Anatomic M-mode echocardiography: A new approach to assess regional myocardial function - A comparative in vivo and in vitro study of both fundamental and second harmonic imaging modes

Objective: To evaluate the accuracy of anatomic M-mode echocardiography (AMM). Methods: Eight phantoms were rotated on a device at different insonation depths (IDs) in a water beaker. They were insonated with different transducer frequencies in fundamental imaging (FI) and second harmonic imaging (SHI), and the diameters were assessed with conventional M-mode echocardiography (CMM) and AMM with the applied angle correction (AC) after rotation. In addition left ventricular wall dimensions were measured with CMM and AMM in FI and SHI in 10 volunteers. Results: AC had the greatest effect on the measurement error in AMM followed by ID (AC: R-2 = 0.295, ID: R-2 = 0.268; P < .0001). SHI improved the accuracy, and a difference no longer existed between CMM and AMM with an AC up to 60 degrees. In vivo the limit of agreement between AMM and CMM was -1.7 to +1.8 mm in SHI. Conclusion: Within its limitations (AC < 60 degrees; ID < 20 cm), AMM could be a robust tool in clinical practice.