Electrophysiologic effects of d-sotalol in humans

Sotalol is a beta-adrenergic blocking agent that prolongs the duration of the cardiac action potential in humans, without affecting the upstroke velocity of depolarization. The dextrorotatory isomer, d-sotalol, retains these class III effects, but has little beta-blocking activity in vitro. d-Sotalol has not been studied extensively in humans. The electrocardiographic (ECG) and electrophysiologic effects of d- and d,l-sotalol were therefore assessed in a prospective randomized study of 20 patients. Each patient received either d-sotalol (1, 1.5 or 2 mg/kg body weight) or d,l-sotalol (1 mg/kg) by intravenous infusion. The QT and QTc intervals were prolonged and refractoriness increased in the atrium, atrioventricular (AV) node, His-Purkinje system and right ventricle after both d- and d,l-sotalol. After d-sotalol, the increases in both QT and QTc intervals and in atrial and ventricular effective refractory periods were dose dependent. Highly significant linear correlation was demonstrated between the plasma sotalol level and the change in QT (r = 0.86, p = 0.001) and QTc intervals (r = 0.79, p = 0.002), and between the plasma sotalol level and the effective refractory period of the right atrium (r = 0.75, p = 0.005) and ventricle (r = 0.70, p = 0.025). This study confirms that d-sotalol has effects consistent with class III properties. It demonstrates these effects in humans, and suggests that d-sotalol may prove to be a useful antiarrhythmic agent.     

Patients' experience of epilepsy and health care

OBJECTIVE: The aim of this study was to assess the severity of epilepsy and its effect on patients lives, and to describe patients' use of and attitudes to health care. METHOD: A questionnaire was sent to 595 people with epilepsy identified from 14 general practices in north-west Bristol. All patients aged 16 years and over receiving anti-epileptic medication for their epilepsy were included in the study. Areas investigated included severity of epilepsy and its effect on quality of life, anti-epileptic medication and its perceived effect, health care utilization and preferences for health care. RESULTS: Seizure frequency was strongly associated with adverse effects of epilepsy. Attacks of epilepsy were experienced at least monthly by 20.4% (95% confidence intervals (Cl) 17.0-23.7%) of patients, 29.4% (25.4-33.4%) took more than one anti-epileptic drug, 56.1% (50.1-62.2%) reported drug side effects, 74.1% (70.3-77.8%) would prefer to receive all or most of their epilepsy care in a general practice setting, and 69.8% (63.5- 76.2%) would like contact with a primary care-based epilepsy specialist nurse. During the previous year 42.4% (35.9-48.8%) of patients had not seen a doctor about their epilepsy. Of patients who had attended the general practice only 13.4% (9.6-17.2%) had regular arrangements to see their GP about epilepsy. Patients receiving both primary and secondary care had the greatest needs and wants for improved care. CONCLUSIONS: Structured care, including regular appointments, co-ordination of primary and secondary care, and increased monitoring and discussion, may improve the quality of life of people with epilepsy, but requires evaluation.      

Duplications of the alimentary tract. Clinical characteristics, preferred treatment, and associated malformations.

Duplications of the alimentary tract are unusual congenital anomalies that frequently present a diagnostic as well as therapeutic challenge to the surgeon. Because these lesions occur so infrequently, they are often not suspected until encountered intraoperatively. Due to the complicated anatomy and common blood supply shared between the duplication and associated native bowel, appropriate management requires a familiarity with the anatomy and clinical characteristics of this entity. To better define the range of patient characteristics, clinical presentation, and preferred therapy, 20 enteric duplications were reviewed in 17 patients treated at the Children's Hospital Medical Center from 1956 to 1986. Ages of patients ranged from 1 day to 11 years; 60% were less than 2 years of age at initial presentation. Seven duplications in six patients involved alimentary tract structures of foregut derivation (esophagus, stomach, and Parts I and II of duodenum), with a predominance of girls (4 of 6). Most of these patients (67%) presented with moderate to severe acute respiratory distress and a mass present on chest radiograph. In 67% of the patients, the correct diagnosis was established before operation. None required emergency operative intervention. By contrast, 13 duplications in 11 patients were of midgut or hindgut derivation (Parts III and IV of the duodenum, jejunum, ileum, and colon). In this group of patients, 62% of the duplications involved the cecum, 23% involved the ileum, and 16%, the jejunum. Seventy-eight per cent of the patients were boys. The most common symptoms were nausea and vomiting, and the most common sign was a palpable abdominal mass. Emergency operative intervention was required of eight of 11 patients with duplications involving the small bowel and colon. Three patients presented with an intussusception, four with signs and symptoms consistent with acute appendicitis, one with a small bowel obstruction, and two with gastrointestinal hemorrhage due to the presence of ectopic gastric mucosa within the duplication. It was found that two important points must be considered in regard to the management of enteric duplications: (1) the common blood supply shared between the duplication and native bowel must be carefully protected to avoid undue sacrifice of normal bowel, and (2) the presence of heterotopic gastric mucosa in 35% of patients negates internal drainage.(ABSTRACT TRUNCATED AT 400 WORDS)     

Short-Ti inversion-recovery pulse sequence: analysis and initial experience in cancer imaging

Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy.     

Solitary rectal ulcer syndrome: findings at barium enema study and defecography

Sixteen cases of histopathologically proved solitary rectal ulcer syndrome were encountered. Fifteen patients underwent barium enema study; in nine cases the findings--including rectal stricture, granularity of the mucosa, and thickened rectal folds-were nonspecific. In six cases the study was normal. All patients had a long history of defecation disorders, and defecography was performed in all. In seven cases, intussusception of the rectal wall was seen; in another case the intussusception was accompanied by a rectocele. One case showed rectal prolapse. In four cases, failed relaxation of the puborectalis occurred and prevented the passage of the bolus; in another case there was abnormal perineal descent. In two patients studies were normal. In patients with defecation disorders, the possibility of this syndrome should be considered. Defecography is the method of choice for establishing the diagnosis.