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Biomedical subjects

H Shimamoto

Publications and source records attributed to H Shimamoto.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Transesophageal Doppler echocardiographic measurement of cardiac output using mitral anulus method].

The method of measuring cardiac output with transesophageal pulsed Doppler two-dimensional echocardiography was developed and validated by comparison with the thermodilution technique in 65 adult patients. With the use of transesophageal four-chamber view, the Doppler sample volume was placed in the center of the mitral ring and the mitral flow velocity-time integral was obtained through planimetric measurements of the mitral flow velocity curve. The diameter of the mitral valve anulus was measured at the time of peak rapid filling flow velocity, and the cross-sectional area of the mitral valve anulus was calculated, assuming a circular shape. Doppler-determined cardiac output was calculated by using the following formula: Cardiac output [1.min-1] = pi (D [cm] /2)2.MFVI [cm].heart rate [bpm].10(-3), where MFVI is mitral flow velocity-time integral, and D is the diameter of the mitral valve anulus. There was a weak correlation between thermodilution and Doppler measurements of cardiac output (r = 0.64, p less than 0.01), while a good correlation was observed between percent changes in thermodilution-derived cardiac output and those in Doppler-determined cardiac output (r = 0.92, p less than 0.01) during different loading conditions. It has been suggested that this method may be useful for assessing relative changes in cardiac output during short time periods.

Adult↗
PubMed1991

[Influences of intra-aortic balloon pumping on peripheral hemodynamics].

The influences of intra-aortic balloon pumping (IABP) on peripheral dynamics were assessed by Doppler echocardiography. The subjects were 20 patients requiring IABP support, postoperatively, to control low cardiac output state. The flow velocity integral in systole (Int S) and that in diastole (Int D) were measured from left common carotid, superior mesenteric, and terminal aortic flow pattern, and the sum of Int S and Int D (Int S + Int D) was calculated with and without balloon pumping. 1) IABP increased cardiac output significantly (p less than 0.01). 2) Common carotid flow: IABP increased Int S significantly (p less than 0.01), but neither Int S nor Int S + Int D changed significantly with IABP. 3) Superior mesenteric flow: IABP increased Int D significantly (p less than 0.01), but both Int S and Int S + Int D remained unchanged with IABP. 4) Terminal aortic flow: None of Int S, Int D and Int S + Int D changed significantly with IABP. These results suggest that the carotid area can receive much of the increase in cardiac output in systole with IABP, and that the superior mesenteric area can receive much of the volume of blood displaced in the aorta by balloon inflation in diastole.

Aged↗
PubMed1991

[Mitral flow responses to three-week salt loading in elderly hypertensives].

Three-week effects of a high sodium diet on mitral flow pattern were assessed in 23 patients with essential hypertension (81.8 +/- 6.8 years). Transmitral flow was recorded during different rates of salt intake: 7 g/day for 8 weeks, 20 g/day for 3 weeks. With sodium loading, 19 patients whose mean blood pressure (MBP) increased by 10 percent or more were termed the salt-sensitive (SS) group, and 4 patients whose MBP did not change, or increased by less than 10 percent were termed the non salt-sensitive (NSS) group. With mitral velocity integral, cardiac output (CO) and total peripheral resistance (TPR) were calculated. Fourteen of the SS patients, in which an increase in TPR was greater than that in CO with sodium repletion, were defined as "SST". In the remaining 5 SS patients, termed "SSC", an increase in CO was greater than that in TPR with salt loading. CO increased significantly in the SSC patients, but did not change in the SST or NSS group with sodium loading. TPR increased significantly in the SST, and remained unchanged in the SSC or NSS patients. Peak velocity of transmitral flow in the rapid filling phase (R) decreased significantly in the SST patients, increased significantly in the SSC group, and remained unchanged in the NSS subjects. While, peak velocity of transmitral flow in the atrial contraction phase (A) increased significantly in the SSC group, it remained unchanged in the SST and NSS patients. There was a significant increase in A/R in the SST group and a significant decrease in A/R in the SSC patients with sodium loading.

Aged↗
PubMed1990

Influences of propranolol and atenolol on the circadian rhythm of heart rate in elderly patients with essential hypertension.

1. The influence of long-acting propranolol and of atenolol on the circadian rhythm of heart rate was assessed using 24 h electrocardiographic recordings in elderly patients with essential hypertension. Eighteen elderly patients were investigated before treatment and after 12 weeks on 60 mg of long-acting propranolol once a day; 21 elderly patients were studied before treatment and after 12 weeks on 50 mg of atenolol once a day. The mean hourly heart rate in 24 h electrocardiographic recordings was used to fit cosine curves by the statistical technique of least squares, and the following parameters were estimated: mesor (rhythm-adjusted mean of the heart rate), amplitude (one-half of the total diurnal variation of the heart rate) and acrophase (the time when the heart rate was at its peak above the mean). 2. The cosine curves were fitted with a P value of 0.01 or less before and after treatment in all patients. 3. In the long-acting propranolol group, the mesor and amplitude were reduced significantly after treatment. The acrophase appeared significantly earlier after treatment than before treatment. 4. In the atenolol group, the mesor and amplitude decreased significantly after treatment. However, the acrophase did not change with treatment. 5. We conclude that both propranolol and atenolol decrease the mesor and amplitude through blocking cardiac beta 1-receptors, and that only propranolol may have some effects on the central nervous system, resulting in the circadian phase shift.

Aged↗
PubMed1990

Time course of hemodynamic responses to sodium in elderly hypertensive patients.

Thirty-one patients with essential hypertension (81.6 +/- 6.9 years old) were studied during two different regimens of sodium intake: 120 meq/day for 8 weeks and 344 meq/day for 2 weeks. Systemic hemodynamic data were measured with Doppler echocardiography from which the mitral flow velocity integral, cardiac index, and total peripheral resistance were calculated. The salt-sensitive patients in whom the increase in total peripheral resistance was greater than the increase in cardiac index with salt loading were termed SST. In the salt-sensitive patients termed SSC, the increase in cardiac index was greater than the increase in total peripheral resistance with increased sodium intake. All SST patients on day 7 of the high sodium diet remained in the SST group on day 14. Nine of 13 patients in the SSC group on day 7 remained in the SSC group on day 14, and the remaining four patients in the SSC group on day 7 fell into the SST group on day 14. Four of eight non-salt-sensitive (NSS) patients on day 7 of the high salt regimen remained in the NSS group on day 14, whereas the remaining four patients in the NSS group on day 7 fell into the SSC group on day 14. Our data suggest a changing pattern with sodium loading of initially high cardiac index followed by a persistently raised total peripheral resistance. The celiac, superior mesenteric, and renal arteries vasoconstricted with sodium repletion in both SST and SSC patients. With salt loading, the terminal aortic vascular bed vasodilated in the SSC patients and vasoconstricted in the SST patients.

Aged↗
PubMed1990

[Hemodynamic changes during dietary salt loading in elderly patients with essential hypertension].

Hemodynamic changes with dietary salt loading were assessed by Doppler echocardiography during different sodium intake (7 g/day for 8 weeks, 20 g/day for 1 week) in 29 elderly patients with essential hypertension (81.6 +/- 6.7 years, 4 men, 25 women). With salt loading, 24 patients whose mean blood pressure (MBP) increased by 10% or more were defined as salt sensitive (SS) group, and 5 patients whose MBP did not change, or increased by less than 10% were defined as non-salt sensitive (NSS) group. Based on the mitral flow velocity integral, cardiac output (CO) was calculated, and total peripheral resistance (TPR) was calculated as MBP divided by CO. Nine of the 24 SS patients were termed "SS (COdep)" whose CO increased significantly with salt loading. In the remaining 15 SS patients termed "SS (TPRdep)", TPR increased significantly with sodium repletion. Blood flow in the common carotid, superior mesenteric, or terminal aorta was calculated from each flow velocity integral. The percent change in peripheral resistance calculated by dividing MBP by each blood flow was obtained. There were no significant percent changes in the common carotid resistance in SS (COdep), SS (TPRdep) or NSS groups. The superior mesenteric resistance increased significantly in all three groups. The terminal aortic resistance increased in the SS (TPRdep) group, but decreased in the SS (COdep) or NSS group. These results indicate that salt sensitivity is ascribable to changes in regional vascular resistances.

Aged↗
PubMed1990

[Secondary hypothermia with brain tumor in an elderly woman and the circadian rhythm of body temperature].

An elderly case of secondary hypothermia associated with brain tumor was reported. An 84-year old woman developed hypothermia. Although her rectal temperature remained below 37 degrees C, the circadian rhythm of rectal temperature was preserved. Brain computerized tomography (CT) and brain magnetic resonance imaging (MRI) revealed a solitary brain tumor involving the hypothalamus. It appears that her hypothermia may not be due to inability to thermoregulate but to stem from her abnormal target temperatures. Body temperature is normally controlled at around 37 degrees C, but in this patient thermoregulation might have been reset at a lower temperature.

Aged↗
PubMed1990

[Effects of intra-aortic balloon pumping on mitral flow dynamics after aortocoronary bypass surgery].

Improvement in left ventricular function following intra-aortic balloon pumping (IABP) in 15 patients (aged 51 to 86 years) after coronary artery bypass grafting was evaluated. Using transesophageal atrial echocardiography, the mitral flow velocity integrals in the rapid filling phase (IntR) and in the contraction phase (IntA) were measured from transmitral flow patterns, and the sum of IntR and IntA (IntR + IntA), and the ratios of IntA to IntR (IntA/IntR) were calculated for ON and OFF states of balloon pumping (IABP OFF test). The same parameters were determined during 1:2 assist balloon pumping (IABP 1:2 test); the cardiac cycle with balloon assist was defined as "ON", and that without balloon assist as "OFF". 1. IABP OFF test: IABP increased IntR from 6.4 +/- 1.6 cm to 7.6 +/- 1.9 cm (p less than 0.01), suggesting that a decreased afterload improves left ventricular relaxation. IntA did not change with balloon assist (ON 3.5 +/- 1.2 cm, OFF 3.7 +/- 1.2 cm). IntR + IntA increased from 10.0 +/- 2.0 cm to 11.1 +/- 2.4 cm during IABP (p less than 0.01). IABP reduced the IntA/IntR from 0.62 +/- 0.25 to 0.50 +/- 0.20 (p less than 0.01). The increment in the IntA/IntR without IABP suggests that impaired diastolic filling of the left ventricle due to an increased afterload may be compensated for by enhanced left atrial contraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Influences of intra-aortic balloon pumping on superior mesenteric flow dynamics].

The influences of intra-aortic balloon pumping (IABP) on arterial flow of the superior mesenteric artery were assessed by Doppler echocardiography. The subjects were 13 patients postoperatively, requiring IABP support to control low cardiac output state, in which distal aspects of balloons were distal to the superior mesenteric artery. Superior mesenteric flow velocity integral in systole (IntS) and that in diastole (IntD) were measured from superior mesenteric flow pattern, and the sum of IntS and IntD (IntS + IntD) was calculated ON and OFF balloon pumping (IABP ON-OFF test). The same parameters were obtained with balloon inflating on every other beat (IABP 1:2 test); the cardic cycle with balloon assist was defined as "1:2 ON", and that without balloon assist was defined as "1:2 OFF". 1) IABP ON-OFF test. IABP increased IntS from 7.07 +/- 2.56 cm to 9.20 +/- 3.19 cm (p less than 0.05), IntD from 3.00 +/- 1.18 cm to 3.62 +/- 1.40 cm (p less than 0.05), and IntS + IntD from 10.07 +/- 3.48 cm to 12.82 +/- 4.04 cm. Cardiac output increased from 3.89 +/- 1.34 l/min to 4.24 +/- 1.64 l/min with IABP support. The increments in IntS, IntD and IntS + IntD with IABP are attributed, to a large extent, to an increase in cardiac output. 2) IABP 1:2 test. Without balloon inflation, IntS increased (1:2 ON; 7.16 +/- 2.91 cm, 1:2 OFF; 8.41 +/- 3.30 cm, p less than 0.05), and IntD decreased (1:2 ON; 3.51 +/- 1.60 cm, 1:2 OFF; 2.33 +/- 1.25 cm, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Annular pustular psoriasis associated with affective psychosis.

An eighty-year-old man presented with recurrent annular erythema with pustules on the axillae, trunk, and groin consistent with a diagnosis of annular pustular psoriasis. Over the years, exacerbations of his skin lesions directly followed manic episodes. Use of major tranquilizers, including chlorpromazine, brought about a favorable remission of both the manic symptoms and the cutaneous lesions.

Affective Disorders, Psychotic↗
PubMed1989

[The influence of total parenteral nutrition on the circadian rhythm of the heart rate in elderly patients with wasting diseases].

The circadian rhythm of the heart rate was assessed using 24 hour electrocardiographic recordings in 18 hospitalized elderly patients with wasting diseases receiving total parenteral nutrition. The nutrient solutions were administered at doses ranging from 360 to 1640 kcal/day. To determine if the heart rate fluctuates rhythmically with a circadian period, the mean hourly heart rate on 24 hour electrocardiographic recordings was used to fit cosine curves by the statistical technique of least squares, and three parameters of the rhythm--designated the mesor, amplitude, and acrophase--were estimated. The cosine curves fitted with a P value of 0.01 or less in all patients before and after insertion of central venous catheters. The mesor represented the rhythm--adjusted mean of the heart rate. The mesor increased significantly with increase in the energy infusion rate (p less than 0.01). The amplitude values were derived from one half of the total diurnal variation of heart rate and the acrophase indicated the time when heart rates were at their peak above the mean. Neither amplitude nor acrophase changed significantly with increase in the energy infusion rate. Furthermore, neither norepinephrine nor epinephrine plasma levels changed with nutrient administration. There were no significant changes in thyroid hormone concentrations. There was a significant positive correlation between mesor changes and rectal temperature with increase in the energy infusion rate (r = 0.76, p less than 0.01). In severely malnourished subjects, changes in the level of feeding can profoundly affect cardiac functions and thermogenic response.

Aged↗
PubMed1989

[Factors influencing serum free T3 and free T4 in elderly euthyroid subjects].

Thyroid function was investigated in 222 elderly euthyroid subjects (79.6 +/- 7.6 years, males 68, females 154). Serum free T3, free T4, and TSH levels were measured by radioimmunoassay. To assess the factors influencing serum free T3 and free T4, we applied multiple regression analysis. 1) Serum free T3 concentrations were directly proportional to both serum albumin levels and hemoglobin levels. Serum free T3 levels were lower in bedridden male subjects and in female subjects with dementia. 2) Serum free T4 concentrations were negatively correlated to serum TSH levels in male. Serum free T4 levels were higher in bedridden female subjects, and increased in proportion to serum albumin concentrations in females. 3) Age had no apparent effect on either serum free T3 or free T4 concentrations.

Aged↗
PubMed1989

[The influence of thyroid function on the circadian rhythm of heart rate in elderly euthyroid subjects].

The influence of thyroid function on the circadian rhythm of heart rate was assessed using 24 hour electrocardiographic recordings in 196 elderly euthyroid subjects (78.4 +/- 8.1 years; male 60, 76.1 +/- 9.1 years; female 136, 79.4 +/- 7.4 years). Serum free T3, free T4 and TSH levels were measured by radioimmunoassay. To determine if heart rate fluctuates rhythmically with a circadian period, mean hourly heart rates in 24 hour electrocardiographic recordings were used to fit cosine curves by the statistical technique of least squares, and the parameters of the rhythm--the mesor, amplitude, acrophase, maximal and minimal hourly heart rates--were estimated. To investigate the factors influencing the diurnal variation of heart rate, we applied multiple regression analysis. The cosine curves were fitted with a P value of 0.01 or less in all subjects. The mesor, maximal and minimal hourly heart rates were inversely proportional to serum TSH concentrations in males. Neither amplitude nor acrophase had relation to the thyroid function in males. The mesor, maximal and minimal hourly heart rates were directly proportional to serum-free T4 concentrations and inversely proportional to serum TSH concentrations in females. The increase in the acrophase correlated with the increase in serum-free T4 levels, and the acrophase increased in proportion to serum-free T3 levels in females.

Aged↗
PubMed1989

[Brain function and blood flow velocity in the middle cerebral artery in subarachnoid hemorrhage: evaluation with multimodality evoked potentials (MEPs) and transcranial Doppler (TCD) ultrasound].

Brain dysfunction and blood flow velocity changes in the middle cerebral artery (MCAFV) were studied in 59 patients with ruptured cerebral aneurysms presenting subarachnoid hemorrhage. Brain function and blood flow velocity were evaluated by multimodality evoked potentials (MEPs) consisting of ABR, SEP and VEP as reported, and transcranial Doppler (TCD) ultrasound. The abnormality on MEPs were graded into 4 grades. Nearly normal, mildly abnormal, moderately abnormal and severely abnormal. The results on MEP study were compared with clinical Hunt and Hess (H. H) grade or Fisher's CT group of subarachnoid hemorrhage in 44 patients. MCAFV was measured in 15 patients and mean velocity as well as CO2 reactivity and effect of head elevation were studied. Control value of MCAFV was 64 +/- 13 cm/sec in 50 healthy adults. CO2 reactivity was determined by K values obtained from the modified formula of cerebral blood flow by Olesen et al. MEP grade in H. H grade III and IV patients showed, on admission, variations in their grades in comparison with those in H. H grade I II and V patients. There was no definite correlation between the abnormality in MEPs and the degree of subarachnoid hemorrhage in Fisher's group 3 and 4 patients. When the surgical results in early and late operation in H. H grade III and IV patients were compared, it was shown that the outcome was favourable in early operated patients of H. H grade III if initial MEP grades were between I-III.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Kindler's syndrome.

A 3-year-old girl with congenital poikiloderma had episodic blistering spontaneously or after trauma. Growth and development had been normal. Family history did not show any evidence of cutaneous disease. We believe that this case best fits the designation of Kindler's syndrome.

Blister↗
PubMed1988

Premature opening of the pulmonary valve in endomyocardial fibrosis.

Two-dimensional and Doppler echocardiographic findings in a 67-year-old man with endomyocardial fibrosis (EMF) are described. The two-dimensional echocardiogram showed typical features of EMF, right ventricular endomyocardial calcification, a thickened right ventricular wall, obliteration of the apex of the right ventricle and marked dilatation of the right atrium. In addition, premature opening of the pulmonary valve was observed during late diastole. The Doppler echocardiogram revealed forward flow from the right ventricle to the pulmonary artery, indicating the conduit state of the right ventricle. These findings were supported by cardiac catheterization and autopsy. Thus, two-dimensional and Doppler echocardiography are useful not only in making the diagnosis, but also in understanding the hemodynamic condition in EMF.

Aged↗
PubMed1988

Acute effects of captopril on blood pressure and regional blood flows in two types of renovascular hypertensive rats in conscious state.

Mean arterial pressure and three regional blood flows--renal, superior mesenteric, and hindquarter flows--were monitored in conscious normotensive control rats (NCR), in two-kidney, one-clip (two-kidney), and in one-kidney, one-clip (one-kidney) hypertensive rats. After administering captopril, an angiotensin-converting enzyme inhibitor, mean arterial pressure decreased in all three groups. However, lowering of arterial pressure was not statistically significant in any of the groups. Renal flow increased significantly in the intact artery of two-kidney hypertensive rats, whereas it did not significantly increase in the clipped artery of one-kidney hypertensive rats and in the intact artery of NCR. Superior mesenteric flow increased significantly only in one-kidney hypertensive rats. Hindquarter flow did not significantly change in the three groups. Regional resistance reduced significantly in not only renal but also in superior mesenteric vascular area in two-kidney hypertensive rats, whereas it did not reduce significantly in these two vascular areas in one-kidney hypertensive rats and in NCR. The present findings show that the renin-angiotensin-mediated vasoconstriction plays a role in not only renal but also in superior mesenteric vascular area in two-kidney hypertensive rats, whereas it hardly plays a role in these three vascular beds in one-kidney hypertensive rats.

Animals↗