Biomedical subjects

Naohisa Shindo

Publications and source records attributed to Naohisa Shindo.

6 recordsLinked to original sources

PubMed2006

Decrease of fractional flow reserve shortly after percutaneous coronary intervention.

BACKGROUND: The aim of the present study was to quantitatively assess the physiological acute recoil after percutaneous coronary intervention (PCI), and to determine the relation between it and target lesion revascularization (TLR) in the chronic phase. METHODS AND RESULTS: This study evaluated 76 patients who underwent elective PCI between May 1997 and December 2001: plain old balloon angioplasty (POBA) in 50 patients and bare metal stent implantation in 26 patients. Fractional flow reserve (FFR) was measured immediately (FFR0m) and 15 min (FFR15m) after the final dilation, and the difference (dif-FFR) was calculated. In POBA patients with TLR, FFR15m was significantly low (0.79+/-0.05 vs 0.87 +/-0.08, p<0.001) and dif-FFR was significantly high (0.06+/-0.04 vs -0.01+/-0.04, p<0.001) compared with the patients without TLR. The patients with a larger dif-FFR value (> or =0.05) had a higher rate of TLR (92%). Dif-FFR was the strongest independent predictor of TLR. CONCLUSIONS: The changes in FFR during the time course shortly after coronary intervention can be detected and a decrease in the first 15 min after PCI is associated with a higher rate of TLR.

Aged↗

PubMed2005

[Intracoronary temperature in patients with coronary artery disease].

OBJECTIVES: Measurements of changes in plaque temperature may predict plaque rupture. The present study investigated variations in temperature within the atherosclerotic coronary artery using a pressure guide wire with thermal sensor (dual sensor guide wire). METHODS AND RESULTS: Seventy-seven patients (78 lesions), who had no significant lesion at the orifice of the culprit coronary artery, were studied. The patients had acute myocardial infarction (22 patients), unstable angina pectoris (20 patients), and stable angina pectoris (35 patients). The thermal sensor was calibrated at the orifice of the coronary artery, and then inserted into the culprit coronary artery. deltaT was defined as the difference between the intracoronary temperature at the position of the pressure gradient and at the orifice. deltaT was higher in patients with acute myocardial infarction and unstable angina pectoris than in patients with stable angina pectoris (0.09 +/- 0.07 and 0.07 +/- 0.07 vs 0.03 +/- 0.04 degrees C, p < 0.001, p = 0.02, respectively). There was no significant difference in deltaT between patients with acute myocardial infarction and unstable angina pectoris (p = 0.48). Patients with acute myocardial infarction and unstable angina pectoris showed a significant relationship between deltaT and C-reactive protein (r = 0.59, p = 0.0004). CONCLUSIONS: The variations in intracoronary temperature of the culprit coronary arteries in patients with acute coronary syndrome were higher than those in patients with stable angina pectoris. These variations may be related to inflammation of vulnerable plaque.

Aged↗

PubMed2004

[Influence of serum homocysteine level on coronary atherosclerosis in Japanese].

OBJECTIVES: This study investigated the relationship between serum homocysteine level and coronary artery disease in Japanese. METHODS: Serum homocysteine level was measured in 200 consecutive patients who underwent coronary angiography for the assessment of ischemic heart disease. Patients with acute myocardial infarction were excluded, so 197 patients were included in this study. The patients were classified into four groups based on number of diseased vessels identified by coronary angiography: no significant stenosis group (non-vessel group), one-vessel group, two-vessel group, and three-vessel group. More than 50% stenosis was defined as diseased vessels. RESULTS: Serum homocysteine level in the three-vessel group (13.5 +/- 8.0 microM) was significantly higher than that in the non-vessel group (9.9 +/- 2.7 microM), one-vessel group (9.1 +/- 2.3 microM), and two-vessel group (10.4 +/- 3.3 microM). Patients were classified into quartile groups according to the serum homocysteine level. The number of diseased vessels and frequency of three-vessel disease tended to be higher with increasing serum homocysteine level. There was no significant relationship between serum homocysteine level and coronary risk factors (diabetes mellitus, hyperlipidemia, smoking habit) except hypertension. Multivariate analysis for the predictor of number of diseased vessels showed diabetes mellitus, hypertension, and serum homocysteine level were independent predictors. CONCLUSIONS: Elevation of plasma homocysteine level is related to the severity of coronary artery disease in Japanese.

Aged↗

PubMed2003

Coronary flow--pressure relationship distal to epicardial stenosis.

To assess the coronary flow velocity - pressure relationship distal to a stenosis, and to evaluate the influence of microvascular abnormalities on this relationship, coronary flow velocity and coronary pressure were measured simultaneously in 38 patients (42 vessels). The instantaneous peak coronary flow velocity was plotted against the simultaneous measured distal coronary pressure, and the slope of the relation in the phase of diastolic flow decrease was calculated as the flow - pressure slope index (FPSI) and the X-intercept of the slope was calculated as zero-flow pressure (Pzf). The slope of the curve increased from 2.0+/-2.6 to 4.5+/-4.1 (p<0.001) and the X-intercept decreased from 42+/-16 to 27+/-13 mmHg (p<0.001) after papaverine injection. After successful coronary intervention, Pzf increased from 23+/-10 to 35+/-11 (p<0.01) and FPSI decreased from 6.8+/-5.1 to 3.5+/-1.8 (p<0.05). Pzf was higher in patients with an old myocardial infarction. It is feasible to assess the relationship between coronary flow and pressure distal to a stenosis in the clinical setting, and the relationship may provide additional information regarding coronary microcirculation. Microvascular abnormalities may play an important role in the coronary flow - pressure relationship distal to stenosis.

Aged↗

PubMed2003

[Hypertrophic cardiomyopathy with mid-ventricular obstruction complicated by apical aneurysm appearing as delayed contrast hyperenhancement on magnetic resonance imaging: two case reports].

Case 1: A 52-year-old man presented with a chief complaint of palpitation. Diabetes mellitus was pointed out in 1992. Electrocardiography (ECG) revealed left ventricular hypertrophy in 1997. He visited our department in October 1997. Echocardiography showed increased wall thickness at the interventricular septum. The diagnosis was hypertrophic cardiomyopathy. Holter ECG revealed nonsustained ventricular tachycardia in December 1997. After this, he visited our outpatient clinic. Echocardiography indicated ventricular aneurysm in January 2002, so he was hospitalized in March 2002. Case 2: A 64-year-old woman was transferred to our hospital because of chest discomfort and tachycardial attack. She had been treated for hypertension and diabetes mellitus. She was taken to a hospital by ambulance. On admission, ECG showed wide QRS tachycardia. Cardiac magnetic resonance imaging in both patients disclosed almost complete obstruction of the mid-ventricle in the systolic phase on long- and short-axis cine images, and gadolinium delayed imaging revealed contrast hyperenhancement corresponding to an apical ventricular aneurysm on both long- and short-axis images. The final diagnosis was mid-ventricular obstructive hypertrophic cardiomyopathy with apical aneurysm characterized by delayed hyperenhancement on magnetic resonance imaging with gadolinium.

Cardiomyopathy, Hypertrophic↗

PubMed2002

[Measurement of fractional and coronary flow reserve using dual sensor guide wire].

OBJECTIVES: Fractional flow reserve and coronary flow reserve (CFR) are indices of the severity of coronary artery stenosis influenced by both epicardial and microcirculatory dysfunction. The CFR was measured using the new pressure guide wire with thermal sensor (dual sensor guide wire) on the basis of the thermodilution principle (CFR-thermo), and compared to the CFR as measured by the Doppler method (CFR-Doppler), and the relationships were evaluated between CFR-thermo, fractional flow reserve and stress myocardial scintigraphy. METHODS AND RESULTS: CFR-thermo and CFR-Doppler were measured in 14 patients (20 vessels) by the dual sensor guide wire and Doppler guide wire, respectively. A significant positive correlation was found between CFR-Doppler and CFR-thermo (y = 0.80 x + 0.10, r = 0.70, p < 0.0001). Stress myocardial perfusion single photon emission computed tomography (SPECT) was performed before coronary angiography in 56 patients (70 vessels), and then fractional flow reserve and CFR-thermo were measured using the dual sensor guide wire. CFR-thermo and fractional flow reserve were significantly lower in coronary segments with positive SPECT image (n = 32) than in coronary segments with negative SPECT image (n = 38) (1.29 +/- 0.24 vs 1.96 +/- 0.69, p < 0.0001; 0.61 +/- 0.13 vs 0.85 +/- 0.09, p < 0.0001). The cut-off values of CFR-thermo and fractional flow reserve for detection of ischemic segments demonstrated by SPECT image were 1.47 and 0.76, respectively. The sensitivity and specificity for detecting ischemia were 78% and 84% for CFR-thermo, 88% and 92% for fractional flow reserve, respectively. CONCLUSIONS: A significant correlation was found between CFR-thermo measured by the thermodilution principle using the dual sensor guide wire and CFR measured by the Doppler method. CFR-thermo measured by the dual sensor guide wire may be useful to detect myocardial ischemia.

Coronary Circulation↗