[Tricuspid regurgitation induced by transvenous right ventricular pacing: echocardiographic and pathological observations]

To assess tricuspid regurgitation (TR) in patients with permanent transvenous right ventricular (RV) pacing, we performed phonocardiographic, contrast and pulsed Doppler echocardiographic studies in 18 patients with transvenous leads for RV pacing. In addition, a pathological study was performed on 26 autopsy cases with transvenous leads for RV pacing. None of the patients had right-sided heart failure. The previous phonocardiograms revealed regurgitant murmurs of TR in one clinical case and five autopsy cases. In the clinical study, definite TR was diagnosed both by contrast and pulsed Doppler echocardiography in five cases (28%). Probable TR was diagnosed only by one technique in three cases (17%), and the absence of TR was confirmed by both techniques in 10 cases (55%) (non-TR group). The average right atrial dimension was 59 +/- 5.3 mm in the definite TR group and 39 +/- 2.4 mm in the non-TR group (p less than 0.01). The average inferior vena cava dimension was 19 +/- 1.7 mm in the definite TR group and 15 +/- 0.8 mm in the non-TR group (p less than 0.05). Right atrial and inferior vena cava dimensions showed a significantly positive correlation (r = 0.58, p less than 0.05). In the pathological study, the presence of TR, which was explained by the position of the pacemaker lead in relation to the valve structure, was confirmed in 11 cases (42%). Valve motion interference was classified as type I (two cases), in which the lead was suppressed and the leaflet immobilized, type II (4 cases), in which chordae tendineae were involved by a pacemaker lead, and type III (five cases), in which both mechanisms contributed to valvular regurgitation. In conclusion, TR may follow transvenous RV pacing in approximately half of the cases with RV pacing. Contrast and pulsed Doppler echocardiography are sensitive noninvasive techniques for detecting this valvular abnormality and they should be used in the follow-up of such pacemaker recipients.

Comparison of enzymatic, anatomic and electrocardiographic estimates of myocardial infarct size in man

Myocardial infarct size is definitely related to cardiac function and prognosis. For a critical evaluation of infarct size estimation methods, we weighed infarcted myocardium from 44 autopsy cases (24 men and 20 women, mean age of 76.8 yr.), and compared the weight with the peak value of serum CPK activity (peak-CPK), the peak value of serum CPKMB isoenzyme activity (peak-CPKMB), the total CPK release (sigma CPK), and the QRS scoring system in the standard 12-lead electrocardiogram (ECG) modified by Wagner et al.. The mean infarcted myocardial weight (MI weight) of the 44 cases was 38.4 g. The mean value of the peak-CPK, peak-CPKMB, and sigma CPK were 2487, 221, and 4597 IU/ml, respectively, and the mean QRS point score was 7.2. The interval between serial CPK determination and ECG recording or autopsy averaged 130.1 or 52.4 days, respectively. There were significant (p less than 0.01) correlations between the MI weight and peak-CPK (r = 0.63, n = 17), peak-CPKMB (r = 0.79, n = 17), sigma CPK (r = 0.72, n = 11), and the QRS scoring system (r = 0.64, n = 39), respectively. Especially in cases of non-transmural myocardial infarction, the QRS scoring system showed a high correlation with MI weight (r = 0.82, n = 11, p less than 0.01). We conclude that the peak-CPK, peak-CPKMB, sigma CPK, and the QRS scoring system are useful for the estimation of myocardial infarct size.

Clinicopathological study on left ventricular hypertrophy in elderly hypertensive patients

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.

Antihypertensive treatment with metoprolol or hydrochlorothiazide in patients aged 60 to 75 years. Report from a double-blind international multicenter study

In a randomized double-blind study (N = 562), a traditional treatment schedule, starting antihypertensive treatment in elderly hypertensive patients (60 to 75 years old) with 25 mg of hydrochlorothiazide once daily and doubling the dose if a satisfactory response was not achieved, was compared with antihypertensive treatment of 100 mg of metoprolol once daily, adding 12.5 mg of hydrochlorothiazide for patients whose response was not satisfactorialy achieved with metoprolol alone. Systolic and diastolic blood pressure was significantly reduced with both regimens. The frequency rates of responders (diastolic blood pressure, less than or equal to 95 mm Hg) in the metoprolol group and the hydrochlorothiazide group were 50% and 47% after four weeks and 65% and 61% after eight weeks, respectively. There were no significant differences in total symptom score or single symptoms between the regimens, but significantly more patients had hypokalemia and hyperuricemia with the hydrochlorothiazide regimen. Thus, we conclude that beginning antihypertensive treatment with 100 mg of metoprolol once daily and adding a small dose of hydrochlorothiazide (12.5 mg) in patients whose response is not satisfactory with metoprolol alone appears to be effective and safe in elderly hypertensive patients.

[Mitral valvular disease secondary to mitral ring calcification: a clinicopathologic study]

Fifteen cases with mitral valvular disease caused by mitral ring calcification (MRC) were observed among 2,800 consecutive autopsy patients more than 60 years of age. They consisted of one man and 14 women whose average age was 86.4 years. All had been diagnosed as having mitral valvular disease during life. For this clinicopathologic study, the cases were categorized as nine cases with mitral regurgitation (MR Group) and six with mitral stenosis (MS Group). Among the 15 cases, phonocardiograms were obtained in 14 and echocardiograms in 6. In addition, 122 cases with MRC, the length of which was 5 mm or more, were selected from 900 recent consecutive autopsies of senile patients, to evaluate the site of calcification and to analyze the ratio of calcification length to mitral valve ring circumference. The following conclusions were obtained: The prevalence of mitral valvular disease due to MRC in the aged was 15/2,800 (0.5%). MR was observed in nine cases and MS in six. Phonocardiograms of the MR Group revealed a holosystolic murmur in seven cases, a late systolic murmur in one, a third heart sound in four and a fourth heart sound in five. In the MS Group, a holosystolic murmur was found in four, a presystolic murmur in four, a diastolic rumble in one, but no opening snap in any case. A diamond-shaped systolic murmur was found in nine cases with MS or MR, suggesting an ejection systolic murmur caused by an associated calcified aortic valve. Echocardiograms showed markedly decreased DDR in five cases and increased echo intensity of the aortic valve in four. Pathologic findings revealed that the mean length of MRC was 36.6 mm in the MR Group and 58.0 mm in the MS Group. The calcification ring ratio (CRR = MRC/MVR X 100) was 50.3% in the MR Group and 69.8% in the MS Group. In the MR Group, MRC involved the anterolateral commissure in three, posteromedial commissure in five, and both in one. In five of six cases with MS, both commissures were involved by MRC. The study of 122 cases with MRC length greater than or equal to 5 mm suggested that MRC occurred first in the middle scallop of the posterior mitral leaflet, and extended to the posterior scallop, subsequently extending up to the anterior scallop, and finally involved the anterior mitral leaflet beyond the commissures.(ABSTRACT TRUNCATED AT 400 WORDS)

Clinical evaluation of bisoprolol in patients with hypertension: interim report

The antihypertensive effect and possible adverse effects of bisoprolol were assessed in 96 Japanese patients with mild to moderate hypertension. After a 2- to 4-week placebo period, bisoprolol was administered to 68 outpatients at a daily dose of 5 mg to 20 mg for 6 to 8 weeks, and to 28 inpatients with the same dose range up to a maximum of 4 weeks. For outpatients, blood pressure and heart rate were recorded every 2 weeks, while for inpatients, in addition to daily measurements, the effect of bisoprolol on diurnal variation of blood pressure was also studied. Bisoprolol lowered blood pressure and heart rate significantly in both groups of patients. The most common adverse effect was bradycardia. It is expected that bisoprolol will be a very effective and useful antihypertensive drug.

The treatment of mild hypertension in the elderly, a prospective study using multiple regression analysis

In order to examine the effect of treatment of mild hypertension of the aged, a 4 year prospective trial was performed in 41 placebo and 38 drug-treated patients with an average age of 76.5 years. Patients were matched for blood pressure, sex and age. Patients with cardiovascular complications or blood pressure elevation above 200/110 were categorized as dropouts and totaled 17 cases (41.5%) in the placebo group, and 4 cases (10.5%) in the drug-treated group (p less than 0.01). In diastolic hypertension, dropouts formed 63.6% of the placebo group (mean BP, 170/92), and 9.5% of the drug group (mean BP, 179/94) (p less than 0.001). In systolic hypertension, dropouts were of 15.8% in the placebo group (mean BP, 164/79), and of 11.8% in the drug group (mean BP, 167/79), and no significant difference was observed. In the placebo group, dropouts were significantly higher in patients with pretreatment systolic blood pressure over 170 mmHg or diastolic blood pressure over 90 mmHg. In patients of 75 years of age or more, dropouts were 46.4% in the placebo group, and 13.0% in the drug treated group showing the beneficial effect of drug treatment even in those over the age of 75. However, no beneficial effect was observed over the age of 85. Stepwise multiple regression analysis of total case revealed that the greatest predictor for dropout was the presence of placebo (i.e. no treatment), explaining 12.2% of the variation in future dropout. Similarly, diastolic hypertension explained 7.5%, creatinine 6.7%, and age 4.6% of this variation.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopharmaceutical evaluation of methylcellulose as an excipient for nitroglycerin tablets

To examine the bioavailability of nitroglycerin in sublingual tablet, 5 healthy adult volunteers underwent simultaneous sublingual administration of a tablet prepared with methylcellulose and a tablet prepared with lactose containing 0.15 mg of nitroglycerin and 0.15 mg of nitroglycerin-15N3, respectively. In 4 of 5 volunteers, no difference in plasma concentration determined by gas chromatography-mass spectrometry (GC-MS) was observed between 2 tablets described above, so it was well accepted that nitroglycerin in tablets prepared with methylcellulose had a similar bioavailability to that in tablets prepared with lactose. The simultaneous administration of the 2 nitroglycerin tablets to a healthy volunteer, one of which containing the drug labeled with a stable isotope followed by GC-MS assay, seems to be the most suitable method for a precise comparison of bioavailability of the formulations.

[A clinicopathologic study of valvular aortic stenosis in the aged]

To evaluate the usefulness of phonocardiography (PCG), carotid pulse recording (CAG) and echocardiography (UCG) used in diagnosing valvular aortic stenosis (AS) in the aged, we performed a clinicopathologic study of 23 autopsied patients with pathological evidence of aortic stenosis (AS). There were eight men and 15 women, whose ages averaged 82 years. PCG and CAG were available in 15 patients, and UCG was available in 13 patients. We classified the subjects into three groups; Group A with calcified AS, Group B with bicuspid AS and Group C with rheumatic AS. The following results were obtained. There were 12 patients in Group A, four in Group B and seven in Group C. Patients in Group A were older than those in Group B or C (A; 84-year-old, B; 80-year-old, C; 79-year-old on the average). The mean heart weight of Group A was less than that of Group B or C (A; 345 g, B; 453 g, C; 486 g). Congestive heart failure was more frequent in Groups B and C than in Group A. The fourth heart sound was recorded on the PCG in nine of 11 patients without atrial fibrillation, but there was no difference in incidence among the three groups. An ejection systolic murmur was recorded in all cases and a diastolic murmur of aortic regurgitation in 10. No patients had shudder formation on the CAG. The T-time tended to be prolonged in AS, especially in Groups B and C. The peak of the systolic murmur tended to be late in systole in Groups B and C. A1-peak/LVET was significantly increased in Groups B and C (A; 0.38, B; 0.51, C; 0.47). The decreased amplitude of aortic valvular opening (AVO) and the dense diastolic echo of the aortic valve were observed in all AS cases. The AVO of Group A was significantly less in amplitude than that of Group C (A; 3.6, C; 6.4). Thus, we could differentiate Group A from Groups B and C by various non-invasive techniques. These findings may be attributed to the different anatomic features of the aortic valves among these three groups.

Nonbacterial thrombotic endocarditis as a cause of cerebral and myocardial infarction

Clinicopathologic correlations of nonbacterial thrombotic endocarditis (NBTE) were studied with special reference to their pathogenetic role in cerebral and myocardial infarction. In 2340 cases of consecutive autopsies of the aged, NBTE was observed in 217 cases or 9.3%. The age distribution of NBTE revealed a gradual increase with advancing age. The underlying diseases of NBTE were malignant neoplasm (51.6%), infection (28.3%) and other diseases (20.1%). The incidence of NBTE in each cancer was high in cancers of the colon (16.2%), pancreas (15.2%), gall bladder or bile duct (14.1%) and lung (13.0%). The vegetations of NBTE were found on the aortic valve in 46.1%, on the mitral valve in 40.6% and on the both valves in 8.3%. The incidence of myocardial infarction and scar was 51.2% in the NBTE group, while it was 38.6% in the non-NBTE control group (p less than 0.02). This difference was marked in patients with a small infarction (10.6% vs. 5.3%) and a myocardial scar (30.4% vs. 19.0%). The grade of coronary stenosis was less in the NBTE group than in the control group (p less than 0.001), suggesting that the origin of the myocardial ischemic lesion was embolism from NBTE. The incidence of large cerebral infarction was 14.7% in NBTE and 9.2% in the control group, and that of medium sized cerebral infarction was 35.0% and 23.6% respectively. In this latter group, cortical infarction comprised 57.9% in the NBTE group and 26.6% in the control group. In large cerebral infarction, cerebral atherosclerosis was less severe in NBTE than in the control group (p less than 0.001), also suggesting an embolic mechanism. Disseminated intravascular coagulation was found in 41.9% of NBTE.(ABSTRACT TRUNCATED AT 250 WORDS)

Lymphangiomatosis of bone--lymphographic and CT findings

A case of lymphangiomatosis of bone associated with arachnoid cysts of the spinal cord is presented. This disease is very rare and in some cases the definitive diagnosis has been made radiologically rather than histologically. Lymphography and CT scanning showed on inflow of the oily contrast medium within the bony trabeculae. CT was also effective in detecting other anomalies that were otherwise not expected.

Peripheral arterial disease diagnosed with high-count-rate radionuclide arteriography

Thirty-seven patients with peripheral vascular disease involving the legs were studied with first-pass peripheral radionuclide arteriography (RNA) and contrast arteriography to determine whether RNA could be used to evaluate perfusion of the toes. Data were acquired for 100 seconds using a multicrystal gamma camera following bolus injection of 30-35 mCi (1,110-1,295 MBq) of Tc-99m-labeled albumin during reactive hyperemia. Peripheral time-activity curves were examined and the time required for activity to decline to 75% of peak activity ( T75 ) was recorded. When an abnormal RNA was defined as T75 greater than or equal to 50 seconds, sensitivity was 92%, positive predictive accuracy 100%, and negative predictive accuracy 75%. These data suggest that peripheral RNA of the toes is a reliable, noninvasive procedure for evaluation of peripheral arterial disease; it can be valuable as a screening test prior to contrast arteriography as well as for follow-up.

Atrial fibrillation as a cause of myocardial and cerebral infarctions

Pathogenetic role of atrial fibrillation (AF) on myocardial and cerebral infarctions was studied in 2340 consecutive autopsies of the aged. AF was found in 405 cases or 17.3%, and the incidence of AF increased with age. Myocardial infarction and scar were found in 56.8% in AF, but in 36.4% in non-AF (p less than 0.001). Small myocardial infarction was 2.9 times (12.6% vs. 4.3%), and the scar was 1.5 times (27.2% vs. 18.7%) as prevalent in AF as in non-AF. Intracardiac mural thrombus was found in 14.8% in AF and in 4.8% in non-AF, 8 to 10 times as prevalent in small myocardial infarction (29.4% vs. 3.7%) and scar (17.4% vs. 1.7%) in AF as in non-AF. Coronary stenotic index revealed no difference between AF and non-AF. Large cerebral infarction was observed in 21.9% in AF and 7.3% in non-AF, and this difference was prominent in cases with myocardial infarction or myocardial scar indicating the common pathogenetic role of AF. In cases with large cerebral infarction severe cerebral atherosclerosis was less frequent in AF than in non-AF. Medium sized cortical infarction was also prevalent in AF. The prevalences of myocardial and cerebral infarctions were not different in AF complicated with valvular heart disease from those without it, but increased in the permanent AF in comparison to the transient AF. AF induced small myocardial infarction and large or medium sized cerebral infarctions by embolism from mural thrombus. The mechanism for the difference in size is discussed.

Differential rate of age-related decline in immune functions in genetically defined mice with different tumor incidence and life span

Immunological studies were performed in aging C57BL/6 and BDF1 mice. In C57BL/6 mice the incidence of malignant tumor was high and their mean life span was 665 days in males and 649 days in females. In BDF1 mice, the incidence of malignant tumors was significantly lower, and their mean life span was 954 days in males and 846 days in females. Immunologically, either the onset of decline occurred earlier, the rate of the age-related decline in activity was more rapid, and/or the magnitude of decline was greater in the shorter-lived C57BL/6 than in the longer-lived BDF1 mice. The close relationship between (a) the susceptibility especially to malignant lymphoma; (b) the onset, rate and magnitude of age-related decline in T-cell-dependent immunologic activities, and (c) the life span would suggest that T-cell immunity may be playing an important role in the resistance against life-shortening malignant lymphoma in C57BL/6 mice.

Hemodynamic effects of salbutamol, an oral long-acting beta-stimulant, in patients with congestive heart failure

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.

Characteristics of body surface mapping in the aged

1) Body surface mapping was performed in 15 patients with ischemic heart disease and 5 control subjects before and after isoproterenol infusion. In ischemic heart disease, ST map developed negative areas in the left anterior chest wall extending from mid line to left axillar line after isoproterenol. This distribution on ST depression was different from that of left ventricular hypertrophy or complete left bundle branch block which spared mid anterior chest. The point of maximal ST depression corresponded to one of the conventional chest lead in 6 of 15 cases. In other 9 cases, the point of maximal ST depression was mostly located superiorly to V3-V5. epsilon ST depression correlated well with the maximal ST depression (r = 0.90) but not very well with ST depression at V5 (r = 0.70). On 201 T1 stress scan, a reversible large perfusion defect was detected in 2 out of 5 patients with marked ST depression. These findings suggested that isoproterenol induced ST map changes are useful in diagnosis of myocardial ischemia. 2) Body surface map was obtained in 16 cases with chronic pulmonary disease. The location of the maximum R and initial R was relatively inferior to that of normal controls. Relatively deep S waves were frequently observed. Pulmonary function tests correlated with the maximum R voltage but not with the deepest S. Cases with relatively high pulmonary conus voltage were proved to have right ventricular hypertrophy on 201 T1 myocardial scintigraphy or on echocardiography.

The pathogenetic role and treatment of elderly hypertension

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.

Prospective study on the treatment of mild hypertension in the aged

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.

High and low density lipoprotein cholesterol in myocardial and cerebral infarction

High density lipoprotein (HDL) and low density lipoprotein (LdL) cholesterol levels were measured in fasting blood samples from 950 healthy subjects and 188 aged patients by a new simple method. The HDL-cholesterol levels and HDL/LDL-cholesterol ratios are significantly higher in females than in males. In the healthy subjects, there are slight decreases in the levels of HDL-cholesterol and HDL/LDL-cholesterol ratio with aging in both sexes. The patients with myocardial infarction had significantly lower HDL-cholesterol levels and HDL/LDL-cholesterol ratios as compared to those of the group without infarction. On the contrary, no differences in total lipoprotein cholesterol levels were observed in the patients with cerebral infarction. The results, obtained in respect of electrocardiographic findings after the isoproterenol stress test, suggest that the HDL-cholesterol levels and HDL/LDL-cholesterol ratios may be related not only to the established myocardial infarction, but also to the presence of coronary atherosclerosis and stenosis.

Comparison of hemodynamic effects of exercise and isoproterenol infusion in normal young and old men

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.

A study on the effects of nifedipine in hypertensive crises and severe hypertension

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.