Pulmonary hypertension - is a certain state of the pulmonary system, in which the flow in the pulmonary artery blood flow increases dramatically intravascular pressure.Interestingly, the pulmonary hypertension develops due to the influence of one of the two major pathological processes: both because of the sharp increase in direct volume of blood flow and subsequent pressure increases due to increased blood volume and an increase of intravascular pulmonary pressure unchanged volume of blood flow.On the occurrence of pulmonary hypertension to say when the rate pressure in the pulmonary vein than 35 mm Hg
Pulmonary hypertension - a complex, multi pathological condition.In the course of its development and the gradual disclosure of all clinical signs gradually affected and destabilized cardiovascular and pulmonary systems.Advanced stages of pulmonary hypertension and its separate forms, which are characterized by high activity (eg, forms of idiopathic pulmonary hyperten
should be understood that the survival of patients with the pulmonary hypertension depends on timely diagnosis and medical treatment of the disease.Therefore, we must first clearly define the key features of pulmonary hypertension and its pathogenesis links, to assign timely therapy.
Pulmonary hypertension causes
Pulmonary hypertension can also occur as a soloist (primary) disease, and emerged as a result of certain underlying causes.
primary or idiopathic (of unknown origin) pulmonary hypertension - now is the most poorly studied subtype of pulmonary hypertension.Its main reasons for the development based on genetic disorders that occur during embryonic tab future vessels that provide the pulmonary system.Also, thanks to all the same effects defects genome, the body will experience failure synthesis of certain substances that may expand narrowing of blood vessels or vice versa: endothelial factor, serotonin and angiotensin special factor 2. In addition to the above-described two factors is a prerequisite primary pulmonary hypertension,also there is another factor premise: excessive platelet aggregation.As a result, many small blood vessels in the pulmonary circulatory system is clogged thrombi.
As a consequence, dramatically increase intravascular pressure in the pulmonary circulatory system, and this pressure will act on the walls of the pulmonary artery.Since arteries have a more enhanced muscle layer, then, in order to cope with the increasing pressure in his bloodstream, and "push" the right amount of blood within the vessels, the muscle wall of the pulmonary artery will increase - it will develop compensatory hypertrophy.
addition hypertrophy and thrombosis of small pulmonary arterioles in the development of primary pulmonary hypertension can also take part the phenomenon of concentric fibrosis of the pulmonary artery.During the lumen of the pulmonary artery is narrowed and, as a consequence, the pressure of the blood flow therein will increase.
As a result of high blood pressure, inability to normal pulmonary vascular support the promotion of blood flow to have a higher than normal pressure or insolvency of abnormal blood vessels to facilitate the movement of blood flow with normal pressure in the pulmonary circulatory system develop another compensatory mechanism - arise becausecalled "workarounds", namely open arteriovenous shunts.Passing on these shunts the blood, the body tries to reduce high pressure in the pulmonary artery.But as arteriolar muscular wall is much weaker, very soon, these shunts will break down and form multiple areas that likewise will increase the pressure in the pulmonary artery in pulmonary hypertension.In addition, these shunts violate the correct flow of blood through the systemic circulation.During this process violated the oxygenation of blood and oxygen supply to the tissues.
In secondary hypertension course of the disease a little bit different.Secondary pulmonary hypertension is caused by a huge number of diseases: chronic obstructive lesions of the pulmonary system (such as COPD), congenital heart disease, thrombotic lesions of the pulmonary artery of hypoxic conditions (Pickwick syndrome) and, of course, cardiovascular disease.Moreover, cardiac diseases that can lead to secondary pulmonary hypertension can be divided into two subclasses: diseases that cause impairment of left ventricular function, and the diseases that lead to increased pressure in the chamber of the left atrium.
to the disease, the root causes of pulmonary hypertension associated with the development of left ventricular failure include ischemic infarction of the left ventricle, and it kardiomiopaticheskie myocardio damage, malformations of the aortic valve, coarctation of the aorta, and the impact on the left ventricle hypertension.For diseases that cause an increase in pressure in the chamber of the left atrium and the subsequent development of pulmonary hypertension include mitral stenosis, tumor lesion of the left atrium and the abnormal development: trehpredserdnoe abnormal heart or development of abnormal fibrous ring located above mitarlnym valve ("supravalvular mitral ring").
During the development of secondary pulmonary hypertension are the following basic pathogenetic links.Usually they can be divided into functional and anatomical.The functional mechanisms of pulmonary hypertension develops as a result of violations of normal or abnormal appearance of new functional features.That their elimination or correction will be sent to the subsequent medical therapy.Anatomical mechanisms of pulmonary hypertension are due to certain anatomical defects of the pulmonary artery and the pulmonary circulation.These changes cure drug therapy is almost impossible, some of these defects can be corrected by performing certain surgical aids.
The functional mechanisms of pulmonary hypertension include abnormal reflex Savitsky, an increase in cardiac output, the impact on the pulmonary artery of biologically active substances and increased intrathoracic pressure, increased blood viscosity and the impact of frequent bronchopulmonary infections.
pathological reflexes Savitsky developed in response to the obstructive lesion of the bronchi.If bronchial obstruction occurs spastic contraction (constriction) of the pulmonary artery branches.As a consequence a significantly increased pulmonary artery pressure and the intravascular blood flow resistance in the pulmonary circulation.As a result, normal blood flow through these vessels broken, slows and fabric prepared in full oxygen and nutrients, during which hypoxia.In addition, pulmonary hypertension causes hypertrophy of the muscle layer of the pulmonary artery (as mentioned above) and hypertrophy and dilatation of the right heart.
minute volume of blood in the pulmonary hypertension occurs as a response to the hypoxic effects of increased intravascular pressure in the pulmonary artery.Low oxygen content in the blood affects certain receptors that are aortalnokarotidnoy zone.In the course of this action automatically increases the amount of blood that the heart can pump through you in one minute (minute volume of blood).First, this is a compensatory mechanism and reduces the development of hypoxia in patients with pulmonary hypertension, but quickly increased blood volume, which will pass through the narrowed artery will lead to further development and worsening of pulmonary hypertension.
Biologically active substances produced as a result of the development of hypoxia.They cause spasm of the pulmonary artery and the increase in aortic-pulmonary pressure.The main biologically active substances that can narrow the pulmonary artery is considered histamine, endothelin, thromboxane, lactic acid and serotonin.
intrathoracic pressure often occurs when lesions of COPD pulmonary system.In the course of these lesions is sharply increased, it compresses the alveolar capillaries and promotes the pressure in the pulmonary artery and the development of pulmonary hypertension.
With increasing viscosity of the blood increases the ability of platelets to settle and the formation of blood clots.As a result, develop changes similar to those in the pathogenesis of essential hypertension.
frequent bronchopulmonary infection are two-way influence on worsening of pulmonary hypertension.The first way - is a violation of pulmonary ventilation and hypoxia.Second - this is direct toxic effects on the myocardium and possible development myocardio lesions of the left ventricle.
anatomical mechanisms of pulmonary hypertension include the development of the so-called reduction (reduce the amount) of pulmonary vascular circulation.This is due to thrombosis and pulmonary vascular sclerosis small circulation.
Thus, we can distinguish the following main stages in the development of pulmonary hypertension: increased pressure in the pulmonary artery;malnutrition of tissues and organs and the development of hypoxic injuries;hypertrophy and dilatation of the right heart and the development of "pulmonary heart".
Pulmonary hypertension symptoms
Since pulmonary hypertension is by nature quite complex disease develops in the course of the action of certain factors, it and its clinical signs and syndromes are characterized by a great variety.It is important to understand that when the first clinical signs of pulmonary hypertension will appear when the pressures are in the bloodstream of the pulmonary artery in 2 and more times higher than normal levels.
first signs of pulmonary hypertension - is the appearance of shortness of breath and hypoxic organ damage.Shortness of breath is associated with a gradual decrease in the respiratory function of the lungs, due to the high intraaortic pressure and decreased blood flow in the pulmonary circulation.Shortness of breath when pulmonary hypertension develops quite early.First, it occurs only as a result of the impact of physical activity, but soon begins to appear independently of them and becomes permanent.
Besides dyspnea and hemoptysis often develops.Patients may celebrate coughed a small amount of sputum streaked with blood.Hemoptysis appears because the resulting impact of pulmonary hypertension in the pulmonary circulation congestion occurs.As a result - will be observed propotevanie part of the plasma and red blood cells through the vessel and the appearance of the individual streaks of blood in the sputum.
On examination of patients with pulmonary hypertension can detect cyanosis of the skin and a characteristic change in the phalanges and nail plates - "drumsticks" and "hour glass".These changes occur due to malnutrition of tissues and gradual development of degenerative changes.In addition, "drumsticks" and "watch glasses" are a clear sign of bronchial obstruction, which may also be an indirect sign of the development of pulmonary hypertension.
Auscultatory can determine the increase in pressure in the pulmonary artery.This would indicate an audible through microstethophone gain 2 tones in the 2nd intercostal space on the left - the point where the usually auscultated pulmonary valve.During diastole, the blood passing through the pulmonary valve occurs with high blood pressure in the pulmonary artery and the sound is listened at the same time will be much louder than normal.
But one of the main clinical symptoms of pulmonary hypertension is the development of so-called pulmonary heart.Pulmonary heart - hypertrophic this change of heart right divisions that develop in response to high blood pressure in the pulmonary artery.This syndrome is accompanied by a number of objective and subjective symptoms.Subjective symptoms of pulmonary heart syndrome in the presence of pulmonary hypertension is constant pain in the heart (cardialgia).These pains will disappear when inhaled oxygen.The main reason for such a clinical manifestation of pulmonary heart is hypoxic myocardial damage during impaired oxygen transport to it due to the high pressure in the lung and the blood circle high impedance normal blood flow.In addition to the pain associated with pulmonary hypertension can also be celebrated strong and recurrent palpitations and general weakness.
Besides subjective grounds on which it is impossible to fully assess the presence or absence of the patient developed pulmonary heart syndrome in pulmonary hypertension, there are objective signs.When percussion area of the heart can be left to determine the offset of its borders.This is due to an increase in right ventricular and left parts of their marginalization beyond the normal boundaries of percussion.Just the increase in right ventricular hypertrophy due to lead to the fact that it will be possible along the left border of the heart to determine the pulsation or the so-called cardiac impulse.
decompensated pulmonary heart will develop signs of increased liver and swollen neck veins.Also characteristic indicator of pulmonary heart decompensation is a positive symptom of baldness - with pressure on the enlarged liver will simultaneously jugular vein.
Pulmonary hypertension degree
Pulmonary hypertension is classified by many different symptoms.The main features of the classification of pulmonary hypertension in stages to the degree of development of pulmonary heart disease, disorders of ventilation, the degree of hypoxic tissue damage, hemodynamic, radiological, electrocardiographic signs.
Accepted provide 3 degrees of pulmonary hypertension: transient, stable and consistent with severe circulatory failure.
Grade 1 (transient degree of pulmonary hypertension) is characterized by the absence of clinical and radiological signs.At this stage, will be observed primary and minor signs of failure of external breathing.
2 degree of pulmonary hypertension (pulmonary hypertension stable stage) will be accompanied by the development of dyspnea, which will occur when customary before exertion.In addition to shortness of breath at this stage there will be a acrocyanosis.The objective will be determined by enhanced apical cardiac impulse that will testify to initiate the formation of pulmonary heart.Auscultatory at 2 degrees of pulmonary hypertension is already possible to listen to the first signs of high blood pressure in the pulmonary artery - the above accent 2 tones on auscultation point of the pulmonary artery.
In general thoracic radiograph can be seen bulging contour of the pulmonary artery (due to high pressure in it), the expansion of the roots of the lungs (also due to the impact of high pressure in the blood vessels of small pulmonary circulation).An electrocardiogram will already be determined by the signs of overload of the right heart.In the study of respiratory function will be a trend towards the development of arterial hypoxemia (reduction of oxygen).
In the third stage of pulmonary hypertension to the above clinical signs added diffuse cyanosis.Cyanosis is the characteristic color - gray, "warm" type of cyanosis.It will also appear swelling, painful enlarged liver and jugular veins.
Radiological features inherent to the stage 2 is added also visible on X-ray enlargement of the right ventricle.