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SUMMARY The exercise capacity and cardiopulmonary response to progressive dynamic exercise of eight healthy recipients of heart-lung transplants were compared with those of matched recipients of orthotopic cardiac transplants and normal controls. In both transplant groups the maximum workloads were lower than that in the normal group. The transplant recipients had higher pre-exercise heart rates and lower maximum heart rates than the normal controls. Ventilation during submaximal exercise was similar in the heart transplant group and the controls. The heart-lung group had an increased ventilatory response associated with lower end tidal carbon dioxide concentrations.Exercise capacity after combined heart-lung transplantation is similar to that after cardiac transplantation. Transplant recipients have an abnormal heart rate response during exercise related to cardiac denervation. The altered ventilatory response in heart-lung recipients may be the result of pulmonary denervation.Combined heart-lung transplantation is a therapeutic option for patients with end stage pulmonary vascular disease' and parenchymal lung disease.2 Successful transplantation can relieve symptoms and improve the patient's quality of life.' However, exercise capacity after transplantation is below predicted values4 and the physiological consequences of this extensive operation have not been fully evaluated.We compared the exercise capacity and cardiopulmonary response to exercise of a group of healthy recipients of heart-lung transplants with that of cardiac transplant recipients and normal controls. Patients and methodsWe studied eight recipients ofheart-lung transplants who were free of cardiopulmonary complications (with the exception of treated hypertension). They were compared with eight normal individuals and eight recipients of cardiac transplants who were matched as closely as possible for age and sex. The transplant recipients were also matched for time afterRequests for reprints to Dr Nicholas R Banner, Cardiothoracic Unit, Harefield Hospital, Harefield, Middlesex UB9 6JH.

A preliminary epidemiological study has been carried out to investigate a report that some men working in a factory manufacturing polyvinylchloride (PVC) had abnormally low values of the single breath diffusing capacity for carbon monoxide (TLCO). All monoxide (TLCO). All 265 present and past employees of the PVC factory were studied, together with 219 men from the workforce of a nearby foundry. Each man's TLCO was measured and a smoking history and detailed occupational history obtained. The distribution of standardised TLCO results from all persons examined was symmetrical and did not indicate an unexpectedly high proportion of men with having allowed for age, height, weight, and smoking habit, TLCO was associated with a history of working in the PVC factory before 1975 (when levels of vinylchloride monomers (VCM) were much higher than subsequently), and slightly associated with working in jobs where exposure to VCM was likely to have been highest. The men with low TLCO also tended to have smoked more heavily than controls. The relative importance of occupational factors and smoking in relation to low TLCO is not clear, but the results give some support to the hypothesis that work in the PVC factory before 1975 entailed exposure to a substance that caused impairment of lung function in a small number of men.

To determine whether dust-related "clinically important" deficits of lung function still occur in British coal miners we have analyzed the relationship between lifetime cumulative exposure to respirable dust and risk of defined functional deficits in a population of miners who were examined between 1981 and 1986. The study group consisted of a sample of men who had worked at any one of three collieries (South Wales, Yorkshire, and North East England) between 1970, when new dust standards were introduced, and date of medical survey. There were 1,671 men studied, including men who had left the collieries. "Clinically important" deficits of FEV1 from predicted values derived in this population were defined by comparisons with questionnaire data on exercise tolerance limited by breathlessness. The mean FEV1 of men in the South Wales colliery, for example, who said they had to stop for breath when walking at their own pace on level ground was 942 ml less than the predicted value for nonsmokers after taking age and stature into account. Individual cumulative exposures to respirable dust were calculated from a long-term program of measurements of dust concentrations and occupational records commencing in 1953. In the three colliery populations, 24, 24, and 12% in South Wales, Yorkshire, and the North East, respectively, had FEV1 deficits that were at least as severe as the average deficit associated with the severe grade of exertional dyspnea described above. In all collieries deficits were more common in smokers than in nonsmokers, and more common in men who had left the industry than in men still within it.(ABSTRACT TRUNCATED AT 250 WORDS)

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