Arrhythmias, Cardiac ; Brugada Syndrome ; Cardiac Conduction System Disease ; Heart ; Heart Conduction System ; abnormalities ; Humans ; Magnetic Resonance Spectroscopy

Arrhythmias, Cardiac ; diagnosis ; Brugada Syndrome ; Cardiac Conduction System Disease ; Coronary Vessels ; pathology ; Heart Conduction System ; abnormalities ; Humans ; Male ; Middle Aged

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

Arrhythmias, Cardiac ; Brugada Syndrome ; Cardiac Conduction System Disease ; Coma ; etiology ; Electrocardiography ; Female ; Heart Conduction System ; abnormalities ; Humans ; Organophosphate Poisoning ; complications ; diagnosis

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

Acute Coronary Syndrome ; therapy ; Angina, Unstable ; Arrhythmias, Cardiac ; Brugada Syndrome ; Cardiac Conduction System Disease ; Heart Conduction System ; abnormalities ; Humans ; Myocardial Infarction

Restoration of blood flow is the definitive therapy to salvage myocardium following ischemic injury. Sudden restoration of blood flow to the ischemic myocardium may, however, also cause reperfusion injury. Therefore, to prevent such ischemia/reperfusion (I/R) injury, one strategy could be to evoke endogenous myocardial protective mechanisms. Ischemic preconditioning (IPC) and postconditioning (I-postC) are endogenous protective mechanisms capable of protecting the myocardium from myocardial infarction, stunning, and ventricular arrhythmia induced by I/R injury. The mechanisms involve induction of triggers, activation of signaling pathways, and end-effectors, which attenuate generation of free radicals and calcium overload induced by I/R. The fact that I-postC can be applied after a prolonged period of ischemia offers a novel approach to myocardial protection. This article mainly reviews the cardioprotection, mechanisms, and application to clinical cardiology of I-postC.
Animals ; Arrhythmias, Cardiac ; Brugada Syndrome ; Cardiac Conduction System Disease ; Heart Conduction System ; abnormalities ; Humans ; Ischemic Postconditioning ; Myocardial Infarction ; Myocardial Reperfusion Injury ; Myocardium ; Reperfusion Injury ; Signal Transduction

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

OBJECTIVETo investigate the clinical characteristics of a Chinese pedigree with cardiac conductive disease complicated by atrial fibrillation and the therapeutic effect of the treatments.

METHODSAll the family members including the proband were screened with routine examination, electrocardiography, echocardiograpy, Holter recording, chest X-ray, blood biochemistry tests and autoantibody test. The proband received dual chamber pacemaker implantation combined with oral amiodarone treatment for 3 months. The patient was monitored for thyreoid function and chest X-ray during the treatments, and was followed up for another 3 months.

RESULTSClinical evidence of organic heart disease was found in none of the family members. The proband showed recurrent dizziness and chest distress, which exacerbated after exercise, and ECG showed atrial fibrillation and severe A-V block. The proband's uncle was found to have atrial fibrillation and III degree A-V block after a syncope episode at the age of 30, and received a pacemaker treatment. Her grandpa died from a heart attack without detailed clinical documentations. No other family members showed abnormal ECG or a history of any heart events. The proband's condition was improved by treatments, after which ECG and Holter recording showed pace rhythm without atrial fibrillation.

CONCLUSIONCardiac conductive disease with atrial fibrillation can present in one family, and can be managed effectively and safely with implantation of dual chamber pacemaker combined with oral amiodarone.

Asian Continental Ancestry Group ; Atrial Fibrillation ; complications ; genetics ; therapy ; Atrioventricular Block ; complications ; genetics ; therapy ; Cardiac Resynchronization Therapy ; Female ; Heart Conduction System ; abnormalities ; Humans ; Pedigree ; Young Adult

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