Adult ; Arrhythmias, Cardiac ; diagnosis ; physiopathology ; Brugada Syndrome ; Cardiac Conduction System Disease ; Electrocardiography ; Female ; Heart Conduction System ; abnormalities ; physiopathology ; Humans ; Young Adult

The early cardiac biological pacemaker studies were mostly around HCN channel, and how to build a biological pacemaker through the enhanced If current. In recent years, however, people found that the genes of Tbx3 could play an important role in the development of cardiac conduction system, especially in processes of the maturity of the sinoatrial node and maintenance of its function. And the Tbx3 can further optimize the biological pacemaker. Therefore, it could be a new therapeutic focus in biological pacemaker and treatment of cardiac conduction system disease. This paper summarizes some of the latest research progress of the Tbx3 in biological pacemaker in recent years. We hope that this review could provide theoretical basis for the clinical applications of Tbx3.
Arrhythmias, Cardiac ; genetics ; Biological Clocks ; Brugada Syndrome ; Cardiac Conduction System Disease ; Heart ; physiopathology ; Heart Conduction System ; abnormalities ; Humans ; Sinoatrial Node ; T-Box Domain Proteins ; genetics

PURPOSE: Recent studies show positive association of early repolarization (ER) with the risk of life-threatening arrhythmias in patients with coronary artery disease (CAD). This study was to investigate the relationships of ER with myocardial scarring and prognosis in patients with CAD. MATERIALS AND METHODS: Of 570 consecutive CAD patients, patients with and without ER were assigned to ER group (n=139) and no ER group (n=431), respectively. Myocardial scar was evaluated using cardiac single-photon emission computed tomography. RESULTS: ER group had previous history of myocardial infarction (33% vs. 15%, p<0.001) and lower left ventricular ejection fraction (57+/-13% vs. 62+/-13%, p<0.001) more frequently than no-ER group. While 74 (53%) patients in ER group had myocardial scar, only 121 (28%) patients had in no-ER group (p<0.001). During follow up, 9 (7%) and 4 (0.9%) patients had cardiac events in ER and no-ER group, respectively (p=0.001). All patients with cardiac events had ER in inferior leads and horizontal/descending ST-segment. Patients with both ER in inferior leads and horizontal/descending ST variant and scar had an increased adjusted hazard ratio of cardiac events (hazard ratio 16.0; 95% confidence interval: 4.1 to 55.8; p<0.001). CONCLUSION: ER in inferior leads with a horizontal/descending ST variant was associated with increased risk of cardiac events. These findings suggest that ER in patients with CAD may be related to myocardial scar rather than pure ion channel problem.
Aged ; Arrhythmias, Cardiac/physiopathology ; Cicatrix/*physiopathology ; Coronary Artery Disease/*pathology/*physiopathology ; Death, Sudden, Cardiac/pathology ; Female ; Heart Conduction System/abnormalities/physiopathology ; Humans ; Male ; Middle Aged ; Myocardium/*pathology ; Prognosis

We discuss two cases of incessant atrial tachycardia (AT), including the presentation and clinical course. It is important to differentiate AT from other causes of supraventricular tachycardia, such as atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT), as it would have implications on clinical management. Electrocardiographic features of AT, especially the presence of an AV Wenckebach phenomenon with 'grouped beating', are critical for differentiating AT from AVRT and AVNRT. It is also vital to identify the P waves and their relations to QRS on electrocardiography, as this would aid in the differentiation of various supraventricular tachycardias.
Aged ; Diagnosis, Differential ; Electrocardiography ; Electrophysiology ; Female ; Heart Conduction System ; abnormalities ; Hemodynamics ; Humans ; Male ; Respiration ; Tachycardia ; diagnosis ; Tachycardia, Atrioventricular Nodal Reentry ; diagnosis ; Tachycardia, Supraventricular ; diagnosis ; Tricuspid Valve ; physiopathology

We investigated whether the presence of J wave on the surface electrocardiography (sECG) could be a potential risk factor for ventricular fibrillation (VF) during acute myocardial infarction (AMI). We performed a retrospective study of 317 patients diagnosed with AMI in a single center from 2009 to 2012. Among the enrolled 296 patients, 22 (13.5%) patients were selected as a VF group. The J wave on the sECG was defined as a J point elevation manifested through QRS notching or slurring at least 1 mm above the baseline in at least two leads. We found that the incidence of J wave on the sECG was significantly higher in the VF group. We also confirmed that several conventional risk factors of VF were significantly related to VF during AMI; time delays from the onset of chest pain, blood concentrations of creatine phosphokinase and incidence of ST-segment elevation. Multiple logistic regression analysis demonstrated that the presence of J wave and the presence of a ST-segment elevation were independent predictors of VF during AMI. This study demonstrated that the presence of J wave on the sECG is significantly related to VF during AMI.
Arrhythmias, Cardiac/*diagnosis ; Creatine Kinase/blood ; *Electrocardiography ; Female ; Heart Conduction System/*abnormalities ; Humans ; Male ; Middle Aged ; Myocardial Infarction/*diagnosis/pathology ; Retrospective Studies ; Risk Factors ; Ventricular Fibrillation/*diagnosis/pathology/physiopathology