Efficacy and safety of inhaled Salmeterol (Serevent) as maintenance therapy for asthma in Nairobi.

An open study to assess the efficacy and safety of 50 micrograms inhaled Salmeterol (Serevent) administered twice daily as maintenance therapy for asthma was undertaken by the Respiratory Diseases Research Unit (RDRU) in Nairobi between August and October, 1992. Salmeterol (Hydroxynaphthoate) is a long acting selective beta-2-agonist. Seventy-three adult patients recruited at Kenyatta National Hospital underwent a two weeks treatment period during which they were assessed over three visits. At Visit 1, eligibility was confirmed, baseline lung function indices measured, the study drug introduced and all the previous medications withdrawn. After treatment for one week (Visit 2) and two weeks (Visit 3), lung function indices were measured again and subjective patients' and physicians' assessments of efficacy documented. Patients with obstructive ventilatory defect (OVD) at baseline had significant improvement in their lung function compared to those without at the end of the treatment period. A significant number of patients reported decreased number of nocturnal awakenings and increased tolerance to physical activity. Cough, headache and itchy throat were adverse events possibly related to the use of Salmeterol. The patients treated with Salmeterol gained improved control of their asthma symptoms. The drug offers a convenient dose schedule and we recommend its use for maintenance therapy for mild to moderate asthma.

Pulmonary vascular sling: report of seven cases and review of the literature.

A total of 130 cases of pulmonary vascular sling, including seven new cases in our collection, were studied. The sex distribution was 60% male and 40% female. The age at presentation was in the first year of life in approximately 90% of cases. Barium-esophagraphy showing anterior indentation was diagnostic in most of the cases. Bronchoscopy and tracheobronchography were useful in detecting associated tracheobronchial anomalies preoperatively. The analysis of 68 autopsied cases revealed associated tracheobronchial anomalies in 40% of the cases. Anomalies of the tracheobronchial tree took three major forms: abnormal distribution of cartilage in the walls of the trachea and major bronchi, intrinsic stenosis, and abnormal branching, the latter being that of bronchus suis. Acquired changes secondary in the sling resulted in compression of the major respiratory pathway by the anomalous left pulmonary artery. Major associated cardiovascular anomalies were present in 30% of the cases. These were represented by ventricular septal defect, atrial septal defect, patent ductus arteriosus, tetralogy of Fallot, common ventricle, and coarctation of the aorta.

Anatomic features of congenital pulmonary valvar stenosis.

A total of 31 specimens of hearts with congenital pulmonary valvar stenosis were studied. To define the anatomy of the normal pulmonary valve, 210 specimens of hearts considered to have a normal pulmonary valve were also reviewed. On the basis of gross morphology of the valve leaflets and annulus, the stenotic valves were subgrouped into domed, unicommissural, bicuspid, tricuspid, hypoplastic annulus, and dysplastic. The valve leaflets in all subgroups were thickened. The thickness varied in degree, but involved the entire length of the leaflet. Microscopically, the thickness in most cases was due to an increase in myxomatous tissue. In a few cases, the elastic and collagen components of the leaflet were increased. The valve annulus was abnormal in most cases. The abnormalities included replacement of the fibrous backbone of the annulus by myxomatous tissue and partial or complete absence of the annulus. The impact on valvar anatomy by direct surgical valvotomy (14 patients) and closed Brock valvotomy (two patients) was reviewed. Precise knowledge of pulmonary valve anatomy is an aid to successful balloon pulmonary valvuloplasty.

Cardiovascular collapse in infants: association with paroxysmal atrial tachycardia.

Four infants, aged 16 to 28 days (mean 23 days), were seen in the emergency room with acute cardiovascular collapse and with normal heart rate and rhythm. During evaluation for cardiovascular collapse, no infant had sepsis; cardiac assessment revealed normal intracardiac anatomy but global cardiac chamber enlargement and poor left ventricular systolic function, which resolved with supportive treatment. However, three of the four infants demonstrated ventricular preexcitation on their surface electrocardiogram and, subsequently, two infants had transient episodes of tachycardia. During a transesophageal pacing study to evaluate inducibility and electrophysiologic characteristics of tachycardia, sustained tachycardia was initiated in all four infants. Reentrant tachycardia used an accessory atrioventricular connection as evidenced by the presence of preexcitation during sinus rhythm (three infants), the ability to initiate and terminate tachycardia by programmed electrical stimulation (four infants), minimum ventriculoatrial interval recorded in the esophagus (V-Aeso) exceeded 70 ms (four infants), transient bundle branch block during tachycardia prolonged the cycle length and the V-Aeso by 30 to 50 ms (three infants). Findings in these infants suggested prior episodes of prolonged tachycardia as the probable etiology of the cardiovascular collapse.