Aortic insufficiency is a valvulopathy characterized by sigmoid aortic valve injury from different causes, and the result is incomplete closure of these valves during ventricle diastole (relaxation). The direct consequence is the discharge into the left ventricle during diastole of a portion of the blood flow from the aorta. Among the most common causes of aortic insufficiency include:
rheumatic fever, which causes scarring and retraction of the valves;
infective endocarditis which produces valvular vegetation and valvular destructions;
bicuspid aortic valves, which is the most common congenital malformation of the aortic valve;
dilatation of the aorta in the aortic dissection, thoracic trauma which acts by traction on the aortic ring, valves which will never unite in the ventricular diastole;
Various collagen diseases that alter the composition of connective tissue that makes up the aortic valve.
Aortic valves can be opened in one direction, towards the aortic lumen (in systole), blood from the left ventricle being ejected into the arterial system. Normally, in diastole, due to the pressure differences between the left ventricular cavity and the aorta, the valves close, get in touch, closing tight the aortic orifice.
Aortic insufficiency represents just a total inability aortic valve closure in diastole, some blood found in the aortic lumen reaching back into the left ventricle. From anatomical point of view, a consequence of the aortic regurgitation of blood into the left ventricle is dilatation and hypertrophy of the left ventricle and dilation of the aorta. Dilation and ventricular hypertrophy represent adaptive cardiac mechanisms. Aortic insufficiency may occur suddenly, not having time to reshuffle adaptive through ventricle hypertrophy or dilatation, situation called acute aortic insufficiency.
The left ventricle responds through dilation to the new conditions caused by aortic insufficiency in order to receive in diastole the blood from the left atrium and the aorta regurgitated, without significant changes of intra ventricular pressure at the end of diastole. Also respond and through hypertrophy (increase ventricular muscle mass) in order to intensify the developed force during systole, thus maintaining flow in normal systolic, ejection fraction and volume of blood in the ventricle at the end of systole.
Ventricular hypertrophy has however some negative consequences:
because of the increased myocardial mass, the left ventricle in diastole is no longer expanding properly;
There is a degree of myocardial ischemia since the hypertrophied myocardium needs for its amount activity which is becoming bigger in oxygen brought by the coronary blood flow which has remained constant.
Symptoms of aortic insufficiency
The clinical picture is installed more quickly in acute aortic insufficiency; the pressure at the end of the diastole is increasing in the left ventricle. Therefore, the left atrium cannot empty the optimal parameters, leading to a load of blood, retrograde, into the pulmonary veins and into the pulmonary capillaries. It may occur as pulmonary edema.
Chronic aortic insufficiency is because of the fact that the left ventricle has had time to adjust through dilatation and hypertrophy, may remain asymptomatic for a long time. When there are symptoms consist of palpitations, sweating, difficulty breathing physical effort, excessive fatigue, headaches.
Objectives signs are to inspect the patient: extensive and rapid carotid pulse reflecting an increased systolic flow, systolic contraction of the pupils. Systolic blood pressure (maximum) is high and diastolic pressure (minimum) is low. Blood pressure measured in the lower limbs is higher than blood pressure in the arms. On auscultation with a stethoscope in the focus aorta, the second right intercostal space, second noise is diminished or inaudible because the aortic valves are calcified and immovable and it charge a diastolic breath audible in the first part of diastole or the entire diastole.
In acute aortic insufficiency, the clinical picture is dominated by symptomatology generated by pulmonary charge: dyspnea, orthopnea, paroxysmal nocturnal dyspnea, symptoms of acute pulmonary edema. Most common signs of left heart failure: cyanotic extremities, cold, low blood pressure, tachycardia.
Laboratory investigations are useful in the diagnosis of aortic insufficiency: echocardiography, cardiac catheterization and electrocardiogram. Chronic aortic insufficiency is well tolerated by patients who may not have any symptoms for years. After the signs of left ventricular suffering are installed, the disease is rampant, between 50-60% of patients died in the next three years.
Treatment in aortic insufficiency are likely either medical or surgical. Among the medical we recall the measures to prevent infectious endocarditis through antibiotic treatment (when the patient supports dental treatment or surgery on the digestive tract or urinary tract), reducing blood pressure with calcium blockers, converting enzyme inhibitors, diuretics (for the left ventricle to perform less effort in systole, pumping blood into an arterial system in which the pressure is reduced) treatment of possible heart rhythm disorders with anti-arrhythmic medicines, treatment of acute pulmonary edema occurred in the context of acute aortic insufficiency to surgical intervention of the replacement of the aortic valve, because in acute aortic insufficiency the treatment of choice is the surgical one.
Surgical treatment aims to replace the injured aortic valve with a new valve biological or metal. Biological valves are used in younger women who want to have a child in the future and in patients aged over 70. For the others will use the metal valves. Operative mortality is between 1-4%.