Surgical Treatment of Angina Pectoris:V. Pre- and Postoperative Lung Function Studies and Chest X-ray Findings Including Diaphragmatic Kymography

Abstract

Static and dynamic spirometry, nitrogen washout and measurement of PaO₂ and PaCO₂ were made before and 1 year after operation in 25 patients where a diaphragm graft (G) operation was performed and in 17 where a modified Beck (B) operation was done. The results were compared with values obtained from 11 healthy men, 15 patients with mitral stenosis, 45 subjects with different lung diseases and pre- and postoperatively from a group of 11 patients thoracotomized for diseases not affecting heart or lungs. In the two ischaemic heart disease (IHD) groups chest radiographs and diaphragmatic kymographies were also obtained. Regional lung function was evaluated one year postoperatively on 10 subjects from group G and 5 from group B.

Both IHD groups shawed pre-operatively, in relation to the predicted normal, a low VC and FEV₁ and a still lower MVV, a pattern which was not seen in the other groups of patients or in normal subjects. The difference (FEV₁-MVV) in per cent of predicted seemed to be related to the IHD as it was more pronounced in subjects with a low work tolerance. The subjects with low work tolerance more often showed arterial hypoxemia.

Thoracotomy only gave a minor decrease in FRC. VC decreased by 0.49 1 in the B-group and 0.73 1 in the G-group. FEV₁ decreased by 0.46 1 in the B-group and by 0.58 1 in the G-group. MVV changed significantly only in the G-group (-18 1, P<0.01). Both radiography and radiospirometry localized the changes to the basal part of ths left lung. The B-group mainly had pleural changes while the G-group had abnormal kymographies.

It is suggested that the two revascularization operations should not be performed in subjects with a FEV₁ of less than 2.0 1 as ventilation might become the limiting factor for their physical work capacity.