Biomedical subjects

N Ohte

Publications and source records attributed to N Ohte.

45 records · Page 3Linked to original sources

PubMed1990

[Noninvasive evaluation of left ventricular function using new systolic time intervals obtained from continuous-wave Doppler echocardiography].

Left ventricular function was evaluated using parameters derived from the flow velocity waveforms at the ascending aorta as obtained at the suprasternal notch by continuous-wave Doppler echocardiography in 39 patients; 12 with chest pain but without coronary stenosis, eight with angina pectoris; and 19 with myocardial infarction. Peak flow velocity and the time interval from the beginning of the Q wave of lead II of the ECG to peak flow velocity (Q-V peak) correlated with specific invasive hemodynamic parameters, such as max dp/dt and (max dp/dt)/IP (IP: total left ventricular pressure at the same instant) during isometric contraction of the left ventricle measured with a catheter tip manometer, and left ventricular ejection fraction (LVEF) obtained by bi-plane cineangiography (using the area-length method). There was no correlation between the peak flow velocity and the invasive hemodynamic parameters. However, significant negative correlations were observed between the Q-V peak time and max dp/dt, with r = 0.40 (p less than 0.05), and between the Q-V peak time and (max dp/dt)/IP with r = -0.61 (p less than 0.01). A negative correlation was obtained between the Q-V peak time and LVEF (r = -0.75, p less than 0.01). The regression equation was LVEF = -0.67 x (Q-V peak) + 176. To compare the effectiveness for predicting LVEF between the Q-V peak and the established systolic time intervals as PEP and PEP/ET, these time intervals were measured from flow velocity waveforms invasively obtained with a catheter-type electromagnetic flowmeter inserted into the ascending aorta in 14 patients selected from the original subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

[A case of chronic recurrent pulmonary embolism treated by pulmonary embolectomy and Günther vena caval filter implantation].

A case report of chronic recurrent pulmonary embolism treated by embolectomy and Günther vena caval filter. A 62-year-old man had suffered from dyspnea on effort for 4 years, and his feeling of dyspnea had gradually increased during the past 3 months. On the day of admission he was in a preshock state, and his pulmonary artery pressure was very high at 90/30 mmHg. Pulmonary blood perfusion scintigraphy showed multiple defects of isotope uptake. Immediately after the scintigraphy, pulmonary embolectomy was performed while using extracorporeal circulation. The operation was successful and his physical activity was markedly improved. After the operation, anti-coagulant and anti-platelet therapies were continued, but recurrence of pulmonary emboli was detected by scintigraphy, and some thrombi were found by venography in deep veins of the lower parts of both legs. To prevent recurrent pulmonary embolism, a Günther vena caval filter was inserted into the inferior vena cava. We considered this case as an acute worsening of chronic recurrent pulmonary embolism and we had the impression that pulmonary embolectomy is a very effective therapeutic method for serious pulmonary embolism, and that insertion of the Günther vena caval filter is a very easy and safe procedure.

Chronic Disease↗

PubMed1988

Detection of impaired left ventricular function in coronary artery disease with acceleration index in the first derivative of the transthoracic impedance change.

In order to detect impaired left ventricular (LV) function in coronary artery disease (CAD) patients using acceleration index (Ac) of impedance cardiography (ICG), exercise ICG was performed in 29 patients with chest pain but without CAD (Group 1) and 21 patients with CAD (Group 2), and their resting values were compared with 30 healthy controls (Group 3). The acceleration index, which reflects indirectly aortic blood flow acceleration, was calculated as the ratio of dZ/dtmax to its accelerating time (AT). At rest, the values for Ac in Groups 1, 2, and 3 were 23 +/- 10, 15 +/- 6, and 36 +/- 13 omega/s2, respectively. There were significant differences between Group 1 versus 3, 2 versus 3, and 1 versus 2 (all p less than 0.001). At maximal exercise, Ac showed the largest percent change among the various indices used in this study. An increase of 198% for Group 2 was markedly lower than that of 250% in Group 1 (40 +/- 14 vs. 68 +/- 24 omega/s2, p less than 0.001). With a value of less than or equal to 40 omega/s2, Ac can detect the CAD patients, with a sensitivity of 62% and specificity of 90%, superior to stress ECG using CM5 lead. It is concluded that: (1) Ac is the sole index capable of distinguishing not only between the normals and diseased groups, but also between CAD patients and suspected CAD cases at rest. (2) Ac is a remarkably sensitive index for detecting impaired LV function at maximal exercise. (3) Exercise ICG is useful for predicting CAD from the population predisposing to CAD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1986

[Relation of mitral valve motion to left ventricular end-diastolic pressure assessed by M-mode echocardiography].

Left ventricular end-diastolic pressure (LVEDP) was estimated noninvasively using cardiac parameters obtained from simultaneous recordings of the echocardiograms, electrocardiograms and phonocardiograms in 30 patients who underwent diagnostic left cardiac catheterization. Special attention was paid to the mitral valve motion which reflects global left ventricular function. The interval from the onset of the Q wave of the ECG to the echocardiographic C point of mitral valve closure (Q-C), the interval from the aortic component of the second heart sound to the E point of the mitral echogram (IIa-E), and the time from the opening of the mitral valve (D point) to the E point (D-E) were measured. A good correlation with LVEDP was observed with Q-C/IIa-E (r = 0.87, p less than 0.001), and inversely with D-E time (r = -0.81, p less than 0.001). The correlation of Q-C/D-E and LVEDP was most significant (r = 0.89, p less than 0.001). The regression equations were LVEDP = 36.6 X (Q-C/IIa-E) -10.9 and LVEDP = 4.49 X (Q-C/D-E) +5.56. This noninvasive and easily repeated method for predicting LVEDP is very useful clinically.

Adult↗

PubMed1982

Two cases of viral myocarditis and one case of viral pericarditis.

Two cases of myocarditis, who had suffered from ventricular extrasystole, leucocytosis and elevated serum enzyme for a long period died from congestive heart failure and/or arrhythmias. The biopsy specimens from the right ventricle in one of them showed a positive reaction against Coxsackie B virus (1, 3, 4 and 5) in the fluorescent antibody method. One case of virus pericarditis had 5 recurrences over a five-year period. He suffered from dyspnea, chest oppression and general fatigue at each recurrence. Cardiomegaly on a chest X-ray, electrocardiographic abnormalities, leucocytosis and elevated serum enzyme appeared. However, serum neutralizing antibody titers against Coxsackie B2 had not risen significantly except during the first attack. Interferon administration inhibited its recurrence successfully.

Adult↗

PubMedDate not supplied

Left ventricular isovolumic relaxation flow and left ventricular systolic performance.

We investigated isovolumic relaxation flow in patients with coronary artery disease (CAD) and evaluated the relationship between its velocity and left ventricular performance in 23 patients with atypical chest pain, 30 patients with CAD without prior myocardial infarction (MI), and 57 patients with prior MI, in whom cardiac catheterization was performed. The isovolumic relaxation flow velocity was measured at the basal portion of the left ventricle with pulsed Doppler echocardiography. The isovolumic relaxation flow ( > 15 cm/sec) was detected in 98 of 110 patients. The isovolumic relaxation flow velocity was significantly lower in patients with prior MI than in patients with atypical chest pain (p < 0.001) and in those with CAD without prior MI (P < 0.05). It was significantly lower in patients with CAD without prior MI than in those with atypical chest pain (p < 0.05). The isovolumic relaxation flow velocity showed a significant positive correlation with left ventricular ejection fraction. It also showed a significant negative correlation with left ventricular end-systolic volume index. These findings suggest that the isovolumic relaxation flow velocity is decreased in patients with CAD and is influenced by left ventricular systolic performance. Isovolumic relaxation flow may be a clinical manifestation of elastic recoil of the left ventricle.

Angina Pectoris↗

PubMedDate not supplied

Simultaneous evaluation of the Doppler-derived transmitral flow velocity waveform and left ventricular isovolumic relaxation time in patients with coronary artery disease.

We studied the usefulness of simultaneous evaluation of the Doppler-derived transmitral flow velocity waveform and left ventricular isovolumic relaxation time (IRT) in patients with coronary artery disease (CAD). Subjects consisted of 26 healthy volunteers, 54 patients with prior myocardial infarction (MI), and 27 patients with CAD but without prior MI. IRT was measured as the time from the beginning of the aortic valve closure sound to the onset of transmitral flow. Peak filling velocity during early diastole (E-wave velocity), peak filling velocity during atrial contraction (A-wave velocity), and IRT were compared among the three groups. No significant difference in A-wave velocity was found among these groups. Whereas E-wave velocity was significantly lower and IRT was significantly longer in patients with CAD but without prior MI than in healthy subjects, no significant differences in E-wave velocity or IRT were observed between patients with prior MI and healthy subjects. We then divided the patients with prior MI into two subgroups, one consisting of 45 patients with mean pulmonary capillary wedge pressure (mPCWP) < 16 mm Hg and the other consisting of 9 patients with mPCWP > or = 16 mm Hg. There was no significant difference in A-wave velocity between the two subgroups and healthy subjects. E-wave velocity was significantly lower in patients with MI and lower mPCWP than in healthy subjects, however, no significant difference in E-wave velocity was found between the patients with MI and higher mPCWP and the healthy subjects. On the other hand, IRT was significantly longer in those with lower mPCWP and significantly shorter in those with higher mPCWP than in healthy subjects. In conclusion, normal transmitral flow velocity waveform with short IRT suggests a 'pseudonormal' pattern due to elevated mPCWP in patients with CAD.

Adult↗

PubMedDate not supplied

Estimation of pulmonary capillary wedge pressure from M-mode mitral echograms.

We investigated whether the isovolumic relaxation time (IRT) and an interval from the start of opening to the maximal amplitude of the anterior mitral leaflet in early diastole (D-E interval) would be useful predictors of the pulmonary capillary wedge pressure (PCWP). We recorded M-mode mitral echograms and phonocardiograms in 33 patients (aged 38-70 years) with acute myocardial infarction (AMI) in the coronary care unit and in 34 patients (aged 40-75 years) with prior myocardial infarction (OMI) during cardiac catheterization. All patients underwent the insertion of a flow-directed pulmonary artery catheter to obtain the PCWP. We measured the IRT and the D-E interval from the phonocardiograms and the M-mode echograms. There was no significant correlation between the IRT and the mean PCWP (mPCWP) in patients with AMI and in patients with OMI. The D-E interval was significantly and inversely correlated with the mPCWP (r = -0.91, p <0.0001) in all patients. The regression equation was mPCWP = -0.42 x (D-E) +47.9. The D-E interval of < or = 75 ms indicated a high mPCWP (mPCWP > or = 18 mm Hg) with high sensitivity (96%) and specificity (88%). The derived equation was tested in a prospective group of 32 additional patients (aged 43-75 years). A significant correlation was observed between the predicted and measured mPCWP (r = 0.91, p <0.0001). Thus, the PCWP can be estimated by using the D-E interval derived from M-mode mitral echograms in patients in the coronary care unit and in patients with chronic heart disease.

Adult↗

PubMedDate not supplied

Coronary risk factors in angiographically defined patients with chest pain.

Coronary risk factors were assessed in 186 consecutive patients who received coronary angiography. The severity of coronary luminal narrowing was scored as the coronary sclerosis index (CSI). Patients were divided into normal coronary arteries (N, n = 72), coronary sclerosis without infarction (C, n = 73) and previous myocardial infarction (MI, n = 41). The CSI increased with age. A significant difference in serum triglycerides, HDL cholesterol and atherogenic index was observed between Groups C or MI and N. Multivariate analysis revealed that CSI had correlated with total- and HDL-cholesterol, uric acid and age in subjects under 55 years; and with age, blood sugar, factor H and HDL cholesterol in those of 55 years or over. When patients were classified by their total and LDL cholesterol level, a significantly different CSI was found between the desirable and high cholesterol levels in subjects under the age of 55, but it was not significant in those over 55. Therefore, disorders in lipid metabolism should be corrected in early middle age.

Adult↗