Abstract Organized atrial tachycardias (ATs) are broadly categorized as either focal (centrifugal activation originating from a discrete site that incorporates automaticity, triggered activity, and microreentrant mechanisms) or macroreentrant (a relatively…
Abstract A working definition of an atypical bypass tract (BT) is a conduction pathway that bypasses all or part of the normal conduction system but is not a rapidly conducting…
Abstract Sinus tachycardia is a physiological response to sympathetic activation and/or parasympathetic withdrawal. Inappropriate sinus tachycardia (IST) is a nonparoxysmal tachyarrhythmia characterized by a persistent increase in resting sinus rate…
Abstract Cardiac arrhythmias are a common problem in patients with congenital heart disease (CHD), particularly after they have undergone reparative or palliative surgical procedures. Atrial tachyarrhythmias are the most prevalent,…
Abstract Normally, the entire mass of ventricular myocardium is depolarized in about 80 to 100 milliseconds. The term intraventricular conduction disturbances (IVCDs) refers to abnormalities in the intraventricular propagation of…
Abstract While conventional mapping techniques, guided by fluoroscopy, have been very successful in guiding mapping and ablation of stable arrhythmias with predictable anatomical locations or characteristics identifying endocardial electrograms, those…
Abstract Cardiac mapping refers to the process of identifying the temporal and spatial distributions of myocardial electrical potentials during a particular heart rhythm. Mapping aims at elucidation of the mechanism…
Abstract Invasive electrophysiological (EP) testing involves recording a portion of cardiac electrical activity and programmed cardiac electrical stimulation via multipolar catheter electrodes positioned percutaneously strategically at various locations within the…
Abstract Atrioventricular (AV) block can be defined as a delay or interruption in the transmission of an impulse from the atria to the ventricles caused by an anatomical or functional…
Abstract Radiofrequency (RF) is the most frequently used mode of ablation energy for most atrial and ventricular arrhythmias. A major limitation of standard RF ablation is the relatively small depth…
