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Biomedical subjects

N Kanemoto

Publications and source records attributed to N Kanemoto.

At least 55 records · Page 3Linked to original sources
PubMed1990

Significance of U wave polarity in patients with a prior inferior myocardial infarction.

Sixty consecutive patients who underwent coronary angiography and left ventriculography from six to eight weeks after the onset of definite inferior myocardial infarction were divided into three groups according to the polarity of U waves in (1) leads II, III, a VF and (2) in leads V4 to V6 (positive = Group P, flat or isoelectric = Group F, and negative = Group N). The following parameters were analyzed: (1) ECG score; (2) global ejection fraction: (3) regional area change: (4) number of asynergic, and akinetic segmental radii; (5) number of asynergic and akinetic areas: and (6) number of diseased coronary arteries and the incidence of left anterior descending artery (LAD) disease. There were no significant differences among the three groups according to the polarity of U waves in two subgroups by the site of U waves in age, gender, systemic blood pressure, and ECG scores. The polarity of U waves in leads II.III.a VF (subgroup 1) correlated with the size of myocardial infarction; regional area changes in inferior segment (Area 2) were 64.1 +/- 8.2 in group P1, 31.8 +/- 14.7 in group F1, and 21.0 +/- 15.8 in group N1 (p less than 0.01, F = 32.8). The polarity of U waves in leads V4-6 (subgroup2) correlated with anterolateral wall motion; regional area changes in anterolateral segments (Area 5) were 76.8 +/- 11.6 in group P, 66.5 +/- 18.5 in group F, and 48.9 +/- 17.1 in group N (p less than 0.01, F = 18.6). The incidence of multivessel disease increased from group P2 (36.4%), to group F2 (54.5%), to group N2 (75.0%), and the incidence of LAD disease increased from 27.3%, to 45.5%, to 68.8%, respectively. A negative U wave in either location suggested severely decreased apical wall motion, and there was a tendency for global ejection fractions to decrease in the following order: group P, group F, and group N. From these results, the authors conclude that the polarity of U waves may be one of the parameters correlating with the wall motion and left ventricular function in prior inferior myocardial infarction.

Adult↗
PubMed1990

Intravenous recombinant tissue-type plasminogen activator in patients with acute myocardial infarction--a report from the multicenter thrombolysis trial.

The efficacy and safety of intravenous infusion of human tissue-type plasminogen activator (rt-PA), developed in Japan (TD-2061), were investigated in 205 patients (154 men and 51 women) with evolving myocardial infarction (EMI). TD-2061 was given at a rate of 3.2 to 50 mg over 1 h after angiographic documentation of complete or subtotal (99%) occlusion. Nineteen patients were excluded as they did not meet the inclusion criteria. A total of 186 patients were divided into 6 groups according to the total dose given: Group I, 3.2 mg, 10 patients (pts); Group II, 6.4 mg, 15 pts; Group III, 12.8 mg, 15 pts; Group IV, 25.6 mg, 38 pts; Group V, 33.3 mg, 70 pts; Group VI, 50.0 mg, 38 pts. Ages ranged from 30 to 70 years (mean 60 +/- 1). Coronary angiography was done at 30 min and 1 h. In patients with TIMI grades 0 and 1, reperfusion was accomplished after 1 h in 22% of Group I, 50% of Group II, 64% of Group III, 70% of Group IV, 67% of Group V, and 74% of Group VI patients. Complications were hypotension, nausea and vomiting, bradycardia and bleeding at the puncture site. These findings suggest that clot-selective coronary thrombolysis can be induced in patients with EMI by means of human tissue-type plasminogen activator without concomitant induction of a severe systemic lytic state. The optimal dose for Japanese patients is considered to be 33.3-50.0 mg from the standpoint of reperfusion.

Adult↗
PubMed1990

Sinus tachycardia masquerading as ventricular tachycardia.

We describe here a 87-year-old male who came to the emergency room with the chief complaints of dyspnea and chest pain. His electrocardiogram showed a wide QRS tachycardia with a heart rate of 140 beats/min, a left bundle branch block pattern and low voltage in leads I, aVL, V5 and V6. A long strip showed a premature ventricular complex, and the sinus beat just after the extrasystole showed P waves which were positive in leads I, II, III and a VF similar in shape to those in sinus rhythm. Therefore, a diagnosis of sinus tachycardia with tachycardia dependent left bundle branch block was made. The low voltage in the left lateral leads was ascribed to pneumothorax of the left lung. When a wide QRS tachycardia is encountered in an emergency situation, marked sinus tachycardia with coexistent bundle branch block or aberrant ventricular conduction should be taken into consideration.

Aged↗
PubMed1989

Reversibility of primary pulmonary hypertension with vasodilator, anticoagulant and nocturnal oxygen therapy.

Successful vasodilator therapy of a 19 year old woman with primary pulmonary hypertension is described. Long-term home oxygen therapy during sleep (2 1/min, 8 hours) in combination with vasodilator drugs (prazosin 2 mg and long-acting ISDN 20 mg bid) and an anticoagulant (ticlopidine 100 mg bid) brought significant reduction of pulmonary artery pressure and a rise of cardiac output 3 years later. This combination therapy may be effective in selected patients with primary pulmonary hypertension.

Adolescent↗
PubMed1989

Present status of primary pulmonary hypertension.

More than a century has passed since the first description of pulmonary arteriosclerosis of unknown origin. The development of our understanding of primary pulmonary hypertension (PPH) can be divided into four periods. The first period, which extended from the introduction of the concept until about 1930, may be described as the dawn of this disease. In the second period (1930-1950) the morphological aspects of the disease were recognized and studied. In the third period (1950-1960), the advent of right heart catheterization made it possible to link pathological physiology with morphology and the disease entity as primary pulmonary hypertension was firmly established. Since 1960 (the fourth period) the etiology and therapy of this disease have been studied. This paper will review chronologically the history of PPH since the 19th century and then will discuss the etiologies, pathology, and clinical manifestation including symptoms and signs, laboratory findings, therapy, and prognosis based on the nationwide survey in Japan as well as the author's own experience.

Adolescent↗
PubMed1988

A case of atrial dissociation.

A patient with brain tumor without cardiopulmonary abnormalities whose electrocardiogram revealed atrial dissociation is described. The rate of ectopic atrial rhythm was 207 beats/min and this rhythm was considered to originate from the superior, posterior and lateral portion of the left atrium.

Electrocardiography↗
PubMed1988

Disappearing false aneurysm of the ventricular septum without rupture: a complication of acute inferior myocardial infarction--a case report.

An interseptal false aneurysm of the left ventricle due to the dissection of the septum in a patient with acute inferior myocardial infarction is described. The aneurysm was demonstrated as a cystic bulge of the left ventricular cavity into the inferoposterior interventricular septum with a small orifice from the left ventricle without any protrusion or rupture into the right ventricular cavity. Two-dimensional echocardiography, magnetic resonance imaging, and dynamic computed tomography were the most useful and reliable noninvasive diagnostic modalities. Repeated examinations demonstrated a significant reduction of the aneurysm in six months.

Aged↗
PubMed1988

Complete right bundle branch block (CRBBB) with three different mean frontal plane QRS axes--a case report.

A routine ECG of a seventy-year-old man, who had been followed for five years because of complete right bundle branch block (CRBBB) with first-degree atrioventricular (AV) block, showed CRBBB and three different mean frontal plane QRS axes suggesting normal conduction, bradycardia-dependent left anterior hemiblock, and tachycardia-dependent left posterior hemiblock--all within the same tracing. Holter recording demonstrated transient advanced AV block, and a permanent pacemaker was implanted.

Aged↗
PubMed1988

Electrocardiographic and hemodynamic correlations in primary pulmonary hypertension.

In order to evaluate the pulmonary hemodynamics in primary pulmonary hypertension, the relation between the standard 12-lead electrocardiogram (ECG) and pulmonary hemodynamics as determined by right-heart catheterization was analyzed. Significant positive correlations were noted between amplitude of the R in V1, the R/S ratio in V1, and the pulmonary artery systolic pressure (r = 0.46 and 0.50, respectively, p less than 0.01). An amplitude of the R in V1 of more than 1.2 mV indicated a pulmonary artery systolic pressure of more than 90 mmHg with a sensitivity of 94% and a specificity of 47%. The cardiac index showed a significant positive relationship with amplitude of the R in V5 and V6 and the R/S ratio in V5 and V6 (r = 0.46, 0.46, 0.39, and 0.48, respectively; each with a p less than 0.01). Moreover, an AQRS greater than or equal to 100 degrees, and either an SV6 greater than or equal to 0.7 mV, or R/SV6 less than or equal to 2 indicated a cardiac index of less than 2.8L/min/m2 with a sensitivity of 82% and 84% and a specificity of 86% and 100% respectively. This study suggests, therefore, that the 12-lead ECG is useful for the evaluation of the severity of pulmonary hypertension by its ability to predict pulmonary artery systolic pressure and cardiac index with clinically useful accuracy.

Adult↗
PubMed1988

[Ventricular septal dissection: a case report].

A rare case of dissection in the posteroinferior interventricular septum complicating acute myocardial infarction was described. A 79-year-old man was admitted to our hospital for treatment of a bleeding gastric ulcer and an acute inferior myocardial infarction. His hospital course was uneventful. Two-dimensional echocardiography performed before his discharge revealed an echo-free space representing an aneurysmal bulge into the posteroinferior interventricular septum, probably due to its dissection. Dynamic computed tomography of the chest demonstrated a cyst-like filling of the contrast medium within the posteroinferior interventricular septum. It communicated with the left ventricular cavity, but not with the right ventricular cavity. Left ventriculography demonstrated an aneurysmal bulge at the posteroinferior portion of the interventricular septum. Through a narrow orifice, there was a jet-like expulsion of radiopaque material from the left ventricular cavity, but there was no communication with the right ventricular cavity. This is the first reported case of ventricular septal dissection uncomplicated by ventricular septal perforation.

Aged↗
PubMed1988

[Natural history of primary pulmonary hypertension elucidated by pulmonary hemodynamics].

The present study was undertaken to clarify the natural history of primary pulmonary hypertension (PPH) from a hemodynamic point of view. The subjects consisted of 83 patients (18 men and 65 women), whose ages ranged from 14 to 69 years and averaged 33 years. They were contacted through a nationwide survey. All patients underwent right-sided cardiac catheterization; cardiac output was measured in 52 patients and pulmonary capillary wedge pressure, in 40 patients. The following results were obtained. 1. The patients who died within three months of their cardiac catheterization were in severe right ventricular failure as shown by their elevated right atrial pressures and decreased cardiac indices. 2. The patients who died suddenly within two years of their cardiac catheterization had the same degree of right ventricular failure. The only difference was severe hypoxia in the patients with cardiac failure (54 +/- 21 vs 66 +/- 4 mmHg, p less than 0.05). 3. The patients who survived more than two years had normal right ventricular function. 4. Among the hemodynamic variables used to estimate prognosis; namely, pulmonary artery diastolic pressure, pulmonary capillary wedge pressure, cardiac index, pulmonary vascular resistance and pulmonary to systemic vascular resistance ratio, the cardiac index was the best predictor of prognosis.

Adolescent↗
PubMed1988

[Combined valvular disease with the scimitar triad: a case report].

A case of combined valvular disease with the scimitar sign is reported. A 48-year-old woman was admitted to our hospital for treatment of congestive heart failure due to combined valvular disease following an upper respiratory infection. Chest radiography revealed hypoplasia of the right lung, dextroposition of the heart and a curved vascular opacity adjacent to the right cardiac border having the appearance of a scimitar sign. The latter was better demonstrated by chest tomography. A lung scan showed a marked decrease in perfusion of the right lung. A CT scan of the thorax revealed hypoplasia of the right lung, dextroposition of the heart and an abnormal, curved and thickened right pulmonary vein which drained into a markedly enlarged left atrium. Right heart catheterization demonstrated elevated pressures in the right side of the heart. However, no shunt was demonstrated. A pulmonary angiogram revealed an anomalous pulmonary vein, having the appearance of a scimitar sign draining normally into the left atrium. Only five cases like the present case have been reported in the world literatures. The results in the present case indicate that patients with radiological evidence of the scimitar syndrome should be examined using computed tomography of the chest to rule out the "pseudoscimitar sign."

Electrocardiography↗
PubMed1987

Natural history of pulmonary hemodynamics in primary pulmonary hypertension.

To study the relationship between the hemodynamic characteristics and prognosis in PPH, we analyzed the data on patients whose prognosis was well documented from the time of hemodynamic monitoring. Our subjects were 87 patients obtained from a nationwide survey in Japan. PCWPs were obtained in 44 patients and COs were measured in 59 patients. The average age was 33 years (range 14 to 69). Patients were followed prospectively for up to 100 months and were categorized based on the survival period from the time of catheterization. Hemodynamic variables that showed significant differences or prognostic trends were RVedp, pulmonary artery diastolic pressure, PCWP, CI, PVR, and PVR/SVR ratio. The CI correlated with the number of survival months (r = 0.583; p less than 0.01). The hemodynamic state of patients who died suddenly within 1 year from the time of catheterization was no different from those who died of clinical right-sided heart failure. The partial pressure of oxygen of arterial blood was the only variable discriminating sudden deaths from right-sided heart failure deaths (54 +/- 2 vs 66 +/- 4 mm Hg; p less than 0.05). The results of this study indicate that the major determinant of prognosis is right ventricular function and that the CI might be used as a prognostic indicator. In addition, sudden death is more likely to occur in patients with severe hypoxia.

Adolescent↗
PubMed1987

Radionuclide cardiac monitoring system using dual cadmium telluride (CdTe) detectors: specification and some clinical applications.

The construction, physical characteristics, software and some clinical applications of a computerized dual cadmium telluride (CdTe) detectors system for continuous cardiac monitoring are described. The detectors and collimators are small, light and convenient for attachment to the chest wall. Data can be collected at 0.05 s intervals and for up to 3 h. Clinical studies in 33 patients using a prototype system demonstrated reasonably good correlation with left ventricular ejection fractions determined by a scintillation camera-computer system (r = 0.928). The application of this system to continuous monitoring of left ventricular function during exercise or drug stimulations has been found to be clinically useful.

Adult↗
PubMed1987

A case of atrial septal aneurysm in normal heart.

Atrial septal aneurysms are rare, usually associated with congenital heart disease causing atrial pressure elevation. We describe here a case of atrial septal aneurysm with no other cardiac abnormalities that was diagnosed by two-dimensional echocardiography.

Adult↗