Diagnosis of heart failure

Diagnosis of left ventricular heart failure

Clinical examination. During physical examination of the cardiovascular system, left ventricular failure is manifested by an enlargement of the left ventricle, and by percussion - by widening of the boundaries of relative cardiac dullness to the left. A decrease in the contractility of the myocardium is manifested by both muffled heart sounds, to a greater extent the first sound at the apex, and the appearance of additional sounds: the protodiastolic third sound (due to increased pressure in the left parts of the heart and decreased myocardial tone) and the presystolic fourth sound. The latter appears as a result of increased pressure in the left atrium and, as it were, auscultation of atrial systole. Tones III and IV are auscultated at the apex of the heart, they often merge and form the so-called summation gallop rhythm. Often, the third and fourth sounds are also auscultated in healthy children, especially with a vagotonic orientation of the vegetative supply. With normal heart boundaries and the absence of other signs of heart failure, these phenomena can be considered physiological.

Instrumental methods. Diagnostics of left ventricular failure is also based on the data of instrumental examination methods. Thus, the most informative in this regard are ECG data: the size of the left atrium, left ventricle, and the ejection fraction. In left ventricular failure, these indicators can change significantly. A pronounced increase in the left atrium cavity, as a rule, reflects a high degree of overload of the pulmonary circulation and coincides with the clinical signs of pulmonary hypertension. An increase in the left atrium in some cases is more important than an increase in the left ventricle cavity. Undoubtedly, the most informative echocardiographic indicator of a decrease in the contractile function of the left ventricle should be recognized as a change in the ejection fraction, on average it is 65-70%, this is a derivative of the end-systolic and end-diastolic diameters of the left ventricle. Thus, the smaller the difference between these values, i.e. the less mobility of the walls of the left ventricle, the more pronounced the congestive phenomena of the left ventricular type.

An essential and mandatory addition to the examination is Doppler echocardiography, which allows determining the blood flow velocity, pressure in the heart cavities, the presence and volume of pathological blood flow.

Before echocardiography became widely used in clinical practice, a decrease in myocardial contractility was judged by a decrease in heart pulsation during cardiac fluoroscopy. And at present, the radiological examination method should not be forgotten, at least for the reason that unexpected findings may be revealed during chest radiography. Therefore, cardiac radiography in three projections (direct and two oblique) should complement other examination methods. An objective indicator of an increase in the size of the heart is an increase in the cardiothoracic index, determined by the ratio of the diameter of the heart shadow to the diameter of the chest. Normally, the cardiothoracic index does not exceed 50% on average, although there are certain standard indicators for each age. Small children may be an exception; sometimes, against the background of flatulence, an imitation of an increase in the heart shadow in diameter is possible due to the high position of the diaphragm.

There is no doubt that ECG was and remains an informative examination method, since the ECG recording technique is objective and does not depend on the skill and qualifications of the researcher to the same extent as EchoCG and radiography.

Since left ventricular failure necessarily implies an increase (overload) of the left sections of the heart, the corresponding changes are also detected on the ECG.

The ECG shows signs of left atrial overload: an increase in the duration of the P wave, a change in the shape of the P wave (double-humped in leads I, V1), the presence of a pronounced negative phase in lead V1; signs of left ventricular overload are also revealed: R in V6 > R in V5 > R in V4> 25 mm; secondary ST-T segment changes in the left chest leads.

Electrocardiographic signs of left atrium enlargement (P-mitrale) appear already with sufficiently pronounced clinical manifestations of left ventricular failure, i.e. to a certain extent, left atrium enlargement is a demonstration of increased pressure in the pulmonary circulation. Increased pressure in the pulmonary circulation leads to overload of the right sections, in particular the right atrium.

Some ECG features may suggest a morphological cause (basis) for the changes detected. Thus, with an increase in the muscle mass of the left ventricle due to hypertrophy of its walls, a moderate increase in the voltage of the QRS complex is possible, as well as a shift of the ST segment below the isoline (depression), as a sign of concomitant subendocardial ischemia of the left ventricular myocardium.

In addition to signs of enlargement of the left atrium and left ventricle, signs of right atrial overload are visible in the form of the appearance of a sharp positive phase of the P wave and signs of subendocardial ischemia of the left ventricle in the form of ST segment depression in lead V6.

In these leads, it is also possible (but not necessary) for a deepened O wave to appear due to a relative deficit in coronary blood flow.

In cases of cardiosclerosis, for example, in congestive cardiomyopathy or chronic myocarditis resulting in cardiosclerosis, the voltage of the QRS complexes may be reduced in standard leads, and the appearance of theQS form is possible in leads V1-V3-4.

Diagnosis of right ventricular heart failure

Clinical examination. During physical examination of the cardiovascular system, percussion may expand the boundaries of relative cardiac dullness to the right, but even with a large increase in the cavity of the right ventricle, the bistinal cardiac hump is more pronounced. Epigastric pulsation associated with enlargement and volume overload of the right ventricle (cardiac impulse) is determined by palpation.

Auscultatory changes in the heart depend on the nature of the underlying disease. In the presence of pulmonary hypertension, some characteristic changes in the second tone appear in the second intercostal space on the left. Such a sign may be a splitting of the second tone, which is normally determined in healthy individuals during inhalation, since during inhalation the closure of the pulmonary artery valve is delayed. Such a "normal" splitting of the second tone during inhalation is heard only in the second intercostal space on the left in the lying position. If the splitting of the second tone is also heard at the apex, then the patient has pulmonary hypertension. With further increase in pulmonary hypertension, the aortic and pulmonary components of the second tone merge, the second tone becomes more accentuated and, with high pulmonary hypertension, acquires a metallic tint, which is characteristic of primary pulmonary hypertension, as well as secondary, in particular, Eisenmenger's syndrome.

An interesting auscultatory symptom is a noise along the left edge of the sternum, with the point of maximum listening in the lower third of the sternum, arising as a result of tricuspid regurgitation due to relative insufficiency of the tricuspid valve. If the cause of right ventricular failure was pale defects, in particular, a defect of the interventricular septum, then the specified noise merges with the main noise (shutdown noise) and is not differentiated. If right ventricular failure arose for other reasons, for example, due to hypertrophic cardiomyopathy, then the noise of tricuspid regurgitation is heard, but significantly decreases with a decrease in the degree of heart failure in parallel with a decrease in the size of the liver (usually against the background of drug treatment).

Instrumental methods.

Echocardiographic and radiological signs of right ventricular failure are reflected by an increase in the cavity of the right ventricle and right atrium.

When assessing the severity of heart failure, one should not forget about the general methods of physical examination, in particular about the characteristics of blood pressure. Blood pressure indicators in heart failure can indicate the severity of the patient's condition. Thus, a decrease in cardiac output leads to a decrease in systolic pressure. However, with good pulse pressure indicators (40-50 mm Hg), the patient's well-being (not the condition - as an indicator of the immediate prognosis, depending on the underlying disease) can be satisfactory or even good. With an increase in total peripheral vascular resistance (TPVR) due to a slowdown in blood flow, an increase in the volume of circulating blood and other factors that determine the formation of heart failure, diastolic pressure increases, which is sure to affect the patient's well-being, since cardiac output decreases. Nausea or vomiting, abdominal pain (right ventricular failure), the appearance or increase in the severity of a wet cough (left ventricular failure) are possible.

Differential diagnosis of heart failure

Differential diagnostics of heart failure syndrome is difficult only with inattentive examination and underestimation of individual symptoms of the condition. Thus, quite often in practical work one has to deal with a situation when long-standing complaints of abdominal pain and vomiting, which usually occur after physical exertion, are regarded as signs of gastroenterological pathology, although for an adequate assessment of the condition it is only necessary to conduct a competently complete physical examination of the patient.

There is also another extreme: complaints of increased fatigue, possibly shortness of breath with adequate physical activity in untrained children and adolescents are considered a sign of cardiac decompensation.

In some cases (severe course of some childhood infections, complicated pneumonia, sepsis, etc.) heart failure is a complication of the underlying disease. Symptoms of heart failure undergo reverse development against the background of recovery from the underlying disease.

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