Aortic Stenosis


Aortic stenosis represents a lesion that consists of narrowing the aortic orifice thus realizing an obstacle to emptying the left ventricle. The causes can be either congenital (lesion being present since birth) and acquired by calcification, sclerosis and interesting for Rheumatic valve.

Causes

Aortic StenosisThe most common form of aortic stenosis is congenital bicuspid aortic valve, in which the foils that makes the aortic valve are fused to the periphery, so that the valve is turning into a diaphragm provided with a hole in its central area. Initially the valve is thickened and along with aging, it fibroses and gains limestone deposits, these entire phenomena further narrowing the orifice. Clinical manifestations will occur in case of bicuspid around the age of 40-50 years. Aortic stenosis acquired during life are either degenerative either from the rheumatic cause. The degenerative appear at over 60 years, unlike congenital stenosis; valvular foils are not fused, finding only a thickening of the valvular with a secondary deposition of calcium and fibrosis. Rheumatic aortic stenosis is associated quite frequently with other mitral lesion.

Because of the left ventricle must pump blood against the obstacle represented by aortic stenosis, while he develops the muscle mass hypertrophying. The degree of hypertrophy is directly proportional to the severity of aortic stenosis. This stage is compensated. In the final stages, the left ventricle cannot pump blood in the systole the entire amount of content and begins to dilate increasingly more to the stage of heart failure. Changes that installs retrograde are: dilated left atrium (because it increases pressure in the left ventricle diastolic) pressure increases in the pulmonary circulation and the right ventricle undergoes hypertrophy (increases muscle mass) and then dilate. Initial portion of the aorta shows changes in shape, dilating below the stenosis level.

left ventricle hypertrophy in aortic stenosis

The myocardial mass development of the left ventricle (LV hypertrophy) occurs as a compensatory mechanism to maintain normal systolic flow in spite of the trouble aortic orifice, due to the increase of contraction force. As ventricular hypertrophy is more pronounced, the more impaired ventricular relaxation in diastolic slowing down the filling of the left ventricle with blood coming from the left atrium. Thus ventricular diastolic function is impaired. The systolic function alteration of the left ventricle appears later, even after a few years, and is due to myocardial fibrosis and ischemia.

Ischemia, imbalance between oxygen supply to the myocardium and greatly increased oxygen demands of the myocardium is explained by the increase of myocardial mass of the left ventricle and contractility increase as compensatory mechanisms. Myocardial ischemia may underlie the generation of atrial fibrillation, once installed, quickly deteriorating hemodynamic status.

Symptoms

Obstacle to the flow of blood ejected from the left ventricle into the aorta causes an increase in pressure within the ventricle. Increased pressure in the left ventricle during diastole, makes it difficult for the left atrium to empty, incomplete, inducing retrograde an increased pressure in the pulmonary veins, pulmonary capillaries, and finally dyspnea aortic stenosisinto the pulmonary artery. Therefore patients will present dyspnea, initially at high physical effort, because later on by lesion progression, at smaller efforts. In advanced stages of paroxysmal nocturnal dyspnea appears imminent choking sensation during the night, the patient adopting a sitting position with legs dangling from the edge of the bed. This position, called orthopnea position improves breathing.

In the early stages, of the left ventricle pump function is not altered because its fibers myocardial hypertrophy is compensatory. By hypertrophy is evident that the necessary (demand) of oxygen increases, but oxygen supply brought by coronary blood remains constant. Thus there is a discrepancy between supply and demand which is the very definition of myocardial ischemia. This pathological mechanism and the others of the left ventricle pump function deteriorate progressively decreasing systolic flow (volume of blood pumped by the ventricle in a systole) and cardiac output (amount of blood ejected per minute).

Reduced cardiac output produces the following symptoms:

  • increased heart rate;

  • increased respiratory rate;

  • sweating;

  • pale;

  • feelings of fatigue;

  • angina-type pain (retrosternal pain induced by the effort that gives promptly to sublingual nitroglycerin or bed rest);

  • Loss of consciousness by reducing oxygen to the brain.

The pulse and the blood pressure are normal in most cases. Only in conditions of severe aortic stenosis, the pulse becomes weak perceptible to the touch.

Investigations

  1. Radiography heartChest Radiography: in mild and medium, even in the presence of ventricular hypertrophy, the heart appears normal size. This is because of the left ventricle muscle growth occurs towards the inside of the ventricular cavity. It can detect an increased heart size in the time of the onset of the ventricular dilation. On the radiography can be observed calcification of the aortic valve, aortic dilatation.

  2. Echocardiography: the most efficient method for investigating noninvasive providing reliable data on the location of the stenosis and the degree of stenosis. It highlights the fattening aortic valve, dilated ascending aorta, ventricular hypertrophy and is measured the area of the aortic stenosis.

  3. EchocardiographyElectrocardiogram (EKG): shows the appearance of left ventricular hypertrophy, ischemia or when there is atrial fibrillation.

Treatment of aortic stenosis

For patients with aortic stenosis that is installed as in the clinical picture previously described therapeutic indication is surgery. Surgical treatment is taken into account if the patient is asymptomatic but has severe aortic stenosis (determined by echocardiography).

There are two surgical methods:

  • Dilatation of the aortic orifice with a balloon inserted into the arterial system through the femoral artery. When the ball reached the aortic annulus, thereby causing dilation swell. This method is called balloon angioplasty.

  • Valvular prosthesis that is the injured aortic valve replacement with a biological prosthesis or metal.

Patients can resume their normal activities about three months after the intervention.

Aortic Stenosis surgery indication for valve replacement

Aortic Stenosis surgery indication for valve replacement


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4 Responses

  1. Yvonne says:

    I have had high
    Bp for 7 yrs. 7 yrs ago I also began having crippling migraines. Only thing that helped with migraines was oxygen at the er. I took 3 severe attacks beginning 4 yrs ago. First one June 2011- June 2012 and then August 2013. 2013 my doctor put me off work as I could no longer stand for very long. My
    Bp has gone into stage 2 hypertension. I’ve also had palpitations over the past 7 yrs that had increased significantly to happening frequently everyday now. My doc refused tests. I am still nt being treated for anything. My pulse spikes. I have not been able to excercise or work now for over 2 yrs. I was a sent for an ECG in dec 2014. It warranted something severe enough that I was sent the next day for a stress test. The cardiologist that did the stress test had to stop it within 2 mins and he prescribed me nitro glycerin. I then seen my family doc next day. He told me I have a severe heart condition. I was then sent for a stress echo in January of 2015 where they found a bicuspid aorta. I seen a cardiologist that my doc recommended. Cardiologist told me it’s all in my head. My doc has also been telling me for yrs that it’s all in my head and it’s anxiety. Even after finding this out. I have seen a number of different physicians in clinics and the er numerous times. And eveyone of them have said the same thing- something serious is going on and my doc needs to run more tests and get me treatment. Everyone of these doctors wrote in the report to my family doctor that he needs to find out immediately what is wrong as I am extremely high risk of stroke and heart attack. I am only 42 yrs old right now and have never been over wieght. My doctor has refused me out right a number of times this year To run any tests and refuses me a referral to another cardiologist. In Nova Scotia you need a referral to see any specialist. I have tried numerous times to get the referral from other docs and they all tell me it has to be my family doctor. I am still without any help. And as of today in writing this from my bed where I lay with pneumonia. Bicuspid aorta runs in my family. But did not know until after I found out I have it and got my family to be tested my younger brother has it and one of my children as well. But they have not had any symptoms of anything wrong- thank God! All I want is help. To see a cardiologist who will run a cat scan or MRI and find out what is wrong. I’m at a loss here and have tried eveything I can to get help. I don’t know what else to do. It is very hard being sick and not having your life for 2 yrs and being Ill for 7. And having doc and cardiologist tell you it’s all I your head. I did get to my neurologist who as a specialist brought up my er reports on his laptop while I was there. He also wrote to my doc my extremely high risk of stroke and what attack and death. To which my doctor laughed. And again refused me tests and referrals. Last time I seen my doctor was July 2015. After he once again told me there are no tests or treatment and it’s all in my head. I was crying. My doc asked me” why are you crying”? I said, I am crying becuase I want my life back – I want help and your refusing me any help. He then got up from his chair and said there is no help. I wonder if due to his lack of testing and help with high
    Bp 7 yrs ago and not finding out then what was wrong- if it was left too long and now there’s nothing that can be done? And he had this cardiologist back him up my telling met symptoms are all in my head too?? My doctor is not even monitoring me. The cardiologist said he wouldn’t see me for 3 yrs. yeti brother has no symptoms of anything wrong with his bicuspid aorta and his doc is monitoring him every 6 months ?????? HELP

  2. Yvonne says:

    Also I have tried to get anther family doctor here and we are short of doctors in Nova Scotia. I know many people here don’t have a doctor. There is also no cardiologist in the maritimes that specializes in bicuspid aorta. Halifax is the only place in Nova Scotia where they can even help and all they can do is replace the aorta. I live an hour from Halifax. I know if I have heart attack or another stroke my chances of making it to Halifax in time is slim.

  1. April 13, 2014

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