Aortic regurgitation – aortic insufficiency
Aortic insufficiency is the old term for aortic regurgitation. Aortic regurgitation means a leaky aortic valve, the valve between left ventricle and aorta. This leads to leakage of blood back into the left ventricle from the aorta when the heart relaxes (diastole) after contraction (systole). The blood leaking back is again pumped back in next systole, increasing the workload of the heart. The left ventricle gradually enlarges if the leak is large and eventually fails if the leaky is quite high.
What causes aortic regurgitation?
Aortic regurgitation can occur due to diseases of the aortic valve. It can also occur if the aorta is enlarged due to diseases so that the valve becomes relatively small and is unable to close properly. Diseases which involve the aortic valve can be birth defects or acquired diseases. The commonest birth defect is a bicuspid aortic valve in which the valve has only two cusps instead of three. These valve have defective closing as well as opening. Hence they can be leaky and long term damage can lead to narrowing of the orifice in addition (aortic stenosis).
In older age group degenerative changes in the valve is an important cause for regurgitation. Rheumatic fever involves the aortic valve and is major cause in developing countries where the disease is still prevalent. In the yesteryears when syphilis was common, late stages of the disease (tertiary syphilis) would involve the aorta, enlarging it and the valve becomes leaky. But this type of aortic regurgitation is seldom seen now. Aortic enlargement causing aortic regurgitation is seen in many diseases of the connective tissue like ankylosing spondylitis, annuloaortic ectasia etc. A defect in the partition between the two ventricles (ventricular septal defect) can be associated with aortic regurgitation when it occurs as a birth defect.
What are the symptoms?
Mild cases will be asymptomatic. Large leaks may produce palpitation, breathlessness and sometimes heart failure. The valve can get infected by bacteria spreading through the bloodstream (infective endocarditis) which leads to additional symptoms.
What can be done for aortic regurgitation?
Mild to moderate leaks need only follow up and prompt treatment of infections. Large symptomatic leaks may need aortic valve repair or replacement. Volume of leak can be reduced by giving medications which lower the blood pressure and thereby unload the left ventricle. Those in heart failure can be treated medically while surgical repair is being planned.