From the Guidelines
The correct answer is that cardiac ejection fraction is typically increased in conditions with left-to-right shunts, but the provided options do not directly state this, however option C "It is decreased in mitral incompetence" is incorrect as ejection fraction is typically increased in mitral incompetence. Cardiac ejection fraction, which measures the percentage of blood ejected from the ventricle with each contraction, is a crucial parameter in assessing cardiac function 1. In conditions like ventricular septal defects, the ejection fraction is typically elevated due to the left-to-right shunt, causing the left ventricle to eject more blood than normal. In contrast, ejection fraction is not a reliable indicator of cardiac dysfunction in the elderly as age-related changes can affect measurements. Some key points to consider when evaluating cardiac ejection fraction include:
- Ejection fraction remains crucial in the classification of heart failure, as it was originally used to differentiate HFrEF and evaluate its pathophysiology and response to therapy 1.
- The European Association of Cardiovascular Imaging expert consensus paper provides a comprehensive review of cardiovascular magnetic resonance normal values of cardiac chamber size and aortic root in adults and recommendations for grading severity, including left and right ventricular ejection fraction grades 2.
- Predictors of overall mortality in dilated cardiomyopathy include ejection fraction, end-diastolic dimension or volumes, male gender, older age, hyponatraemia, persistent third heart sound, sinus tachycardia, elevated pulmonary capillary wedge pressure, systemic hypotension, and atrial fibrillation 3. However, the most recent and highest quality study 1 suggests that ejection fraction is a crucial parameter in assessing cardiac function, and its measurement and interpretation should be done with caution, considering the underlying condition and age-related changes.
From the Research
Cardiac Ejection Fraction
- The cardiac ejection fraction (EF) is a measure of cardiac function, but its interpretation can be ambiguous and misleading 4.
- EF is widely accepted as a clinical marker of cardiac function, despite its limitations 5, 6.
- EF is calculated as the stroke volume divided by end-diastolic volume, and its estimation is generally based on geometric assumptions 5.
- EF is both preload- and afterload-dependent, and can change substantially based on loading conditions 5.
Relationship with Mitral Stenosis and Mitral Incompetence
- There is no direct evidence in the provided studies to suggest that EF is increased in mitral stenosis.
- Mitral regurgitation (MR) is a common feature of heart failure with preserved ejection fraction (HFpEF), and percutaneous edge-to-edge mitral valve repair (pMVR) can improve heart failure symptoms in HFpEF patients 7.
- EF can be decreased in mitral incompetence, as mitral regurgitation can lead to a decrease in EF 7.
Relationship with Ventricular Septal Defect
- There is no direct evidence in the provided studies to suggest that EF is increased in ventricular septal defect.
Accuracy as an Indicator of Cardiac Dysfunction
- EF may not be an accurate indicator of cardiac dysfunction in all cases, particularly in the elderly or in patients with heart failure with preserved ejection fraction (HFpEF) 5, 6, 8.
- A more comprehensive assessment of cardiac function, including measures of left and right ventricular function, left ventricular geometry, left atrial size, and valvular function, may be necessary to accurately diagnose and manage cardiac dysfunction 5.