Diastology
What Is It?
Diastolic dysfunction refers to the heart’s impaired ability to relax and fill during diastole, leading to elevated pressures within the left ventricle (LV) and, ultimately, the left atrium (LA). It doesn’t take a reduction in ejection fraction for a heart to fail—diastolic dysfunction can progress silently for years, culminating in diastolic heart failure. Echocardiography is the gold standard for this assessment, offering a real-time evaluation of hemodynamics using PW of the mitral inflow, TDI of the LV, CW through tricuspid regurgitation, and volumes of the left atrium.
In patients with a normal left ventricular ejection fraction (LVEF), diastolic function is assessed using four key criteria: the average E/e’ ratio, septal and lateral e’ velocities, tricuspid regurgitant velocity, and the left atrial volume index.
If three or four of these criteria are positive, we move on to the next step, which is the "Mitral Inflow" chart. But if the patient has an abnormal LVEF, we skip this first chart entirely and go straight to the “Mitral Inflow” chart.
In patients with an abnormal left ventricular ejection fraction (LVEF), diastolic function is evaluated using the following measurements: E/A ratio, E-wave peak velocity, E/e’ ratio, peak tricuspid regurgitant velocity, and left atrial volume index.
Assessment begins at the top of the flow chart, progressing step by step to determine the severity of diastolic dysfunction based on these values.
Key Takeaways
Diastolic dysfunction means the ventricle is stiff and doesn't fill properly, leading to increased pressures.
A stiff ventricle needs higher filling pressures, which we assess using echocardiography.
The E/e' ratio estimates left ventricular filling pressures; a high value suggests impaired relaxation.
Septal and lateral e' velocities reflect how well the ventricle relaxes—lower values mean reduced compliance.
Peak TR velocity helps estimate right atrial pressure; high values may indicate volume overload.
Left atrial volume index signals chronic diastolic dysfunction. E/A ratio and peak E wave help grade severity.
Use these echo markers with the diastolic dysfunction flow chart and follow local guidelines for accurate classification.
