Aortic valve insufficiency is a heart valve defect of the aortic valve, which is positioned between the left ventricle and the aorta. In aortic valve insufficiency, the aortic valve no longer closes sufficiently, so there is a leak, causing blood to flow back into the left ventricle against the actual direction of flow. This additional volume puts a strain on the left ventricle and, as it progresses, leads to an increase in muscle mass and widening of the chamber.
Aortic valve insufficiency can either come from a disease of the valve itself or the ascending aorta following the aortic valve is diseased. This can then also cause damage to the aortic valve in the further course of the disease. In general, chronic aortic valve insufficiency can be distinguished from acute aortic valve insufficiency.
Aortic valve insufficiency can be classified according to its temporal progression – acute or chronic – or its severity. Acute aortic valve insufficiency occurs suddenly and is usually caused either by bacterial inflammation of the aortic valve or by dissection (wall splitting with bulging of the outer layers) of the aorta. Chronic aortic valve insufficiency is characterized by a slow progression with gradual development of the symptoms and can have many different causes.
The severity of the insufficiency can be determined by examining the heart using ultrasound, colour Doppler examination and ECG. Decisive for the classification are the blood return flow and the damage to the heart muscle resulting from the additional stress. First-degree aortic valve insufficiency is characterized by a return flow from the aorta through the non-closing aortic valve into the left ventricle, which is visible in the heart ultrasound (best seen in the color Doppler examination).
The reflux has not yet damaged the heart, the walls of the left ventricle are not yet thickened, and accordingly the ECG and the x-ray are unremarkable. The difference between systolic and diastolic blood pressure is still normal and is less than 60 mmHg (blood pressure amplitude). If the aortic valve closes increasingly poorly, the backflowing blood volume increases.
This can be measured in the colour Doppler examination. The ultrasound of the heart shows a beginning enlargement of the left ventricle due to the continuous volume strain. The signs of an enlarged left ventricle (so-called left heart hypertrophy) are also visible in the ECG and in the X-ray image.
The blood pressure amplitude is now elevated and lies between 60 and 75 mmHg for second-degree insufficiency. In third-degree aortic valve insufficiency, the amount of blood flowing back is now more than half to three-quarters of the amount ejected. The volume load for the left ventricle is high, which can be clearly seen in the ECG, cardiac ultrasound and X-ray. The blood pressure amplitude is about 110 mmHg with a low diastolic value (e.g. 160 mmHg systolic to 50 mmHg diastolic). The high blood pressure amplitude is generally a characteristic of aortic valve insufficiency.