Echocardiography (EchoCG) is a method of noninvasive visualization of the heart using reflected ultrasound signals, which allows assessing the morpho-functional parameters of heart structures. Several modes are used: one-dimensional, two-dimensional, Doppler, etc., together allowing to assess the contractility of the heart, conduct a phase analysis, measure the parameters of the walls and cavities, determine the pressure in the chambers, examine the condition of the valves. EchoCG is used to diagnose heart defects and tumors, coronary artery disease, intracardiac thrombi, thoracic aortic aneurysm, exudative pericarditis, endo- and myocarditis, etc. cardiopathology. The cost increases when using Doppler analysis.
The diagnostic significance is extremely high. Being a highly informative non-invasive technique, echocardiography serves to detect changes in the heart that do not manifest themselves clinically and are not determined by ECG. Echocardiography is performed on special echocardiographs equipped with an ultrasound generator with a frequency of 1-10 MHz, a sensor that perceives reflected ultrasound signals, a converter of ultrasonic vibrations into electromagnetic ones and a recording device that displays the studied structures of the heart in the form of an echocardiogram. Modern echocardiograph devices have an electrocardiographic channel for simultaneous ECG recording and are synchronized with a computer for fast and high-quality data processing.
In cardiology, one-dimensional echocardiography is used in A-, M- and B-modes of echo signal display; two-dimensional echocardiography, as well as Doppler echocardiography. Modifications of transthorocal ultrasound cardiography are contrast echocardiography, transesophageal echocardiography, stress echocardiography. The cost depends on the type and methodology of the study, the class of echocardiographic apparatus. Echocardiography requires the results of the last ECG, previously performed EchoCG, daily monitoring of ECG and blood pressure (if available).
The objectives are to study the structures of the heart, the pericardial space, the detection of pericardial effusion, intracavitary thrombi, scars, and the assessment of the functional reserves of the heart. Echocardiography is performed in patients with auscultatively determined cardiac murmurs, detected ECG changes, complaints of chest pains, interruptions, shortness of breath, increased blood pressure. Echocardiography is prescribed by a cardiologist if congenital or acquired defects, myocarditis, myocardial infarction, endocarditis, pericarditis, heart tumors, aneurysmal expansion of the thoracic aorta, heart failure, arrhythmia, cardiomyopathy are suspected. Dynamic examination of patients in the post-infarction period or after cardiac surgery also requires echocardiography.
This diagnostic procedure is recommended for patients with thrombophlebitis, varicose veins of the lower extremities to exclude the threat of PE. EchoCG can be prescribed for rheumatic diseases, after complicated infections (ARVI, flu, sore throat), with endocrinopathies. In sports medicine, EchoCG is performed for people experiencing intense physical exertion. In women of the cardiological risk group, echocardiography is included in the pregnancy management program. If fetal cardiac pathology is suspected, fetal echocardiography can be performed starting from the 18th week of pregnancy.
Echocardiography has no contraindications and complications, can be performed in seriously ill and children. Severe obesity, gigantomastia, emphysema of the lungs, chest deformities, local skin inflammation in the scanning area can serve as limitations to the EchoCG.
Methodology of conducting
Echocardiography should be performed by a specialist who is well acquainted with the topography, normal morphology of the structures and functioning of the heart, possible deviations in various nosological forms and their display on the echocardiogram in different phases of the cardiac cycle. Echocardiography is performed for 20-40 minutes. The patient is placed on his back or left side. The different positions of the sensor located above the heart provide a study of its various departments. The main approaches (windows) of heart scanning are parasternal (in 3-4 intercostal spaces), suprasternal (in the area of the jugular fossa), subcostal (in the area of the xiphoid process) and apical (in the projection of the apical thrust). Transesophageal access is used during transesophageal echocardiography.
All positions used in echocardiography provide optimal visualization of the zones of interest in the sagittal, horizontal plane and the plane passing through all the chambers of the heart. Modern heart ultrasound equipment allows performing various echocardiography options. With one-dimensional echocardiography, echo signals are displayed in A-, M- and B-modes. The M-mode, which graphically reproduces the movement of the heart walls and valves, which is important for assessing the size of the heart and the systolic function of the ventricles, has received the greatest practical application.
Two-dimensional echocardiography reproduces a slice of moving cardiac structures along a short or long axis. During two-dimensional EchoCG, the size of the cardiac cavities and the thickness of the ventricular walls are determined, the functioning of the valves, global and local contractility of the ventricles are evaluated, and the thrombosis of the chambers is detected. Doppler echocardiography is used to study central hemodynamics – the speed and direction of blood flow. For a full-fledged analysis of hemodynamics, pulse-wave, constant-wave and color Doppler modes are used.
Usually, when performing echocardiography, a certain algorithm is followed. First, the heart valves are identified taking into account their mutual location; cardiac septa (interventricular, atrial) are recognized, their continuity is traced during polypositional and polyprojection scanning, the type of movement is evaluated (normokinesis, hypokinesis, akinesis, dyskenesia). Then proceed to the assessment of the anatomical interposition of the interventricular septum and valves, as well as the nature of the movement of the valves. Further, in the process, the thickness of the walls and the dimensions of the heart cavities are measured, the presence and severity of myocardial hypertrophy, dilation of the cavities are determined. At the final stage, Doppler echocardiography and two-dimensional EchoCG are performed to exclude or detect stenoses, valvular regurgitation, pathological intracardiac blood bypass.