Bipolar electrogram amplitudes in the left atrium are related to local conduction velocity in patients with atrial fibrillation

Abstract

There was a significant slowing of local conduction in the LVZ defined as <0.5 mV and was frequently associated with fractionated or double potentials in patients with AF.

The Na+/K+ pump is an important modulator of refractoriness and rotor dynamics in human atrial tissue

“…In contrast, AFERinduced changes in ionic currents lead to only a slight decrease in steady-state CV from 47.97 cm/s in control to 46.17 cm/s in AFER, using the MGGT model, and from 58.14 cm/s in control to 56.38 cm/s using the CRN model. This decrease (49) in steady-state CV in AFER is in agreement with results in clinical studies (44,47) and quantitatively consistent with those reported in previous studies of AF (13).…”

“…Our study focused on the importance of ionic mechanisms in modulating electrophysiological properties related to rotor dynamics, and, therefore, other important aspects such as ectopic activity, structural changes during AF, tissue anisotropy, and heterogeneities caused by vagal stimulation are not investigated (15,20,39,44). Even though their effect on AF-related reentry could be important as shown in previous studies (15), they would have a confounding effect on the results interpretation and should be the focus of further investigations.…”

Three-Dimensional Mapping of Cardiac Arrhythmias

“…38 We examined how the low-voltage zone was related to the local conduction velocity and electrogram morphology in those with an early stage of AF. 39 We found that the low-voltage zones were mainly distributed along the septal, anterior and posterior LA, and those with a low-voltage zone had a longer total activation time than those without (107±25 ms vs. 85±13 ms, P<0.05). We also found that the conduction velocity was slower in the areas with a low-voltage zone as compared to those without (1.4±0.6 mV vs. 0.8±0.5 mV, P<0.01) and that they had a higher prevalence of double or fragmented electrograms.…”

Left Atrial Wall Stress Distribution and Its Relationship to Electrophysiologic Remodeling in Persistent Atrial Fibrillation

“…31,32 Furthermore, low voltage may denote zones of slow conduction. 33 Foci of high wall stress may induce remodeling by directly activating signaling pathways such as cAMP, angiotensin II, and others. 34 However, the observation that an acute decrease in intra-atrial pressure can cause an immediate increase electrogram amplitude and conduction velocity suggests a role for focal activation of stretch activated ion channels.…”