Purpose: The aim of this study was to quantify LV longitudinal and septal contribution to SV (SVlong% and SVsept%) and test the hypothesis that these parameters could predict treatment effects in patients undergoing CRT.
Methods: Eighty-one patients (22 women) eligible for CRT were prospectively recruited for CMR. SVlong% and SVsept% (Figure 1) were compared to outcome measures. Outcome was assessed as LV reverse remodeling, defined as reduced LV end-systolic volume (LVESV) measured by echocardiography. CMR measures were compared with 20 age and gender matched healthy controls.
Results: Fifty-four patients completed the study protocol (18 women; 67.8 ± 7.9 [mean ± SD] years). Septal movement in patients contributed -0.5 ± 13.5% to SV vs 9.5 ± 4.4% in controls (p<0.01) and longitudinal AVPD movement 8.2 ± 2.7 mm vs 15.3 ± 1.6 mm in controls (p=0.5). ?LVESV between six months follow-up and baseline was -18.0 ± 20.5%. There were no differences in SVlong% nor SVsept% between responders and non-responders (Table 1).
Conclusion: Quantitative assessment of septal movement showed almost half of the patients eligible for CRT had a septal shift towards the right ventricle during systole. This negative septal contribution to SV was compensated by increased lateral contributions. However, LV reverse remodeling did not relate to pre-operative septal motion to the left or right or to longitudinal contribution to SV.