Mapping myocardial elasticity changes after RF-ablation using supersonic shear imaging

Shear Wave Imaging was used to monitor radiofrequency ablation (RFA) of myocardial tissues in vivo and in vitro. This technique was used to quantify and to map the myocardial stiffness before and after cardiac ablation. Experiments were performed in vivo on a sheep and in vitro samples of bovine muscle. The feasibility of mapping the myocardial elasticity was demonstrated in vitro after RFA. A strong increase of the myocardial stiffness was found after RFA. In vivo, the normal variation of the myocardial stiffness was measured during the cardiac cycle. The Young´s modulus was found 8 times higher in the systolic phase than in the diastolic phase. During ablation a significant increase of the Young´s modulus was observed in the diastolic phase whereas a sudden decrease was observed in systole.