Biomedical subjects

M Fukuki

Publications and source records attributed to M Fukuki.

12 recordsLinked to original sources

PubMed1996

Decreased heart rate variability in patients with diabetes mellitus and ischemic heart disease.

We investigated the characteristics of decreased heart rate variability (HRV) in diabetic patients with ischemic heart disease (IHD). Twenty-one healthy control subjects, 17 diabetic patients without IHD, and 33 diabetic patients with IHD were studied. The diabetic patients with IHD were subdivided into 2 groups according to the severity of their IHD: severe or mild. HRV was evaluated in all subjects using the spectral variables of the all-frequency, low-frequency, high-frequency (AF, LF, HF) components and the LF/HF ratio were determined from Holter recordings. The AF and LF components in patients with diabetes only or diabetes and severe IHD were significantly lower than in control group, but the HF component was significantly lower only in the group of patients with diabetes and severe IHD. The LF/HF ratio did not differ significantly among the 4 groups, but was the lowest in diabetic patients without IHD. Patients with diabetes and mild IHD showed a slight decrease in HRV, but this was not significant. With regard to the circadian rhythm of HRV, the AF and LF components in patients with diabetes-only or diabetes and severe IHD were significantly decreased and showed the same pattern throughout the day. However, the HF component was decreased during more time zones in patients with diabetes and severe IHD, whereas the LF/HF ratio was lower during more time zones in the diabetes-only group. All spectral variables showed a tendency to be inversely related to the duration of diabetes in all diabetic patients. In particular, the LF/HF ratio showed a significant negative correlation. The HRV of diabetic patients was characterized by a decreased LF/HF ratio. It was concluded that, although HRV in diabetic patients with severe IHD was reduced mainly as a result of diabetic neuropathy, this was also partly due to a decline in parasympathetic tone as a result of myocardial injury.

Aged↗

PubMed1996

Cardiac angiosarcoma.

Angiosarcoma is one of the most common cardiac tumors, but early detection of this tumor is often difficult, as exemplified by our patient, a 55-year-old woman whose cardiac tumor was first detected by echocardiography. Surgical removal of the tumor was impossible due to its extensive pericardial invasion. Pathological diagnosis was not complete before autopsy because of the wide occupied necrotized area of the tumor. There is no diagnostic imaging technique available to detect such a necrotized area. An imaging technique more powerful than echocardiography and able to diagnose angiosarcoma earlier is needed.

Biopsy↗

PubMed1995

Plasma concentrations and coronary vasodilation after sublingual and intracoronary administration of isosorbide dinitrate.

To investigate the relationship between plasma levels and coronary vasodilation after administration of isosorbide dinitrate (ISDN), the plasma concentration and diameters of six segments of the left coronary artery were measured before and after sublingual (SL) ISDN (5 mg) and left intracoronary (IC) administration of ISDN (3 mg) in 12 patients. After SL-ISDN, the systolic aortic pressure decreased with no significant concomitant changes in heart rate or diastolic aortic pressure. After IC-ISDN, all hemodynamic parameters showed significant changes, and these were greater after IC-ISDN than those after SL-ISDN. The individual mean vasodilation of six segments induced by SL- and IC-ISDN, were 23 +/- 9 and 35 +/- 11% (p < 0.01), respectively. Before SL-ISDN, ISDN was not detected in plasma. After SL- and IC-ISDN, however, the plasma values of the ISDN were 36.1 +/- 53.3 and 101.5 +/- 90.0 ng/ml (p < 0.01), respectively. Thus, both coronary vasodilative responses and plasma ISDN levels after IC-ISDN were significantly greater than those after SL-ISDN. However, neither the individual mean coronary vasodilation nor the hemodynamic changes correlated significantly with plasma ISDN levels. Consequently, with administration of the same dose, the coronary vasodilative response to ISDN did not correlate with plasma levels. Furthermore, IC-ISDN dilutes coronary arteries more effectively than SL-ISDN.

Administration, Sublingual↗

PubMed1994

Characteristics of ventricular premature contractions and their clinical course.

One hundred patients with frequent (> 1,000 beats/day) ventricular premature contractions (VPCs) were followed for 4 years. All of the patients, except those with non-cardiac death (n = 8), were classified into 3 groups based on their outcome. Group A consisted of 29 patients with idiopathic VPCs who survived the study period. Group B consisted of 49 patients with underlying diseases who survived the study period. Group C consisted of 14 patients who suffered cardiac death. There was no significant difference in the daily number of VPCs. However, groups B and C had more patients with Lown grade 4a or 4b VPCs than group A. The mean coupling interval was significantly longer in group C than in group A, and the standard deviation of the coupling interval was significantly larger in group C than in group A. Forty patients underwent serial Holter monitorings to assess changes in the number of VPCs. VPCs spontaneously decreased in 13 patients, while the other 27 patients continued to have frequent VPCs. Most of these 13 patients were classified as Lown grade 2. The results suggest that in patients with frequent VPCs, longer and more varied coupling intervals may predict a poor prognosis, and Lown grade 2 may predict a spontaneous regression.

Adult↗

PubMed1994

Coronary artery ectasia with annuloaortic ectasia.

A 50-year-old Japanese woman with annuloaortic ectasia was found to have total coronary artery ectasia without evident atherosclerosis. The coronary ectasia may have been secondary to or of similar etiology to the annuloaortic ectasia. There was neither stigmata of Marfan's syndrome nor any sign of dissection of the ascending aorta or coronary arteries. Furthermore, the patient was not elderly, and had no hyperlipidemia, diabetes mellitus, or history of smoking. There was a marked blood pressure difference between the arms, and linear calcification was present in the aortic wall. A stenotic lesion was present in the right mid-subclavian artery. Although it is impossible to rule out atherosclerosis as the etiology of these findings, the possibility that they may be a manifestation of Takayasu's arteritis is discussed.

Angiography↗

PubMed1992

Comparison of coronary responses to intracoronary and intraaortic ergonovine and isosorbide dinitrate in patients with atypical chest pain.

Fifty patients with atypical chest pain were studied to compare coronary responses to intracoronary and intraaortic ergonovine. The diameters of the proximal, middle (1) and (2) (proximal segments of segments 2 and 3 [AHA classification], respectively), and distal segments of the right coronary artery were measured before and after intracoronary ergonovine (4 micrograms/minute over 4 minutes) and isosorbide dinitrate (ISDN) (2 mg) in 24 patients, and before and after intraaortic ergonovine (0.2 mg) and ISDN (5 mg) in 26. Mean vasoconstriction by intracoronary and intraaortic ergonovine were 13 +/- 1.5% and 9 +/- 0.8%, respectively (p < 0.02). Irrespective of the methods of administration, the responses to ergonovine were similar in the 4 segments. Mean vasodilation by intracoronary and intraaortic ISDN, which were used to quantify the degree of basal coronary tone, were 25 +/- 2.2% and 27 +/- 1.5%, respectively (p = not significant [NS]). There were significant negative linear correlations between the responses to ergonovine and ISDN in the middle (2) (r = -0.51; p < 0.05) and distal (r = -0.53; p < 0.01) segments in patients with intracoronary injection, and the proximal (r = -0.41; p < 0.05), middle (1) (r = -0.66; p < 0.01) and middle (2) (r = -0.69; p < 0.01) segments in patients with intraaortic injection. These observations indicate that low-dose administration of intracoronary ergonovine produces sufficient coronary vasoconstriction, similar to or slightly greater than that of intraaortic ergonovine in patients with atypical chest pain, but basal coronary tone may influence the vasoreactivity to ergonovine.

Aorta↗

PubMed1992

Cardiac neurosis: interactions between cardiac arrhythmias and symptoms using ambulatory ECG monitoring.

To investigate interactions between cardiac arrhythmias and subjective complaints and the background, ambulatory electrocardiographic (ECG) monitoring and a mental test [Cornell Medical Index (CMI)] were performed on 32 patients who complained of anxiety due to palpitation and/or tachycardic feelings without organic heart disease. The patients were classified into two groups according to the Holter ECG. In one group symptoms corresponded with cardiac arrhythmias (Group C; n = 15); and the other group lacked corresponding arrhythmias in spite of their significant symptoms (Group B; n = 17). From psychological view points, 65% of Group B and 40% of Group C patients showed grades III or IV of CMI tests, whereas only 5% showed grade III in normal volunteers (Group A; n = 20). Patients suffering symptoms without associated cardiac arrhythmias may have psychophysiologic backgrounds, at least in a part. It might be necessary in the treatment of these patients to pay attention to the factor of cardiac neurosis.

Adult↗

PubMed1991

Clinical study on coupling interval of ventricular premature contraction in patients with organic heart disease.

The characteristics of the coupling interval (CI) of ventricular premature contraction (VPC) were studied in 100 patients with frequent VPCs using 24 h ambulatory ECG recording. All R-R intervals were registered on computer to determine the mean value of CIs (Mean CI) and the standard deviation of CIs (SD-CI). We compared the Mean CI and the SD-CI between idiopathic VPCs and VPCs with organic heart disease (OHD). In addition, we evaluated the efficacy of disopyramide (DP) and mexiletine (MX) and we examined the relationship between the efficacy of these drugs and the characteristics of CI. The Mean CI of VPCs with OHD was longer than that of idiopathic VPCs (530 vs. 494 msec, p less than 0.05). The SD-CI of VPCs with OHD was larger than that of idiopathic VPCs (54.1 vs. 39.3 msec, p less than 0.01). In all treated cases, the drug efficacy was not different between DP (11/18, 61%) and MX (9/19, 47%). However when we isolated cases of OHD, we found a tendency that DP (9/12, 75%) was more effective than MX (7/16, 44%). In cases where DP was administered, the Mean CI of VPCs was not different between effective and ineffective cases, while in cases where MX was administered, the Mean CI of ineffective cases had a tendency to be longer than that of effective cases (552 vs. 506 msec, p less than 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Complexes, Premature↗

PubMed1991

Significance of coronary artery tone assessed by coronary responses to ergonovine and nitrate.

The coronary artery response to ergonovine (EM) and nitrate of the proximal, middle and distal segments of the three major coronary artery branches and the main trunk was quantified in 67 patients without coronary spasm and in 69 patients with coronary spasm without significant organic stenosis. The changes in control diameter and diameter after EM administration compared to diameter after nitrate were used as the index of coronary artery tone. EM increased coronary artery tone regardless of the occurrence of coronary spasm (p less than 0.01). In all segments, basal coronary artery tone was greater in patients with spasm than in patients without spasm (p less than 0.01) in a way similar to the coronary responses to EM (p less than 0.01). In patients with spasm, both coronary artery tone after EM and basal coronary tone were greater in the spastic segments than in the nonspastic segments (p less than 0.01), which were greater than those in patients without spasm (p less than 0.01). Our data suggest that patients with spasm may have increased basal tone, and that coronary artery spasm may be based on increased coronary tone. Clinically, evaluation of the basal tone and response to EM in the entire coronary artery tree may be useful for predicting the presence of coronary artery spasm.

Cardiac Catheterization↗

PubMed1990

A case of secundum atrial septal defect combined with aortic stenosis and coronary artery disease showing a single second heart sound.

We describe an extremely rare case of secundum atrial septal defect with aortic stenosis and coronary artery disease showing a single second heart sound throughout the respiratory cycle by echocardiogram with simultaneous phonocardiogram. Aortic valve closure corresponded to the single second heart sound. We were unable to detect pulmonary valve closure (PVC) on echocardiogram. Because of the presence of pulmonary hypertension, the pulmonary component of the second heart sound (P2) was presumed to be increased in intensity, and the PVC-P2 interval was thought to be abbreviated. Carotid pulse tracing showed a prolongation of the left ventricular ejection time. We concluded that the single second heart sound was due to both prolongation of left ventricular systole and pulmonary hypertension.

Aortic Valve Stenosis↗

PubMed1989

Effect of luteinizing hormone-releasing hormone on the mechanical activity of the guinea-pig cardiac muscle.

1. The inotropic effect of physiological concentrations of luteinizing hormone-releasing hormone (LH-RH) in isolated guinea-pig cardiac muscles was studied. 2. LH-RH increased the contractile force elicited by either fast and slow responses in a dose-dependent manner. 3. These effects of LH-RH were affected by phentolamine and diltiazem but not by propranolol and cold condition. 4. This study showed the positive inotropic effect of LH-RH on myocardium through the affection to intracellular Ca, and the difference from the effect of cardiotonic steroids.

Animals↗

PubMedDate not supplied

Effects of guanabenz acetate on the pacemaker activity of rabbit sinoatrial node cells.

The effects of guanabenz acetate on the electrophysiological properties of isolated rabbit sinoatrial node were studied using conventional microelectrode and double-microelectrode voltage clamp methods and were compared with those of clonidine and guanethidine. In spontaneously beating sinoatrial node preparations, guanabenz decreased the heart rate, the maximum rate of rise (Vmax), the action potential amplitude and the rate of diastolic depolarization in a dose-dependent fashion, whereas the action potential duration at 50% repolarization was prolonged. In comparison with clonidine and guanethidine, the inhibitory potency of guanethidine on the heart rate is weaker than that of guanabenz and clonidine. On the current systems, the voltage clamp experiments showed that guanabenz reduced the slow inward current and the time-dependent potassium outward current. These observations indicate that guanabenz acts directly on cardiac tissues and its bradycardic action can be mainly explained by a reduction of delayed current systems.

Action Potentials↗