Endocardial mapping during sinus rhythm in patients with coronary artery disease and nonsustained ventricular tachycardia

Human Histopathology of Electroanatomic Mapping After Cooled‐Tip Radiofrequency Ablation to Treat Ventricular Tachycardia in Remote Myocardial Infarction

“…Ablation of VT often requires the use of modern mapping tools enabling substrate‐based ablation approaches in effectively suppressing VT in over 80% 4–6,10–15 . Electroanatomic mapping is specifically helpful in identifying regions of myocardial scar based on the amplitudes of endocardial electrograms.…”

“…Based on experimental data in animals it is assumed that electrogram amplitudes ≤0.5 mV are generated by dense scar tissue, whereas normal myocardium has electrogram amplitudes ≥1.5 mV. The exit area of VTs known to be within diseased myocardial areas can be approximated by pace mapping and ablated without further need for a “running” tachycardia 4–15 . No morphological correlation of morphological damage of human ventricular tissue to these voltage cutoff values exists.…”

“…The exit area of VTs known to be within diseased myocardial areas can be approximated by pace mapping and ablated without further need for a "running" tachycardia. [4][5][6][7][8][9][10][11][12][13][14][15] No morphological correlation of morphological damage of human ventricular tissue to these voltage cutoff values exists. In addition, only limited knowledge from case reports on the human morphology of radiofrequency (RF) ablation lesions in ischemic diseased hearts exists.…”

Endocardial Electrogram Analysis after Intramyocardial Injection of Mesenchymal Stem Cells in the Chronic Ischemic Myocardium

“…Based on a three‐dimensional electromechanical mapping technique, the present study analyzes the change of LV endocardial electrogram fragmentation, duration, and amplitude in the area of the injected cells. A pathological increase of these parameters would exhibit the electrophysiological precondition for intramyocardial depressed conduction velocity and ventricular reentry tachycardias 10–13 . Therefore, the aim of the study was to evaluate the substrate modification and potential of arrhythmogeneic effects after intramyocardial MSC injection in a large animal model.…”

Substrate Mapping:

“…Abnormal patterns of endocardial activation and electrogram characteristics during sinus rhythm have been described in humans with coronary artery disease and ventricular arrhythmias using catheter mapping 20,21 . Most extensive endocardial electrogram abnormalities were observed in patients who presented with sustained monomorphic VT and correlated with induction of sustained arrhythmia 22 . Initial attempts at surgical ablation of VT based on sinus rhythm mapping demonstrated that electrogram characteristics were not sufficiently specific to guide discrete ablation of VT 20 , 23 .…”