Left anterior fascicular block (LAFB) is a heart disease identifiable from an abnormal electrocardiogram (ECG). It has been reported that LAFB is associated with an increased risk of heart failure. Non-specific intraventricular conduction delay due to the lesions of the conduction bundles and slow cell to cell conduction has also been considered as another cause of heart failure. Since the location and mechanism of conduction delay have notable variability between individual patients, we hypothesized that the impaired conduction in the ventricular myocardium may lead to abnormal ECGs similar to LAFB ECG patterns. To test this hypothesis, based on a computer model with a three dimensional whole-heart anatomical structure, we simulated the cardiac exciting sequence map and 12-lead ECG caused by the block in the left anterior fascicle and by the slowed conduction velocity in the ventricular myocardium. The simulation results showed that the typical LAFB ECG patterns can also be observed from cases with slowed conduction velocity in the ventricular myocardium. The main differences were the duration of QRS and wave amplitude. In conclusion, our simulations provide a promising starting point to further investigate the underlying mechanism of heart failure with LAFB, which would provide a potential reference for LAFB diagnosis.
Adult ; Bundle-Branch Block/diagnostic imaging* ; Computer Simulation ; Electrocardiography ; Heart/diagnostic imaging* ; Heart Atria/diagnostic imaging* ; Heart Conduction System/physiopathology* ; Heart Failure/diagnostic imaging* ; Heart Ventricles/diagnostic imaging* ; Humans ; Male ; Models, Anatomic ; Models, Theoretical ; Muscle Cells ; Myocardium ; Phantoms, Imaging ; Poisson Distribution

OBJECTIVETo observe the changes in electrocardiographic parameters in children with complete left bundle branch block (CLBBB) after the transcatheter closure of simple ventricular septal defect (VSD).

METHODSA total of 21 children with CLBBB early after transcatheter closure of perimembranous VSD were recruited. Another 21 children without any type of arrhythmia after transcatheter closure of perimembranous VSD were enrolled as the control group. The sex, age, and the size of occluder were matched between the two groups. The changes in the following indices were compared between the two groups: left ventricular voltage, QT interval, corrected QT interval (QTc), QT dispersion (QTd), corrected QT dispersion (QTcd), JT dispersion (JTd), and corrected JT dispersion (JTcd) on the electrocardiogram before transcatheter closure and at 1, 3, 5, 30 days after transcatheter closure.

RESULTSLeft ventricular voltage and JTcd changed with operation time in the CLBBB and control groups (P<0.05). There were interaction effects between time and grouping in the changes in left ventricular voltage and QTd (P<0.05). There was a significant difference in JTcd between the CLBBB and control groups (P<0.05). There was also a significant difference in left ventricular voltage between the CLBBB and control groups at 3 and 5 days after the transcatheter closure (P<0.05).

CONCLUSIONSThere are significant differences in electrocardiographic left ventricular voltage and JTcd between VSD children with and without CLBBB early after transcatheter closure. JTcd might be useful in predicting the development of CLBBB early after transcatheter closure of VSD.

Adolescent ; Bundle-Branch Block ; physiopathology ; Cardiac Catheterization ; Child ; Child, Preschool ; Electrocardiography ; Female ; Heart Septal Defects, Ventricular ; surgery ; Humans ; Male ; Postoperative Complications ; physiopathology

Cardiac resynchronization therapy (CRT) has been shown to reduce the risk of death and hospitalization in patients with advanced heart failure with left ventricular dysfunction. However, controversy remains regarding who would most benefit from CRT. We performed a meta-analysis, and meta-regression in an attempt to identify factors that determine the outcome after CRT. A total of 23 trials comprising 10,103 patients were selected for this meta-analysis. Our analysis revealed that CRT significantly reduced the risk of all-cause mortality and hospitalization for heart failure compared to control treatment. The odds ratio (OR) of all-cause death had a linear relationship with mean QRS duration (P=0.009). The benefit in survival was confined to patients with a QRS duration > or =145 ms (OR, 0.86; 95% CI, 0.74-0.99), while no benefit was shown among patients with a QRS duration of 130 ms (OR, 1.00; 95% CI, 0.80-1.25) or less. Hospitalization for heart failure was shown to be significantly reduced in patients with a QRS duration > or =127 ms (OR, 0.77; 95% CI, 0.60-0.98). This meta-regression analysis implies that patients with a QRS duration > or =150 ms would most benefit from CRT, and in those with a QRS duration <130 ms CRT implantation may be potentially harmful.
Bundle-Branch Block/physiopathology ; Cardiac Resynchronization Therapy/*methods ; Cardiac Resynchronization Therapy Devices ; Defibrillators, Implantable ; Electrocardiography ; Heart Failure/mortality/physiopathology/*therapy ; Humans ; Myocardial Contraction/*physiology ; Treatment Outcome ; Ventricular Dysfunction, Left/mortality/physiopathology/*therapy

A patient with non-ischaemic cardiomyopathy, and pre-existing atypical atrial flutter and left bundle branch block, developed broad complex tachycardia. In this unique and uncommon case of double tachycardia, we discuss the diagnostic approach of ventricular tachycardia in patients with broad complex tachycardia, and the use of different contemporary algorithms to help diagnose ventricular tachycardia and differentiate it from supraventricular tachycardia with aberrant conduction.
Algorithms ; Atrial Flutter ; complications ; diagnosis ; Bundle-Branch Block ; physiopathology ; Cardiomyopathies ; complications ; diagnosis ; Diagnosis, Differential ; Echocardiography ; Electrocardiography ; Humans ; Male ; Middle Aged ; Tachycardia, Supraventricular ; diagnosis ; physiopathology ; Tachycardia, Ventricular ; diagnosis ; physiopathology

BACKGROUNDIncomplete right bundle branch block (ICRBBB) is commonly associated with atrial septal defect (ASD), but lacks sufficient diagnostic test characteristics. An abnormal T wave is also often observed in ASD, with horizontal or inverted displacement of the proximal T wave limb in the right precordial leads, termed "defective T wave" (DTW).

METHODSWe examined the diagnostic test characteristics of combining ICRBBB with DTW as a new index to diagnose ASD. A total of 132 consecutive patients with ASD and 132 cases of age/gender-matched controls without ASD were enrolled.

RESULTSSensitivities of DTW, ICRBBB, and both were 87.1% - 87.9%. Specificities were 97.0%, 96.2%, and 100%, respectively. Positive predictive values were 1.3%, 1.1%, and 100.0% respectively, while negative predictive values were 99.9% for each.

CONCLUSIONCombining ICRBBB with DTW in electrocardiogram (ECG) as a new index significantly increased the specificity and positive predictive values while maintaining a high sensitivity in diagnosing ASD.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Bundle-Branch Block ; diagnosis ; physiopathology ; Child ; Child, Preschool ; Electrocardiography ; Female ; Heart Septal Defects, Atrial ; diagnosis ; Humans ; Male ; Middle Aged ; Predictive Value of Tests ; Sensitivity and Specificity

OBJECTIVETo simplify the methods of transcatheter mapping and ablation in the pediatric patients with left posterior fascicular tachycardia.

METHODWhile in sinus rhythm, the fascicular potential can be mapped at the posterior septal region (1 - 2 cm below inferior margin of orifice of coronary sinus vein), which display a biphasic wave before ventricular wave, and exist equipotential lines between them. When the fascicular potential occurs 20 ms later than the bundle of His' potential, radiofrequency was applied. Before applying radiofrequency, catheter position must be observed using double angle viewing (LAO 45°RAO 30°), and it should be made sure that the catheter is not at His' bundle. If the electrocardiogram displays left posterior fascicular block, the correct region is identified and ablation can continue for 60 s. Electrocardiogram monitoring should continue for 24 - 48 hours after operation, and notice abnormal repolarization after termination of ventricular tachycardia. Aspirin [2 - 3 mg/(kg·d)] was used for 3 months, and antiarrhythmic drug was discontinued. Surface electrocardiogram, chest X-ray and ultrasound cardiography were rechecked 1 d after operation. Follow-up was made at 1 month and 3 months post-discharge. Recheck was made half-yearly or follow-up was done by phone from then on.

RESULTFifteen pediatric patients were ablated successfully, and their electrocardiograms all displayed left posterior fascicular block after ablation. None of the patients had recurrences during the 3 to 12 months follow-up period. In one case, the electrocardiogram did not change after applying radiofrequency ablation and the ventricular tachycardia remained; however, on second attempt after remapping, the electrocardiogram did change. The radiofrequency lasted for 90 seconds and ablation was successful. This case had no recurrences at 6 months follow-up.

CONCLUSIONTranscatheter ablation of the fascicular potential in pediatric patients with left posterior fascicular tachycardia can simplify mapping, reduce operative difficulty and produce a distinct endpoint for ablation.

Adolescent ; Bundle-Branch Block ; physiopathology ; surgery ; Catheter Ablation ; methods ; Child ; Electrocardiography ; Female ; Humans ; Male ; Tachycardia, Ventricular ; physiopathology ; surgery

Adult ; Brugada Syndrome ; complications ; physiopathology ; Bundle-Branch Block ; Electrocardiography ; Humans ; Male

INTRODUCTIONAntimonial compounds are regarded as the treatment of choice for cutaneous leishmaniasis (CL). Systemic administration of these drugs has some side effects including cardio toxicity and electrocardiogram (EKG) changes. The objective of our study was to evaluate EKG changes in the patients with CL treated with systemic glucantime.

MATERIALS AND METHODSOne hundred and thirty-one patients were enrolled in this prospective study. All of the selected patients had confirmed CL and were candidates for treatment with systemic glucantime. The patients were treated with systemic glucantime and EKG was performed before, during (weekly) and 1 month after cessation of the treatment. All of the collected data were analysed using SPSS software.

RESULTSThe most common change was prolonged QT interval that was seen in 19% of the patients. ST depression occurred in 6.1% of the patients. Minimal ST elevation occurred in 3% and inverted T was observed in 7.4% of the patients. Single premature atrial contraction (PAC) and single premature ventricular contraction (PVC) occurred in 0.7% and 2.29% of patients, respectively. Bradycardia was observed in 10.6% and left bundle branch block in 0.7% of the patients. All of these changes reversed after stopping the treatment except 1 case with left bundle branch block that lasted for 1 month after the treatment.

CONCLUSIONSOur results showed that treatment with glucantime can induce many ECG changes as QT prolongation have significant risk. We suggest that ECG monitoring should be performed in high-risk patients undergoing glucantime treatment with special attention to ECG changes mostly prolonged QT interval.

Administration, Oral ; Adult ; Animals ; Antimony ; Antiprotozoal Agents ; administration & dosage ; adverse effects ; Atrial Premature Complexes ; chemically induced ; physiopathology ; Bradycardia ; chemically induced ; physiopathology ; Bundle-Branch Block ; chemically induced ; physiopathology ; Dose-Response Relationship, Drug ; Electrocardiography ; drug effects ; Female ; Follow-Up Studies ; Humans ; Leishmaniasis, Cutaneous ; complications ; drug therapy ; physiopathology ; Male ; Meglumine ; administration & dosage ; adverse effects ; Organometallic Compounds ; administration & dosage ; adverse effects ; Prognosis ; Prospective Studies ; Ventricular Premature Complexes ; chemically induced ; physiopathology

This paper presents a method of using feature searching algorithm based on maximal divergence value to get the optimized feature combinations at different dimensions from feature space. Feature space is obtained through wavelet transform on ECG beat. Then the feature vector is determined by analyzing the changes of divergence value of those optimized feature combinations along with the dimensions. BP artificial neural network is trained by the feature vector and four types of ECG beats(normal beat, left bundle branch block beat, right bundle branch block beat and paced beat) obtained from MIT-BIH database are classified with a success of 93.9%.
Algorithms ; Bundle-Branch Block ; classification ; physiopathology ; Electrocardiography ; methods ; Humans ; Neural Networks (Computer) ; Signal Processing, Computer-Assisted

BACKGROUNDUsing tissue Doppler imaging and conventional echocardiographic technique, we examined the cardiac function and synchronicity in individuals with isolated right bundle branch block (RBBB) or left bundle branch block (LBBB) and assessed the relationship between QRS duration and synchronicity.

METHODSSubjects with isolated RBBB (n = 20), LBBB (n = 10) and normal controls (n = 20) were studied with conventional echocardiography and tissue Doppler imaging. The difference between aortic and pulmonary preejection intervals was defined as interventricular delay. Parameters in septum and lateral wall were measured using tissue Doppler imaging, including peak sustained systolic velocity (S(M)), peak early (E(M)) and late (A(M)) diastolic velocities as well as time to peak velocities (T(S), T(E) and T(A)).

RESULTSSubjects with LBBB had lower S(M) and longer T(S) than did the RBBB and control groups (P < 0.05, P < 0.001 respectively). A significant difference was observed in E(M), being the lowest in the LBBB and the highest in the control group (P < 0.05). Moreover, T(E) was longer in the LBBB group compared with the other two groups (P < 0.001). Both A(M) and T(A) were similar among three groups (P > 0.05). In the bundle branch block groups, one ventricle lagged about 40 ms behind the other. A significant correlation was found between interventricular delay and QRS duration (r = 0.713, P < 0.001).

CONCLUSIONSCardiac ventricles were not well synchronized with one ventricle lagging about 40 ms behind the other in subjects with LBBB or RBBB, even though only LBBB group showed barely perceptible, impaired cardiac function. In addition, QRS duration and cardiac asynchronicity were positively correlated.

Adult ; Aged ; Bundle-Branch Block ; diagnostic imaging ; physiopathology ; Diastole ; Echocardiography, Doppler ; methods ; Electrocardiography ; Female ; Heart ; physiopathology ; Humans ; Male ; Middle Aged ; Systole