1/113. Electrophysiologic characteristics of accessory atrioventricular connections in an inherited form of wolff-parkinson-white syndrome.INTRODUCTION: A familial form of wolff-parkinson-white syndrome (WPW) occurs in association with hypertrophic cardiomyopathy and intraventricular conduction abnormalities. This syndrome, demonstrating autosomal dominant inheritance and segregating with a high degree of penetrance but variable expressivity, has been genetically linked to chromosome 7q3. The purpose of this study is to detail the electrophysiologic characteristics of accessory atrioventricular connections (AC) in four members of a kindred with this syndrome. methods AND RESULTS: We clinically evaluated 32 members of a single kindred and identified 20 individuals with ventricular preexcitation, abnormal intraventricular conduction including complete AV block and/or ventricular hypertrophy. genetic linkage analysis mapped the disease gene in this kindred to the chromosome 7q3 locus (maximum logarithm of the odds score = 6.88, theta = 0); recombination events in affected individuals reduced the genetic interval from 7 centimorgans (cM) to 5 cM. Electrophysiologic study of four individuals with preexcitation, identified seven AC (1 right sided, 3 septal, and 3 left sided). All four individuals had inducible orthodromic tachycardia; while three had multiple AC. Bidirectional conduction was demonstrated in 6 of 7 AC. Successful ablation was accomplished in 5 of 7 AC. CONCLUSION: The electrophysiologic characteristics and location of AC in family members having this complex cardiac phenotype are similar to those seen in individuals with isolated WPW. Identification of WPW in more than one family member should prompt clinical evaluation of relatives for additional findings of ventricular hypertrophy or conduction abnormalities.- - - - - - - - - - ranking = 1keywords = complex (Clic here for more details about this article) |
2/113. Wide QRS complex tachycardia: ECG differential diagnosis.Wide QRS complex tachycardias (WCT) present significant diagnostic and therapeutic challenges to the emergency physician. WCT may represent a supraventricular tachycardia with aberrant ventricular conduction; alternatively, such a rhythm presentation may be caused by ventricular tachycardia. Other clinical syndromes may also demonstrate WCT, such as tricyclic antidepressant toxicity and hyperkalemia. Patient age and history may assist in rhythm diagnosis, especially when coupled with electrocardiographic (ECG) evidence. Numerous ECG features have been suggested as potential clues to origin of the WCT, including ventricular rate, frontal axis, QRS complex width, and QRS morphology, as well as the presence of other characteristics such as atrioventricular dissociation and fusion/capture beats. Differentiation between ventricular tachycardia and supraventricular tachycardia with aberrant conduction frequently is difficult despite this clinical and electrocardiographic information, particularly in the early stages of evaluation with an unstable patient. When the rhythm diagnosis is in question, resuscitative therapy should be directed toward ventricular tachycardia.- - - - - - - - - - ranking = 6keywords = complex (Clic here for more details about this article) |
3/113. First-trimester fetal heart block: a marker for cardiac anomaly.BACKGROUND: fetal heart block in the second and third trimesters may be caused by transplacental passage of auto-antibodies or cardiac defects. Little is known about the etiology of first-trimester fetal heart block. MATERIALS AND methods: fetal heart block was diagnosed in four patients (negative antibody serology) referred for first-trimester sonographic evaluation of increased fetal nuchal fold thickness with bradycardia. Two-dimensional echocardiography was complemented by color Doppler flow imaging of the fetal heart. Fetal arrhythmia was verified by M-mode, pulsed wave Doppler and/or color M-mode echocardiography. RESULTS: All fetuses had congenital heart disease, atrioventricular valve regurgitation, heart block and edema. autopsy confirmed heterotaxy in three cases (left atrial isomerism with atrial septal defect; left isomerism with double-outlet right ventricle, great artery malposition and ventricular septal defect. The third case had dextrocardia with atrioventricular canal defect and the fourth case dextrocardia with great artery transposition. CONCLUSION: First-trimester fetal bradycardia may result from heart block of the type associated with complex congenital heart disease. Accelerated edema formation in this setting may be the basis of nuchal edema formation. First-trimester fetal echocardiography offers the potential for early diagnosis and intervention in these cases with poor prognosis.- - - - - - - - - - ranking = 1keywords = complex (Clic here for more details about this article) |
4/113. tachycardia-dependent right bundle-branch block with supernormal conduction.This paper reports the case of a 76-year-old man in whom atrial flutter with varying atrioventricular block and intermittent right bundle-branch block was found. This is the first report on tachycardia-dependent right bundle-branch block associated with supernormal conduction in a case of atrial flutter. When an impulse is conducted to the ventricles beyond 0.72 s after a QRS complex of right bundle-branch block configuration, the impulse falls after the abnormally long effective refractor period of the right bundle branch and passes through the right bundle branch. When the conducted impulse occurs within 0.72 s after a QRS complex of right bundle-branch block configuration, the impulse usually falls in the refractory period and is blocked in the right bundle branch; however, only when the impulse occurs 0.48 or 0.49 s after that does it fall in the supernormal period and passes through the right bundle branch. The findings in the present report strengthen our previous suggestion that the presence of supernormal conduction plays an important role in the initiation of reentrant ventricular tachycardia.- - - - - - - - - - ranking = 2keywords = complex (Clic here for more details about this article) |
5/113. Orthodromic tachycardia with atrioventricular dissociation: evidence for a nodoventricular (Mahaim) fiber.We describe a patient in whom two tachycardias with AV dissociation were inducible by ventricular extrastimulation. The first tachycardia was characterized by a narrow QRS preceded by a His deflection with an HV interval identical to that recorded in sinus rhythm (40 ms). Premature ventricular depolarization delivered when the His bundle was refractory advanced the next His deflection. These findings suggest the presence of a nodoventricular bypass tract involved in an orthodromic tachycardia. The second tachycardia was induced after propafenone infusion and exhibited a wide QRS complex with left bundle branch block morphology; each ventricular complex was consistently associated with a His deflection with a HV interval of -15 ms. The second tachycardia may be considered to represent an antidromic tachycardia through the nodoventricular tract. However, a ventricular tachycardia cannot be excluded.- - - - - - - - - - ranking = 2keywords = complex (Clic here for more details about this article) |
6/113. Late onset of accessory pathway conduction in a patient with complete AV block.This case report discusses a patient with complete AV block in early childhood. The patient required a permanent pacemaker. At 6 years of age, intermittent preexcited beats were noted on telephonic transmissions. At 7 years of age, 1:1 preexcitation was noted in sinus rhythm. Therefore, late onset of antegrade accessory pathway function is demonstrated. This case provides evidence of developmental changes in accessory pathways. This may explain age related differences in the onset of narrow complex tachycardia in the school age years.- - - - - - - - - - ranking = 1keywords = complex (Clic here for more details about this article) |
7/113. QT interval prolongation in asymptomatic anti-SSA/Ro-positive infants without congenital heart block.OBJECTIVE: To analyze the electrocardiograms (EKGs) of infants born to mothers with anti-SSA/Ro antibodies in order to evaluate the QT interval (the time from the beginning of the QRS complex to the end of the T wave). methods: Sera from mothers and children were analyzed for anti-Ro and anti-SSB/La antibodies by enzyme-linked immunosorbent assay (ELISA) and by Western blot analysis. Fine specificity of anti-Ro antibodies was evaluated by solid-phase ELISA against recombinant 52- and 60-kd proteins and by Western blot. A retrospective chart review was conducted for EKG analysis. Twenty-eight EKG tracings (21 from anti-Ro-positive and 7 from anti-Ro-negative infants born to mothers with autoimmune diseases) were analyzed by a single investigator who was blinded to the infant's antibody status. The QT interval was measured and corrected for heart rate according to Bazett's formula. RESULTS: The mean QT interval was significantly longer in anti-Ro-positive than in anti-Ro-negative infants, also after correction for heart rate (QTc) (P = 0.001). Nine of 21 anti-Ro-positive infants and 0 of 7 anti-Ro-negative infants had QTc values above the upper normal limit (440 msec). A 24-hour EKG recording was performed on 5 patients and confirmed the QT prolongation. These infants were subsequently treated with a beta-blocker in order to prevent arrhythmias. CONCLUSION: Infants born to mothers who carry anti-Ro autoantibodies may show QT interval prolongation and should be monitored with EKG during the first months of life.- - - - - - - - - - ranking = 1keywords = complex (Clic here for more details about this article) |
8/113. Pseudo-retrograde conduction in complete A-V heart block due to ectopic His bundle activity.A case with complete A-V heart block in whom retrograde P- waves following some of the ventricular complexes were due to an ectopic junctional activity with the characteristics of parasystole is reported. His bundle electrogram showed an infrahisian block. After administration of 1 mg atropine intravenously the retrograde P- waves were detached from the ventricular automatic complexes and an H' deflection preceded each inverted P- wave with an H'-A' interval of 40 msec.- - - - - - - - - - ranking = 2keywords = complex (Clic here for more details about this article) |
9/113. 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 = 1keywords = complex (Clic here for more details about this article) |
10/113. A case of fetal complete heart block recorded by magnetocardiography, ultrasonography and direct fetal electrocardiography.Fetal magnetocardiograms (FMCGs) were recorded in a case of fetal complete heart block (CHB) from the 30th to the 37th week of gestation using the multichannel SQUID system (Hitachi, japan). M-mode ultrasonography and direct fetal electrocardiography using needle electrodes revealed fetal CHB. We identified independent fetal P-waves and QRS complexes in the FMCG recorded in the 32nd week of gestation when the fetal atriums were close to the FMCG sensor. We also recorded FMCG P-waves in the 37th week of gestation when the fetal heart was larger. fetal heart position and size are important for obtaining a useful FMCG. To establish FMCG as a diagnostic tool of fetal arrhythmia, comparative studies with FECG are needed.- - - - - - - - - - ranking = 1keywords = complex (Clic here for more details about this article) |
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