Feasibility of Echocardiographic Diastolic Parameters and Algorithms
Most of the 2016 parameters had feasibility above 95 %, except TR Vmax (65 %), pulmonary parameters (64-70 %), mitral valve A velocity and E/A ratio (93 %) (Table 2). Poor feasibility of TR Vmax was due to indistinct visualization of an envelope for proper labelling, the mitral valve A velocity, and as consequence E/A ratio, was mostly (73 %) due to atrial fibrillation. The remaining parameters used in the 2009 guidelines had moderate feasibility below 80 %, except the mitral valve DT (99 %) (Table 2).
The 2009 algorithm is challenged with many indeterminate cases by its assumption of a combined enlarged LA and reduced e’, in order to distinguish DD from normal diastolic function (Figure 2). In our population all cases were assumed as having abnormal diastolic function, since patients were planning to undergo cardiac surgery. According to the 2009 algorithm DD was graded by allowing the majority of the five suggested parameters (E/A ratio, decrease in E/A ratio during Valsalva, time difference between the pulmonal reversal A-wave and mitral A-wave, average E/e’ and mitral valve DT) decide the gradings. 85 cases (24 %) had indeterminate gradings. According to the 2016 algorithm, 39 cases (11 %) had indeterminate grading of DD; 27 with unavailable E/A ratio, 8 with two available criteria and unavailable S/D ratio and 4 with only one available criterion.