A transducer arrangement causes target tissue of the body to vibrate and senses resulting vibration of the target tissue. Changes in one or more mechanical properties of the target tissue are measured based on the sensed vibration. Changes in one or more electromechanical properties of the target tissue can also be measured based on the sensed vibration and various electrical parameters. An output indicative of the measured changes in the one or more mechanical and/or electromechanical properties of the target tissue is generated. Changes in elasticity of the target tissue, for example, can be measured based on the sensed vibration, such as changes resulting from ablation of the target tissue.