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Biomedical subjects

R Kusukawa

Publications and source records attributed to R Kusukawa.

At least 55 records · Page 3Linked to original sources
PubMed1989

Analysis of digital subtraction coronary angiography for estimation of flow reserve in critical coronary stenosis.

To examine the accuracy of digital subtraction angiographic assessment of coronary flow reserve in critical coronary stenosis, time-density curves were obtained from digital angiograms for a myocardial region of interest. Time-to-peak contrast (TPC) and contrast washout rate (T) were measured in 11 patients with critical 1-vessel lesions before and after percutaneous transluminal coronary angioplasty (PTCA). Collectively, the values of TPC and T were significantly shortened, from 5.8 +/- 1.1 to 4.4 +/- 1.0 seconds (p less than 0.01) and from 11.3 +/- 4.0 to 5.2 +/- 1.2 seconds (p less than 0.001) after PTCA, respectively. All 11 patients except 1 showed shortened T after PTCA; however, in 5 of the 11 patients, TPC after PTCA had approximately the same values as those before PTCA. In experiments in dogs with critical circumflex stenosis, coronary flow and posterior wall thickening at rest were not different from control; however, contrast media-induced hyperemia was markedly attenuated, accompanied by a significant prolongation of T (7.7 +/- 4.5 vs 15.8 +/- 1.9 seconds, p less than 0.01) and completely unchanged TPC (both 6.8 seconds). With simultaneous tracings of coronary flow and time-density curves, TPC and the washout phase on the curve corresponded with contrast-induced transient flow reduction and hyperemic phases, respectively. It is concluded that T appears more sensitive than TPC when basal coronary flow is maintained to almost normal levels, as in patients with stable effort angina pectoris having critical coronary stenosis.

Aged↗
PubMed1989

Usefulness of negative dP/dt upstroke pattern for assessment of left ventricular relaxation in coronary artery disease.

It has been reported that regional asynchrony due to acute ischemia disturbs the exponential nature of left ventricular (LV) pressure reduction and may alter the pattern of (-)dP/dt upstroke curve. If LV pressure decreases exponentially during the isovolumic relaxation period (P = Ae-t/T + B, where A and B = constants, t = time and T = time constant), the (-)dP/dt upstroke curve should also be exponential and upward-convex because dP/dt = A(-t/T)e-t/T. To test this theory in humans, the LV (-)dP/dt upstroke curve was analyzed in 9 normal subjects, 12 patients with effort angina pectoris (AP) and 15 with old myocardial infarction (MI) under the basal conditions. The (-)dP/dt upstroke was convex-upward in all normal subjects, but convex-downward in 9 of 12 patients with AP and in all patients with MI, which suggests nonexponential decrease in LV pressure in the groups with AP and MI. The dP/dt (20/60), which is the ratio of the (-)dP/dt value at 20 ms after peak (-)dP/dt to that at 60 ms after peak (-)dP/dt, was significantly lower in the group with AP (1.70 +/- 0.07) and in the group with MI (1.61 +/- 0.13) than in normal subjects (2.08 +/- 0.18) (p less than 0.005). This indicates that (-)dP/dt upstroke 20 to 60 ms after peak (-)dP/dt increases more slowly in the groups with AP and MI than in normal subjects. Theoretical consideration showed that such a slower increase of the upstroke resulted from impaired early to midrelaxation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Left atrial conduit function for left ventricular filling dynamics in patient with myocardial infarction.

This study observed the left function in determining filling dynamics of the left ventricle in patients with myocardial infarction. The study consisted of eight control subjects and ten patients with myocardial infarction. The left ventricular filling volume is considered to be composed of the left atrial passive emptying, active emptying, and conduit volumes. The change of left ventricular filling volume was correlated with that of conduit volume (r = .87, P less than .01). However, the change of left ventricular filling volume did not have any correlation to those of left atrial passive emptying and active emptying volumes. These results suggested that the left atrial conduit function was important in determining filling dynamics of the left ventricle.

Adult↗
PubMed1989

Thallium-201 myocardial scintigraphic evidence of ischemia in a patient with angina pectoris and normal coronary arteriogram: significance of thallium-201 washout analysis.

We present a patient who had anginal pain and an abnormal exercise electrocardiogram but a normal coronary arteriogram. We thought that myocardial ischemia was responsible for this symptom in view of the exercise left ventriculogram, exercise thallium-201 myocardial scintigraphy and effect of nitroglycerin on the anginal pain. The left ventriculogram at rest was normal but exercise worsened the entire left ventricular wall motion. Exercise thallium-201 myocardial images showed minimal reduction of radio-activity in the anterior, apical, antero-lateral and postero-lateral wall. Myocardial thallium-201 washout analysis revealed washout abnormalities all over the left ventricular myocardium similar to those of triple vessel disease, supporting the exercise left ventriculographic finding. Myocardial thallium-201 washout analysis as well as the visual method should be performed in patients with angina pectoris and normal coronary arteriograms.

Adult↗
PubMed1989

Effect of diltiazem on aortic pressure-diameter relationship in dogs.

To study the effects of diltiazem (Dz) on aortic (Ao) pressure-diameter (P-D) relationships, the external diameter (D) of the thoracic Ao (sonomicrometry) and Ao pressure (AoP, micromanometer) were simultaneously measured in 10 anesthetized dogs. The P-D relationship from 80 ms after the dicrotic notch of AoP (t80) to 20 ms after the peak of the next R wave on the electrocardiogram (ECG) (t20) was plotted at 30-ms intervals. To depict the P-D relationship in a wide range of AoP, Ao occlusion immediately after the release of inferior vena caval (IVC) occlusion was performed both before and after a Dz (0.03 mg.kg-1.min-1, over 10 min) infusion. The P-D relationship so obtained was a sigmoid curve under both conditions and was reasonably described by a cubic curve (P = aD3 + bD2 + cD + d, where a, b, c, and d are constants and r greater than 0.99). The first derivative of cubic regression equation (dP/dD) value of the cubic curve was used as an index of Ao stiffness. In all dogs, the dP/dD-D relationship, which was parabolic, was similar to the delta P/delta D-D relationship measured from the actual P-D relationship (delta P/delta D is the ratio of the change in AoP to that in AoD), suggesting that it corresponded to a cubic curve.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

A case of myocardial damage following acute paracetamol poisoning.

A 24-year-old woman was admitted to our hospital with acute paracetamol poisoning, and severe hepatic injury. The peak blood level of GOT, GPT and LDH were 32,600 U, 119,200 U and 36,500 U respectively. Glucagon-insulin and glutathione were administered to save the liver function. On the third hospital day, hemodialysis was administered to treat acute renal failure. On the 16th hospital day, when the liver and renal functions recovered, severe pulmonary congestion occurred and right heart catheterization revealed high pulmonary pressure. Echocardiography showed left ventricular enlargement accompanied by a severe diffuse impairment of left ventricular wall motion. Multi-focal ventricular arrhythmia was frequent during this period. Hemodialysis and artificial respiration were carried out for the treatment of heart failure. Three months after admission, myocardial perfusion scintigram showed patchy reduction in the uptake of Tl-201 throughout the myocardium, and left ventriculography showed mild diffuse impairment of the LV wall motion (ejection fraction: 49%). In this case, acute heart failure appeared approximately 2 weeks after the severe hepatic injury. Apparently myocardial damage following paracetamol overdosage is caused not only by direct toxicity but by severe metabolic derangement.

Acetaminophen↗
PubMed1989

Hemodynamic benefits of long-term bunazosin (alpha-1 blocker) therapy in rats with myocardial infarction and heart failure.

To determine whether bunazosin (alpha 1-adrenoceptor blocking agent) can alter the hemodynamic profile of chronic heart failure secondary to myocardial infarction, the drug was administered to Wistar rats 4 weeks after coronary ligation, and continued for 4 weeks. In rats without bunazosin treatment, the left ventricular end-diastolic pressure (LVEDP) and the total vascular resistance index (TVRI) increased as a function of infarct size, while the cardiac index (CI) decreased. But in infarcted rats with bunazosin treatment, the mean aortic pressure and TVRI were reduced, the LVEDP was modestly lessened, and the CI was maintained. The greatest increase in CI after the treatment occurred in rats with infarcts of small and moderate size. Thus, long-term therapy with bunazosin improved LV dysfunction, relative to the size of infarction. This study suggests the beneficial effects of bunazosin therapy in patients with chronic heart failure.

Adrenergic alpha-Antagonists↗
PubMed1989

Echocardiographic assessment of aneurysm of the aortic valve caused by infective endocarditis--a case report.

No aneurysm of the aortic valve associated with infective endocarditis has yet been reported. This report describes the clinical echocardiographic and pathologic findings in a patient who developed infective endocarditis resulting in aneurysm of the non-coronary cusp with aortic regurgitation. Surgical treatment was performed because of gradual expansion of the aneurysm and gradual thinning of its wall. Two-dimensional and color Doppler echocardiographies proved useful for the initial diagnosis and serial follow-up of this unusual case and for its successful surgical management.

Aortic Valve↗
PubMed1989

[Serum lipoprotein abnormalities in patients with nephrotic syndrome and effects of steroid therapy].

With polyacrylamide gel electrophoresis (PAGE), we studied serum lipoprotein (Lp) abnormalities in patients with nephrotic syndrome (NS) caused by primary glomerulonephritis. Nineteen untreated nephrotic patients were studied. Seven patients of them were followed up with PAGE in the remitting course. Serum total cholesterol, triglycerides and beta-Lp concentrations were higher in untreated patients than those in normal control. Serum HDL-cholesterol concentration was lower in untreated patients than those in normal control. PAGE showed broad midband-Lp and increased pre-beta-Lp in 16 of 19 untreated patients. Those findings suggested that untreated nephrotic patients had impaired catabolism of VLDL to LDL in peripheral tissue or impaired hepatic catabolism of IDL and LDL. Furthermore, PAGE showed decreased alpha-Lp in all patients with untreated NS. Correlation was not found between histological classification of glomerulonephritis and broad midband or hyperlipidemia. After administration of prednisolone, PAGE revealed the appearance of chylomicron, and increased pre-beta-LP and alpha-Lp. After remission, broad midband-Lp and pre-beta-Lp were markedly decreased or dis appeared in all 6 patients with broad midband-Lp in untreated phase, and serum total cholesterol and beta-Lp concentrations were markedly decreased, and HDL- cholestrol was markedly increased. In the course of remission, serum total cholesterol, triglycerides and beta-Lp concentrations had negative correlation with serum albumin concentration. Furthermore, serum total cholesterol and beta-Lp concentrations were decreased along with decrease of urinary protein excretion. The results of the present study suggest that the loss of serum albumin and/or some other substances to the urine cause broad midband.

Adolescent↗
PubMed1989

[Accuracy of the measurements of left ventricular volume and ejection fraction determined by multigated blood pool tomography].

Accuracy of the measurements of LV volumes and ejection fraction determined from multigated blood pool tomography (MGBPT) was tested in 23 patients with various heart diseases who underwent cineventriculography (CV). Preliminary phantom studies showed that a 42% threshold value was found to provide the best relationship between measured and actual volumes (r = 0.99, standard error of the estimate (SEE) = 4.7 ml). The patients studies were performed at 16 frames/cardiac cycle at 18 angles over a 180 degrees rotation for one minute per angle. Long-axis horizontal views were reconstructed. The numbers of LV voxel with counts above the threshold value were summed and multiplied by the known volume of a voxel. Measurements of LV volume (r = 0.82, SEE = 29 ml), end-systolic LV volume (r = 0.83, SEE = 25 ml), end-diastolic LV volume (r = 0.68, SEE = 33 ml), and ejection fraction (r = 0.73, SEE = 10%) determined from MGBPT correlated well with those determined by CV. However, the ratios (Y) of the difference of the MGBPT-volume from the CV-volume to the CV-volume were decreased progressively and negatively as the CV-volumes (X) were smaller (Y = 38-3,996/X). Thus, we conclude that the determinations of volume by MGBPT would lead to more errors with the smaller volumes.

Aged↗
PubMed1988

Mitral valve motion during diastole in patients with complete heart block: relation of pressure gradients between left atrium and left ventricle.

We analyzed the high-fidelity left atrial and left ventricular pressures and the echocardiograms of the mitral valve, left atrium, and left ventricle in patients with complete heart block. During left ventricular diastole, the mitral valve opened, and no pressure gradient was observed between the left atrium and the left ventricle before the left atrial contraction. After the left atrial contraction, the mitral valve closed with persistent higher left ventricular than left atrial pressure. These findings indicated that during the left ventricular diastole in patients with complete heart block, the mitral valve closed after the left atrial contraction, which appeared to be maintained by the pressure gradient between the left ventricle and the left atrium.

Aged↗
PubMed1988

Effect of afterload on the left ventricular pressure fall during isovolumic relaxation period in man.

To assess the effect of afterload on the left ventricular pressure (LVP) fall during isovolumic relaxation period (IRP) in man, we examined the peak (-)dP/dt, (-)dP/dt upstroke pattern in IRP, and time constant (T) in 15 patients [normal (N): 5 valvular heart disease (VHD): 5, dilated cardiomyopathy (DCM): 5]. LVP and echocardiographic internal diameter were measured simultaneously at rest and after about 30 mmHg increment of LV peak systolic pressure (PSP) by drip infusion of angiotensin (20 ng/kg/min). After augmentation in afterload, heart rate (HR) increased slightly in VHD. T increased significantly (p less than 0.05) in N (from 32 +/- 3 to 39 +/- 4 ms) and DCM (from 56 +/- 18 to 72 +/- 12 ms), but not in VHD (from 41 +/- 5 to 46 +/- 8 ms) probably due to increased HR. LV end-systolic dimension had the same trend as T. Although there was no significant change in peak (-)dP/dt in N (from 1937 +/- 385 to 1945 +/- 189 mmHg/s), VHD (from 1521 +/- 210 to 1730 +/- 462 mmHg/s), or DCM (from 814 +/- 143 to 814 +/- 131 mmHg/s), the (-)dP/dt upstroke pattern during IRP became nonexponential in N and more downward convex in VHD or DCM. Thus, these changes of T and (-)dP/dt upstroke pattern suggest the afterload dependence of LVP fall during IRP in normal and diseased hearts.

Adult↗
PubMed1988

Relationship between the relative regional thallium-201 uptake and the regional systolic or diastolic filling function.

Both the resting thallium-201 imaging and resting gated radionuclide ventriculography were conducted in the left anterior oblique view in 35 patients with isolated disease of the left anterior descending coronary artery (LAD), and the corresponding involved region was compared from two differing perspectives, one measuring regional ventricular function and the other regional myocardial perfusion. In the thallium-201 imaging, the thallium activity in the septal or apical region supplied by the LAD was calculated as an activity ratio between the mean value of the normally perfused lateral region and that of the septal or apical region, and was called relative thallium uptake (%T1 uptake). In the gated radionuclide ventriculographic study, a computer program subdivided the image of the left ventricle into 4 regions. The time-activity and first-derivative curves were computed in the septal and apical regions. Significant positive correlations were present between the %T1 uptake and the ejection fraction or peak ejection rate both in the septal and apical regions, indicating that the regional systolic function diminishes progressively as the perfusion abnormality increases. However, positive but poor and scattering correlations were found between the %T1 uptake and the peak filling rate, and there were no significant correlations between the %T1 uptake and the filling period in these affected regions. Thus, we could suppose that the regional systolic function is closely related to the regional %T1 uptake which probably reflects the amount of the residual viable myocardium, but there is the possibility that the regional diastolic filling function may be not so much related to the amount of the viable myocardium as is systolic function or may be modulated by some factors other than the amount of the regional viable myocardium.

Adult↗
PubMed1988

A case of left ventricular aneurysm associated with an anomalous coronary artery.

A 54-year-old man presented with continual angina pectoris at rest, associated with an anomalous coronary artery. He also had an aneurysm at the submitral region of the left ventricular postero-lateral wall, without evidence or prior myocardial infarction, which showed hypokinetic inward motion during systole. We assume that this was a rare case of left ventricular aneurysm without prior myocardial infarction, the etiology which might related to the anomalous coronary artery.

Cineangiography↗