Aortic Valve

Aortic valve

What an aortic valve is:

The heart valve present in between the left ventricle and aorta is called aortic valve which is a tricuspid valve. In some people about 1% of the population has inborn bicuspid aortic valve. The valve is named so because it is present in between the left ventricle and aorta as well as it controls the flux of blood from left ventricle towards aorta.

Function:

When there is a ventricular systole the pressure in the left ventricle increases and this leads to the greater pressure in the left ventricle as compared to the aorta and ultimately this all results in the opening of the aortic valve. As the aortic valve the blood flux moves from left ventricle into the aorta. At the completion of the ventricular systole the ventricular pressure drops suddenly and at the same time the pressure in the aorta rises and this leads to the closure of the aortic valve. This opening and closing of the aortic valve produces the heart sound S2.

Disorders relating aortic valve:

There are two types of disorders responsible for the improper working of the aortic valve and those are:

• Aortic stenosis
• Aortic regurgitation

Aortic stenosis stands for the incomplete opening of the aortic valve hence blood doesn’t completely move into the aorta while aortic regurgitation is the disorder in which the aortic valve doesn’t close properly and in return the blood moves towards the wrong direction i.e. back towards the left ventricle is the disorder in which the aortic valve doesn’t close properly and in return the blood moves towards the wrong direction i.e. back towards the left ventricle.

Causes of aortic valve disorders:

Rheumatic fever is the common cause of both aortic stenosis and aortic regurgitation while other causes of aortic stenosis are degenerative calcification and inborn bicuspid aortic valve. Enlargement of the aorta, infective endocarditis, myxomatous, Marfan’s syndrome and breakdown of the aortic valve are responsible for the aortic valve regurgitation.

Bicuspid aortic valve:

It is an inborn disorder of aortic valve and it is present in only 1% of the population. In this congenital disorder there are two leaflets of the aortic valve instead of the three leaflets. This disorder is left undiagnosed until the symptoms of aortic stenosis occur in later life. The occurrence of aortic stenosis in bicuspid aortic valve people is faster then the people with normal tricuspid aortic valve. Turner’s syndrome is also a cause of associated bicuspid aortic valve.

Aortic valve replacement:

The replacement of a diseased aortic valve with a new healthy valve is called aortic valve replacement. There are different diseases which can leads to the aortic valve replacement. Two conditions can lead to aortic valve replacement which is either the leakage of the aortic valve or the partial closure of the aortic valve. There are further two types of aortic valve replacement which depends upon the type of valve used to replace the diseased aortic valve. There are two types of aortic valves which are:

• Biological aortic valve:
This type of aortic valve is extracted from a living being and is placed in the diseased patient.

• Mechanical valve:
This type of valve is also called artificial aortic valve as this valve is made up of cloth, metal or artificial tissues.

Endocarditis

Endocarditis

Endocarditis is the inflammation inside the layer of the heart, known as the endocardium. The heart valves are the most common portions of the heart that is involved. The classification of endocarditis is done by infection or non-infection. The cause depends entirely on the microorganism that has caused the problem. The valves in the heart do not get any blood supply of their own due to which the defense mechanisms in the blood (such as white blood cells) cannot enter the heart. It so happens that if an organism (like bacteria) gets inside the valves of the heart, the body is unable to get rid of them. There are many kinds of heart diseases from which there are millions who suffer from. The types of heart diseases are such that they can create severe complications if it is neglected or diagnosed wrongly.

The flow of blood is normal through the valves inside the heart. Bacteria enter the heart when one has ailments like rheumatic fever and other such bacterial diseases. Infective endocarditis is divided into two forms known as acute and subacute. In the subacute version of endocarditis, patients tend to live longer than the acute ones. The classification of the disease can show the progression rate and intensity of endocarditis. Subacute bacterial endocarditis (SBE) is caused by streptococci of low virulence and illness. The illness can be mild and moderate along with slow progress over weeks or months. Acute bacterial endocarditis (ABE) is a fulminant illness that can be caused by the staphylococcus aureus that is of more intense disease causing factor. In infective endocarditis, there are two types known as culture positive and culture negative.

Culture-negative endocarditis is caused due to micro-organisms requiring longer time to be identified in the laboratory. Organisms of these kinds are termed as'fastidious' because they have certain requirements. Pathogens causing culture-negative endocarditis are Aspergillus species, Brucella species, Coxiella burnetii, Chlamydia species, and HACEK bacteria. There is marked difference between native-valve endocarditis and prosthetic-valve endocarditis. The identification of the two types is very important. Endocaditis can happen when an individual is injecting narcotics intravenously that enters the staphylococcus aureus in the heart. Those without intravenous experience, have endocarditis on the left side of the heart.

In endocarditis, the valves are damaged severely. The damage can be caused by congenital defects, auto-immune mechanisms, surgeries or by mere old age. The damaged valve has clots formed on it that in clinical term is known as non-bacterial thrombotic endocarditis (NBTE). When there is clot inside the valve of the heart, the bacteria present attaches itself with the clot thereby giving rise to infections inside it. Bacteremia that is the flowing of the bacteria with the blood stream from cut; can be caused by dental process like extraction of teeth or other procedures. Those suffering from heart diseases are first administered with medications in order to prevent any kind of bacterial infections that can lead to endocarditis. The bacteria that cause endocarditis can also enter the body by diseases like colorectal cancer, urinary tract infections and IV drug. Those using the IV drugs have the right side of their heart valves affected.