Echocardiography plays a pivotal role in the diagnosis and differentiation of heart failure types, serving as a fundamental tool in assessing cardiac function and structure. It is especially critical in distinguishing between systolic and diastolic heart failure. In cases of systolic heart failure, or heart failure with reduced ejection fraction (HFrEF), the echocardiogram typically reveals a dilated ventricle with impaired contractility, leading to a decreased ejection fraction. This reflects the heart's reduced ability to pump blood efficiently. In diastolic heart failure the echocardiogram may show a normal ejection fraction with signs of increased ventricular stiffness and impaired relaxation capabilities. These characteristics indicate the heart's inability to fill properly during diastole, despite being able to contract normally. Echocardiographic findings in diastolic dysfunction include normal to elevated ejection fractions alongside indicators of impaired ventricular relaxation, such as alterations in the E to E prime ratio. This ratio, derived from Doppler imaging, assesses the diastolic function by comparing the flow velocities across the mitral valve during passive filling and atrial contraction.
Although the American Society of Echocardiography (ASE) offers detailed guidelines for evaluating left ventricular diastolic function by echocardiography, anesthesia providers are cautioned that these guidelines may not fully translate to the perioperative setting. Other factors should be considered when assessing the patient.
Evaluating diastolic function also necessitates considering the patient's age, as left ventricular (LV) relaxation inherently decreases with aging, potentially mimicking mild diastolic dysfunction observed in younger individuals. Unlike age, certain parameters such as the E/e’ ratio—rarely exceeding 14 in healthy individuals—provide age-independent insights. Markers including left atrial enlargement, in the absence of chronic atrial arrhythmia, and significant LV hypertrophy are indicative of chronic left atrial pressure elevation and an increase in LV stiffness, respectively, suggesting diastolic dysfunction.
Anesthesia providers must recognize that a single measurement within normal limits for any age group does not conclusively denote normal diastolic function; a comprehensive evaluation incorporating clinical observations alongside doppler echocardiographic data is essential. This holistic approach is particularly critical given that diastolic function algorithms may not be entirely accurate in the perioperative environment, where rapid hemodynamic shifts could impact echocardiographic findings. While preoperative echocardiographic data can be invaluable for assessing a patient's diastolic function in a non-surgical context, intraoperative reassessment of these markers is often necessary to navigate the complexities of diastolic dysfunction management during surgery effectively.
