Filter by keywords:



Filtering documents. Please wait...

1/75. Sinus escape-capture bigeminy and sinus extrasystolic bigeminy.

    Blocking conduction between the sinus node and the atria (SA block) can be responsible for symptomatic rhythm problems. However, in atrial escape-capture bigeminy with SA block, when atrial escape P waves originate in a site within or close to the sinus node, the diagnosis of SA block is not easy. Electrocardiograms were selected from 7 people with atrial bigeminy because (1) all atrial deflections (P waves) were almost the same in shape and in length of PR intervals, (2) comparatively long PP intervals alternated with comparatively short PP intervals, and (3) occasionally the atrial bigeminy changed to normal regular sinus rhythm in which 2 or more sinus P waves were found in succession. An attempt is made to clarify the mechanism for these cases. When regular sinus rhythm changed to bigeminal rhythm, the long PP interval introduced the bigeminy in 3 cases, indicating the presence of "sinus" escape-capture bigeminy; whereas the short PP interval introduced the bigeminy in the other 4 cases, indicating the presence of "sinus" extrasystolic bigeminy. In cases of sinus escape-capture bigeminy associated with SA block, the cases may occasionally be diagnosed wrongly as ordinary sinus arrhythmia not associated with SA block. Therefore, it seems that sinus escape-capture bigeminy is not so rare as is generally believed. patients with SA block often require implantation of the artificial pacemaker. Thus, the authors believe that differentiation of sinus escape-capture bigeminy from other forms of "sinus" bigeminy is clinically important.
- - - - - - - - - -
ranking = 1
keywords = block
(Clic here for more details about this article)

2/75. Fetal and neonatal arrhythmia in one of the twins--a case history.

    There are a lot of publications about fetal arrhythmia in singletons, but up to now there are no published data about fetal arrhythmia in multiple pregnancies. In the present study a case history of fetal and neonatal arrhythmia in one of twins from two mothers treated with betamimetic agents due to imminent preterm labor is reported and discussed. A first case with fetal bradycardia due to complete A-V block had congenital cordis abnormalities (VSD and PFO). The second case with prenatal detected extrasystoles had normal heart anatomy. digoxin was administered to the mother, in the aim to treat fetal arrhythmia without success, because the baby had postnatal bradycardia. After hospitalisation in cardiology Department the described cases were successfully treated. In both cases the second twins were without neonatal arrhythmia and with no structural heart abnormalities. We summarise that in situation of detection fetal arrhythmia the complexity of the problems experienced may warrant early referral to a tertiary centre where the overall management of the mother, fetus and neonate, may be undertaken.
- - - - - - - - - -
ranking = 0.16666666666667
keywords = block
(Clic here for more details about this article)

3/75. Premature depolarization concealed in two pulmonary veins.

    A case is presented in which a premature depolarization emanated from a partially activated left inferior pulmonary vein, activated the entire left superior pulmonary vein, but did not activate the atria ("concealed"). The site of conduction block between each vein and the left atrium was the anatomic atriovenous junction. At times, the same depolarization would activate the atria and initiate atrial fibrillation. The shortest depolarization coupling interval that activated the atria was significantly longer than the atrial fibrillation cycle length recorded in either vein. Observations in this case support two concepts: (1) the existence of myocardial "tracts," extending into and between pulmonary veins; and (2) a "mismatch" between pulmonary vein activation ingress and egress.
- - - - - - - - - -
ranking = 0.16666666666667
keywords = block
(Clic here for more details about this article)

4/75. atrial flutter in the recipient atrium induced by premature beats arising from the donor atrium 10 years after orthotopic heart transplantation.

    BACKGROUND: Several mechanisms for the genesis of supraventricular arrhythmias in patients after orthotopic heart transplantation have been reported. methods AND RESULTS: We describe a 58-year-old male patient in whom atrial flutter occurred 10 years after orthotopic heart transplantation. During an electrophysiological study, bidirectional conduction between the recipient and donor atria was found. atrial flutter in the recipient atrium was induced by programmed stimulation of the donor atrium using a single extrastimulus. The clinical symptoms were caused by atrial flutter arising from the recipient atrium with 1:1 to 3:1 conduction to the donor atrium. Mapping the anastomosis between the two atria indicated fragmented potentials at a discrete site of conduction. Delivery of radiofrequency energy at this site terminated conduction in both directions. Subsequent atrial pacing of the donor and recipient atria, respectively, demonstrated bidirectional conduction block. CONCLUSION: Symptomatic arrhythmias in patients after heart transplantation can indirectly originate from the donor atrium via bidirectional recipient-donor atrial conduction. This type of arrhythmia can be successfully treated with radiofrequency ablation.
- - - - - - - - - -
ranking = 0.16666666666667
keywords = block
(Clic here for more details about this article)

5/75. Clinical implications of fetal magnetocardiography.

    OBJECTIVES: To test the usefulness and reliability of fetal magnetocardiography as a diagnostic or screening tool, both for fetuses with arrhythmias as well as for fetuses with a congenital heart defect. methods: We describe 21 women with either a fetal arrhythmia or a congenital heart defect discovered during prenatal evaluation by sonography. Four fetuses showed a complete atrioventricular block, two an atrial flutter, nine ventricular extrasystole, and one a complete irregular heart rate. Five fetuses were suspected to have a congenital heart defect. In all cases magnetocardiograms were recorded. RESULTS: Nine fetuses with extrasystole showed a range of premature atrial contractions, premature junctional beats or premature ventricular contractions. Two fetuses with atrial flutter showed typical flutter waves and four fetuses with complete atrioventricular block showed an uncoupling of P-wave and QRS complex. One fetus showed a pattern suggestive of a bundle branch block. In three of four fetuses with confirmed congenital heart defects the magnetocardiogram showed abnormalities. CONCLUSION: Fetal magnetocardiography allows an insight into the electrophysiological aspects of the fetal heart, is accurate in the classification of fetal arrhythmias, and shows potential as a tool in defining a population at risk for congenital heart defects.
- - - - - - - - - -
ranking = 0.5
keywords = block
(Clic here for more details about this article)

6/75. Differentiation between parasystole and reentry in concealed bigeminy.

    There are two different theories to explain the mechanism of concealed bigeminy: one is '2:1 concealed reentry'; the other is 'irregular parasystole.' Two exemplary cases of the even-number variant of concealed bigeminy are presented. In case 1, the mechanism can be explained by an irregular parasystole due to a modulated parasystole; however, findings during temporary sinus arrest caused by vagal stimulation indicate that this case is not governed by a parasystole, but by a 2:1 concealed reentry. In case 2, the mechanism can be explained by a 2:1 concealed reentry without parasystole; however, findings during temporary sinus arrest indicate that this case is governed by an irregular parasystole due to a type-I second-degree entrance block. Thus, in cases of concealed bigeminy without pure ectopic cycles, it does not seem easy to explain the mechanism of concealed bigeminy on the theory of a modulated parasystole.
- - - - - - - - - -
ranking = 0.16666666666667
keywords = block
(Clic here for more details about this article)

7/75. Ashman's phenomenon--a source of nonsustained wide-complex tachycardia: case report and discussion.

    The refractory period of the right bundle branch is increased when the R-R interval between the prior two conducted impulses is long. Thus, an impulse that arrives soon after the second of two impulses separated by a long R-R interval may be aberrantly conducted with a right bundle branch block morphology on electrocardiogram. This aberrant conduction is termed "Ashman's phenomenon" and is often responsible for isolated wide QRS complexes in the presence of underlying atrial fibrillation. This process may also produce runs of wide QRS complexes that must be distinguished from nonsustained ventricular tachycardia. A case of such multibeat Ashman's phenomena is presented, and the characteristics used to identify this phenomenon are discussed. A brief review of several recent studies on the differentiation of sustained ventricular tachycardia from supraventricular tachycardia with aberrancy in the setting of a regular underlying rhythm is given as well.
- - - - - - - - - -
ranking = 0.16666666666667
keywords = block
(Clic here for more details about this article)

8/75. Failure of parasystolic impulses to appear on schedule. Exit block due to concealed conduction of sinus impulses.

    A 45-year-old patient free of any heart disease was admitted to the hospital with an electrocardiographic pattern of ventricular parasystole. The parasystolic rhythm was relatively fast, such that several consecutive ectopic complexes manifested. A later tracing reflected only isolated parasystolic complexes with long and fixed coupling intervals. The interectopic intervals, however, were once more in multiple of the parasystolic cycle as directly measured during the phases of undisturbed parasystolic rhythm. In the latter tracing, several scheduled parasystolic impulses did not yield a response, despite calculation suggesting that these impulses occurred outside the refractory period. In other words, an exit block was present. Analysis of the tracing suggests that the exit block was caused by concealed penetration of the sinus impulses into the ectopic-ventricular junction. That is, any sinus impulse penetrates into the junction and renders it refractory, in such a way that only parasystolic impulses that are relatively late within the sinus cycle may be conducted to the surrounding myocardium and result in a parasystolic complex.
- - - - - - - - - -
ranking = 1
keywords = block
(Clic here for more details about this article)

9/75. Mechanism of bradycardia-dependent appearance of manifest extrasystoles in concealed bigeminy. A theoretical model derived from the concepts of longitudinal dissociation and multilevel block in the reentrant pathway of extrasystoles.

    A case of bradycardia-dependent appearance of manifest extrasystoles in concealed bigeminy is presented. To explain the mechanism of such bradycardia-dependent appearance, a theoretical model is derived from the concepts of "longitudinal dissociation" and "multilevel block" in the reentrant pathway of extrasystoles. In the theoretical model, functional longitudinal dissociation divides the reentrant pathway into dual pathways F and S. When manifest extrasystoles are not found for a long time, alternate sinus impulses pass through both pathways F and S, but become concealed extrasystoles because of insufficient conduction delay in the pathways. The other alternate sinus impulses are blocked in the pathways; in pathway F, the impulses are blocked at the entrance, while in pathway S, the impulses are blocked at a more distal level. When sinus cycles gradually lengthen, one of such alternate sinus impulses passes through the entrance of pathway F and, traveling very slowly, is blocked at a more distal level. The next sinus impulse is blocked at the entrance of pathway F; namely, 3:2 Wenckebach block occurs at the entrance of pathway F. Thus this sinus impulse enters only pathway S and passes through pathway S with enough conduction delay to become a manifest reentrant extrasystole.
- - - - - - - - - -
ranking = 1.8333333333333
keywords = block
(Clic here for more details about this article)

10/75. Spontaneous onset of ventricular fibrillation in brugada syndrome with J wave and ST-segment elevation in the inferior leads.

    We report the case of a 52-year-old man with variant brugada syndrome who was successfully resuscitated from ventricular fibrillation (VF). Resting ECG showed J wave and ST-segment elevation in the inferior leads but no coved or saddleback ST-segment elevation in the right precordial leads. Pilsicainide infusion provoked coved-type ST-segment elevation in the right precordial leads and mild ST-segment elevation 80 ms after the J point in the inferior leads. During an emergency, 12-lead ECG showed that spontaneous onset of VF was preceded by left bundle branch block and superior axis-type ventricular extrasystoles. The present case provides additional information on the site of origin of VF in patients with brugada syndrome.
- - - - - - - - - -
ranking = 0.16666666666667
keywords = block
(Clic here for more details about this article)
| Next ->


Leave a message about 'Cardiac Complexes, Premature'


We do not evaluate or guarantee the accuracy of any content in this site. Click here for the full disclaimer.