Voltage and activation mapping. how the recording technique affects the outcome of catheter ablation procedures in patients with congenital heart disease

Long-Term Outcome After Ablation of Right Atrial Tachyarrhythmias After the Surgical Repair of Congenital and Acquired Heart Disease

“…Crucial pathways of the reentry circuit of most noneCTI-dependent AFL were located between areas of scar tissue, predominantly in areas of the anterolateral right atrium, indicating necessity of accurate delineation of low-voltage areas. 19 Typical CTI-dependent AFL circuit is the predominant macroreentrant arrhythmia in structurally normal hearts as it occurs in patients operated on for AHD. In contrast, in patients operated on for CHD, the reentrant circuits are highly variable because of individual differences in original anatomy and surgical modifications.…”

Modern Electrophysiology Mapping Techniques

“…Again, consideration of the activation wavefront in the adjacent myocardium will assist with annotation. However, activation times should not be assigned to areas representing scars, as suggested by a bipolar endocardial amplitude of <0.05-0.1 mV in the atrium and <0.5 mV in the ventricle, and the absence of capture at 10 mA [14,15,17]. APPROPRIATE WINDOW OF INTEREST.…”

“…Anatomic sites with interesting electrophysiological observations such as double potentials, fractionated EGMs, late or mid-diastolic potentials are also "tagged". Typically, areas with a bipolar endocardial amplitude of <0.05-0.1 mV in the atrium (equivalent to baseline noise in EAM systems) and <0.5 mV in the ventricle, in conjunction with absence of capture at a pacing output of 10 mA, are defined as "dense scars" [14][15][16][17]. Identification of scars within the myocardium is often critical for understanding the propagation of macro-reentrant arrhythmias.…”

Arrhythmias in Adult Congenital Heart Disease

“…34 IARTs are highly organized and often associated with multiple, anatomically complex circuits. [35][36][37][38][39] These circuits are "channeled" into macro-reentrant loops by anatomic boundaries created by natural conduction barriers (such as valve annuli and caval ostia), surgical incisions, cannulation sites, prosthetic patches and baffles, and regions of atrial scarring caused by long exposure to adverse hemodynamic stresses and intermittent inflammatory effects of surgical intervention (Fig. 2).…”