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H Kasanuki

Publications and source records attributed to H Kasanuki.

At least 145 records · Page 8Linked to original sources
PubMed1987

The feasibility of beat-to-beat detection of His-Purkinje activity by finite element method.

A noninvasive method has been applied on human and canine subjects to observe beat-to-beat activity of the His-Purkinje system without using signal averaging. Recordings were performed with multiple Ag/AgCl electrodes, very low noise, high gain amplifiers and by analog filtering. The subjects were in a supine position during the recording. In order to reduce random noise inherent in the high-gain body surface recording, a finite element method (FEM) was applied to calculate His-Purkinje activity. The dimensional relationship between electrode sites, necessary for the calculation, was pre-estimated by x-ray computed tomographs of the subject. A prominent waveform was observed between the atrial and ventricular complexes and corresponded to His bundle activity which was simultaneously recorded by an intracardiac electrode (on every beat). It was, however, difficult to recognize the His-Purkinje activity during inhalation due to the thoracic electromyogram on some human subjects. This interference could theoretically be reduced by increasing the number of body surface electrodes used for this technique.

Animals↗
PubMed1987

Endomyocardial biopsy approach to patients with ventricular tachycardia with special reference to arrhythmogenic right ventricular dysplasia.

Right ventricular endomyocardial biopsies were performed in patients with repetitive ventricular tachycardia (VT; 8 patients) or ventricular premature beats (1 patient) which showed left bundle branch block morphology in electrocardiograms. These 9 male patients ranging in age from 21-55 years (mean 37.7 years) revealed enlargement and/or asynergy of the right ventricle in the ventriculogram. Randomly selected biopsied patients with dilated cardiomyopathy (DCM; 18 patients) and chronic right ventricular overloading (14 patients) who did not show the above-described arrhythmias served as controls. A histopathological analysis revealed advanced myocardial interstitial fibrosis associated with an increase in fatty tissue in 8 of the 9 patients (89%). Moreover, advanced hypertrophy of myocytes (grade 2 or more of our criteria), disarrangement of muscle bundles and endocardial thickening were prominent with incidences of 75%, 75% and 78%, respectively. Incidence of all findings was more pronounced in the ARVD group. Suggestiveness of post-myocarditic change in the biopsied specimen was high in 1 patient, showing a lower incidence (12%) than the DCM group (17%). From these results, we can conclude that different etiological factors may be the bases of these pathological changes. We believe that the presence of a large amount of fatty tissue within the myocardial tissue is an important element in the etiology of ventricular arrhythmias as it has also been recognized in patients with non-ARVD idiopathic ventricular tachycardia in our biopsy series.

Adult↗
PubMed1987

Prognosis of dilated cardiomyopathy: from a retrospective to a prospective study employing multivariate analysis.

To determine the prognostic factors of dilated cardiomyopathy (DCM), a retrospective long-term investigation of 111 patients seen between 1967 and 1983 was carried out. Fifty-four deaths were divided into 3 subgroups: (1): sudden death (n = 6); (2): sudden death on the basis of heart failure (n = 17); (3): refractory heart failure death (n = 31). Multivariate analysis was employed to ascertain the prognostic score, which was constructed from the grading of the New York Heart Association functional classification, the cardiothoracic ratio, electrocardiographic findings and cardiac function. Individual variables were indicated on the first (I) and second (II) principal component axes. The mean center points for the death modes were as follows: (1): I = -0.4, II = +0.8, (2): I = +0.7, II = +1.1, (3): I = +1.4, II = -0.8. Surviving cases (n = 57) showed I = -0.6, II = +0.1. Forty-one cases examined during 1984-1985 were analyzed to evaluate the prognostic efficacy of this score. Fourteen of 17 cases (82%) located in the refractory heart failure death group died within one year after determination of the prognosis, showing thereby that the prognostic determination by multivariate analysis is effective.

Adult↗
PubMed1987

Natural history of atrial fibrillation.

The clinical significance of atrial fibrillation was analyzed in cases with chronic or acute heart disease and its significance at the acute and chronic stages of the disease was investigated in various disease groups. The types of disease, number of patients, and incidence of atrial fibrillation were: atrial septal defect (92, 14.1%), mitral valve disease (128, 79.7%), nonrheumatic valvular disease (32, 56.2%), aortic regurgitation (71, 2.8%), aortic stenosis (10, 10.0%), hypertrophic cardiomyopathy (181, 11.6%), dilated cardiomyopathy (111, 37.8%), acute myocardial infarction (823, 9.0%), healthy subjects (31,886, 0.3%). A histopathological and electron-microscopic evaluation of the atrial heart muscle revealed that the advancement of the morphological changes was closely related to the occurrence of atrial fibrillation. Decrease in size of F waves in the electrocardiogram correlated well with the extent of right and left atrial fibrosis. Also, it was noteworthy that the atrial fibrillation in cases with dissecting aneurysm (n = 60) was an expression of the myocardial damage due to the infiltration of the bleeding into the right atrium. Intra-atrial electrogram in 48 patients with various heart diseases revealed that the electric potentials obtained from various parts of the atrium varied to a great extent and finally the patient's condition transformed to that of atrial standstill. We conclude that atrial fibrillation is an expression of some important aspect of the progression of heart disease and is not directly associated with hemodynamic overloading to the atrium. A strategy for quinidine treatment was also introduced.

Age Factors↗
PubMed1986

Idiopathic sustained ventricular tachycardia responsive to verapamil: clinical electrocardiographic and electrophysiologic considerations.

Fifteen cases of idiopathic VT responsive to verapamil were studied to examine its clinical, electrocardiographic and electrophysiologic features. All patients were male, aged 15-49, average age 28. Initial onset of VT occurred at ages 9-48 (average 21). Time from onset of VT to first admission was 1-20 years (average 8.2 years), and patients had been followed for 17-40 months (average 27 months). 13 cases had palpitations, 5 had faintness, 1 had syncope, but no deaths were reported. ECG's at time of VT exhibited CRBBB + LAD pattern in 12 cases, CRBBB + RAD pattern in 1, and LBBB in 2. VT rate was 130-200 bpm (average 163 bpm), with QRS width of 0.11 - 0.16 sec (average 0.14 sec). ECG's during sinus rhythm revealed no ST/T abnormalities, although in 6 cases they were found post-VT. 5 cases had recognizable H waves during VT, and HV intervals were shorter than that during sinus rhythm. VT could be induced by programmed electrical stimulation in 14 cases. VT or RVR could be induced by atrial pacing in 6 of 14, single RV extra-stimuli in 12 of 14, paired pulses in 5 of 12, RV overdrive pacing in 7 of 14, and burst pacing in 6 of 14 cases. VT could be terminated by RV burst pacing in 14 of the 15 cases, while single RV stimuli were effective in 5 out of 12 cases. Among the 12 cases in which VT could be induced by single RV extra-stimuli, the relationship between changes in premature interval for the induction of VT and the echo interval of VT (extrastimulus to first VT complex) was examined. 8 showed an inverse relationship, 3 showed a concordant relationship and 1 case could not be assessed. An inverse relationship was found between changes in paced cycle length and echo interval for the 2 cases in which VT could be induced by rapid pacing. Verapamil terminated sustained VT in 12 out of 13 cases, and in another case had a pronounced decelerating effect. Prior to termination, VT rate was drastically reduced (from 163 +/- 29 bpm to 128 +/- 29 bpm). Verapamil was able to prevent the induction of VT in 6 out of 14 cases, while in 6 cases the VT zone was expanded and in 2 cases the VT zone was narrowed.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1986

Long-term management of bradyarrhythmias following open heart surgery: surgical A-V block and sick sinus syndrome after surgery for secundum atrial septal defects treated with permanent cardiac pacing.

Postoperative clinical findings from 25 patients with surgical A-V block and 12 with SSS following surgery for ASD who received permanent pacemakers were analyzed in order to consider the long-term management of postoperative bradyarrhythmias. Surgical A-V block: Episodes of Adams-Stokes were observed in 11/25 patients before pacemaker implantation, and in 6 of these (55%) the onset of episodes occurred more than a year after open heart surgery. Of 8 cases for which ECG's during Adams-Stokes were available, 2 had bifascicular or trifascicular block which progressed to complete A-V block below the His bundle. The 6 others (75%) had ventricular tachycardia or ventricular flutter-fibrillation during Adams-Stokes. 2 of these had blocks above the His bundle. 4/25 had improvement of complete A-V block within a month. Following pacemaker implantation, 3 died of heart failure and 3 of sudden death. 5 year survival was 70%. Therefore, surgical A-V block requires careful long-term management, and the presence of ventricular tachyarrhythmias as well as the location of block are important predictors of patient risk. SSS after surgery for ASD: 10/12 patients had Adams-Stokes, of which 6 (60%) had initial onset over 5 years after surgery, and 9 had paroxysmal atrial flutter and fibrillation which coincided with the onset of Adams-Stokes. 3 of 7 patients (42%) for whom preoperative ECG's were available had sinus bradycardia. Thus, SSS after ASD surgery may be preceded by preoperative deterioration of sinus node function and succeeded by late onset of Adams-Stokes, necessitating pre- and postoperative assessment of sinus node function. The presence of atrial tachyarrhythmias also serves as an important indicator of the severity of SSS after ASD surgery. The onset of Adams-Stokes varied by patient over a wide range of time, emphasizing the need for careful long-term follow-up. Clinical symptoms and prognosis were affected by tachyarrhythmias as well as the severity of the bradycardia. Therefore, the presence of ventricular/atrial tachyarrhythmias is an important factor in the long-term management of postoperative bradyarrhythmias.

Adams-Stokes Syndrome↗
PubMed1985

A case with bronchogenic cyst diagnosed by reconstruction CT prior to surgery which showed cardiac abnormalities.

A case report of a patient with bronchogenic cyst who presented with cardiogenic symptoms was described. The precise diagnosis was finally made after completing various diagnostic procedures which included reconstruction computed tomography. The patient, a 30-year-old man, was admitted to our hospital because of palpitation, chest pain and fever of three weeks duration. An electrocardiogram (ECG) revealed evidence suggestive of left atrial overloading and frequent atrial premature beats. A chest roentgenogram showed an abnormal shadow behind the right upper portion of the heart and a cross-sectional echocardiogram revealed abnormal echoes with ill-defined margins in the left atrium. Computed tomography (CT) revealed the presence of the left atrial tumor but left atriography suggested that it was extracardiac and compressing the left atrium. Reconstruction CT was therefore performed and the cyst was diagnosed as being in a subcarinal position. A mobile calcified mass was also demonstrated by the CT. An operation was performed and a cyst, 6 X 3 cm, was removed almost completely and a histopathological diagnosis of bronchogenic cyst was made. In this particular case, ECG abnormalities which suggest atrial damage and the diagnostic usefulness of reconstruction CT are stressed.

Adult↗
PubMed1985

The usefulness of electrophysiological-pharmacologic studies in the long-term therapy of paroxysmal tachycardias.

In 96 cases of paroxysmal tachycardia, results of chronic pharmacological assessment (CPA) were compared with acute electrophysiological-pharmacologic assessments (EPA) to evaluate the usefulness of EPA. I. Patients with sustained VT (31 cases): Sustained VT and repetitive ventricular response (RVR) could be induced in 61% and 23% respectively. More than one effective drug was found by EPA for 23 of 24 subjects. Of the 22 followed by CPA, the effectiveness of medication was excellent for 14 (64%), moderate for 1, slight for 4, and ineffective for 3 (14%). II. Patients with non-sustained VT (23 cases): RVR could be induced in 52%. Effective medication was identified by EPA for 8 of 10 patients. Of the 7 followed by CPA, the effectiveness of medication was excellent for 2(28.5%) moderate for 2, and ineffective for 3. III. Patients with PSVT (42 cases): PSVT could be induced in 90% of cases. Effective medication was found for all 31 cases which underwent EPA. Of the 23 cases followed by CPA, the chronic efficacy of drugs was excellent for 7 (30%), moderate for 5 (22%), slight for 7 (30%), and noneffective for 4 (18%). Therefore, we conclude that the usefulness of EPA differs according to the type of tachycardia. EPA is most useful in predicting chronic results for patients with sustained VT, especially when the sustained VT is readily reproducible by electrical stimulation. It is less useful for nonsustained VT and PSVT. With nonsustained VT, EPA is limited by difficulty in repeatedly inducing RVR, and by difficulty in predicting the appropriate medication for chronic oral therapy. With PSVT, even though the PSVT can be induced with greater success, EPA is limited by variations in pharmacologic effects over time, which create discrepancies between EPA and CPA.

Administration, Oral↗