Predicting the outcome in patients with unexplained syncope and suspected cardiac cause: Role of electrophysiologic studies

Objective: Unexplained syncope is a challenge facing electrophysiologists. The prognosis varies widely depending on underlying causes, specially, cardiac ones. We sought to determine the abnormal electrophysiolgic (EP) study results as predictors of prognosis in syncope patients with suspected cardiac cause and risk factors associated with mortality. Methods: A total of 227 consecutive patients with unexplained syncope were prospectively enrolled in this study. EP study was performed in 177 patients in base of inclusion criteria. These patients, in whom a cardiac cause of syncope was suspected, underwent EP study and if negative, head-up tilts test (HUTT). Complete follow-up was obtained for 132 patients for 20.0±10.8 months. Results: A cardiac cause of syncope was established in 35, a neurally mediated syncope in 35.6, and in the rest 29.4 the cause of syncope remained unexplained despite a throughout neurologic and cardiologic evaluation. Logistic analysis revealed that the significant predictors of a cardiac cause of syncope were the absence of prodromal symptoms, left bundle branch block (LBBB), sever left ventricle (LV) dysfunction and male gender. At logistic analysis, the presence of LBBB (OR=6.63; 95 CI: 1.09-40) was significantly associated with outcome of death. Conclusion: The present study provides evidence that presence of LBBB, abnormal EP study result and structural heart disease (SHD) have prognostic value in patients with suspected cardiac cause of syncope. The patients with SHD and unexplained syncope who had a negative EP study have a good long-term prognosis even in the presence of LV dysfunction. © 2015 by Turkish Society of Cardiology

Predicting the outcome in patients with unexplained syncope and suspected cardiac cause: Role of electrophysiologic studies Kalp nedenli oldu�undan ��phe edilen ve a�ıklanamayan senkoplu bir hastada sonucun kestirilmesi

Objective: Unexplained syncope is a challenge facing electrophysiologists. The prognosis varies widely depending on underlying causes, specially, cardiac ones. We sought to determine the abnormal electrophysiolgic (EP) study results as predictors of prognosis in syncope patients with suspected cardiac cause and risk factors associated with mortality. Methods: A total of 227 consecutive patients with unexplained syncope were prospectively enrolled in this study. EP study was performed in 177 patients in base of inclusion criteria. These patients, in whom a cardiac cause of syncope was suspected, underwent EP study and if negative, head-up tilts test (HUTT). Complete follow-up was obtained for 132 patients for 20.0�10.8 months. Results: A cardiac cause of syncope was established in 35, a neurally mediated syncope in 35.6, and in the rest 29.4 the cause of syncope remained unexplained despite a throughout neurologic and cardiologic evaluation. Logistic analysis revealed that the significant predictors of a cardiac cause of syncope were the absence of prodromal symptoms, left bundle branch block (LBBB), sever left ventricle (LV) dysfunction and male gender. At logistic analysis, the presence of LBBB (OR=6.63; 95 CI: 1.09-40) was significantly associated with outcome of death. Conclusion: The present study provides evidence that presence of LBBB, abnormal EP study result and structural heart disease (SHD) have prognostic value in patients with suspected cardiac cause of syncope. The patients with SHD and unexplained syncope who had a negative EP study have a good long-term prognosis even in the presence of LV dysfunction. � 2015 by Turkish Society of Cardiology

Presence of macrovolt T wave alternans and short coupled PVC simultaneously in a patient with long QT syndrome

This report presents a patient with macrovolt T wave alternans, PVC with R on T or a long-short sequence followed by torsades de pointes

Mid-term follow-up of patients with Brugada syndrome following a cardioverter defibrillator implantation: A single center experience

BACKGROUND: Brugada syndrome is an arrhythmogenic disease characterized by an ECG pattern of ST-segment elevation in the right precordial leads and an increase risk of sudden cardiac death. Risk stratification for the life-threatening arrhythmic events in Brugada syndrome is not yet established. In the present study, we report our experience in patients with Brugada syndrome, following an ICD implantation. METHODS AND RESULTS: A total of 12 patients (11 men, 1 woman) with a mean age of 46.5±11.8 were studied. At diagnosis, 7 patients had syncope of unknown origin, 2 patients were asymptomatic, 2 patients were survivors of cardiac arrest, and 1 had documented clinical VT requiring direct cardioversion for termination. Age was similar between the symptomatic and asymptomatic patients (46.6±13 vs. 46±2.8, respectively). Two patients reported a family history of sudden cardiac death. In 3 patients, spontaneous coved-type ECG was found at baseline. In 9 patients, a class I antiarrhythmic drug administration unmasked the characteristic type I ECG. In 4 patients (2 symptomatic with syncope at presentation and 2 asymptomatic), who underwent PES, sustained polymorphic VT or VF was induced. VF was induced by single extrastimuli in 2 symptomatic patients (1 from RV apex and 1 from RVOT). In 2 asymptomatic patients, VF was induced by two and triple ventricular extrastimli (1 from RV apex and 1 from RVOT). None of them experienced an event during follow-up. No significant difference was found between symptomatic and asymptomatic patients (p=NS). The mean follow-up period for the entire study population was 27.83±11.25 months. During follow-up, 2 patients (one with prior cardiac arrest and another with syncope) had VF. Both of them had a type I ECG after provocation with a class I antiarrhythmic drug. None of them had undergone programmed ventricular stimulation. Five patients (41.7 %) had inappropriate ICD interventions during follow-up. The cause of inappropriate therapy was sinus tachycardia in 2 patients, AF in 2 patients and T wave oversensing in 1 patient. CONCLUSION: Knowledge about Brugada syndrome is steadily progressing but there are still unanswered issues dealing with the risk stratification and the management of patients

Multiple arrhythmogenic substrate for tachycardia in a patient with frequent palpitations

We report a 26-year-old woman with frequent episodes of palpitation and dizziness. Resting electrocardiography showed no evidence of ventricular preexcitation. During electrophysiologic study, a concealed right posteroseptal accessory pathway was detected and orthodromic atrioventricular reentrant tachycardia incorporating this pathway as a retrograde limb was reproducibly induced. After successful ablation of right posteroseptal accessory pathway, another tachycardia was induced using a concealed right posterolateral accessory pathway in tachycardia circuit. After loss of retrograde conduction of second accessory pathway with radiofrequency ablation, dual atrioventricular nodal physiology was detected and typical atrioventricular nodal reentrant tachycardia was repeatedly induced. Slow pathway ablation was done successfully. Finally sustained self-terminating atrial tachycardia was induced under isoproterenol infusion but no attempt was made for ablation. During 8-month follow-up, no recurrence of symptoms attributable to tachycardia was observed

Optimal side of implant for single-lead VDD pacing: Right-sided versus left-sided implantation

Background: Atrial undersensing occurs in a considerable number of patients with single-lead VDD pacing. This study tried to determine the role of implant side in maintenance of the VDD mode in patients with isolated atrioventricular (AV) block. Methods: Eighty-two patients with isolated AV block (46 females; mean age, 58 ± 17 years) received a single-lead VDD pacemaker (Medtronic Kappa, n = 70 and St. Jude Medical Affinity, n = 12). The patients were randomly assigned to one of two implantation groups (group I: right-sided VDD and group II: left-sided VDD). In each group, the P-wave amplitudes were determined at implantation, predischarge, 2-month, and 6-month follow-up. At each follow-up visit, stored event histograms of pacemaker were also retrieved. The atrial sensing measurements were compared between two groups. Results: Implantation was easier from right side (1.7 ± 1.0 vs 2.8 ± 1.7 attempts, P = 0.001). Implant P-wave was higher in group I compared to group II (4.2 ± 1.7 vs 2.7 ± 1.0 mV, P < 0.0001). During follow-up, higher P-wave amplitudes were obtained in group I both at predischarge (2.6 ± 1.3 vs 1.4 ± 1.1 mV, P < 0.0001), 2-month (2.8 ± 1.8 vs 1.3 ± 1.0 mV, P < 0.0001), and 6-month (2.9 ± 1.7 vs 1.3 ± 0.9 mV, P < 0.0001) evaluations but remained stable throughout the 6 months in both groups. After implantation, VDD function was better maintained in group I than group II (100 vs 90, P = 0.026). Incidence of atrial undersensing was lower in group I than group II (P = 0.026) in last follow-up visit. Conclusions: Implant side has a significant influence on atrial sensing performance in single-lead VDD pacing. Thus, right-side implantation should be the preferred approach for the implantation of VDD single-lead systems

Coexistence of atrioventricular nodal reentrant tachycardia and idiopathic left ventricular outflow-tract tachycardia

Double tachycardia is a relatively rare condition. We describe a 21 year old woman with history of frequent palpitations. In one of these episodes, she had wide complex tachycardia with right bundle branch and inferior axis morphology. A typical atrioventricular nodal tachycardia was induced during electrophysiologic study, aimed at induction of clinically documented tachycardia. Initially no ventricular tachycardia was inducible. After successful ablation of slow pathway, a wide complex tachycardia was induced by programmed stimulation from right ventricular outflow tract. Mapping localized the focus of tachycardia in left ventricular outflow tract and successfully ablated via retrograde aortic approach. During 7 month's follow-up, she has been symptom free with no recurrence. This work describes successful ablation of rare combination of typical atrioventricular nodal tachycardia and left ventricular outflow tract tachycardia in the same patient during one session

Latent atriofascicular pathway participating in a wide complex tachycardia: Differentiation from ventricular tachycardia

Accessory pathways with anterograde decremental conduction properties usually are characterized by presence of antegrade preexcitation during atrial pacing. We report a 38-year-old man with frequent episodes of palpitation. No evidence of ventricular preexcitation was seen during sinus rhythm or atrial pacing. All electrophysiologic maneuvers were compatible with an antidromic tachycardia using atriofascicular pathway as the antegrade limb and the atrioventricular nodal pathway as retrograde limb. Radiofrequency ablation at recording site of accessory pathway potential resulted in cure of tachycardia with no recurrence during 3-month follow-up. This report indicated that atriofascicular pathway-mediated tachycardia should be considered in differential diagnosis of all cases of wide complex tachycardia with left bundle branch morphology and left axis. © 2006, The Authors

Is the activation potential of Mahaim pathway always a fast potential? Implication for radiofrequency catheter ablation

Introduction: Accessory pathways (AP) exhibiting Mahaim physiology are amenable to radiofrequency (RF) catheter ablation. The recording of an AP potential is an excellent guide for selection of ablation site. The purpose of this study is to determine whether the pathway potential is always a fast potential. Methods: Ten patients (six females, mean age, 30±12 years) with preexcited tachycardias involving a Mahaim pathway underwent electrophysiological study and subsequent attempts at RF ablation. Mahaim potentials (M-potential) recorded at the site of successful ablation were reviewed and classified by at least two reviewers. Results: In all patients, Mahaim pathways were characterized as atriofascicular types. The M-potential was fast in seven patients (group one), and slow in the remaining patients (group two). All group two patients had a history of prior failed ablation. Atrial electrograms were recorded closer to the QRS onset in group one. Atrium to fast M-potential (42±15 ms) was shorter than atrium to slow M-potential (83±12 ms, P=0.03) but M-potentials were recorded with similar distance before local ventricular electrogram (P=NS). Ablation was successful in all patients with mean of 2.9±1.4 RF applications per patient. Ablation data were similar between the two groups (P=NS). No complications occurred. During 12 months of follow-up, no recurrence was observed. Conclusion: Our results illustrated that the activation potential of Mahaim pathways is not always a fast potential. One-third of Mahaim pathways can be mapped and ablated when the slow type of M-potential was used as a target for ablation. We also confirmed high efficacy of catheter ablation of Mahaim pathways guided by activation potentials. © 2005 The European Society of Cardiology. Published by Elsevier Ltd. All rights reserved