P697New indices for a best quantification of left ventricular function in heart valve diseases

Aims.

The Assessment of left ventricular (LV) function remains a clinical challenge especially in patients with preserved LV ejection fraction (EF) and valvular heart diseases (VHD). Mechanical dispersion is supposed to be a strong predictor of events and, to be related to the extent of fibrosis. Regional cardiac work is a new validated and very promising approach to quantify LV-function.

We investigated the differences in mechanical dispersions and global LV work (totW) and wasted work fraction (WWF) in normal subjects and in patients with severe primary mitral regurgitation (MR) and severe aortic stenosis (AS).

A complete transthoracic echocardiography was performed in 21 normal subject, 97 patients with severe valvulopathy (47 AS, 50 MR) and preserved LV EF. Segmental strain analysis was performed in all patients and the dispersion of regional LV strain curves was computed automatically considering peaks and integrals. The LV-pressure was estimated non-invasively using a standard waveform fitted to valvular events and scaled to systolic blood pressure. Using pressure-strain loops, regional cardiac work indices were computed.

LVEF was 66±12 in controls, 65±9 in MR and 65±4% in AS (p=0.125). Global longitudinal strain was -23±2.7 in controls, -24±2.9 in MR and -18±3.2% in AS (p < 0.001). The mechanical dispersion was 38±7.9 in controls, 36±11 in MR, and much higher in the hypertrophied LV of the AS: 60±19ms (p < 0.001). Cardiac work was 2200±260 in controls, 2100±270 in MR, and much lower in AS: 1700±280 mmHg.% (p < 0.001). The wasted work fraction (WWF) was even more describing how different the LV systolic function is in the 3 groups (figure1).

Longitudinal strain data are robusted and new indices might be calculated based on them. These seem especially promising for a more pathophysiological driven analyzing of LV-functions. Abstract P697 Figure.

Abstract P697 Figure.