Age-related intramyocardial patterns in healthy subjects evaluated with Doppler tissue imaging

The aim of this study is to analyse spatial distribution of myocardial velocities (MV) and myocardial velocity gradient (MVG) with color M-mode Doppler tissue imaging (DTI) and to analyse the influence of age in such parameters.

A prospective study including 66 healthy volunteers was carried out with color M-mode DTI. Postprocessing of images was performed using proprietary software allowing the division of the myocardial wall into subendocardium, mesocardium and subepicardium. MV corresponding to the three layers and MVG time curves were obtained and systolic, early diastolic and late diastolic peak values were identified. MV were highest in subendocardium in systole, protodiastole and telediastole compared to external layers. Protodiastolic peak MV decreased in all layers with age, but with a higher impact in the subendocardium (r = 0.72, b = 0.136 (IC 95% 0.107-0.164), p = 0.0005). Older age resulted in larger telediastolic peak MV, without significant differences among layers. Linear correlation between protodiastolic peak mitral flow and peak protodiastolic velocity was higher in endocardium than in other layers (r = 0.79, p = 0.0005).

Color M-mode DTI multilayer analysis showed that endocardium is more susceptible to age-related changes involving diastolic function. This dependency on age should be considered when assessing MV in other clinical settings.