Diagnosis of dilated cardiomyopathy

Diagnosis of dilated cardiomyopathy should be based on the exclusion of other causes of heart failure, for example due to coronary heart disease, congenital and acquired heart diseases, hypertension.

[1], [2], [3]

Diagnostic criteria of idiopathic (primary) dilated cardiomyopathy

• Left ventricular ejection fraction <45% and / or shortening fraction <25%, assessed by echocardiography, radionuclide scanning or angiography.
• The finite-diastolic size of the left ventricle is> 117% of the estimated value, corrected according to age and body surface area.
• Criteria for excluding the diagnosis of DCMP.
• Systemic hypertension (> 160/100 mmHg).
• Atherosclerotic lesion of the coronary arteries (stenosis> 50% in one or more large branches).
• Alcohol abuse (> 40 g / day for women and> 80 g / day for men for more than 5 years after a 6-month abstinence).
• Systemic disease, which could lead to the development of dilated cardiomyopathy.
• Diseases of the pericardium.
• Congenital and acquired heart defects.
• Pulmonary heart.
• Confirmed accelerated supraventricular tachycardia.

Patients usually describe the presence of various symptoms of heart failure, which have been increasing "for the past few months or years. Symptoms may appear earlier than with the help of echocardiography and radiography of chest organs will be detected cardiomegaly. It is necessary to actively clarify the abuse of alcoholic beverages, since it can play a role in the progression of primary dilated cardiomyopathy. At the general inspection, signs of heart failure are determined: acrocyanosis, edema of the lower extremities, the position of orthopnea, an increase in the volume of the abdomen, swelling of the cervical veins.

With auscultation of the lungs in the lower parts, moist, unvoiced small-bubbling rales can be heard.

With palpation of the heart, note the accelerated, spilled, shifted to the left and down the apical impulse. Often a diffuse and intensified cardiac impulse and epigastric pulsation is revealed due to hypertrophy and dilatation of the right ventricle.

With percussion, the displacement of the boundaries of the relative dullness of the heart to the left and right is determined by dilatation of the left and right ventricles, and with dilatation of the left atrium, upwards. Absolute stupidity of the heart can be expanded due to dilatation of the right ventricle.

With auscultation of the heart, the I tone on the tip is weakened, and the proto diastolic rhythm of the canter can be heard at the tip (due to the appearance of the III tone), which is associated with volumetric overload of the ventricles. The noise of relative insufficiency of the mitral and tricuspid valves is typical. With the development of atrial fibrillation or extrasystole, cardiac tones are arrhythmic.

For a more accurate assessment of the clinical state of the patient with DCM and CHF, the Russian Clinical State Assessment Scale (SCOX), containing 10 items, was proposed. The examination and examination of the patient in accordance with points SHOKS reminds the doctor about all the necessary studies that he must take to examine the patient. During the examination, the doctor asks questions and conducts studies corresponding to points 1 to 10. The card marks points that are then summed up. I FC CHF corresponds to the scale SHOKS <3 points, II FC - 4-6 points. III FC - 7-9 points, IV FC> 9 points.

Scale of assessment of the clinical state in CHF (SHOKS) (modification of Mareyev V.Yu., 2000)

• Shortness of breath: 0 - no, 1 - at a load, 2 - at rest.
• Has the weight changed during the last week: 0 - no, 1 - increased.
• Complaints about interruptions in the work of the heart: 0 No, 1 - is.
• In what position is in bed: 0 - horizontally, 1 - with a raised head end (two pillows), 2 - with a raised head end and wakes up from suffocation, 3 - sitting.
• Swollen cervical veins: 0 - no, 1 - lying, 2 - standing.
• Choruses in the lungs: 0 - no, 1 - lower divisions (up to 1/3), 2 - up to the scapula (up to 2/3), 3 - over the whole surface of the lungs.
• Presence of a gallop rhythm: 0 - no, 1 - is.
• Baked 0 - not enlarged, 1 - up to 5 cm, 2 - more than 5 cm.
• Edema: 0 - no, 1 - pastoznost, 2 - edema, 3 - anasarca.
• The level of systolic blood pressure: 0 -> 120 mm Hg, 1 - 100-120 mm Hg, 2 - <100 mm Hg.

In laboratory studies with primary dilated cardiomyopathy, no specific changes are observed. They should be aimed at excluding secondary DCMP: assessment of serum levels of phosphorus (hypophosphataemia), calcium (hypocalcemia), creatinine and nitrogen bases (uremia), thyroid hormones (hypothyroidism or hyperthyroidism), iron (hemochromatosis) and others. HIV infection and hepatitis C and B viruses.

[4], [5], [6], [7],

Instrumental diagnostics of dilated cardiomyopathy

• Radiography of chest organs

Cardiac enlargement, cardiothoracic ratio of more than 0.5 - cardiomegaly, signs of pulmonary congestion, interstitial or alveolar edema.

• ECG of rest. ECG monitoring by Holter.

Nonspecific changes in the segment of the ST and the T wave, a decrease in the voltage of the teeth, deformation of the complex, often sinus tachycardia, various disturbances of rhythm and conductivity.

Detects episodes of tachycardia or bradycardia, especially shown in the presence of syncopal and presyncopal episodes.

• Echocardiography. Two-dimensional (B and 20) and one-dimensional (M) modes.

It is possible to assess the size of the chambers and the thickness of the walls of the heart, the presence or absence of blood clots in the cavities, the presence of effusion in the pericardial cavity, and quickly and accurately assess the systolic function of the right and left ventricles.

• Echocardiography. Doppler mode (pulse, continuous and color).

It is most useful for the diagnosis of mitral regurgitation (detection and evaluation of severity with the calculation of the pressure gradient on the valve under study), systolic and diastolic dysfunction of the myocardium.

• Echocardiography. Stress echocardiographic study with dobutamine.

It allows to detect areas of viable myocardium and cicatricial changes and can be useful in resolving the issue of revascularization of myocardium in some patients with IHD - more often for the purpose of differential diagnosis with ischemic dilated cardiomyopathy.

• Cardiac catheterization and angiography.

It is recommended to assess the size of the heart cavities, with the determination of the diastolic pressure in the left ventricle and the left atrium, the pulmonary artery wedge pressure and the level of systolic pressure in the pulmonary artery, and the day of coronary artery disease atherosclerosis in patients older than 40 years, corresponding symptoms or high cardiovascular risk.

• Endomyocardial biopsy.

More often when suspected of inflammatory cardiomyopathy, it is possible to assess the degree of destruction of muscle filaments and cellular infiltration of the myocardium for differential diagnosis of myocarditis and cardiomyopathy.

Example of the formulation of the diagnosis

Idiopathic dilated cardiomyopathy. Atrial fibrillation, permanent form, tachysystole. NK II B, III FC.

[8], [9], [10], [11], [12], [13], [14], [15], [16]

Differential diagnostics

Differential diagnosis is carried out with other forms of cardiomyopathy, and it is also necessary to exclude the presence of an aneurysm of the left ventricle, aortic stenosis, chronic pulmonary heart,

[17], [18], [19], [20], [21], [22]