Motorcycle fatalities: analysis of Birmingham Coroner's records

Analysis of the evidence from 55 coroner's inquests concerning 51 separate motorcycle accidents is reported. Fatal injuries were frequently associated with excessive speed and alcohol consumption. High speed was more common with more powerful machines. Negotiating outside bends seemed particularly hazardous. However, the errors of other road users were the most significant individual cause of fatal accidents. All motorcycle drivers were male, with a peak age group of 17, and most accidents occurred in the summer, frequently in the late evening. Some measures to reduce this mortality are discussed.     

Electrocardiographic effects of myocardial ischemia induced by atrial pacing in dogs with coronary stenosis. I. Repolarization changes with progressive left circumflex coronary. artery narrowing

The electrocardiographic effects of tachycardia in normal dogs and in dogs with progressive coronary stenosis were studied. In five animals, left atrial electrodes were surgically implanted and body surface isopotential patterns were recorded from 84 torso electrodes; pacing at rates of up to 250 beats/min increased recorded voltages registered during the ST segment but did not alter the spatial distribution of these potentials. In 10 dogs, an ameroid constrictor was also implanted about the left circumflex coronary artery. One week after surgery, pacing to rates of 250 beats/min had no effect on ST segment isopotential patterns. However, 2 and 3 weeks postoperatively, when significant coronary constriction was anticipated, pacing-induced ST segment depression was recorded along the inferior anterior and posterior chest surfaces. Abnormal negative voltages were more intense at 3 than at 2 weeks, but the distribution of these abnormalities was unchanged. This pattern was consistent with the location of ischemic myocardium. Calculation of early (10 to 40 ms) ST segment slopes demonstrated that downsloping forms were recorded over most of the area with abnormal ST segment voltages, but that horizontal or upsloping depression occurred at the margins of the abnormal zones. The findings suggest that this canine model may be a useful analog to clinical exercise stress testing to aid in evaluating the significance of clinical electrocardiographic patterns.     

Evaluation of normal variations in S-T segment patterns by body surface isopotential mapping: S-T segment elevation in absence of heart disease

S-T segment elevation is commonly observed in the electrocardiogram of normal persons. To study the possible origins of such patterns, 45 normal volunteers were examined. Electrocardiographic potentials were registered from 150 torso electrodes and processed to construct iso-potential maps at 2 ms intervals throughout the QRS-T interval. The maximal potentials recorded from any of the 150 electrodes were 198 ± 76.4 and 272.1 ± 84.2 μV at instants 40 and 80 ms into the S-T segment, respectively. Maximal voltages recorded by the six standard precordial V leads at these respective time points were 109.7 ± 57.0 and 163.6 ±66.9 μV. Torso maximal potentials were significantly stronger than were those sensed by V leads; the two were significantly correlated but predictability was limited. The duration of overlap between the onset of ventricular recovery and the end of the excitation was determined from isopotential maps and ranged from 4 to 16 ms. There was no significant correlation (p > 0.05) between these values and either torso or V lead potentials at either 40 or 80 ms into S-T segment.These data suggest that (1) standard precordial leads do not accurately predict maximal torso potentials during the S-T segment, and (2) the degree of overlap between repolarization and depolarization is not a major determinant of precordial voltage. Hence, the rationale for use of the term “early repolarization” to describe this clinical condition is not substantiated.     

Hyposplenism and pneumococcemia: Visualization of diplococcus pneumoniae in the peripheral blood smear

We describe three patients with overwhelming pneumococcemia in whom Diplococcus pneumoniae was readily visible in stained smears of peripheral blood. Such a finding, which is distinctly unusual in pneumococcal disease, suggests bacteremia of immense magnitude. All three cases were rapidly fatal, and all occurred in patients with acquired hyposplenism.     

Surface IgM on lymphocytes from pregnant women

Surface IgM on peripheral lymphocytes from pregnant women were passively acquired from autologous serum. These cytophilic IgM antibodies occurred as relatively large molecules, suggesting that they were in the form of complexes or aggregates. The lymphocytes involved were mainly B cells. It was postulated that the present findings could be a mechanism for the modulation of lymphocyte surface receptors by serum factors during pregnancy.     

Filling of a lateral pre-malleolar soft tissue defect with the extensor digitorum brevis flap and the abductor digiti minimi flap

The authors report the filling of a lateral pre-malleolar soft tissue defect after sub-talar arthrodesis. Four months after surgery the loss of substance measured 2,5 cm in depth, 3 cm diameter at the skin level and 5 cm diameter at the bone level. An autologous tricortical bone graft impacted in the sinus tarsi was also exposed. In this area of the body, soft tissue coverage is difficult because of the lake of local sub-cutaneus tissue and muscle. The authors used two locoregional pedicled flaps: the extensor digitorum brevis flap and the abductor digiti minimi flap. These transfers left a minimum of functional and aesthetic after-effects. The optimal coverage of the exposed structures allowed the patient to walk thirty days after surgery. The way to harvest these flaps, their advantages and disadvantages are detailed.