BACKGROUND AND OBJECTIVES: The differential diagnosis of a regular tachycardia, with a wide QRS complex(> or =20 msec) n the 12-lead electrocardiogram(CG), remains an important challenge. Despite the information available on electrocardiography in patients with ventricular tachycardia(T) nd supraventricular ventricular tachycardia, with aberrant conduction or pre-existed bundle branch block(ide-QRS SVT); the data from Korean is limited. The purpose of this study was to report on the differential diagnostic criteria.SUBJECTS AND METHODS: The clinical and electrocardiographic characteristics of 150 patients(5.8%) ith VT, and 78(4.2%) ith wide-QRS SVT, were evaluated. RESULTS: n atrioventricular(V) issociation was found in 44.7%(7/150) f the VTs, which is very useful in differential diagnosis. In the RBBB patterns, a monophasic R, or a biphasic, wave(R, RS), in the V1 lead, were present in 49.0 and 40.6% of VTs, respectively, and an R/S ratio of less than 1, in the V6 lead, was present in 89.6% of VTs. In the LBBB patterns, the duration of the R wave(gt; or =0 msec), the interval from the Q wave to the nadir of the S wave(> or =0 msec) nd the notching of the S wave, in the V1 lead, were present in 61.1, 87.0 and 31.3% of VTs, respectively. When an algorithm, using the AV dissociation and morphological criteria for a VT in the V1 and V6 leads, was tested for differentiation, the sensitivity and specificity were 96.7 and 93.6%, respectively. CONCLUSION: A more accurate, correct, diagnosis of wide-QRS tachycardia can be made by using a stepwise approaching method consisting of AV dissociation and morphological criteria for VT in the V1 and V6 leads.
Diagnosis ; Diagnosis, Differential* ; Electrocardiography* ; Humans ; Sensitivity and Specificity ; Tachycardia* ; Tachycardia, Supraventricular ; Tachycardia, Ventricular

PURPOSE: In dealing with wide-complex tachycardia (WCT), it is important to distinguish between ventricular tachycardia (VT), supraventricular tachycardia with aberrancy (SVTAC), and preexcited tachycardia by using an accessory pathway. The aim of this study was to investigate and compare the Brugada and the Bayesian algorithms and to analyze the parameters. METHODS: Between January 1999 and December 2003, the Brugada and the Bayesian approaches were retrospectively analyzed in 103 WCTs confirmed by electrophysiologic studies. RESULTS: Seven-eight (75) VTs and 25 SVTs were found. The sensitivity and the specificity for VT achieved by using the Brugada approach were 91.0 and 68.0%, respectively, whereas those achieved by using the Bayesian approach were 84.6 and 60.0%. In the Brugada approach, the most important step was the fourth step (odds ratio: 4.33; 95% CI: 1.75-12.14). In the Bayesian approach, triphasic rsR' or rR' morphology (odds ratio: 3.93; 95% CI: 1.46-10.56), r > or = 0.04 s or notched S downstroke or delayed S nadir > 0.06 s in the V1 or the V2 lead (odds ratio: 5.75; 95% CI: 1.26?26.28), and intrinsicoid deflection > or = 0.08 s in the V6 lead (odds ratio: 6.88; 95% CI: 1.33-27.79) were more important parameters. Seven (7) VTs of 103 tachycardias were mis-classified when the Brugada approach was used. Applying additional criteria (QRS width > 0.16 s and intrinsicoid deflection > or = 0.08 s in V6 lead), three of those VTs were diagnosed correctly. CONCLUSIONS: The Brugada algorithm achieved a lower sensitivity and specificity than those reported by Brugada et al. If both the V1 and the V6 leads do not fulfill the criteria for VT, additional parameters should be evaluated.
Diagnosis, Differential* ; Electrocardiography* ; Retrospective Studies ; Sensitivity and Specificity ; Tachycardia* ; Tachycardia, Supraventricular ; Tachycardia, Ventricular

To investigate the value of ventricular tachycardia (VT) score in diagnosing pre-excited tachycardia.
 Methods: Twelve-lead electrocardiograph results were obtained from 30 patients at pre-excited tachycardia attacking stage who were diagnosed by electrophysiology. We scored pre-excitation tachycardia based on the VT score. To analyze the electrocardiogram of pre-excited tachycardia using 7 diagnostic indicators of the VT score and calculate the specificity of 7 diagnostic indicators and right superior axis (-90º to ±180º), the differences were compared among VT score of 2 points and brugada, Wellens, and Vereckei algorithms in diagnosing pre-excited tachycardia. According to the specificity of Vereckei, Wellens, and Brugada algorithms, and VT scores from low to high, their prediction value and differences were analyzed.
 Results: Single indicator such as atrioventricular (AV) dissociation or right superior axis (-90º to ±180º) showed the highest specificity (100%) for identifying pre-excited tachycardia. No patient with VT score was ≥3 points, and the specificity was 100%. The specificity of VT score of 2 point was higher than that of Brugada, Wellens, or Vereckei algorithms in the diagnosing pre-excited tachycardia (76.7% vs 50.0%, 23.3% or 20.0%, P<0.05). The specificity of Vereckei, Wellens, and Brugada algorithms and VT score were gradually increased after each of stepwise individually eliminated VT (20.0%, 40.0%, 66.7%, 83.3%, P<0.05). However, there was no significant difference in the specificity in the remaining false positive cases between the 4 methods and VT score.
 Conclusion: VT score ≥3 points can identify pre-excited tachycardia and VT with 100% specificity. VT score of 2 points cannot completely distinguish pre-excited tachycardia from VT, but specificity of VT score with 2 points is obviously higher than that of Brugada, Wellens, and Vereckei algorithms.
Algorithms ; Diagnosis, Differential ; Electrocardiography ; Humans ; Sensitivity and Specificity ; Tachycardia, Ventricular ; diagnosis

Diagnosis, Differential ; Electrocardiography ; Humans ; Tachycardia, Ventricular ; Torsades de Pointes

In our laboratory, the normal ECG signal, the ECG signals of ventricular tachycardia (VT) and of ventricular fibrillation (VF) are studied with the use of Hurst index value. The Hurst index values of the normal ECG signal, VT, VF are calculated separately. There exist obvious differences among the Hurst values of the three kinds of signals,but they are all higher than 0.5 which is a value indicating the long-term relevant character. The long-term relevant character of the normal ECG signal is the best, and the character of VT is better than that of VF. Therefore, the Hurst Index can be used as an identification criterion for distinguishing normal ECG, VT and VF.
Algorithms ; Electrocardiography ; methods ; Humans ; Signal Processing, Computer-Assisted ; Tachycardia, Ventricular ; diagnosis ; physiopathology ; Ventricular Fibrillation ; diagnosis ; physiopathology

Differentiating arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) from other cardiomyopathies is clinically important but challenging. Although the modified Task Force Criteria can facilitate diagnosis of ARVD/C according to clinical manifestations, histopathological examination plays a pivotal role in excluding other diseases that can mimic ARVD/C. Here, we report a patient with amyloidosis that initially presented similarly to ARVD/C. The diagnosis was confirmed by endomyocardial biopsy, and catheter ablation eliminated the ventricular tachyarrhythmias through an epicardial approach.
Advisory Committees ; Amyloidosis* ; Arrhythmogenic Right Ventricular Dysplasia ; Biopsy ; Cardiomyopathies ; Catheter Ablation* ; Catheters* ; Diagnosis ; Humans ; Tachycardia ; Tachycardia, Ventricular

This is a research with the aim of using joint entropy method to analyze the dynamical complexity information on the electrocardiogram signals recording of normal sinus rhythm (NSR), ventricular tachycardia (VT) and ventricular fibrillation (VF). We included the symbolic dynamical theory and surrogate data concept in it. By calculating the joint entropy between original and surrogate time series, we quantified the dynamical complexity of original series. By computer analysis of actual heartbeat rhythm data, the rationality of joint entropy method was confirmed. The results indicated that the joint entropy values of different signals can be of use in distinguishing the NSR, VT and VF signals.
Diagnosis, Differential ; Electrocardiography ; Entropy ; Humans ; Signal Processing, Computer-Assisted ; Tachycardia, Ventricular ; diagnosis ; physiopathology ; Ventricular Fibrillation ; diagnosis ; physiopathology

PURPOSE: In some patients with an implantable cardioverter defibrillator (ICD), multiple episodes of electrical storm (ES) can occur. We assessed the prevalence, features, and predictors of ES in patients with ICD. MATERIALS AND METHODS: Eighty-five patients with an ICD were analyzed. ES was defined as the occurrence of two or more ventricular tachyarrhythmias within 24 hours. RESULTS: Twenty-six patients experienced at least one ES episode, and 16 patients experienced two or more ES episodes. The first ES occurred 209 +/- 277 days after ICD implantation. In most ES cases, the index arrhythmia was ventricular tachycardia (65%). There were no obvious etiologic factors at the onset of most ES episodes (57%). More patients with a structurally normal heart (p = 0.043) or ventricular fibrillation (VF) as the index arrhythmia (p = 0.017) were in the ES-free group. Kaplan-Meier estimates and a log-rank test showed that patients with nonischemic dilated cardiomyopathy (DCMP) (log-rank test, p = 0.016) or with left ventricular ejection fraction < 35% (p = 0.032) were more likely to experience ES, and that patients with VF (p = 0.047) were less affected by ES. Cox proportional hazard regression analysis showed that nonischemic DCMP correlated with a greater probability of ES (hazard ratio, 3.71; 95% confidence interval, 1.16-11.85; p = 0.027). CONCLUSION: ES is a common and recurrent event in patients with an ICD. Nonischemic DCMP is an independent predictor of ES. Patients with VF or with a structurally normal heart are less likely to experience ES.
Adult ; Aged ; Defibrillators, Implantable/*adverse effects ; Female ; Humans ; Male ; Middle Aged ; Tachycardia, Ventricular/*diagnosis/etiology ; Ventricular Fibrillation/*diagnosis/etiology

Adrenalectomy ; Female ; Humans ; Pheochromocytoma ; diagnosis ; surgery ; Tachycardia, Ventricular ; diagnosis ; Tomography, X-Ray Computed

BACKGROUND: Radiofrequency catheter ablation (RFCA) becomes an useful treatment for idiopathic ventricular tachycardia, especially right ventricular outflow tract ventricular tachycardia (RVOT VT) typically originates from "superior septal" aspect of right ventricular outflow tract. However, some of the right ventricular outflow tachycardias remain resistant despite repeated attempts of RFCA. This study was focused to search the electrocardiographic characteristics suggesting procedural success of radiofrequency ablation in RVOT VT and ventricular tachycardia that can not be ablated by conventional approach confined to right ventricular outflow tract even though to show similar electrocardiographic morphology. METHODS: The study subjects were 25 patients who underwent RFCA with the diagnosis of RVOT VT. We classified the study subjects into 2 groups and in group 1 (N=17, Age 47.5 +/- 16.8) in those successful RFCA was possible in RVOT. In group 2 (N=8, Age 54.8 +/- 8.0), the removal of VT was not possible with the RFCA confined in RVOT. We analyzed the morphologic characteristics of QRS complex of VT or ventricular premature beats in right precordial leads; V(1-3). The QRS and R wave duration, height of R wave, depth of S wave, R/S ratio and R wave duration index were measured. RESULTS: There was no difference of age and sex between group 1 and 2 (Group 1: N=17, Male 29.4%, Age 49.5 +/- 16.8 vs Group 2: N=8, Age 54.8 +/- 8.0, Male 37.5%). The maximal QRS duration in V(1-3) was 144.2 +/- 23.6 ms in group 1 and 136.3 +/- 25.1 ms in group 2. The R wave duration and R wave duration index were not different either between group 1 and 2. However, the R wave duration of lead V 3 in group 2 was 97.0 +/- 34.4 ms and significantly longer than 65.0 +/- 26.0 msec in Group 1 (p=0.04). R wave duration index also showed significant difference between two groups: 72.0 +/- 23.5% of group 2 vs 45.4 +/- 17.8% of group 1. In comparison of R wave height and depth of S wave in V(1-3) between two groups, the R/S ratio of lead V3 in group 2 showed the ratio of 343.4 +/- 227.7% which was significantly larger than 97.4 +/- 92.2% in group 1. CONCLUSION: For the practice of RFCA for RVOT VT, morphologic characterstics of VT or VPC showing wide R wave and high R/S wave ratio in precordial leads, especially in V3 could be an useful electrocardiographic indicator to suspect the unusual focus of idiopathic VT showing inferior axis and LBBB pattern.
Axis, Cervical Vertebra* ; Bundle-Branch Block* ; Cardiac Complexes, Premature ; Catheter Ablation* ; Diagnosis ; Electrocardiography ; Humans ; Male ; Tachycardia ; Tachycardia, Ventricular*