Does Implantation of Sonomicrometry Crystals Alter Regional Cardiac Muscle Function?

Background: Sonomicrometry is a gold standard in experimental studies on myocardial motion. However, limited information exists regarding mechanical and biochemical changes produced by sonomicrometry crystal (SC) insertion into the myocardial wall. Methods: In 10 open-chest pigs, we implanted SCs into the inner half of apical anterior and midposterior regions. Longitudinal strains (systolic lengthening, end-systolic, peak shortening, and postsystolic shortening strains) and strain rate (SR) measurements (peak systolic ejection and early and late diastolic SRs) were obtained by Doppler SR echocardiography along with troponin I levels measured from peripheral blood before and after SC insertion. Results: SR and strain parameters did not change significantly after SC implantation. Troponin I levels increased significantly from less than 0.010 to 0.129 ± 0.138 μg/L (P < .005) after SC implantation. Conclusions: Our study demonstrates that despite biochemical evidence of myocardial injury, carefully implanted SCs do not alter systolic or diastolic regional myocardial function assessed by Doppler echocardiography.