Aortic insufficiency is a heart valve disease in which the aortic valve weakens or balloons, preventing the valve from closing tightly. This leads to backward flow of blood from the aorta (the largest blood vessel) into the left ventricle (the left lower chamber of the heart).

Aortic insufficiency can result from any condition that weakens the aortic valve. The condition causes dilation (widening) of the left lower chamber of the heart, which continues to get worse with time. As this area of the heart becomes dilated, it is less able to pump blood to the rest of the aorta. The heart tries to make up for the problem by sending out larger amounts of blood with each heart contraction. This leads to a strong and forceful pulse (bounding pulse).

In the past, rheumatic fever was the primary cause of aortic insufficiency. Now that antibiotics are used to treat rheumatic fever, other causes are more commonly seen.

Causes may include valve problems that are present at birth, endocarditis, high blood pressure, Marfan's syndrome, aortic dissection, ankylosing spondylitis, Reiter's syndrome, syphilis (now rare), systemic lupus erythematosus, and other disorders.

Aortic insufficiency affects approximately 5 out of every 10,000 people. It is most common in men between the ages of 30 and 60.

• Palpitations
• Bounding pulse
• Irregular, rapid, racing, pounding or fluttering pulse
• Fainting
• Weakness, particularly with activity
• Shortness of breath with activity or when lying down
• Fatigue, excessive tiredness
• Chest pain, angina type (rare)
  • Under the chest bone; pain may move to other areas of the body 
  • Crushing, squeezing, pressure, tightness
  • Pain increases with exercise, and goes away with rest

Auscultation (listening to the chest with a stethoscope) detects a heart murmur. Palpation (examination by hand) may show hyperdynamic (very forceful) beating of the heart. Pulse pressure (the difference between systolic blood pressure -- the pressure during contraction of the heart -- and diastolic blood pressure -- the pressure during relaxation of the heart) may be widened, and diastolic blood pressure may be low. There may be signs of pulmonary edema (fluid in the lungs).

Aortic insufficiency may be seen on:

• Echocardiogram - ultrasound examination of the heart
• Transesophageal echocardiogram (TEE)
• Doppler ultrasound
• Aortic angiography
• Left heart catheterization

An ECG test or chest x-ray may show left ventricular enlargement.

Lab tests cannot diagnose aortic insufficiency, but they may be used to rule out other disorders or causative factors.