Direct operations for the management of life-threatening ischemic ventricular tachycardia

Between June 1978 and 1986, 93 consecutive patients underwent electrophysiologically guided operations for life-threatening recurrent sustained ventricular tachycardia mostly associated with other surgical procedures, such as left ventricular resection (aneurysmectomy) and coronary artery bypass grafting. Data: Eighty-seven percent of the surviving patients were free of spontaneous ventricular tachycardia return or sudden death 1 year after the operation and 77% at 5 years. The instantaneous risk of ventricular tachycardia return was highest immediately after operation, declined rapidly, and by 2 weeks postoperatively had merged with the constant hazard phase, which persisted as long as the patients were observed. Endocardial resection, rather than encircling endocardial myotomy, increased the risk of spontaneous ventricular tachycardia return/sudden death. Survival rates, including hospital deaths, were 95% at 30 days, 89% at 1 year, and 70% at 5 years after operation. The most prevalent mode of death was heart failure. The absence of anterolateral left ventricular aneurysms and the use of more extended encircling incisional techniques for ventricular tachycardia ablation increased the risk of early and late death. Survival was particularly poor in that subset of patients in whom recurrent sustained ventricular tachycardia returned after operation; the most prevalent mode of death in this group was also progressive left ventricular failure. Inferences: (1) Complete and partial encircling endocardial myotomy incisions are the most effective surgical techniques for malignant ventricular tachycardia ablation. (2) Because of their adverse effects on left ventricular structure and function, the arrhythmogenic tissues have to be localized as precisely as possible, and the encompassing incisions should be kept as limited as possible. (3) The late return of ventricular tachycardia may be more related to a progressive ischemic left ventricular cardiomyopathy than to an inadequate operation.     

Heart failure: Effects of beta receptor antagonists on left ventricular function in patients with clinical evidence of heart failure after myocardial infarction. A double-blind comparison of metoprolol and xamoterol Echocardiographic results from the Metoprolol and Xamoterol Infarction Study (MEXIS)

Two hundred and ten patients with clinical evidence of heartfailure, developing after an acute myocardial infarction, wererandomized to treatment with the ß₁ antagonist metoprolol50–100mg b.i.d. (n=106) or the ß₁ partial agonistxamoterol 100–200 mg bid. (n=104). Left ventricular systolicand diastolic function were assessed with echocardiography andtransmitral Doppler cardiography before and after 3 and 12 monthsof double-blind treatment. E-point septal separation and percent left ventricular fractional shortening were used as indicesof systolic function. The ratio between peak early and latemitral diastolic flow (E/A ratio) and isovolumic relaxationtime were used as indices of diastolic function. In the xamoterol group, there was a deterioration in E-pointseptal separation (P<0·05). A difference between thetreatment groups was present both at 3 months (E-point septalseparation 11·4 vs 13·0 mm, P<0·0l,fractional short ening 271 vs 252%, P<005) and 12 months(E-point septal separation Ill vs 13·2 mm, P<0·05fractional shortening 26·9 vs 25·0%, P<0·05).E/A ratio increased in the metoprolol group (P<0·05)but not in the xamoterol group. At 3 months there was a significantdifference (0·85 vs 0·67, P<0·005 betweenthe groups but not at 12 months. In comparison with the ß₁-receptor antagonist metoprolol,the ß₁ partial agonist xamoterol impaired left ventricularsystolic function in patients with clinical evidence of heartfailure after an acute myocardial infarction.     

Results of surgical treatment for atherosclerotic renovascular occlusive disease

In this study we retrospectively examined the results of surgery for atherosclerotic renal artery lesions and analysed the factors that may affect postoperative blood pressure response, changes in renal function and late mortality. A total of 326 patients were operated on over a 15 year period and were followed up for periods from 4 to 165 months (mean follow-up time: 37.2 months). An extra renal vascular area was also involved in 91.4% of cases and in 187 (57.3%) a significant involvement of both renal arteries was found and simultaneously treated. Combined revascularisation of other arteries was performed in 50.3% of patients. The indications for surgery were the treatment of extreme hypertension in 243 patients (74.5%), the improvement of renal function in 45 with renal insufficiency, and preservation of the kidney in 38 (11.7%). The preferred method of reconstruction was transaortic endarterectomy (236 cases, i.e. 72.4%) and postoperative angiography demonstrated a normal patent renal artery in 319 of 338 studied renal arteries (94.4%). There were no deaths in the early postoperative period after isolated renal artery reconstruction. Of the 164 patients with simultaneous renal and aortic reconstruction however 14 died during the early postoperative phase. The overall early mortality was thus 4.3% (14 out of 326 patients) and correlated significantly with the extent of the atherosclerotic disease, the age of the patients, the operative technique used and the different intra- and postoperative management during the two different periods of our experience (1974-1980 v. 1981-1989).(ABSTRACT TRUNCATED AT 250 WORDS)     

Endogenous kynurenic acid disrupts prepulse inhibition.

BACKGROUND: Recent studies show that endogenous levels of kynurenic acid (KYNA) are increased in the cerebrospinal fluid of schizophrenic patients. Prepulse inhibition (PPI) of the acoustic startle reflex is an operational measure of sensorimotor gating that is reduced in neuropsychiatric disorders, such as schizophrenia. Previous studies show that administration of N-methyl-D-aspartate (NMDA) receptor antagonists, such as phencyclidine or MK-801, leads to deficits in sensorimotor gating that mimic those observed in schizophrenic patients. METHODS: The present study examined the effects of the endogenous NMDA receptor antagonist KYNA on startle and PPI in rats. Elevation of endogenous brain levels of KYNA was achieved through intraperitoneal (IP) administration of kynurenine (100 mg/kg), the precursor of KYNA, or by intravenous administration of PNU 156561A (10 mg/kg). RESULTS: A fourfold increase in brain KYNA levels, as induced by kynurenine or PNU 156561A, significantly reduced PPI. There were no differences in startle magnitudes between control rats and drug-treated rats. The disruption of PPI was restored by administration of the antipsychotic drugs haloperidol (.2 mg/kg, IP) or clozapine (7.5 mg/kg, IP). CONCLUSIONS: The present results suggest that brain KYNA serves as an endogenous modulator of PPI and are consistent with the hypothesis that KYNA contributes to the pathophysiology of schizophrenia.     

Weight Status and BMI-Related Traits in Adolescent Friendship Groups and Role of Sociodemographic Factors: The European IDEFICS/I. Family Cohort

BackgroundDuring adolescence, health behaviors and weight status are increasingly influenced by friendship and peer networks. This paper examines resemblances in weight-related characteristics and how they differ by sociodemographic factors.MethodsOver 3,000 friendships were reported by 1,603 adolescents, aged 11–16 years, who participated in the school-based I. Family study in 6 European countries. Each “source child” named 1–10 friends for whom standardized weight-related traits were available in the same survey. The mean value of the friends'' traits weighted by time spent together was calculated, and related to the source child''s trait. Country, age and sex of the source child, parental education, and immigrant background were considered for confounding and moderation.ResultsSource children''s z-scores of body fat percent and BMI were positively associated with their friends'' characteristics, in particular if they had highly educated parents. Positive associations were also found regarding the frequency of fast-food consumption, impulsivity, screen time, preference for sugar-sweetened foods, and hours spent in sports clubs, in increasing order of effect size. Additionally, correlations were observed between friends'' cognitive and school functioning and being bullied. No associations were seen for a preference for high-fat foods, weight concerns, and health-related quality of life. Finally, parental education and immigrant background were associated between friends in all countries except Sweden, where no associations were observed.ConclusionAdolescent friends shared a number of weight-related characteristics. For weight measures per se, positive associations with friends'' characteristics were only observed in adolescents with high parental education. Associations regarding energy-balance behaviors and indicators of school-related well-being did not differ by parental education. Parental education and immigrant background correlated positively in friends in most countries showing that social aggregation is already occurring in adolescence. The wide spectrum of friendship associations in weight-related traits and behaviors suggests that health promotion initiatives in adolescents should be directed towards peer groups in both school-related and leisure-time environments.ISRCTN RegistryPan-European IDEFICS/I. Family children cohort (ID ISRCTN62310987; https://doi.org/10.1186/ISRCTN62310987).     

Comparative study of tocainide and lidocaine in patients admitted for suspected acute myocardial infarction

The antiarrhythmic effects of tocainide, administered as a bolus injection of 750 mg followed by oral therapy, and conventional lidocaine therapy were evaluated in 40 patients admitted for suspected acute myocardial infarction (AMI) and showing high-grade premature ventricular complexes (PVCs). The mean hourly PVC rate before therapy was 928 and its reduction was equally significant in the tocainide group, 73%, and in the lidocaine group, 68%. The number of 5-minute periods with multiform, paired and R/T PVCs or ventricular tachycardia was also significantly reduced, by 78% in the tocainide group and by 71% in the lidocaine group. Ten patients in the tocainide group reported moderate side-effects, compared to 13 in the lidocaine group, where the infusion had to be discontinued in 5 patients and the rate had to be reduced in 4. Tocainide, an amine analogue of lidocaine, is considered just as effective as lidocaine in patients with high-grade PVCs and suspected AMI.     

Total sleep deprivation decreases saliva ghrelin levels in adolescents

Ghrelin, a regulator of food intake and energy expenditure, has been shown to be associated with insufficient sleep. The goal of the present study was to investigate the effect of a single night of total sleep deprivation on fasting saliva ghrelin and on nocturnal variation of saliva ghrelin concentration. A further aim of the study was to investigate the influence of body mass index on changes in saliva ghrelin levels. Altogether 35 adolescents (18 boys; age: 13.8 ± 1.14 years) were studied on two subsequent days (sleep and total sleep deprivation). Saliva samples were collected during the two experimental nights at 21:00 hours, 01:00 hours and 06:00 hours. Total-ghrelin concentration showed a continuous increase from the evening until 06:00 hours. This increase was blunted significantly (p = 0.003) by total sleep deprivation. Total-ghrelin level was significantly lower (p = 0.02) during total sleep deprivation at 06:00 hours (median 403.6 pg ml⁻¹; 95% confidence interval: 343.1–468.9 pg ml⁻¹) as compared with values during the sleep condition (median 471.2 pg ml⁻¹; 95% confidence interval: 205.4–1578.7 pg ml⁻¹). Acyl-ghrelin levels did not present any change at the three time points, and were not affected by total sleep deprivation. Stratifying the study population according to body mass index (normal weight and overweight/obese groups), the blunting effect of total sleep deprivation was more pronounced in the obese/overweight group (sleep: median 428.2 pg ml⁻¹; 95% confidence interval: 331.3–606.9 pg ml⁻¹ versus total sleep deprivation: median 333.1 pg ml⁻¹; 95% confidence interval: 261.5–412.9 pg ml⁻¹; p = 0.0479). Saliva total-ghrelin concentrations gradually increased during the night, and total sleep deprivation significantly blunted this increase. This blunting effect was mainly observed in subjects with overweight/obesity. The physiological and clinical implications of the present observation are to be clarified by further studies.     

Sexual behavior of natural family planning users in Germany and its changes over time

For 10 years, a prospective study has been taking place in Germany to examine the use of natural family planning (NFP). As natural methods are behavioral methods, use-effectiveness, acceptability and continuation rates are very much influenced by patterns of sexual behavior. Therefore we performed an analysis of the sexual behavior of NFP users. Out of the data base of 1211 clients and 21 591 cycles we could identify a group of 300 women, all NFP beginners, with 5900 contraceptive cycles, who contributed at least 12 cycles with reliable recording of their sexual activity. Different groups were analyzed with methods of analysis of variance and regression models to find out significant differences in their sexual behavior with respect to sociodemographic structure and time of use. Nearly half of all the women systematically combine the fertility awareness, part of NFP with other family planning methods. They use barriers in more than 60% of their cycles. The other half never or only in about 7% of their cycles use additional barrier methods. The latter show a clear decrease in barrier use in the course of time, whereas the frequent barrier users constantly combine the advantages of two family planning methods. Regarding the frequency of intercourse they are the sexually more active ones and show distinct sociodemographic characteristics. We could confirm the existence of three groups of NFP users, which differ significantly in their use of NFP as a family planning method. Despite these differences the low pregnancy rates indicate the conscious and risk-related sexual behavior of the group members.

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Resumen Desde hace 10 años se realiza en Alemania un estudio prospectivo con el objeto de examinar el uso de la planificación familiar natural (PFN). Dado que los métodos naturales son métodos de conducta, las tasas de eficacia-uso, aceptabilidad y continuación se ven muy influidas por las modalidades de la conducta sexual. En consecuencia, efectuamos un análisis de la conducta sexual entre usuarias de PFN, asimismo porque frecuentemente era un tema tabú o había sido idealizado. Con nuestra base de datos de 1.211 clientas y 21.591 ciclos, pudimos identificar un grupo de 300 mujeres, todas recién iniciadas en la práctica de la PFN, con 5.900 ciclos anticonceptivos, que contribuyeron al menos 12 ciclos con un registro fiable de su actividad sexual. Se analizaron diferentes grupos con métodos de análisis de modelos de varianza y regresión a fin de determinar diferencias significativas en su conducta sexual con respecto a la estructura sociodemográfica y tiempo de uso. Casi la mitad de todas las mujeres combinan sistemáticamente el elemento de percepción de la fertilidad de la PFM con otros métodos de planificación familiar. Utilizan métodos de barrera en más del 60% de sus ciclos. La mitad restante de las mujeres no usan barreras adicionales o lo hacen sólo en aproximadamente el 7% de sus ciclos. Estas últimas señalan una clara reducción en el uso de métodos de barrera en el curso del tiempo, mientras que las usuarias frecuentes de estos métodos combinan constantemente las ventajas de los dos métodos de planificación familiar. Con respecto a la frecuencia de las relaciones sexuales, son las más activas sexualmente y señalan características socioeconómicas distintivas. Pudimos confirmar la existencia de tres grupos de usuarias de PFN, que difieren significativamente en su uso de la PFN como método de planificación familiar. A pesar de estas diferencias, las bajas tasas de embarazo indican la conducta sexual consciente y relacionada con el riesgo observada en los miembros de los grupos.

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Resumé Une étude prospective en cours depuis 10 ans en Allemagne examine le recours au planning familial naturel (PFN). Les méthodes naturelles étant liées au comportement, les taux d'efficacité, d'acceptabilité et de poursuite sont très influencés par les régularités observées dans les types de comportement sexuel. Nous avons donc procédé à une analyse du comportement sexuel chez les sujets qui ont recours au PFN, et aussi parce que, par le passé, ces méthodes étaient souvent interdites ou idéalisées. Dans notre base de données portant sur 1.211 sujets et 21.591 cycles, nous avons pu identifier un groupe de 300 femmes, toutes débutantes du PFN, correspondant à 5.900 cycles de contraception. Celles-ci ont fourni des renseignements fiables sur leur activité sexuelle concernant au moins 12 cycles. Différents groupes ont fait l'objet d'analyses de variance et de modèles de régression en vue de cerner des différences significatives dans leur comportement sexuel par rapport aux conditions socio-démographiques et à la durée d'utilisation. Près de la moitié des femmes associent systématiquement l'élément connaissance de la période de fécondite de la méthode de PFN à d'autres méthodes de planning familial. Elles ont recours à des barrières pendant plus de 60% de leurs cycles. Quant à l'autre moitié, elles n'utilisent jamais d'autres barrières, ou pendant 7% de leurs cycles seulement. Avec le temps, ces dernières utilisent de moins en moins les barrières, alors que les femmes du premier groupe associent constamment les avantages de deux méthodes de planning familial En ce qui concerne la fréquence des rapports sexuels, ces dernières sont les plus actives et présentent des caractéristiques socio-économiques bien distinctes. Il a été possible de confirmer l'existence de trois groupes ayant recours au PFN, de manières très différentes les unes des autres. Malgré ces différences, les faibles pourcentages de grossesses montrent que les membres de ce groupe sont conscients des risques liés au comportement sexuel.

     

Activation of nigral dopamine neurons by the selective GABAB-receptor antagonist SCH 50911

Summary. Previous studies have shown that systemic as well as local administration of the GABA_B-receptor agonist baclofen is associated with a decrease in firing rate, a regularisation of firing rhythm and a decrease in burst firing activity of dopamine (DA) containing midbrain neurons. In the present electrophysiological study we have utilised the novel, selective and potent GABA_B-receptor antagonist SCH 50911 in order to further analyse the importance of GABA_B-receptors for the overall activity of rat nigral DA neurons. SCH 50911 given intravenously (1–64 mg/kg) or locally, by microiontophoretic techniques, was found to increase firing rate and to increase the burst firing activity of DA neurons. The present data suggest that the GABA_B-receptor antagonist blocks somatodendritic receptors on nigral DA neurons. This GABA-receptor input appears to be of a tonic nature. It is proposed that the activation of nigral DA neurons may underlie the beneficial effects of GABA_B-receptor antagonists in the modulation of cognition and that GABA_B-receptor antagonists may be of therapeutic value in the treatment of Parkinson's disease. Received October 5, 1998; accepted December 2, 1998     

Hospitalization and Health Care Costs Due to Congestive Heart Failure in the Elderly

The objective of this study is to describe the occurrence of readmissions due to congestive heart failure (CHF) in an elderly population and to give insight into the costs associated with readmissions. Two hundred and seven patients ages 65-84, hospitalized due to CHF, were included in the analysis. Seventy-six patients (37%) were readmitted due to CHF within 1 year including 32 (16 %) readmitted within 30 days. The patients with early readmissions had a significantly shorter index hospitalization compared to those not readmitted. The total cost for hospitalization due to CHF was 7,739,488 SEK (8 SEK to $1US). Readmissions accounted for 41% of this amount. We conclude that readmissions are common in patients with CHF and that the frequencyof early readmissions for CHF may be related to the duration of prior hospitalization. Early discharge may lead to increased health care expenditure due to a high frequency of readmissions.