Objective: Hyperoxia is known to influence cardiovascular and endothelial function, but it is unknown if there are differences between younger and older persons. The aim of this study was to monitor changes in myocardial diastolic function and flow-mediated dilatation (FMD) in younger and elderly volunteers, before and after exposure to relevant hyperbaric hyperoxia. Methods: 51 male patients were separated into two groups for this study. Volunteers in Group 1 (n=28, mean age 26±6, “juniors”) and Group 2 (n=23, mean age 53±9, “seniors”) received standard HBO2 protocol (240kPa oxygen). Directly before and after hyperoxic exposure in a hyperbaric chamber we took blood samples (BNP, hs-troponin-t), assessed the FMD and echocardiographic parameters with focus on diastolic function. Results: After hyperoxia we observed a high significant decrease in heart rate and systolic/diastolic FMD. Diastolic function varied in both groups: E/A ratio showed a statistically significant increase in Group 1 and remained unchanged in Group 2. E/e’ ratio showed a slight but significant increase in Group 1, whereas e’/a’ ratio increased in both groups. Deceleration time increased significantly in all volunteers. Isovolumetric relaxation time remained unchanged and ejection fraction showed a decrease only in Group 2. There were no changes in levels of BNP and hs-troponin-t in either group. Conclusion: Hyperoxia seems to influence endothelial function differently in juniors and seniors: FMD decreases more in seniors, possibly attributable to pre-existing reduced vascular compliance. Hyperoxia-induced bradycardia induced a more pronounced improvement in diastolic function in juniors. The ability of Group 1 to cope with hyperoxia-induced effectsdid not work in the same manner as with Group 2.

Left heart catheterization, quantitative angiocardiography, and selective coronary angiography were undertaken in 64 patients with angina pectoris. The (Rackley et al., 1970).This study presents a comparison between results obtained by haemodynamic and angiocardiographic measurement and those recorded by coronary angiography from patients with chronic ischaemic heart disease. Patients and methodsThe findings referred to in this paper were obtained from 64 patients (6i male, 3 female), aged between 32 and 62, who had undergone diagnostic left heart catheterization, Received28 August I973. including angiocardiography, and selective coronary arteriography for investigation of chest pain (Table i) Group III: Occlusion of a major vessel (main right coronary artery, left anterior descending branch, left circumflex branch). Catheterization was performed after moderate sedation and under local anaesthesia. After retrograde catheterization from the femoral artery, 40 to 6o ml 'Visotrast 370X1 were injected continuously or intermittently into 1 VEB Fahlberg List, Magdeburg..4

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