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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ventricular bigeminy in children is regarded as a benign arrhythmia in the absence of coexisting heart disease. We present the case of a patient with an atriofascicular fiber that electrocardiographically presented as wide complex bigeminy and wide complex tachycardia. At electrophysiologic study, the mechanism for the wide complex extrasystoles was reentry within the atriofascicular fiber or at its atrial insertion. Retrograde conduction within the fiber was also demonstrated under the influence of verapamil and ventricular extrastimulus testing. We conclude that conduction through an atriofascicular fiber should be included in the differential diagnosis of wide complex bigeminy having left bundle branch block morphology.
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PMID:Wide complex bigeminy: unusual presentation of an atriofascicular fiber. 753 97

A 38-year-old man with no significant structural heart disease suffered from one episode of wide QRS tachycardia. The electrocardiogram showed a PR interval of 0.20 second and a QRS duration of 0.10 second. His bundle recording revealed an HV interval of 90-100 ms. The tachycardia was inducible with programmed stimulation and displayed a QRS morphology of complete left bundle branch block. It was characterized by an atrioventricular dissociation, a cycle length of 280 ms, and an H deflection preceding each QRS complex. Pacing from the right ventricular apex at a cycle length of 270 ms entrained the tachycardia, while at a cycle length of 260 ms, the tachycardia was terminated. Four years later, the patient presented with complete atrioventricular block with a wide QRS escape rhythm. An electrophysiologic study conducted while he was in 1:1 atrioventricular conduction showed an HV interval of 100 ms. Second-degree infrahisian block developed at an atrial paced cycle length of 700 ms. There was no induction of tachycardia with programmed stimulation before or after isoproterenol. The patient was treated with an implantation of a permanent pacemaker.
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PMID:Progression to complete atrioventricular block in a patient with bundle branch re-entry tachycardia. 759 28

The differential diagnosis of VTs with LBBB morphology includes several well-defined syndromes. Although the majority of cases are attributable to acquired structural heart disease, including ischemia, prior infarction, or dilated cardiomyopathy, consideration of specific right ventricular processes is essential to proper evaluation and treatment. The approach to older patients or those with evidence for heart disease should begin with an evaluation for coronary artery disease and an assessment of biventricular function. Careful evaluation for bundle branch reentry should be performed during electrophysiological study, especially when there is underlying conduction system disease. Younger patients, those without overt heart disease, or those with isolated right ventricular disease, should receive a complete noninvasive evaluation of right and left ventricular size and function. An abnormal SAECG or identification of intracardiac late potentials suggest right ventricular dysplasia or cardiomyopathy, whereas responsiveness to adenosine and absence of detectable heart disease support the diagnosis of idiopathic right VT. Newer techniques, including MRI, show promise in identifying subtle right ventricular disease not otherwise detectable even in the setting of presumed idiopathic right VT. Following surgical repair of selected congenital heart defects, particularly tetralogy of Fallot, symptoms of recurrent palpitations, near syncope, syncope, or aborted sudden death may be attributable to recurrent VT, and diagnostic electrophysiological study should be considered for these patients. Finally, SVTs with LBBB morphology, particularly cases associated with right-sided or septal accessory pathways, should always be considered in this differential diagnosis.
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PMID:Ventricular tachycardias with left bundle branch block morphology. 773 82

Bioimpedance offers a simple non-invasive means of measuring systolic ejection volume and heart rate and thus cardiac output. Four pairs of electrodes are placed on precise locations on the chest and stroke volume is calculated according to the equation developed by Kubicek in 1966 and modified by Sramek in 1980. The aim of this work was to evaluate this method in patients with heart disease. In a series of 50 patients, the coefficient of correlation for cardiac index between impedance values (2.52 +/- 0.71 ml/min/m2) and thermodilution values (2.74 +/- 0.69 ml/min/m2) was 0.63 (p < 0.01). The mean difference was -0.2 l/min/m2 (confidence interval +1 l/min/m2 to -1.4 l/min/m2). There was no statistical correlation in patients with complete left bundle branch block, severe mitral or aortic regurgitation or dilatation of the aorta. In a group of 11 healthy volunteers, there was a good correlation between two measures taken at a 2 day interval (r = 0.95). The coefficient of variation ranged from 1.2 to 7% for ejection volume. Bioimpedance is reproducible and simple, authorizing its use for non-invasive monitoring of cardiac output in a given patient in various clinical situations.
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PMID:[Thoracic electric bioimpedance. A non-invasive method for the measurement of cardiac output]. 774 18

Clinical and electrophysiological features of 20 patients presenting with ventricular tachycardia (VT) of left bundle branch block (LBBB) morphology without evidence of coronary artery disease were studied. The mean age of the patients was 35.2 +/- 12 (range 15-57 years). The rate of VT varied between 140-240/min (182 +/- 80). Six (30%) patients experienced giddiness or syncope during palpitations. Structural heart disease was found in 10 (50%) of these patients, which included arrhythmogenic right ventricular dysplasia in five, submitral left ventricular (LV) aneurysm in one, anterolateral LV dyskinesis in one, dilated cardiomyopathy in one, endomyocardial fibrosis in one and nonobstructive hypertrophic cardiomyopathy in one case. Ten patients were free of structural heart disease. Electrophysiological study was done in all patients. VT with same morphology as spontaneous VT was inducible in only 14 patients. Seventeen patients were treated medically with total or partial amelioration of symptoms. In three patients, two with arrhythmogenic right ventricular dysplasia and one with structurally normal heart, who were unresponsive to drug therapy, the VT focus could be mapped in right ventricular outflow tract and successful electrical ablation was done. Thus in patients who present with VT with LBBB morphology, the heart is often structurally normal but organic disease is not uncommon, and should be carefully searched.
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PMID:Ventricular tachycardia with left bundle branch block morphology in the absence of ischaemic heart disease--clinical and electrophysiological observations. 779 12

LBBB obscures many cardiovascular diagnoses, but it is now possible to diagnose LVH and MI in the presence of LBBB. It is possible from accumulated data to synthesize a new clinical entity: The Complete Left Bundle Branch Block Syndrome. This encompasses the following: Uncomplicated LBBB: (1) the abnormal ECG configuration with normal QRS axis; (2) reversed splitting of the cardiac second sound due to delay of aortic valve closure; (3) significant left ventricular systolic and diastolic dysfunction due to the abnormal sequence of left ventricular activation and relaxation; (4) ventricular septal hypokinesis, and during thallium stress testing ventricular septal perfusion defects which tend to invalidate the results of the test; (5) the vast majority of patients with LBBB have organic heart disease, but 16% have structurally normal hearts except for the conduction system disease; Complicated LBBB: (6) left or right axis deviation or QRS duration greater than 0.14 secs. indicates a greater degree of left ventricular disease and dysfunction than LBBB alone and nearly excludes the presence of conduction disease only; (7) disordered function of the SA node, AV node and right bundle branch.
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PMID:Seeing through the maze of complete left bundle branch block. 802 56

We report on a patient without evidence of structural heart disease who presented with adenosine-sensitive sustained ventricular tachycardia with left bundle branch block and right axis QRS morphology. Endocardial catheter mapping revealed the origin of ventricular tachycardia to be located in the right ventricular outflow tract, where the earliest endocardial activation during ventricular tachycardia was registered 30-40 ms prior to onset of QRS complex in the surface ECG. Pace-mapping provided no additional information; we found a good match between 12 lead surface ECGs registered during spontaneous episodes of ventricular tachycardia and those recorded during pacing in a relatively large area in the right ventricular outflow tract. The 10th application of radiofrequency current abolished ventricular tachycardia temporarily, but it recurred within 30 min. After the 28th radiofrequency current delivery ventricular tachycardia was permanently abolished.
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PMID:Successful radiofrequency ablation of adenosine-sensitive right ventricular outflow tract tachycardia. 808 76

In sustained ventricular tachycardia (VT) unrelated to coronary artery disease, the incidence of reentry with an excitable gap was examined, and rapid pacing was performed to entrain VT in 48 episodes in 42 consecutive patients. Coronary artery disease was excluded by coronary arteriography. The underlying heart diseases were postoperative congenital heart diseases (n = 5), dilated (n = 7) or hypertrophic (n = 4) cardiomyopathy, arrhythmogenic right ventricular dysplasia (n = 6) and miscellaneous heart diseases (n = 5), as well as no demonstrable heart disease (n = 15) in which 8 patients had verapamil-responsive VT. Except for 1 patient with hypertrophic cardiomyopathy, 48 morphologically distinct monomorphic sustained VTs were induced. Twenty-five VTs showed right bundle branch block morphology and 23 left bundle branch block morphology, and VT was entrained in 84 and 96%, respectively. The overall incidence of the entrainment was 89.6% (43 of 48 monomorphic VTs), and the frequency of the ability to entrain VT ranged between 33.3 and 100% in the subgroups. The lowest frequency was found in hypertrophic cardiomyopathy. In conclusion, most inducible monomorphic sustained VT unassociated with coronary artery disease was presumed to be reentry with an excitable gap.
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PMID:Frequency of presumed reentry with an excitable gap in sustained ventricular tachycardia unassociated with coronary artery disease. 821 49

It is important to distinguish proximal right bundle branch block (RBBB) from distal RBBB because patients with both proximal RBBB and left bundle branch block may progress to a late atrioventricular conduction disturbance. Signal-averaged electrocardiograms (SAECGs) were investigated in 35 patients with RBBB following surgical correction of tetralogy of Fallot or ventricular septal defect in order to determine the block site of RBBB noninvasively using a SAECG. The site of RBBB was first identified by a body surface map; 12 patients had proximal RBBB (group 1), and 23 had distal RBBB (group 2). The control groups consisted of 8 patients with RBBB without congenital heart disease (group 3) and 20 normal subjects (group 4). The mean of the filtered QRS duration in the group 1 patients was significantly longer than in the other 3 groups (p < 0.01). The number of fragmented signals in group 1 was significantly greater than that in the other 3 groups (p < 0.01). A filtered QRS pattern was divided into 4 different types (whole, early, late, and normal) according to the successive fragmented signals; the "whole" type was the most common in group 1 (83%). SAECG is successful in identifying those patients with proximal RBBB according to the following indices: a filtered QRS duration equal to or longer than 160 msec, a fragmented signal number greater than 10 and a "whole" type filtered QRS pattern. In conclusion, SAECG is a useful tool for distinguishing proximal RBBB from distal RBBB.
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PMID:Usefulness of the signal-averaged electrocardiogram for evaluating the block site of right bundle branch block following surgical correction of a congenital heart disease. 831 15

Two patients with recurrent episodes of symptomatic, sustained monomorphic ventricular tachycardia (VT) resistant to medical therapy underwent catheter ablation for the relief of VT. One patient had arrhythmogenic right ventricular dysplasia while the other had no structural heart disease. The VT had left bundle branch block morphology with normal axis in both the patients. The cycle length during VT was 260 msec and 270 msec respectively. Site for ablation was guided by pacemapping and the target site was identified in the right ventricular outflow tract in both the patients. Two cathodal shocks of 200 J in the first patient and one shock of 200 J in the second patient resulted in abolition of the arrhythmia. At repeat electrophysiologic testing at 7 days in the first patient and at 8 months in the second, VT was not inducible despite three extrastimuli from two right ventricular sites. Over a follow up of 24 and 26 months respectively, there has been no recurrence without any antiarrhythmic therapy. There were no acute or long term complications. In conclusion, catheter ablation offers a cure in patients with right ventricular tachycardia resistant to antiarrhythmic drugs.
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PMID:Transcatheter ablation of ventricular tachycardia arising from right ventricular outflow tract. 836 34


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