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K Ebe

Publications and source records attributed to K Ebe.

32 records · Page 2Linked to original sources
PubMed1990

Ventricular tachycardia with two possible exits from one re-entrant circuit.

A case of sustained ventricular tachycardia (VT) with two possible exits from one re-entrant circuit is described in this paper. The patient was a 27-year-old female who had undergone corrective surgery for tetralogy of Fallot at the age of 8, and developed VT of distinctly different QRS configurations. The exit of one VT was at the right ventricular (RV) outflow tract and the other at the RV apex as determined by endocardial and pace-mapping. Continuous and split activities were observed at the RV outflow tract during both types of VT. One VT was entrained by rapid pacings, and the causal mechanism was thought to be re-entry and common re-entrant circuit was established for two QRS configurations of VTs. A discrepancy was observed between the site of the earliest activation and the site of the pace-mapping which resulted in QRS configuration of VT of the RV apex origin. The findings in this paper should be considered when contemplating aggressive therapy such as electrical ablation.

Adult↗
PubMed1990

[Abnormal local ventricular electrogram and its relation to induction of ventricular tachycardia in patients with hypertrophic cardiomyopathy].

To investigate the mechanism of induction of ventricular tachycardia (VT) in patients with hypertrophic cardiomyopathy (HCM), we reviewed and analyzed the local ventricular electrograms (LVE) at the pacing sites in 15 patients with HCM and 52 control subjects. Each patient had a clinical history of nonsustained VT or syncope. The results were as follows: 1. Rapid and polymorphic VT was induced in six of the 15 patients with HCM and in 10 of the 52 control subjects. 2. The duration of the LVE at the pacing site was progressively prolonged as the number of extrastimuli were increased or the premature intervals were shortened. Compared with the controls, patients with HCM had longer durations of the LVE by basic drive, single extrastimulus, and by double extrastimuli: 113 +/- 31 vs 95 +/- 16 ms (p less than 0.005), 156 +/- 35 vs 109 +/- 17 ms (p less than 0.001), and 220 +/- 88 vs 133 +/- 25 ms (p less than 0.001), respectively. 3. In the HCM group, the maximum duration of the LVE by double ventricular extrastimuli was significantly longer in patients with inducible VT compared with those with non-inducible VT: 287 +/- 95 vs 183 +/- 56 ms (p less than 0.05). 4. Induction of VT in the HCM group was accompanied by the critical prolongation of the LVE at the pacing site. In two of the six patients with HCM, the LVE at the pacing site spanned the entire cardiac cycle at the time of the initiation of VT.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomyopathy, Hypertrophic↗
PubMed1989

Vasoconstrictor effect of endothelin on the canine coronary artery: is a novel endogenous peptide involved in regulating myocardial blood flow and coronary spasm?

We examined the effect of endothelin on the canine coronary artery (N = 20). The left circumflex coronary artery was cannulated and perfused with arterial blood at constant pressure. Coronary blood flow was monitored by an electromagnetic flowmeter. Intracoronary endothelin provoked a vasoconstriction that was dose-dependent. At a dose of 500 pmol, coronary blood flow was reduced remarkably (91.0 +/- 5.4%, n = 4), and endothelin subsequently produced a fall in systemic blood pressure and ST elevation in the electrocardiogram. At a dose of 100 pmol (n = 9), coronary flow decreased from 16.4 +/- 1.5 ml/min to 12.5 +/- 1.5 ml/min (p less than 0.001) and coronary vascular resistance increased from 6.3 +/- 0.8 mm Hg/ml/min to 9.9 +/- 1.9 mm Hg/ml/min (p less than 0.005). A cumulative dose-response curve to endothelin was obtained and the curves were shifted to the right after both verapamil and nifedipine administration. Therefore endothelin has a potent vasoconstrictor action that is attenuated by the calcium-channel blocker.

Animals↗
PubMed1989

Electrophysiologic evaluation of asymptomatic patients with the Wolff-Parkinson-White pattern.

In the past 4 years, 34 asymptomatic patients with the Wolff-Parkinson-White (WPW) pattern underwent electrophysiologic study. The effective refractory period (ERP) of antegrade conduction over the accessory pathway was 288 +/- 29 msec. In three asymptomatic patients (9%), the antegrade ERP of the accessory pathway was shorter than 250 msec. The antegrade ERP of the accessory pathway became shorter than 250 msec in an additional 12 of 22 (55%) patients after isoproterenol administration. Nineteen (56%) of the asymptomatic patients showed the absence of retrograde conduction over the accessory pathway even after isoproterenol administration. The rate of induction of orthodromic reciprocating tachycardia in the asymptomatic WPW patients was 15% (5/34), which was significantly lower than that in the symptomatic patients. These data suggest that in the asymptomatic patients, the absence of retrograde conduction over the accessory pathway is the reason they remained asymptomatic, free of reciprocating tachycardia. However, even in the asymptomatic patients, some had the accessory pathway in which antegrade ERP was shorter than 250 msec. They may result in rapid ventricular conduction over the accessory pathway when atrial fibrillation develops.

Adult↗
PubMed1989

Sustained ventricular tachycardia responsive to verapamil in patients with hypertrophic cardiomyopathy. Clinical and electrophysiological assessment of drug efficacy.

Recently, we examined 2 cases of hypertrophic cardiomyopathy (HCM) presenting with sustained ventricular tachycardia (VT). One case was a 62 year old male with midventricular hypertrophy and monomorphic sustained VT. After admission, the efficacies of procainamide, disopyramide, aprindin, flecainide, mexiletine and verapamil were evaluated by means of continuous electrocardiographic monitoring. Verapamil prevented the recurrence of sustained VT and markedly reduced the frequency and number of runs of nonsustained VT. In the electrophysiologic study, rapid VT was induced by double extrastimuli at the right ventricular apex. Intravenous verapamil at a dose of 10 mg prevented the induction of VT. The patient was discharged on verapamil and remains asymptomatic after 3 months of follow up. The other case was a 34 year old female who was a survivor of cardiac arrest. Monomorphic VT was observed on emergency admission and was converted to sinus rhythm by direct current cardioversion after resuscitation. In the electrophysiologic study, rapid VT was induced by double extrastimuli at the right ventricular outflow tract. Verapamil at a dose of 10 mg prevented the induction of VT. These 2 cases of HCM are rare in that they presented with sustained VT. It is also of interest that verapamil, which has been used conventionally in HCM, prevented VT.

Adult↗
PubMed1989

[Association of sustained ventricular tachycardia and a mid-systolic click: a case report].

A 27-year-old woman had a history of palpitation at the age of nine. Ventricular tachycardia (VT) was detected four years ago and treatment with procainamide was started. Physical examination disclosed nothing abnormal other than an apical mid-systolic click. Electrocardiogram and chest radiograph were normal, and echocardiogram disclosed borderline mitral valve prolapse (MVP). VT was not provoked by exercise, and Holter monitorings of electrocardiogram were always within a normal limit. Angiography was normal. Electrophysiological study disclosed VT by left ventricular stimulation and the earliest activation was at the apex, VT was abolished by early stimulation from the right ventricular apex. The association of a mid-systolic click and VT was interesting in this case. When the patient had a systolic click at the outpatient clinic, VT frequently occurred within a month (six of seven times), while VT did not occur without an audible systolic click (three of four times). Although it is uncertain whether VT of this patient has any relationship to MVP or to the click, these problems remain to be solved in the future.

Adult↗
PubMed1988

[Evaluation of therapeutic interventions of sustained monomorphic ventricular tachycardia guided by an electrophysiologic study: a case report].

Therapeutic evaluation of sustained monomorphic ventricular tachycardia (VT) using electrophysiologic study (EPS) is presented in a case of refractory VT. A 54-year-old man with a history of recurring syncope underwent coronary angiography which revealed total occlusion of the posterior descending branch of the right coronary artery. Left ventriculography showed a left ventricular aneurysm at the cardiac apex. Ejection fraction of the left ventricle was 36%. He had four VTs of different QRS morphologies in 12 lead electrocardiograms. According to our programmed ventricular stimulations, single or double, and rarely triple, extra stimuli were administered after eight basic stimuli at two basic cycle lengths. Rapid ventricular pacing, up to 210 bpm, was then added. The stimuli were delivered to two different sites in the right ventricle and to at least one site in the left ventricle. When the entire protocol could not induce VT, isoproterenol was given intravenously, and the same protocol was repeated. No drug could prevent VT attacks, even after the surgical resection of two VT foci, VT was still inducible. Postoperative drug therapy could not prevent VT induction in EPS. However, changes in the mode required for VT induction were observed. Among 47 patients with sustained monomorphic VT treated in our hospital, 24 had EPS to evaluate the efficacies of therapeutic interventions, such as drugs and surgery. In 14 patients, no VT was induced by the entire VT induction protocol. Among the remaining 10 patients, four showed changes in the VT induction mode, but VT recurred in their clinical courses even after their treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Pacing, Artificial↗
PubMed1987

Enzymatic synthesis of oligoribonucleotides of defined sequence.

A plasmid DNA vector is described that is suitable for cloning synthetic DNA sequences. These cloned synthetic DNA sequences can be transcribed in vitro to produce oligoribonucleotides of defined sequence. Transcription is directed by a promoter based on the consensus sequence for Escherichia coli promoters and uses E. coli RNA polymerase. The vector is useful for cloning oligodeoxyribonucleotides of mixed sequences, the individual sequences being resolved by transformation and colony selection. Oligoribonucleotide synthesis from the vector is highly specific. Application of these sequences in hybridization experiments is demonstrated.

Cloning, Molecular↗
PubMed1987

Early experiences of endocardial catheter mapping of the left ventricle in patients with sustained ventricular tachycardia--efficacy, safety and complications.

In 23 patients with recurrent sustained ventricular tachycardia (VT) which originated from the left ventricle, endocardial catheter mapping has performed. In an additional 14 patients we also stimulated their left ventricle for non-sustained VT. Multiple sites could be mapped for the recording of local electrical activity, for pacing and for the induction of VT. These procedures could be done without complication. A careful, reasonable, and safe method of endocardial mapping will facilitate clinical electrophysiologic study.

Adult↗
PubMed1983

[Case of immunoblastic sarcoma (IBS)].

A patient with immunoblastic lymphadenopaty which evolved into immunoblastic sarcoma is reported. A 48-year-old female was admitted to our department because of cough and fever. A diagnosis of immunoblastic lymphadenopathy had been made two years before the present admission. Physical examination revealed generalized lymphadenopathy. Chest radiograms showed a left hilar mass. The pulmonary tumor and enlarged lymphnodes were treated by irradiation. Although there was marked improvement at first, she experienced several relapses. One year after the admission, chest radiograms showed multiple pulmonary lesions. She developed pancytopenia and bone metastases. At autopsy, the lymphnodes showed histological evidence of immunoblastic sarcoma; a pulmonary lesion showed immunoblastic lymphadenopathy.

Anemia, Hemolytic, Autoimmune↗
PubMedDate not supplied

Prototype system for an MR simulation of intracavitary brachytherapy for cervical cancer: preliminary results in six cases.

We report a newly developed MR simulation system for intracavitary brachytherapy for cervical cancer and subsequent treatment results. MR simulation was performed on six patients. The spatial relationship of the tumor to the bladder, rectum, bowel, applicators, etc. was depicted well. Doses to the tumor and surrounding normal tissues were read from isodose curves superimposed on the T2-weighted sagittal image. This system promises to be useful in customizing the dose distribution.

Aged↗