Central hemodynamic parameters
CARDIAC OVERLOAD
The assessment of arterial wave reflection was performed non-invasively using a commercially available tonometry device (SphygmoCor, AtCor Medical, Sydney, Australia). The SphygmoCor system uses a validated generalized transfer function to generate the corresponding central aortic pressures after acquiring 10 sequential waveforms. Aortic systolic pressure (ASP), aortic pulse pressure (APP), augmentation pressure (AP), augmentation index (AIx), SEVR and ejection duration (ED) derived from pulse waveform analysis. SEVR is an index of subendocardial viability that has already been compared with invasive methods and has been considered a measure of myocardial perfusion relative to cardiac overload. In pulse wave analysis, SEVR was defined as SEVR = aortic diastolic area/ aortic systolic area.