Peculiarities of the prognostic value of stress-echocardiography in the diagnosis of heart disease

Relevance. One of the ways to reduce mortality from coronary artery disease is early diagnosis and timely treatment. There are various algorithms for diagnosing coronary artery disease both in our country and abroad (Sedov V.P., Alekhin M.N., Korneev N.V., 2000), and in the USA (AHA / ACC 2007), including mandatory stress echocardiography (stress echocardiography) before performing selective coronary angiography (CAG). The sensitivity of standard samples (dobutamine with atropine, dipyridamole with atropine) is relatively low and is about 80.0% (Sedov V.P., Alekhin M.N., Korneev N.V., 2000). Given the mechanism of action of dipyridamole (“intercoronary steal syndrome”), and dobutamine (stimulation of α-adrenergic receptors, leading to an increase in myocardial oxygen demand), it is advisable to combine them as stress agents during exercise EchoCG.

To exclude false-positive and false-negative results in the diagnosis of coronary artery disease, stress echocardiography should have high sensitivity and specificity.

According to many literature sources, the sensitivity of stress echocardiography with exercise is 91.0% (Alekhin M.N. 2003, Hecht HS 1993, Gani F. 2007, Leischik R. 2007, Picano E. 2007), which is significantly higher than than pharmacological tests. However, there is a group of patients who are not able to perform this particular type of study. For this contingent, a stress echocardiogram with pharmacological tests (dipyridamole, dobutamine) is indicated.

The purpose of the study: to study the role and possibilities of stress-Doppler echocardiography in the diagnosis of coronary artery disease.

Materials and research methods. The control group consisted of 20 apparently healthy patients aged from 60 to 60 years (49.1±2.98) without clinical manifestations of coronary artery disease and the absence of its main risk factors. Depending on the clinic, the results of the study, the patients were divided into 2 groups. Group I patients consisted of 20 apparently healthy men aged 37 to 61 years (49.2±2.87) with two risk factors for CHD. Group II included 20 men aged 39 to 64 years (49.5±3.01) with typical angina attacks. All examined patients underwent tissue stress echocardiography with physical activity. Physical activity according to the method was used as a stress agent. The patient was discontinued beta-blockers, cardiac glycosides, calcium antagonists and nitrates 2 days before stress echocardiography. Tissue stress echocardiography was performed in the parasternal position at the level of the papillary muscles along the long axis (PLax) and short axis (SaxPM), apical 4-chamber (4Ch) and 2-chamber (2Ch) positions, as well as using pulsed-wave mode of longitudinal tissue Doppler. Systolic regional parameters of myocardial contractility were determined in the main blood supply basins: anterior descending artery (ADA), circumflex artery (OA), right coronary artery (RCA). The increase in maximum segmental systolic velocity (MSV) for each of the segments at all stages of the stress test was assessed. The tissue stress-dechoCG test was considered positive if the MSS for any of the segments decreased at the next stage of the test.

Research results. MCC indicators at rest during stress-dechocardiography in the control group (n=20). There is a direct linear relationship between the increase in MCC and the stage of the stress test in the control group. Thus, there is an increase in MCC by an average of 1.31 times, and with a combined stress-DechoCG test - by an average of 1.87 times. In patients without clinical manifestations of coronary artery disease with no major risk factors with a positive VEM test (n=20), the sensitivity and specificity of the combined stress echocardiography was 100% (p0.001). It was found that 90.0% of patients in this group with pathological changes in the ST segment had no coronary lesions (p0.05). In the group of patients with newly developed angina pectoris, the presence of 2 or more risk factors for coronary artery disease and a negative VEM test, atherosclerotic lesion of the coronary artery was noted in 70.0%. The results of the combined stress echocardiography fully corresponded to those in CAH both in terms of the location of the affected artery and the prevalence of the pathological process (p0.001).

Conclusion. Stress echocardiography is the preferred imaging technique due to lower cost, wide availability, and, most importantly, the absence of ionizing radiation. Combined stress Doppler echocardiography can be successfully used both to form groups of patients subject to coronary angiography and to assess the effectiveness of angiosurgical treatment of coronary artery disease.