Adult ; Bundle-Branch Block ; physiopathology ; Electrocardiography ; Humans ; Male ; Myocardial Infarction ; complications ; Syndrome ; Ventricular Fibrillation ; etiology ; 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

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

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

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

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

BACKGROUNDPatients with heart failure were candidates for cardiac resynchronization therapy (CRT) regardless of underlying aetiology. This study observed the effect of CRT in patients with ischaemic or nonischaemic cardiomyopathy.

METHODSOne hundred and forty-two patients with refractory chronic heart failure and left bundle branch block received cardiac resynchronization therapy, 91 men and 51 women, average age 60 years. Left ventricular ejection fraction (LVEF) was severely depressed (mean 29%), left ventricular end diastolic diameter (LVEDD) enlarged (mean 72 mm) and QRS width was lengthened (mean 147 ms). Ninety-eight had nonischaemic cardiomyopathy and 44 had ischaemic cardiomyopathy.

RESULTSAfter cardiac resynchronization therapy, the heart function was significantly improved. The mean LVEF increased from 29% to 36% after pacing. In patients with nonischaemic cardiomyopathy, the LVEF was improved from 28% to 37%, and in patients with ischaemic cardiomyopathy, the LVEF was improved from 30% to 36%. No significant difference of the improvement was found between the two groups (P > 0.05).

CONCLUSIONSCardiac resynchronization therapy could significantly improve cardiac function in patients with chronic heart failure regardless of the underlying heart disease.

Bundle-Branch Block ; physiopathology ; therapy ; Cardiac Pacing, Artificial ; methods ; Electrocardiography ; Female ; Heart Failure ; physiopathology ; therapy ; Humans ; Male ; Middle Aged ; Time Factors ; Treatment Outcome ; Ventricular Function, Left ; physiology

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

Malignant lymphoma can involve the cardiac cavity or myocardium as a mass. Clinical symptoms of its cardiac involvement are usually absent or nonspecific, making the diagnosis of the cardiac involvement very difficult before death. We experienced a patient with secondary myocardial non-Hodgkin's lymphoma presenting with sustained ventricular tachycardia (VT) as a primary clinical problem. A 39-yr-old woman visited our hospital because of dyspnea and palpitation for 7 days. Physical examination revealed rapid heart beat with variable intensity of the first heart sound and soft mass in the lower abdomen. VT with a cycle length of 480 msec was recorded in resting 12-lead electrocardiogram. Two well-circumscribed hypo-echogenic round masses were demonstrated in the interventricular septum and left ventricular posterior wall. Cytological examination of aspirated pericardial fluid and percutaneous needle biopsy of the abdominal mass revealed a diffuse large cell type non-Hodgkin's lymphoma. Myocardial masses and ventricular tachycardia resolved with chemotherapy using cyclophosphamide, adriamycin, vincristine and prednisone regimen. To our best knowledge, the same case as ours has not been reported previously.
Abdominal Neoplasms/secondary ; Adult ; Biopsy, Needle ; Bundle-Branch Block ; Echocardiography ; Electrocardiography ; Female ; Heart Neoplasms/*pathology ; Humans ; Lymphoma, Non-Hodgkin/*complications/diagnosis/*pathology ; Myocardium/*pathology ; Tachycardia, Ventricular/*etiology/physiopathology

In order to verify the hypothesis that left ventricular epicardial (LV-Epi) pacing and biventricular (BiV) pacing unavoidably influence the myocardial electrophysiological characters and may result in high risk of malignant ventricular arrhythmia, we calculated, in both normal mongrel dogs and dog models with rapid-right-ventricular-pacing induced dilated cardiomyopathy congestive heart failure (DCM-CHF), the monophasic action potential duration (MAPD) and the transmural dispersion of repolarization (TDR) in intracardiac electrogram together with the QT interval and T(peak)-T(end) (T(p(-T(e)) interval in surface electrocardiogram (ECG) during LV-Epi and BiV pacing, compared with those during right ventricular endocardial (RV-Endo) pacing. To prepare the DCM-CHF dog model, rapid right ventricular pacing (250 bpm) was performed for 23.6+/-2.57 days to the dog. All the normal and DCM-CHF dogs were given radio frequency catheter ablation (RFCA) to His bundle with the guide of X-ray fluoroscopy. After the RFCA procedures, the animals were under the situation of complete atrioventricular block so that the canine heart rates could be voluntarily controlled in the following experiments. After a thoracotomy, ECG and monophasic action potentials (MAP) of subendocardial, subepicardial and mid-layer myocardium were recorded synchronously in 8 normal and 5 DCM-CHF dogs during pacing from endocardium of RV apex (RV-Endo), epicardium of LV anterior wall (LV-Epi) and simultaneously both of the above (biventricular, BiV), the later was similar to the ventricular resynchronization therapy to congestive heart failure patients in clinic. The Tp-Te) meant the interval from the peak to the end of T wave, which was a representative index of TDR in surface ECG. The TDR was defined as the difference between the longest and the shortest MAPD of subendocardial, subepicardial and mid-layer myocardium. Our results showed that in normal dogs, pacing participating of LV (LV-Epi, BiV) prolonged MAPD of all the three layers of the myocardium (P<0.05) with the character that mid-layer MAPD was the longest and subepicardial MAPD was the shortest following subendocardial MAPD. At the same time, TDR prolonged from 26.75 ms at RV-Endo pacing to 37.54 ms at BiV pacing and to 47.16 ms at LV-Epi pacing (P<0.001). Meanwhile in surface ECG, BiV and LV-Epi pacing resulted in a longer Tp-Te) interval compared with RV-Endo pacing (P<0.01), without parallel QT interval prolongation. Furthermore, all the DCM-CHF model dogs showed manifestations of congestive heart failure and enlargement of left ventricles. Based on the lengthening of mid-layer MAPD from 257.35 ms to 276.30 ms (P<0.0001) and increase of TDR from 27.58 ms to 33.80 ms (P equals;0.002) in DCM-CHF model due to the structural disorders of myocardium compared with the normal dog, LV-Epi and BiV pacing also led to the effect of prolonging MAPD of three layers of the myocardium and enlarging TDR. From these results we make the conclusions that prolongation of MAPD of subendocardial, subepicardial and mid-layer myocardium and increase in TDR during pacing participating of LV (LV-Epi, BiV) may contribute to the formation of unidirectional block and reentry, which play roles or at least are the high risk factors in the development of malignant ventricular arrhythmia, especially in case of structural disorders of myocardium. These findings must be considered seriously when ventricular resynchronization therapy is performed to congestive heart failure patients.
Action Potentials ; Animals ; Bundle-Branch Block ; complications ; physiopathology ; Cardiomyopathy, Dilated ; complications ; physiopathology ; Dogs ; Female ; Heart Conduction System ; physiopathology ; Heart Failure ; etiology ; physiopathology ; Heart Ventricles ; physiopathology ; Male ; Torsades de Pointes ; physiopathology ; Ventricular Dysfunction, Left ; physiopathology ; Ventricular Function, Left