PubMed Health⌕ Search

Biomedical subjects

K Hiejima

Publications and source records attributed to K Hiejima.

At least 19 recordsLinked to original sources
PubMed1992

Atrioventricular nodal reentrant tachycardia with retrograde block induced by aprindine.

Two patients are described who had atrioventricular nodal reentrant tachycardia (AVNRT) with 1:1 relationship in the control state, but in whom a varying degree of VA block during AVNRT was observed during therapy with aprindine. Aprindine, however, did not cause anterograde blockade of conduction over the slow AV nodal pathway during tachycardia. These observations support the conclusion that the bulk of atrial muscle is not a requisite part of the tachycardia circuit in AVNRT and that antiarrhythmic drugs may have disparate effects on conduction in the retrograde and anterograde limbs of the circuit.

Adult↗
PubMed1992

Retrograde supernormal conduction, gap phenomenon in concealed accessory atrioventricular pathways.

We present four patients with the Wolff-Parkinson-White syndrome who exhibited retrograde supernormal conduction or gap phenomenon in concealed accessory pathways. In the first patient, ventricular extrastimulus testing revealed retrograde block at the coupling interval of 520 msec and reappearance of conduction at the coupling interval of 370 msec. In a second patient, 1:1 retrograde conduction was not present but supernormal conduction was demonstrated at coupling intervals of 360 msec to 310 msec during the ventricular extrastimulus testing when the basic drive consisted of atrioventricular (AV) simultaneous pacing. In a third patient, ventricular extrastimulus testing demonstrated retrograde conduction through the accessory pathway only at coupling intervals of 400 msec to 360 msec. In a fourth patient, retrograde block occurred at the coupling interval of 340 msec and retrograde "slow" conduction reappeared at coupling intervals of 300 msec to 250 msec (gap phenomenon) only when the basic drive consisted of AV simultaneous pacing. Thus, concealed accessory pathways may exhibit retrograde supernormal conduction or gap phenomenon. Ventricular extrastimulus testing consisting of AV simultaneous pacing during the basic drive may facilitate demonstration of these unusual properties.

Adult↗
PubMed1992

[Progress in clinical electrophysiologic study (EPS): recent tendency].

About twenty years have passed since the clinical introduction of electrophysiologic study (EPS). The mechanism of arrhythmias can be understood by EPS, and EPS-guided therapy is available theoretically. Of course, not all arrhythmia needs EPS, because other non-invasive tests are available. Clinically, reentry is the most frequently observed mechanism. Therefore, EPS is most suitable for the reentrant arrhythmias which can be repeatedly initiated and terminated by programmed stimulation. In many tachyarrhythmias, slow conduction pathway or area essential for reentry are demonstrated. On the other hand, triggered activity and abnormal automatism have been less frequently observed clinically. Today, application of EPS has been extended to catheter ablation for which precise mapping is required.

Arrhythmias, Cardiac↗
PubMed1991

Combination therapy with aprindine and verapamil for paroxysmal supraventricular tachycardia as assessed by transesophageal atrial pacing.

UNLABELLED: To assess the efficacy of combination therapy of aprindine (40 mg/day) and verapamil (160 mg/day), transesophageal programmed atrial stimulation was performed on 21 patients with paroxysmal supraventricular tachycardia (including 12 patients with atrioventricular nodal reentrant tachycardia and nine patients with atrioventricular reentrant tachycardia) under four conditions: a) control, b) aprindine alone, c) verapamil alone, and d) aprindine + verapamil. RESULTS: a) Aprindine, verapamil, and aprindine + verapamil prevented paroxysmal supraventricular tachycardia induction in 2/21, 3/21, and 9/21 patients, respectively; b) aprindine + verapamil prolonged the cycle length of paroxysmal supraventricular tachycardia more than aprindine or verapamil alone; c) aprindine, verapamil, and aprindine + verapamil decreased the AV blocking rate by 15, 23, and 35 beats/min, respectively, in comparison with the control state; d) aprindine, verapamil, and aprindine + verapamil prolonged the effective refractory period of atrioventricular conduction system by 20, 34, and 76 msec, respectively, compared with the control state. In conclusion, aprindine + verapamil appear to be more effective than aprindine or verapamil alone in preventing paroxysmal supraventricular tachycardia with nodal reentry, but there was less benefit in those without nodal reentry (Wolff-Parkinson-White group).

Administration, Oral↗
PubMed1991

Demonstration of right and left atrial dissociation by atrial rapid pacing or extrastimulation during fast-slow (uncommon) form of atrioventricular nodal reentrant tachycardia.

Some recent works suggest that extranodal atrial fibers may form part of the reentry circuit in the atrioventricular (AV) nodal reentrant tachycardia (AVNRT). This hypothesis is based on the fact that the perinodal dissection successfully abolished AVNRT while preserving intact AV conduction. Apart from the surgical success, the electrophysiological evidence supporting this hypothesis has not been demonstrated, especially in the uncommon (fast-slow) form of AVNRT. We present some electrophysiological evidence suggesting atrial participation in eight patients with the fast-slow form of AVNRT. During the tachycardia, rapid pacing or extrastimulation was done from the orifice of the coronary sinus (CS) and the right atrium (RA), while recording the electrograms of the CS and the low septal RA. In seven patients, right and left atrial dissociation was demonstrated during pacing from the RA, while in the remaining one this was demonstrated from the CS. The interatrial dissociation will be unlikely if the intranodal reentry circuit connects with the atria via a single upper common pathway. This suggests that the upper turnaround of the reentry circuit involves atrial tissue and that the extranodal accessory pathway with long conduction times may form the ascending limb of the circuit (atrionodal reentry). Alternatively, the reentry circuit is entirely intranodal and two or more connecting pathways are present between the atria and the circuit.

Adult↗
PubMed1991

[Catheter ablation].

Explore the source record for details and available documents.

Arrhythmias, Cardiac↗
PubMed1989

Electrophysiological demonstration of anterograde concealed conduction in accessory atrioventricular pathways capable only of retrograde conduction.

Anterograde concealed conduction into the concealed accessory atrioventricular (AV) pathway has been postulated to be one of the factors preventing the reciprocating process via the accessory pathway in patients with the concealed Wolff-Parkinson-White(WPW) syndrome but its presence has not been documented. To demonstrate the occurrence of anterograde concealment, 12 patients with the concealed WPW syndrome were selected for study. A pacing protocol was designed in which the retrograde conduction of the ventricular extrastimulus over the accessory pathway was assessed during ventricular pacing alone (conventional method) and during the AV simultaneous pacing (simultaneous method); the results were then compared. When the high right atrium was simultaneously paced, the effective refractory period of the concealed accessory pathway shortened as compared with the conventional method in five of 12 patients (from 341.7 +/- 110.8 to 312.5 +/- 108.2 msec, n = 12), whereas, it decreased in all patients studied when the coronary sinus near the accessory pathway was simultaneously paced (from 375.7 +/- 135.0 to 287.1 +/- 116.1 msec, n = 7). These results demonstrate that the AV simultaneous pacing frequently shortens the refractoriness of the concealed accessory AV pathway and such facilitation seems to be well explained by the probable anterograde concealment in it and peeling back of the refractory barrier.

Atrioventricular Node↗
PubMed1986

Electrocardiographic masking of a myocardial infarction by a fasciculoventricular Mahaim fiber, atrioventricular reentry with anterograde conduction over a fasciculoventricular Mahaim fiber and retrograde conduction over a concealed Kent bundle.

An intracardiac electrophysiologic study was performed in a patient with paroxysmal tachycardia. The patient had two previous episodes of myocardial infarction, but abnormal Q waves were absent in previously obtained electrocardiograms. Electrocardiographic diagnosis of inferior and anterior infarction was made because the electrocardiogram taken on admission temporarily showed abnormal Q waves. Atrioventricular reentry with anterograde conduction over a fasciculoventricular Mahaim fiber and retrograde conduction over a concealed Kent bundle was observed during the tachycardia. It was also demonstrated that electrocardiographic masking of the Q waves was caused by conduction over a fasciculoventricular Mahaim fiber.

Diagnosis, Differential↗
PubMed1985

Usefulness of invasive and non-invasive electrophysiologic studies in the selection of antiarrhythmic drugs for the patients with paroxysmal supraventricular tachyarrhythmia.

A comparison of the effects of several antiarrhythmic agents was made in a study of 70 patients - 15 with manifest Wolff-Parkinson-White (WPW) syndrome, 17 with concealed WPW syndrome, 18 with AV nodal re-entrant tachycardia, 14 with paroxysmal atrial fibrillation and 6 with paroxysmal atrial flutter - employing intracardiac stimulation and esophageal pacing. For the termination of paroxysmal supraventricular tachycardia, intravenous administration of verapamil or aprindine was more effective than that of disopyramide or procainamide. In AV nodal re-entrant tachycardia, verapamil was the most effective for termination. In the manifest WPW syndrome, disopyramide or aprindine was indicated especially for patients with the accessory pathways of the short antegrade refractory period, because these drugs lengthened the refractory period of the accessory pathways. For the purpose of converting atrial fibrillation or flutter to the sinus rhythm, type IA drugs such as disopyramide were indicated. However, verapamil was effective for slowing down the ventricular rate in atrial fibrillation or flutter except in cases of manifest WPW syndrome. A 6-month follow-up study showed that oral administration of verapamil was also useful for putting a stop to the attacks in 24 out of 32 patients with paroxysmal supraventricular tachycardia, while oral disopyramide prevented the recurrence of atrial fibrillation in only 4 of 10 patients.

Administration, Oral↗