Durability of EIVM-created atrial lesions
This study investigated the long-term effect of EIVM by comparative EAM before, immediately after and at the time of repeated CA for recurrent AT. The nature of the myocardial lesions created by EIVM are distinct from those created by RF owing to their intrinsically different mechanisms. RF lesions, created by external thermal energy, have a variable degree of sustainability, which depends on energy delivery parameters, contact force and atrial tissue characteristics.17 In contrast, retrograde ethanol delivery creates a chemical lesion related to ethanol penetration in the myocardium, with venous drainage depending on the VOM, including a variable extent of the LA posterior wall and MI.2 In dogs, EIVM creates an acute and dense pale patch, visible from the endocardium, which suggests transmural damage and transmyocardial ethanol flow.2 In humans, several studies have consistently shown EIVM creating a low-voltage lesion in the VOM region, although to a variable extent.4–6,18,9,14,15,12However, no study has evaluated the sustainability of EIVM over time.
Here, by demonstrating EIVM-created lesion durability in all consecutive patients referred for repeated CA after EIVM, we closed a knowledge gap regarding EIVM lesion characteristics.