CARDIAC ASTHMA - an attack of shortness of breath with a sensation of suffocation, due to acute stagnation of blood in the pulmonary vessels due to the difficulty of its outflow into the left ventricle of the heart. The reason is narrowing of the left atrioventricular orifice (mitral stenosis) or left ventricular heart failure with myocarditis, acute myocardial infarction, extensive cardiosclerosis, left ventricular aneurysm, aortic heart defects, mitral valve insufficiency, as well as with arrhythmias and paroxysmal myocardial elevations ventricle (for example, with pheochromocytoma). The occurrence of cardiac asthma is facilitated by an increase in blood circulation (for example, during physical exertion, fever), an increase in the mass of circulating blood (for example, during pregnancy, after the introduction of large amounts of fluid into the body), as well as the horizontal position of the patient; this creates conditions for increased blood flow to the lungs. Due to stagnation of blood and an increase in pressure in the pulmonary capillaries, interstitial pulmonary edema develops, disrupting gas exchange in the alveoli and patency of the bronchioles, which is associated with the occurrence of shortness of breath; in some cases, respiratory failure is exacerbated by reflex bronchospasm.
The occurrence of cardiac asthma in the daytime is usually directly related to physical or emotional stress, increased blood pressure, an attack of angina pectoris; sometimes an attack is provoked by plentiful food or drink. Before developing an attack, patients often feel chest tightness, palpitations. If cardiac asthma occurs at night (more often), the patient wakes up from a feeling of lack of air, shortness of breath, tightness in the chest, and the appearance of a dry cough; he experiences anxiety, a sense of fear, his face is covered with sweat. During an attack, the patient, as a rule, begins to breathe through the mouth and necessarily sits down in bed or gets up, since shortness of breath decreases when the body is upright (orthopnea). The number of breaths reaches 30 or more in 1 min; the ratio of the duration of exhalation and inhalation usually varies little. Listened in the lungs - hard breathing, sometimes (with bronchospasm) dry wheezing (usually less plentiful and less "musical" than with bronchial asthma), often small-bubbly moist rales in subscapular areas on both sides or only on the right. Subsequently, a picture of alveolar pulmonary edema may develop with a sharp increase in dyspnea, separation of a light or pink foamy liquid when coughing. During auscultation of the heart, changes characteristic of the mitral or aortic defect are determined, and in the absence of defect, a significant weakening of the I cardiac sound or replacement by its systolic murmur, II tone accent over the pulmonary trunk, often gallop rhythm. As a rule, tachycardia is noted, and with atrial fibrillation, a significant pulse deficiency.
The differential diagnosis is carried out with bronchial asthma, which, unlike cardiac asthma, usually develops against the background of other manifestations of allergies. Her attacks occur with a small change in the frequency of respiration with significant difficulty and prolongation of exhalation; sputum that separates when coughing looks like viscous mucus; the cervical veins on exhalation swell and fall on inhalation, signs of severe emphysema are detected percussion, dry rales are determined during auscultation in the lungs. ECG registration during an attack can be of great help in differential diagnosis, especially if it occurred for the first time in a patient without previous manifestations of chronic heart failure - on this basis, acute heart disease (for example, myocardial infarction , myocarditis) can be assumed.
If urgent medical care cannot be provided, an emergency treatment of cardiac asthma in patients with chronic heart failure is performed by a paramedic or nurse. The patient should be helped to sit comfortably in bed or chair, legs down; the stomach is freed from the belt, the patient is provided with an influx of fresh air, oxygen therapy is given, nitroglycerin is given under the tongue. 40 - 80 mg of furosemide (lasix) is administered intravenously, and with a developing attack of suffocation and signs of beginning alveolar pulmonary edema, morphine (1 ml of a 1% solution). If cardiac asthma is caused by atrial tachycardia, the introduction of cardiac glycosides (corglycon, strophanthin, digoxin) is indicated, which is best done as directed and under the supervision of a doctor. In the presence of acute heart damage, therapy of the underlying disease is performed.
Prevention of cardiac asthma coincides with the principles of prevention of heart failure. In patients with mitral stenosis, attacks of cardiac asthma can be eliminated by surgical treatment of this heart defect.