[A study on the frequency of pseudohypertension in the elderly].
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Biomedical subjects
Publications and source records attributed to I Kuwajima.
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A new polyamine, tetrakis(3-aminopropyl)ammonium, N+ (CH2CH2CH2NH2)4, was identified in cells of an extreme thermophile, Thermus thermophilus. This compound was chemically synthesized and its chemical properties were coincident with those of the amine isolated from the thermophile.
The correlations between blood pressure, left ventricular hypertrophy and left atrial enlargement were examined in 2,010 autopsied cases. The cases were classified into 3 groups: 972 (48.2%) normotension cases, 313 cases (15.5%) of systolic hypertension and 725 cases (36.1%) of diastolic hypertension. The incidence of left ventricular hypertrophy (LVH) was significantly higher in systolic and diastolic hypertensive cases than in normotensives (p less than 0.05), but no significant difference in LVH incidence was found between the 2 hypertensive groups. The incidence of an enlarged left atrium was also significantly higher in both hypertensive groups than in the normotensive group (p less than 0.05). The incidence of congestive heart failure and a large CTR were also higher in both hypertensive groups. However, there were no intergroup differences in atrial fibrillation incidence, despite significant differences in atrial size. Finally, the incidence of moderate to severe coronary artery stenosis was significantly higher in both hypertensive groups, but no difference was found between the 2 types of hypertension. We concluded that both systolic and diastolic hypertension contributed to the genesis of left ventricular hypertrophy, left atrial dilatation, coronary sclerosis and congestive heart failure.
The antihypertensive effect and safety of long-term therapy with nifedipine were evaluated in 132 hypertensive patients, including 100 aged patients who received nifedipine alone or with other antihypertensive agents for a mean duration of 28.6 months. A prompt hypotensive effect was observed 1 month after the initiation of nifedipine therapy. The hypotensive effect persisted for the entire follow-up period and was related to the pretreatment mean blood pressure level. Late drug tolerance was not observed. Dizziness, facial flushing and other unpleasant sensations were observed in 7.5% and ankle edema in 9.8% of the patients. The therapy did not significantly influence serum creatinine levels. Hypotension and side effects were the cause of discontinuation in 10.6% and 4.5% of patients, respectively. We conclude that long-term antihypertensive therapy with nifedipine is both effective and safe, not only in adult patients but also in the high-risk aged patient.
We studied the hemodynamic response to orally administered hydralazine (30 mg) and examined the changes in neurohumoral factors in 16 aged patients with chronic congestive heart failure. After a single 30 mg dose, 9 patients (Group I) demonstrated a greater than 30% decrease in systemic vascular resistance (SVR) and a significant increase in the cardiac index (CI); 7 patients, whose SVR was decreased by less than 30% (Group II), showed a less marked increase in CI. After 3 days of drug administration (90 mg/day), the CI decreased in Group I (p less than 0.05) while it tended to increase further in Group II. Pretreatment plasma norepinephrine was lower in Group I than Group II (p less than 0.05). However, in Group I, it increased after 3 days of therapy, with a concomitant increase in plasma renin activity (p less than 0.01) and total plasma volume (P less than 0.025). We conclude that the higher pretreatment plasma norepinephrine level in Group II, suggestive of more severe derangement of left ventricular function, may be associated with a less pronounced dilatory response of the peripheral vasculature after a single dose of hydralazine, and that the increase in norepinephrine in Group I after 3 days of treatment may limit these patients' late hemodynamic responses to the drug.
As the efficacy of oral long-acting sympathomimetic drugs is not yet well established, we investigated the hemodynamic effects of orally administered salbutamol in eight heart failure patients. Cardiac index, heart rate, blood pressure, and left ventricular filling pressure were monitored for 6 hours after a single oral administration of 4 to 8 mg salbutamol and placebo. In patients who had received salbutamol, a 40% increase in the cardiac index (+0.75 L/min/m2, p less than 0.01) was noted 1 hour post administration; a 44% increase (peak effect) occurred at 2 hours (+0.84 L/min/m2, p less than 0.05); and a significant increase persisted for 6 hours. Changes in heart rate showed a similar time course; however, the increase was less pronounced (+27% at 2 hours). The changes in blood pressure were slight and none of the eight patients developed ventricular arrhythmia or other complications. After placebo administration, no consistent changes in the hemodynamic parameters were noted. The present study suggests that, due to its sustained positive action on cardiac output, the oral administration of salbutamol may be efficacious in ambulatory patients with low cardiac output due to heart failure.
Previous studies have demonstrated a subset of normotensive rats (Wistar-Kyoto, WKY) that has arteriovenous shunts and biventricular hypertrophy. In this study, using the combined radioactive reference sample and microsphere techniques, spontaneously hypertensive (SHR) and WKY rats were found to have arteriovenous fistulas, and the magnitude of this shunting was quantified. In both groups with shunts (WKY and SHR, respectively) mean arterial pressure was lower (117 +/- 3 vs. 125 +/- 2 mmHg, NS; 164 +/- 4 vs. 184 +/- 7 mmHg, P less than 0.001) and cardiac index was higher (518 +/- 52 vs. 259 +/- 10 ml.min-1.kg-1, P less than 0.001: 416 +/- 18 vs. 239 +/- 8 ml.min-1.kg-1, P less than 0.001) than in rats without shunts. Both groups demonstrated sizable shunts, with microsphere trapping in 55 +/- 6 and 47 +/- 5% in WKY and SHR, respectively, and reduced blood flow to every organ. These data demonstrate the need for caution in evaluating hemodynamic and myocardial functional data as well as endocrinologic or metabolic functions in WKY and SHR unless shunting is excluded. Moreover, since these subsets seem to have had arteriovenous shunts from birth, it may be inferred that the development of the arterial hypertension in SHR did not result from tissue hyperperfusion.
Niludipine (Bay a 7168), a newly developed Ca2+-antagonist, was administered to eight aged patients with moderate to severe hypertension in order to study the antihypertensive effects and duration of action of a single dose as well as to evaluate the long-term effects. The subjects in the present study consisted of eight hypertensive, hospitalized patients (four men and four women, average age 74.6 years). After a two-week control period niludipine was administered in doses of 60 or 120 mg daily for five consecutive weeks (drug period) and, then, placebo tablets were administered in the same number of tablets as that of the drug for one week. On the first day of the treatment period, the drug was administered three times in a dose of 20 mg each, and the blood pressure and pulse were measured for 10 h after the administration. The systolic blood pressure was significantly reduced in the second and subsequent weeks of the treatment period, while the diastolic blood pressure was reduced only in the fourth week (P less than 0.05). During the placebo period, the blood pressure was elevated again. No side-effects were noted. In the single dose study, the systolic blood pressure was significantly reduced within 4 h after the administration, reaching its lowest value after 6 h, and tended to return to the pretreatment level after 10 h.
The clinicopathological study on the atherosclerosis and cerebrovascular and cardiac complications was carried out in 1561 consecutive autopsied cases in the elderly. The subjects were classified into 3 groups: 702 cases (45.0%) of normotension, 276 cases (17.7%) of systolic hypertension and 583 cases (37.3%) of diastolic hypertension. The acceleration of atherosclerosis by hypertension was prominent in sixties and seventies, less remarkable in eighties and almost none in nineties. The effect of hypertension was remarkable on cerebral artery, aorta and coronary artery in this order, and no difference was found between the systolic and diastolic hypertension groups. On the basis of atherosclerotic changes, strokes and myocardial infarction were prevalent in both these groups in comparison with the normotension group. The difference between the systolic and diastolic hypertension groups and the normotension group was prominent in sixties and seventies, but in eighties only the diastolic hypertension group showed a significant difference with the normotension group. The effect of hypertension was more remarkable on strokes than myocardial infarction. The lack of remarkable effect of hypertension on the cases over eighty may be attributed to the progression of atherosclerosis with age in normotensive cases. The 4 year prospective trial on the effectiveness of the antihypertensive treatment was performed in 100 mild hypertensive patients of the aged, averaging 76.1 years. The matched pair group was selected by the age, sex and blood pressure. Cerebrovascular and cardiac complications were observed in 4 cases of 10.5% of 38 cases of the drug group, and in 9 cases or 22.0% of 41 cases of the placebo group. When the elevation of blood pressure over 200/110 mmHg, observed in 8 cases in the placebo group, were included as one of the cardiovascular complications, the complications in placebo group reached 41.5%, showing a significant difference. Other complications such as cancers, infections and bone or joint diseases, were observed in 12 cases or 31.6% in the drug group and in 17 cases or 41.5% in the placebo group. Blood pressure was decreased from 171/87 to 151/80 in the drug group in the 4 year period. The present study suggested that antihypertensive treatment was effective in the aged hypertension, and careful follow up was needed not only for cardiovascular complications but also for general health condition.
The 4 year prospective trial on the effectiveness of the antihypertensive treatment was performed in 100 mild hypertensive patients of the aged, the average age being 76.1 years. Dropouts during the drug-off control period were 9 cases. The matched pair group was selected by the age, sex, and blood pressure. Forty-four drug treated cases and 47 placebo treated cases were comparable in blood pressure as well as in laboratory data. Cerebrovascular and cardiac complications were observed in 4 cases or 10.5% in the drug group, and in 9 cases or 22.0% in the placebo group. When 8 cases of blood pressure elevation over 200/110 mmHg in the placebo group were added to the cardiovascular complications, dropouts in placebo group reached 41.5%, and this showed the significant difference. Other complications were observed in 12 cases or 31.6% in the drug group and in 17 cases or 41.5% in the placebo group. Major complications were cancers, infections, and bone or joint diseases. Blood pressure was decreased from 171/87 to 151/80 in the drug group, and the average decrease was 20/7 mmHg in 4 year period. No significant changes in hematocrit, serum protein, urea nitrogen, uric acid, sodium, and potassium were observed during the trial period. The present study suggested that antihypertensive treatment was effective in the aged with mild hypertension, and that careful follow up was needed not only for cardiovascular complications but also for general health condition.
Hemodynamic comparison of ergometer exercise with isoproterenol infusion was carried out in normal young and old men, and age associated difference in responses to exercise and isoproterenol was evaluated. Ergometer exercises of 50, 100 and 150 W in young men, averaging 23.0 years, increased heart rate in linear fashion from 73.8 to 149.2, while stroke index was raised at 50 W and remained at the same level thereafter. The isoproterenol infusion of 0.02 and 0.04 microgram/kg/min increased heart rate, stroke index and cardiac index by similar amount to 50 and 100 W or ergometer exercise respectively. Ergometer exercise elevated systolic, diastolic and mean blood pressure linearly, while isoproterenol infusion lowered diastolic and mean blood pressure. In old men, averaging 73.0 years, the tolerable limit of ergometer exercise was 40 W. The increases in heart rate, cardiac index and blood pressure at the comparable work level were by similar amount to the young subjects, indicating the identical hemodynamic responses in young and old men at the same work load. Cardiac index to isoproterenol infusion of 0.02 microgram/kg/min showed less increase than ergometer exercise of 40 W in the aged. Furthermore, the increase in cardiac index to isoproterenol was less in old than young men, showing a decreased response to beta adrenergic stimulation in the aged.
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Ten mg of Nifedipine, a Ca++ antagonist, was administered orally in 2 groups of patients; Group 1: 6 patients in hypertensive emergency and Group II: 12 patients with intractable, severe hypertension. Following results were obtained. 1) A marked hypotensive effect was observed in all patients of Group I. The maximum effect was observed within 30 to 60 min and lasted for approximately 180 min. Clinical symptoms also improved remarkably with the fall in blood pressure. Any side effect was not observed. 2) A marked hypotensive effect was observed in all cases of Group II. The blood pressure fell by 21.4% systolic (p less than 0.01) and 19.4% diastolic (p less than 0.02). The peripheral vascular resistance also showed the decrease by 26.2% (p less than 0.01). The heart rate and cardiac index increased slightly. It was suggested that the hypotensive mechanism of this preparation is due primarily to the peripheral vasodilation.
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