24 axis deviation was normalorto the right in most individuals. Left axis deviation, and only of mod- erate degree, was present In six individuals, two in the younger unexposed group,three in the older unexposed group, and one in the older exposed group. The electrical position of the heart ina great majority of both the unexposed and exposed subjects was vertical. In 22 subjects it wasintermediate and in 9 (all unexposed) it was moderately horizontal. Rotation ofthe heartelectrically in the combined groupswasclockwise in 25 subjects and counterclockwise in 36, with about equa! distribution between the exposed and unexposed groups. 4, RSTandT Waves. Abnormalvariations were carefully noted for indications of coronary or myocardial insufficiency and/or myocardial disease or damage. Deviations of the RST segmentfrom the isoelectric line were found to be minimal; they occurred in only five of the 84 unexposed subjects andin only one of the 38 exposed subjects. T wave abnormalities were of appreciable degree in only a few instancesin the older group. The abnormalities were chiefly in lower T waves and wererelated to hypertensive disease. T wave changes were most marked in a 51-year-old male ( #80) of the exposed group, whohadarteriosclerotic heartdisease and auricularfibrillation. Marked RST and T wave changes were noted in an 81-year-old male (#46) of the exposed group, who had marked hypertensive and arteriosclerotic cardiovascular disease, and had prolonged auriculoventricular conduction time as noted above. Among the unexposed population there wasevidence of myocardial insufficiency according to RST and T wave changes in a 51-year-old male (#947), a 64-year-old female (#861), a 55-yearold male ( #993), a 64-year-old female (#858), and a 64-year-old male (#884); the last had changes sufficient to indicate a healed anterior septal cardiac infarct. Other Cardiovascular Observations 1. Peripheral Vascular Findings. Clinicalestimation was madeofthe degree of arterial changes in the peripheral vessels (radia!, brachial, and dorsalis pedis). The degree of abnormality was graded by 0 to 4+ sclerosis (see section on aging studies). Arteriosclerosis was seen chiefly in subjects >50 year of age in both exposed and unexposed groups. It was not marked exceptin four individuals >70 years of age in the exposed group, and then toa degree compatible with age. Since there were no individuals examined in the pexposed group >70 years of age for comparisonWa assumption that the arteriosclerosis was increased in these four individuals by their exposureto fallout radiationis unwarranted. Otherwise the presence and the amountofarteriosclerosis was fairly well distributed between both populations, as can be seen in Table 14. It was not observed in a degree premature or advanced for the given age. 2. Arterial Blood Pressures. Blood pressures greater than 140 systolic and 90 diastolic were considered abnormal. On this basis in the exposed group noneofthe 24 subjects <_50 ofage and seven of the 16 subjects >50 had hypertension, but mostly of mild degree. There were 17 cases of hypertension in the unexposed group, 2 in those <(50 years of age and 15 in those >50. The diastolic blood pressure showed only infrequent increase above the level of 90 mm; as would be expected, this occurred chiefly in the older group. The overall incidence of hypertension for the tota! population examined was 9.2%. 3. Oscillometry Readings. Observations were taken on the legs at the mid-calf. In almostall subjects the pulsation was sufficient to indicate normal blood flow. Although the readings were lower in the Marshallese than might be expected in Caucasians, it appeared that peripheral vascuTable 16 Ophthalmological Findings (% Incidence) Pterygium Pinguecula Corneal pigment Corneal scars Arcussenilis Phthisis bulbi Nystagmus Strabismus Argyll-Robertson pupil Cataracts Aphakia Vitreous opacities Retinal arteriosclerosis Chorioretinal scars Macular degeneration Driisen Congenital anomalies Exposed Unexposed 23.0 24.0 12.0 9.0 38.0 1.3 1.3 8.3 1.3 19.0 1.3 4.1 11.0 1.3 0.0 2.6 3.9 21.0 22.0 2.6 3.4 26.0 0.0 0.7 0.7 0,0 10.3 1.3 0.0 12.3 0.7 0.0 0.0 0.0 |