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Biomedical subjects

M Hayano

Publications and source records attributed to M Hayano.

At least 55 records · Page 3Linked to original sources
PubMed1993

A case of tachycardia-induced cardiomyopathy due to chronic ectopic atrial tachycardia.

Only a few reports exist that chronic supraventricular tachycardia causes ventricular dilation and poor left ventricular contraction--so-called "tachycardia-induced cardiomyopathy." Clinical and electrophysiologic features of chronic supraventricular tachycardia including chronic persistent ectopic atrial tachycardia (EAT) in adults have also been described by a few investigators. We report a rare case of long follow-up of chronic EAT-induced severe cardiomyopathy and mitral regurgitation that was well controlled after medical treatment.

Cardiac Catheterization↗
PubMed1993

Sinus and atrioventricular nodal re-entrant tachycardia.

A case of a 42-year-old woman who had combined sinus and atrioventricular nodal tachycardia is reported. Programmed atrial stimulation study showed the induction of the two types of paroxysmal supraventricular tachycardia. The mechanisms of these supraventricular tachycardias were both sinus nodal and atrioventricular re-entrant tachycardia. Sinus nodal re-entrant tachycardia could be induced only after injection of atropine. The tachycardias could no longer be induced after the administration of verapamil.

Adult↗
PubMed1993

[A case of distal aneurysms of bilateral posterior inferior cerebellar arteries].

A case of aneurysms of bilateral distal posterior inferior cerebellar arteries (PICAs) is reported. A 61-year-old man experienced a sudden onset of headache and nausea and was admitted to a hospital immediately. His neurological examination showed no abnormalities, but headache and nausea continued in spite of conservative treatment. The patient was referred to our hospital two days after the onset and the neurological examination revealed slight dysmetria of the right upper extremity. A computed tomography (CT) scan demonstrated a round and heterogeneous high density mass at the cerebellar vermis and some blood coagula at the fourth ventricle and vermis. Angiography showed two aneurysms of the bilateral distal PICAs: The right aneurysm was at the cortical segment and the left one was at the telovelotonsillar segment. The patient underwent a suboccipital craniectomy and both aneurysms were clipped successfully. Sleepiness and headache continued postoperatively due to hydrocephalus. After ventricular drainage he soon recovered without having V-P shunt and was discharged with no neurological deficits. Aneurysms of bilateral distal PICAs are very rare and only three cases have been reported in the literature. The etiology, clinical symptom, CT finding and prognosis in the literature reviewed were briefly discussed.

Cerebellar Diseases↗
PubMed1991

[Clinical studies of 16 cases of carcinomatous pericarditis].

We studied the effects of local therapy on cardiac tamponade caused by carcinomatous pericarditis in 16 cases. Five out of 16 cases (drainage group) received treatment by only drainage of pericardial effusion, and the remaining 11 cases (infusion group) had local infusion of antineoplastic agents into the pericardium after drainage. The median survival time was 16 weeks in the infusion group and 19 weeks in the drainage group. There was no statistically significant difference. Reaccumulation of pericardial effusion was recognized in 3 patients in the drainage group (60%), and in 3 patients in the infusion group (18%). Our conclusion was that local infusion had no effect on prolongation of the survival time, but had a suppressive effect on reaccumulation of pericardial effusion.

Antineoplastic Agents↗
PubMed1990

[Olfactory neuroblastoma complicated by postirradiation pneumocephalus. Case report].

A 56-year-old male was admitted with the complaints of nasal bleeding, gait disturbance, and disturbance of consciousness. Neurological examination revealed drowsiness, right hemiparesis, and choked discs. Computed tomography scan showed an enhanced mass at the frontal base, which extended to the left nasal and paranasal cavities. Angiography showed a tumor stain with a mass sign. The intracranial part of the tumor was removed completely and he was discharged ambulatorily. Two months after surgery, however, he was admitted again for the regrowth of the tumor. Ventriculoperitoneal shunting was placed and radiation therapy was given to the brain and nasal cavity. After 3000 rad irradiation the clinical condition suddenly became worse because of pneumocephalus. The cranial tumor disappeared after irradiation but he died of metastases and general prostration. Clinically this case was diagnosed as an olfactory groove meningioma at first, but immunohistochemical diagnosis was olfactory neuroblastoma.

Brain Neoplasms↗
PubMed1989

[A case of sick sinus syndrome, considered to develop to atrial standstill].

A 25 year old man was admitted to our hospital because of dizziness and bradycardia. Physical examination was normal except for an irregular pulse of 90 beats/min. Chest X-ray film showed no cardiomegaly and no pulmonary congestive changes. ECG showed 2:1 or 3:1 atrial flutter on admission. After atrial flutter was terminated spontaneously, ECG revealed absent P waves, a QRS interval of 0.10 seconds, and A-V junctional rhythm with irregular R-R interval ranging from 1.20 to 2.12 seconds. At times, cardiac arrest was noted. Esophageal electrocardiogram also failed to demonstrate atrial activity while A-V junctional rhythm continued. Mitral valve echocardiogram lacked A point, and then ä waves were absent in both the right atrial and pulmonary capillary pressure recordings. Transient atrial standstill was suspected from these findings, so that electrophysiological study was performed. Right atrial electrogram revealed complete absence of atrial activity. His bundle electrogram revealed H-V prolongation [80-83 msec]. Right atrial pacing was attempted at several atrial sites, including the high lateral, middle lateral, low lateral right atrium, and low right atrial septum. Atrial activity could be elicited with stimulus strength of 3 to 5 volts. These atrial pacing thresholds were mild or moderately higher than usual. After the cessation of atrial pacing at 90 beats for two minutes, the recovery time of the first beat prolonged to 8.46 second. We considered that this case was sick sinus syndrome in young adult which revealed generalized disturbance of conduction system including the atrial muscle, and would develop to atrial standstill in the near future.

Adult↗
PubMed1988

Phasic coronary artery flow velocity determined by Doppler flowmeter catheter in aortic stenosis and aortic regurgitation.

Phasic coronary artery flow velocity was recorded in 14 patients with aortic regurgitation (AR), 4 with aortic stenosis, 61 with other heart diseases and in 2 normal subjects by means of a bidirectional Doppler flowmeter catheter. The normal pattern of the phasic coronary artery flow velocity was characterized by a small forward flow during systole (S wave) and a large forward flow during diastole (D wave). The phasic coronary artery flow velocity in patients with AR showed increased S wave and decreased D wave. The area under the S-wave curve divided by the area under the D-wave curve (S/D ratio) in patients with AR increased (left coronary artery flow velocity 0.66 +/- 0.39, p less than 0.05; right coronary flow velocity 0.79 +/- 0.36, p less than 0.01) as compared with the S/D ratio in patients with other heart diseases (left coronary flow velocity 0.32 +/- 0.12; right coronary artery flow velocity 0.38 +/- 0.17). There was a tendency toward a relative positive correlation between S/D ratio values and AR cineangiographic grades. Decreased S/D ratios were observed in 4 patients with aortic stenosis. It is believed that no reports exist on phasic coronary flow velocity recorded in conscious patients who had aortic valve disease.

Adult↗
PubMed1988

Supraventricular tachycardia in a patient with Lown-Ganong-Levine syndrome associated with apical hypertrophic cardiomyopathy.

Electrophysiologic study of a 55-year-old patient with Lown-Ganong-Levine syndrome associated with apical hypertrophic cardiomyopathy is reported. The patient had a history of recurrent attacks of tachyarrhythmia and his electrocardiogram showed a short P-R interval (0.10 sec) with narrow QRS complex and left ventricular hypertrophy with giant negative T waves. His cineangiogram showed severe apical hypertrophy. An electrophysiologic study was performed. The results of programmed atrial pacing show the existence of the dual A-V nodal pathways. The A-H interval at rapid atrial pacing increased maximally by 103 msec. Atrial stimulation could depolarize parts of the atrium without altering the supraventricular tachycardia. These findings suggested that preferential rapidly conducting A-V nodal and intranodal reentry are the responsible mechanisms in this reciprocating tachycardia. We conclude that the short P-R interval was due to intranodal reentry through the dual A-V nodal pathways. To our knowledge, a case of Lown-Ganong-Levine syndrome with apical hypertrophic cardiomyopathy has not been previously described in the literature.

Cardiac Catheterization↗
PubMed1986

Basilar artery occlusion after superficial temporal artery-superior cerebellar artery anastomosis.

Superficial temporal artery-superior cerebellar artery anastomosis for basilar artery stenosis was performed in a patient who had experienced recurrent nonhemispheric symptoms, and whose angiogram revealed a midbasilar stenosis. Four months after the operation he was readmitted to our hospital complaining of transient motor weakness and numbness of the left extremities. No neurological deficit was found on admission, but 1 hour later the left-sided hemiparesis occurred again and progressed. On the angiograms the upper basilar system was visualized via the superficial temporal artery, and the midbasilar artery was occluded. This conversion seemed to be a natural course rather than the influence of the hemodynamic change after the operation.

Arterial Occlusive Diseases↗
PubMed1986

Sinus node function after selective elimination of sympathetic influences on the sinus node area of the dog.

Six-hydroxydopamine (6OHDA) was injected directly into the subepicardium of the sinus node area in an attempt to damage sympathetic nerve terminals in the sinus node. The changes in sinus node function were observed for 4 weeks. The predominant rhythm was of sinus origin throughout the observation period. The sinus rate progressively decreased from 145.1 +/- 14.2 to 76.2 +/- 12.1 beats/min during the first week after injection of 6OHDA. The sinus rate remained at this level for 2 weeks, followed by a gradual increase to 89.3 +/- 18.2 beats/min 4 weeks after injection of 6OHDA. These sinus rates were only significantly different from control dogs through the 14th postoperative day. The sinus rate was considerably increased by intravenous atropine injections 5 to 7 days after the injection of 6OHDA into the sinus node area. The sinus node recovery time was much longer in dogs with an injection of 6OHDA than that in the control dogs throughout the observed period. These results suggest that elimination of the sympathetic influences on the sinus node can be achieved by direct injection of 6OHDA into the sinus node area in the dog, and that sinus node function can be depressed by decreasing sympathetic tone alone, in the absence of an intrinsic dysfunction of the sinus node.

Animals↗
PubMed1985

Aneurysms associated with fenestrated anterior cerebral arteries. Report of four cases and review of the literature.

Four cases of aneurysms associated with a fenestrated anterior cerebral artery are presented. The combination of aneurysms and fenestration of the anterior cerebral artery is rare, and nine cases including ours have been reported. In all cases fenestrations were found within the distal two-thirds of the horizontal portion of the anterior cerebral artery. It may be presumed that fenestration of the anterior cerebral artery is the remnant of the plexiform anastomosis in the fetal stage, especially between the anterior cerebral artery and the primitive olfactory artery.

Aged↗
PubMed1982

Superior and inferior vena cava flow velocity in patients with anomalous pulmonary vein connection.

The superior and inferior vena cava flow velocities (SVC and IVC flow velocities) of 3 patients with anomalous pulmonary vein connection were recorded with the Doppler flowmeter catheter. The cases consisted of a patient with partial anomalous pulmonary vein connection to the SVC (Case 1), one with total anomalous pulmonary venous connection to the SVC (Case 2), and one with partial anomalous pulmonary vein connection to the IVC (Case 3). The SVC and IVC recordings of these patients were compared with those of 10 normal subjects, 20 patients with atrial septal defect and 150 patients with other heart diseases. The SVC and IVC flow velocities in the latter group of 180 patients showed a biphasic pattern, having systolic (S) and diastolic (D) waves, the peak S wave occurring around midsystole. In Cases 1 and 2, the SVC flow velocity showed a markedly delayed peak S wave, similar to the pattern of the pulmonary vein flow velocity; this pattern was also seen in the IVC flow velocity in Case 3. This abnormal pattern could be useful in diagnosing anomalous pulmonary vein connection.

Adolescent↗
PubMed1981

Meningioma in the tela choroidea of the third ventricle: CT and angiographic correlations.

A meningioma of the tela choroidea of the third ventricle is rare. CT and detailed analysis of angiographic findings in such a case are presented. Ct facilitated the detection of rough location of the tumor and the prediction of its histological features. Carotid and vertebral angiographies were utilized in detailing the three-dimensional, gross anatomical relationship between tumor and the surrounding brain structures. Vertebral angiography also contributed to predicting the histology of the tumor.

Adult↗