Arterial load reduction after cardiac resynchronization therapy: why does it change?

Abstract

We read with interest Zanon et al. 's article1 published in the January 2009 issue, in which the left ventricle (LV)–arterial coupling was evaluated in heart failure patients, as the ratio between the arterial elastance (Ea) and the LV end-systolic elastance (Ees), before and after 1-year of cardiac resynchronization therapy (CRT). The authors found that an increased basal Ea/Ees quotient (afterload mismatch) would determine an increased probability to respond to CRT, when the response was evaluated using the quality-of-life (QoL) score or the LV end-systolic volume (ESV). Based in these results, the authors suggested that ‘the non-invasive quantification of the Ea/Ees may be proposed as an immediate, easy, and optimal tool for quantifying the effect of CRT in patients with heart failure’. The authors said, the Ea/Ees quotient ‘could be useful to select responders to this electrical therapy and to assess the cardiac performance over the time’. We agree with the authors in the Ea/Ees usefulness in the assessment of the cardiac performance. However, we have some questions and comments that we think should be considered at the time of proposing the use of the Ea/Es ratio as a tool to predict the response to CRT and should be taken into account when analysing the Zanon et al. work.1 The authors suggested that the Ea/Ees determination could be useful to quantify the CRT effects and to assess the cardiac performance over time. Accordingly, patients response to CRT was analysed as a function of the basal …