Conclusion : Changes in intracardiac electrograms following defibrillator shocks through transvenous leads are seen with shocks delivered in sinus rhythm and may be related to the proximity of the shocking coil to the distal sensing electrode.     

In Vitro Effect of Anticardiolipin Autoantibodies Upon Total and Pulsatile Placental hCG Secretion During Early Pregnancy

BACKGROUND: The anticardiolipin syndrome is characterized among other features by recurrent thromboembolic events, thrombocytopenia, and recurrent fetal loss associated with high IgG titers of anticardiolipin antibodies and/or the presence of lupus anticoagulant. AIMS: The mechanisms for the fetal loss in this syndrome have not yet been clearly elucidated, although several hypotheses based on experimental data have been put forward. We wanted to evaluated the effect in vitro of anticardiolipin antibodies on the secretion of human chorionic gonadotropin. METHODS: Employing our previous experience with placental explants, we studied the effect of several mouse monoclonal and human polyclonal purified anticardiolipin antibodies (ACA), which were shown by us to induce experimental antiphospholipid syndrome (APLS), to affect the pulsatile secretion of beta human choriogonadotropin. RESULTS: The mouse monoclonal ACA antibodies caused an increase in the pulsatility of beta human choriogonadotropin, while human polyclonal ACA derived from patients with ACA had an inhibitory effect. CONCLUSION: These studies with placental explants show that ACA may have an additional effect on placental hormone secretion and thus affect the fate of the embryo.     

Calcium Carbimide in Alcoholism Treatment. Part 1: a placebo-controlled,double-blind clinical trial of short-term efficacy⋆

A randomized, double-blind, placebo-controlled single cross-over study of the alcohol sensitizing drug, calcium carbimide (CC), was conducted in 128 patients with alcohol dependence. Seventy-one (55%) completed the 4-month study. Patients reported drinking and pill-taking behaviour, and submitted urines (for analysis of alcohol and the tablet marker riboflavin) on 97%, and 91% of treatment days, respectively. All of the 69 analyzable computers were abstinent on at least 85% of days, and 58% (40) were alcohol-free during the study. Medications were taken on at least 85% of days. Symptoms and adverse clinical findings were not increased in frequency during CC, compared to placebo. Seventy-eight per cent of the patients believed they had received CC throughout the study, suggesting that CC exerts a strong psychological deterrent effect. Alcohol consumption was significantly reduced to the same extent with CC and placebo, compared to pre-treatment levels.     

Late Recurrence of Atrial Flutter Following Radiofrequency Catheter Ablation

The success rate for catheter ablation of atrial flutter has been reported to be approximately 90%, but recurrences are common and can be seen in up to 20% of cases. Most of these recurrences are seen within a few weeks following ablation. We report on a patient who developed a recurrence of type I atrial flutter 2 years after an initially successful radiofrequency catheter ablation procedure. Whether the recurrent atriai flutter is due to a new reentrant circuit resulting from slow progression of atrial disease or due to the changes produced by radiofrequency energy in the nearby myocardium is not clear. Further work to define the electrophvsiological changes in the atrial myocardium produced by radiofrequency energy, as well as long-term follow-up of patients undergoing radiofrequency catheter ablation for atrial flutter may help in answering these questions.     

Safety of Long-Term Propafenone Therapy for Cardiac Arrhythmia - Experience with 774 Patients

Long term propafenone therapy was initiated in 774 patients who were evaluated at 27 centers in the United States. The average duration of therapy was 183 days. During the treatment period, at least one toxic side effect occurred in 448 patients (58%). The most common reported adverse reactions were cardiovascular in 209 patients (27%), central nervous system in 160 patients (21%), and gastrointestinal in 159 patients (21%). Of those with cardiovascular side effects, 41 (5.3%) had aggravation of arrhythmia, 26 (3.4%) had the induction or worsening of congestive heart failure, and 65 (8.4%) had new conduction abnormalities. Although side effects were frequent, drug discontinuation due to the adverse reaction was necessary in only 114 patients (14.7%). The majority of side effects were dose related especially when 900 mg/day was administered. Additionally, the incidence of toxicity was directly related to age.
We conclude that side effects are frequent during long-term propafenone therapy, but most are mild, dose related, and do not limit the use of the drug. Drug discontinuation because of an adverse reaction is only infrequently required. It is recommended that drug therapy begin with low doses (150 mg t.i.d) with careful and slow titration up to a maximum of 900 mg/day.