My wife recently said to me that the mitral “E’s and A’s” have been good to me over the years. What does she mean? She is referring to the Doppler assessment of diastolic function. I wanted this President’s page to focus on a topic that is close to my heart, “Diastology.” This is not “Systology,” which is actually intrinsically linked to diastole (global longitudinal strain as an example) but a field that I have been working in for a long time. In fact, there have been over 30,000 publications on diastolic function in the last 20 years. I was taught by the “Diastology” masters including Drs. Hatle, Tajik, Seward, and Thomas. In fact, I was so enthusiastic about diastolic function that I have written a book called “Diastology” and have held yearly symposiums for the last 17 years on the topic.
Why is “Diastology” important to the ASE? Recently Drs. Sherif Nagueh and Otto Smiseth led a team of investigators from ASE and EACVI (who like to “relax” in diastole) in updating the 2009 diastole guideline. The new recommendations on diastolic function were published in JASE in April 2016. After some arm wrestling and détente across both sides of the Atlantic, the writing group agreed to simplify the complex algorithms from the 2009 diastole guideline to easily applied clinical algorithms. This resulted in a document that can be used to provide an estimate of the LV filling pressures and grade of diastolic function in most patients with cardiac pathology and with preserved (HpEF) or reduced ejection fraction (HrEF). After reviewing abnormal parameters such as left volume index and Doppler indices from normal subjects in the NORRE study (n = 1500 subjects from 20 to over 60 years of age), the group recommended important, clinically useful parameters that are measured daily in most echo labs to distinguish normals from abnormals. These included the parameters with cutoff values for the following variables: the average mitral E/é > 14, septal é < 7 cm/s and or lateral é < 10, a left atrial volume index > 34 ml/m 2 and peak TR velocity > 2.8 m/s. If there is a patient referred to the echo lab with hypertension and no known cardiac pathology and preserved systolic function, the clinician can see if > 2 of these 4 parameters are beyond the accepted normal cutoff values and then can label this patient as having abnormal diastolic function with preserved systolic function. Such patients with cardiac pathology (i.e., left ventricular hypertrophy) with preserved EF or a reduced EF (i.e., EF 35%) can get right into the new diastology algorithm.
What does the new algorithm show? Let me tell you! In my view, it is very straightforward to diagnose two conditions: elevated LV filling pressures with Grade 3 diastolic function when the mitral E/A ratio is > 2 or normal filling pressures and Grade 1 diastolic function when the E/A ratio is < 8 and the mitral E wave is <50 cm/s ( Figure 1 ).