Abstract Hypertrophic cardiomyopathy (HCM) is characterized by a thickened but nondilated left ventricle in the absence of any other cardiac or systemic condition capable of producing the magnitude of hypertrophy…
Abstract Bundle branch reentrant (BBR) ventricular tachycardia (VT) is a macroreentrant VT with a well-defined reentry circuit, incorporating the right and left bundle branches as obligatory limbs of the circuit,…
Abstract Bypass tracts (BTs) are remnants of the atrioventricular (AV) concaused by incomplete embryological development of the AV annuli and failure of the fibrous separation between the atria and ventricles….
Abstract A “supraventricular” origin of a tachycardia implies the obligatory involvement of one or more cardiac structures above the bifurcation of the His bundle (HB), including atrial myocardium, atrioventricular node…
Abstract Wide complex tachycardia (WCT) is a rhythm with a rate of more than 100 beats/min and a QRS duration of more than 120 milliseconds. Several arrhythmias can manifest as…
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 The term typical atrial flutter (AFL) is reserved for a macroreentrant circuit with the activation wavefront rotating clockwise or counterclockwise around the tricuspid annulus and using the cavotricuspid isthmus…
Abstract Focal atrial tachycardia (AT) is characterized by atrial activation starting at a small area (focus), from which it spreads out centrifugally. “Focal” implies that the site of origin cannot…
Abstract Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common form of paroxysmal supraventricular tachycardia. The exact electroanatomic circuit responsible for AVNRT remains elusive. Current evidence suggests that dual atrioventricular…
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…
