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Biomedical subjects

M Sumiyoshi

Publications and source records attributed to M Sumiyoshi.

At least 55 records · Page 3Linked to original sources

Intra-His bundle block corresponds with interruption of the branching portion of the His bundle.

We compared His-bundle electrograms with pathological findings of the atrioventricular conduction system in four patients with complete atrioventricular intra-His block with narrow QRS complexes on ECG. Split His electrograms were recorded at the time of electrophysiological study. The patients died from noncardiac causes at 10 days, 1 year, 4 years, and 9 years, respectively, after the pacemaker implantation. Serial sections through the atrioventricular conduction system revealed strictly localized more than 50% reduction of conducting cells replaced by fibrosis at the branching portion of His bundle. The proximal portions of the bundle branches also exhibited decrease of the conducting cells showing a rough positive relation with the patient's age. Therefore, we considered that the H1 spikes seen on His-bundle electrograms originated from the penetrating portion of His, which was virtually intact in our cases, and that the H2 spikes originated from the right side of the distal branching portion of His.

Aged↗

Mesothelioma in the atrioventricular node. Case report.

A patient with complete atrioventricular block and an implanted permanent pacemaker died of colon cancer at the age of 64 years. At autopsy, a cardiac tumor in the region of the atrioventricular node (mesothelioma of the atrioventricular node) was found. The origin of this type of tumor is controversial. Histochemical findings suggested that the tumor in this case was of endodermal origin.

Atrioventricular Node↗

A case of arrhythmogenic right ventricular dysplasia with atrial flutter.

A 57-year-old male who had arrhythmogenic right ventricular dysplasia (ARVD) with recurrent atrial flutter (AF) is reported. The patient had more frequent episodes of AF than of ventricular arrhythmias. Magnetic resonance imaging, echocardiography and right ventriculography revealed dilatation of the right ventricle and endomyocardial biopsy specimens from the right ventricle showed findings which were compatible with ARVD. The left ventricular specimen, however, also revealed a loss of myocytes and interstitial fibroelastic changes. The present case demonstrates an overlap of post-inflammatory or primary endomyocardial fibroelastic changes with ARVD.

Aged↗

A case of idiopathic ventricular fibrillation with incomplete right bundle branch block and persistent ST segment elevation.

We report the case of a 42-year-old male who suffered from ventricular fibrillation (VF) without obvious QT prolongation. His electrocardiogram showed incomplete right bundle branch block (IRBBB) and persistent ST segment elevation in the right precordial leads during sinus rhythm. Cardiac catheterization revealed no overt heart disease except moderate endocardial and subendocardial fibrosis in the left ventricle. Mental stress seemed to trigger VF, and ST elevation became prominent just before VF. Propranolol and mexiletine have been effective in preventing VF for over 3 years.

Adult↗

VDD pacing with a previously implanted single lead system.

Three patients who had undergone implantation of a rate modulated, atrial sensitive RS4 pacemaker, with a single orthogonal lead underwent replacement of a depleted unit with a DDD pulse generator, reusing the original lead with an adapter that allowed conversion of the bipolar atrial electrode into unipolar configuration. The mean atrial electrogram amplitude was 1.8 mV and no significant atrial sensing defects were found during Holter monitoring. As the RS4 pulse generator is no longer available, continued VDD pacing is possible by replacing it with a DDD pulse generator using the previously implanted single lead system.

Aged↗

Clinical significance of QRS duration during ventricular pacing.

To clarify the clinical significance of an abnormally prolonged paced QRS duration, we studied 114 patients who had undergone pacing for atrioventricular block (AVB). Patients were divided into two groups: group I consisted of 29 patients with at least one paced QRS duration greater than or equal to 180 msec during the follow-up period; group II consisted of 85 patients with paced QRS durations less than 180 msec. The clinical background, QRS complexes before pacing, and the echocardiographic findings were assessed. Males (P less than 0.05), those with H-V block (P less than 0.05) and a wider QRS complex of conducted and escape beats (both P less than 0.01) were dominant in group I. The incidence of underlying heart disease was greater in group I than in group II (83% vs 32%, P less than 0.01). Reduced left ventricular ejection fraction (LVEF) and increased left ventricular end-diastolic dimension (LVDd) were more prominent in group I than in group II (LVEF 0.49 +/- 0.17 vs 0.68 +/- 0.10, P less than 0.01, LVDd 57.1 +/- 7.9 mm vs 48.5 +/- 5.6 mm, P less than 0.01). The paced QRS duration correlated with LVEF (r = -0.61) and LVDd (r = 0.81). A paced QRS duration greater than or equal to 180 msec was sensitive and specific for a LVEF less than 0.5 (83.3% and 85.2%) and LVDd greater than or equal to 60 mm (100% and 81.4%). We conclude that patients with a prolonged paced QRS duration have more serious heart disease, and the paced QRS duration can be a useful indicator of impaired LV function.

Cardiac Pacing, Artificial↗

Long-term follow-up study of three patients with the long QT syndrome.

We studied three women with the long QT syndrome. They were aged 42, 52 and 25 years and had experienced recurrent syncopal attacks. We followed case 1 for 17, case 2 for 18, and case 3 for over 6 y. The attacks tended to occur during the premenstrual stage in case 1 and case 2; case 3 often experienced attacks after exercise. The QT(U)c intervals on admission were 0.68, 0.62, and 0.50 in case 1, 2, and 3, respectively. Torsade de pointes followed by ventricular fibrillation was documented in case 1 and case 2. Although each was treated with a beta-blocker, none was fully compliant with the regimen. In case 1, estrogen therapy administered to maintain the hormonal balance premenstrually effectively prevented attacks. Despite the inconsistent use of beta-blockers, the attacks in case 1 and case 2 tended to decrease with age. Case 2 experienced no attacks after menopause. Cause 3 took medication consistently and remained free of attacks for over 6 y. Although she discontinued beta-blocker therapy because of pregnancy, she has experienced no attacks to date. These case studies suggest that hormonal status may be important in the development of syncopal attacks in female patients with the long QT syndrome.

Adult↗

Detection of human papillomavirus DNA in the normal cervices of Japanese women by the dot-blot (Vira Pap) method.

Exfoliated cervical cells obtained from 9 patients with cervical intraepithelial neoplasia (CIN) I and II, 11 with CIN III, 22 with cervical carcinoma, and 599 with cytologically normal cervices (including 63 pregnant women) were evaluated for the presence of human papillomavirus (HPV) by the dot-blot (Vira Pap) method. HPV infection was detected in 33.3% of the CIN I and II cases, in 54.5% of the CIN III cases, in 68.2% of invasive cervical carcinoma cases, and in 4.2% of the normal group. The rate of detectable HPV infection increased in exfoliated cervical cells during pregnancy. These results suggested that a few Japanese women with cytologically normal cervices were infected with HPV.

Adolescent↗

Acute and chronic stability of atrial screw-in leads.

The purpose of this study was to evaluate the acute and chronic stability of the atrial screw-in lead. In this study, we used CPI model 4165, 4166, and 4266 porous tip screw-in leads in 32 patients (12 for AAI pacing and 20 for DDD pacing). All of these leads were fixed to the free wall of the right atrium and used as the unipolar type. Acute voltage and current thresholds, lead impedance, P-wave amplitude, and chronic threshold were measured. Early and late complications were also investigated. The average acute stimulation thresholds at 0.6 msec pulse width were 0.82 +/- 0.43 V and 1.1 +/- 0.6 mA. Mean lead impedance was 627.2 +/- 83.1 ohms, and mean P wave amplitude was 3.1 +/- 1.1 mV. After an average follow-up period of 32 months (range: 2-72 months), we found the results of the chronic threshold study to be satisfactory. The thresholds were usually below 0.1 msec pulse width with the nominally programmed pacemaker output. Only one patient required a higher output due to an increased threshold. With regard to complications, neither lead dislodgment nor cardiac perforation was observed. In conclusion, acute and chronic thresholds were satisfactory and no serious complications occurred. Therefore the atrial screw-in lead has long-term reliability and stability.

Adult↗

[A case of facioscapulohumeral muscular dystrophy complicated with complete A-V block].

Myocardial involvement and serious electrocardiographic abnormalities are rare in patients with facioscapulohumeral (FSH) muscular dystrophy. We reported a case of FSH muscular dystrophy complicated with complete A-V block. The case was that of a 48 year-old male with the complaints of exertional dyspnea. His chest X-ray showed cardiomegaly, and the electrocardiogram recorded on admission showed complete A-V block. On the His bundle electrogram, complete A-H block and prolongation of H-V intervals were noted. Therefore, a permanent pacemaker was implanted, and he has been doing well for over 10 years after implantation. Although it is well known that serious electrocardiographic abnormalities are not infrequently associated with Duchenne's progressive muscular dystrophy (DMD), there are few reports about pacing therapy for patients with muscular dystrophy. Because the daily activity of patients with rapidly progressive type of muscular dystrophy such as DMD is at a very low level, they do not require pacing therapy. Whereas in patients with the FSH type of muscular dystrophy, which is a slowly progressive type, their daily activity is maintained at a high level. Therefore, pacing therapy should be recommended if the FSH type of muscular dystrophy is accompanied with serious bradyarrhythmias.

Facial Muscles↗