[Echographic calculation of left ventricular mass in TM mode]

Area of Science:

• Cardiology
• Medical Imaging
• Echocardiography

Background:

• Transthoracic (TM) measurements of left ventricular mass (LVM) are typically validated using fundamental (F) imaging.
• Newer imaging modalities, harmonic (H) and colour tissue Doppler (CTD), may impact TM measurements of LVM.

Purpose of the Study:

• To evaluate the effect of harmonic (H) and colour tissue Doppler (CTD) imaging on transthoracic (TM) measurements of left ventricular mass (LVM).
• To compare these measurements against traditional fundamental (F) imaging and assess inter-observer reproducibility.

Main Methods:

• A prospective study involving 26 patients with valid TM sections.
• Left ventricular (LV) and LVM parameters were assessed using F, H, and CTD modes, applying both Penn and ASE conventions.
• Inter-observer reproducibility was analyzed for all imaging modes.

Main Results:

• High correlations were observed between F and H (r>0.95) and F and CTD (r>0.95) for LVM measurements, irrespective of convention.
• LVM measurements in H and CTD modes were consistently higher than in F mode (p<0.02).
• False diagnoses of LV hypertrophy occurred in 27% of patients with H and 15% with CTD. Harmonic imaging demonstrated superior inter-observer reproducibility (23+/-15) compared to F (32+/-19) and CTD (59+/-18).

Conclusions:

• Harmonic (H) and CTD imaging lead to an overestimation of LVM, primarily due to increased parietal thickness measurements.
• Inter-observer reproducibility was excellent for H imaging but poor for CTD.
• New formulae are required for validated LVM calculations using harmonic imaging.