Diastolic dysfunction of the left ventricle of the heart is a decrease in its ability to pump blood into its cavity from the pulmonary arterial system. The causes of this phenomenon are for the most part based on a decrease in the ductility of the walls. Signs of diastolic dysfunction of the left ventricle are manifested in an increase in the ratio of the final pressure to the final volume.
Filling steps
The stages of diastolic filling in the left ventricle include relaxation, passive filling and filling due to contraction in the atria. Relaxation is an active transport of calcium ions from actin-myosin filaments. On the basis of ischemia, inhibition of ion elimination occurs, as a result of which relaxation becomes insufficient. With a decrease in filling, arterial and venous hypertension, nocturnal paroxysmal dyspnea, cough, shortness of breath are noted. Relaxation is followed by passive filling. The determinant of blood volume in this case is the compliance of the walls of the ventricle, with a decrease in which the passive filling decreases. Active reduction of the walls of the atrium causes the intake of 15-20% of the diastolic final volume. Rigidity of the walls provokes an increase in the incoming volume. With ischemia and pathological stiffness, atrial fibrillation significantly increases the risk of cardiogenic pulmonary edema.
Diastolic dysfunction of the left ventricle. Causes
The main provoking factors include infiltrative diseases at the level of the systemic type of heart (amyloidosis and others), hypertension, accompanied by hypertrophy in the left ventricle. Among the reasons, experts note hypertrophic cardiomyopathy.
Diastolic dysfunction of the left ventricle. Treatment
Specialists note that theoretically, drugs that reduce LV hypertrophy, increase active relaxation and improve its compliance should theoretically improve. Diastolic dysfunction of the left ventricle is corrected by calcium antagonists and angiotensin-converting enzyme inhibitors. Evidence of beneficial effects was obtained in most patients.
A very positive effect of such, for example, means as Enalapril is noted. Diastolic dysfunction of the
left ventricle lends itself to therapy in a fairly short time. So, usually after eight to sixteen weeks an improvement is already noted. These results are observed even before the onset of a statistically significant regression of hypertrophy in the LV. The effect on improving
heart function is of practical importance in the process of choosing therapy in patients with arterial hypertension and cardiac insufficiency in the chronic course. Experts note the effectiveness
of ACE inhibitors in the early stages, including the asymptomatic course of disorders, as well as in the late stages of decompensation. During treatment, any drug of this group can be prescribed, but preference is given to drugs whose effectiveness has been tested experimentally. Thus, there has been a significant improvement in diastolic function when patients receive therapy with the drug "Lisinopril."