03. Coronary Artery: Narrowing Degree Less Than 50%
A coronary artery narrowing greater than 50% is a "golden indicator" for diagnosing coronary heart disease (CHD). This indicates that plaque has formed and may progress further, causing more severe narrowing. The more significant the coronary artery narrowing, the higher the risk of acute myocardial infarction (heart attack).
CHD is primarily due to long-term lipid metabolism disorders, leading to lipid deposition on the inner walls of arteries, forming plaques that obstruct the coronary arteries. This blockage can cause ischemia in the myocardial cells at the far end of the obstructed vessel, leading to angina. Severe blockage may completely occlude the vessel, resulting in myocardial cell necrosis and an acute myocardial infarction, which can be life-threatening.
Therefore, the focus of CHD treatment is on prevention. Slowing down or reversing coronary artery narrowing (to less than 50%) is crucial.
04. Ejection Fraction: Greater Than 50%
Ejection fraction (EF) is one of the key indicators of heart health. It refers to the percentage of blood pumped out of the heart's ventricles with each beat, compared to the total volume of the ventricles at the end of diastole. EF can be assessed through a cardiac ultrasound.
EF directly reflects the type and severity of heart failure. A higher EF generally indicates stronger heart function, with a normal range of 50% to 70%.
When EF is less than 50%, it suggests a tendency toward heart failure or cardiac insufficiency.
Conditions like dilated cardiomyopathy, atrial fibrillation, and hypertrophic cardiomyopathy can cause changes in heart structure in their final stages, leading to heart failure and a decreased EF. Once EF declines, it is irreversible, and patients are more likely to experience heart failure symptoms such as shortness of breath, fatigue, and edema, requiring active treatment of the underlying heart disease.