UDC 616.13. Abdiramasheva K.S. teacher International kazakh-turkish university named H.A.Yasavi, Turkestan, Kazakhstan MINOR ELECTROCARDIOGRAM ABNORMALITIES AND CARDIOVASCULAR DISEASES. The category of " minor abnormalities " of the Minnesota coding system are the following deviations [1]: - ECG signs of possible cicatricial changes in the myocardium - Slight changes in the ST segment and T wave - High-amplitude R wave in the left leads - ST segment lift - Incomplete blockade of the right bundle bundle leg (IRBBB) - Incomplete blockade of the left bundle branch leg (ILBBB) - Slight elongation of the QT interval - Shortened PR interval - Extended interval PR (AV-blockade of the first degree) - Deviation of the electric axis of the heart (EAH) to the left - Deviation of EAH to the right - Supraventricular extrasystole - Ventricular extrasystole - Extracorporeal combined - Migration of the atrial pacemaker - Sinus tachycardia - Sinus bradycardia - Supraventricular rhythm, constant form - Low-amplitude QRS complexes - Increased right atrium
- Increased left atrium - Fragmented QRS - ECG signs of early circulatory ventricles In general, the literature available for publication on the study of minor deviations of the Q wave is not numerous. Insignificant, isolated changes in the Q wave may be due to the vertical position of the heart, a violation of ventricular conduction and non-ischemic heart disease. This pathology is characterized as Q 0.03 sec., but <0.04 sec. in lead avf. In the study Multi-Ethnic Study of Atherosclerosis, the relationship between minor abnormalities of the Q wave and the development of cardiovascular diseases (CVD) is studied. The study includes 6,551 participants without CVD at the time of the examination. Among them, 38% are Caucasian, 28% are black patients, 22% are Spanish and 12% are of Chinese descent. During the 7.8-year follow-up period, 423 cardiovascular events occurred. The study revealed a link between minor changes in the Q wave and ethnicity. After adjusting for demographic, socioeconomic, traditional risk factors for CVD and other ECG changes, a slight deviation of the Q wave was associated with cardiovascular events in persons of Spanish descent. Thus, according to the authors, the prognostic significance of insignificant isolated abnormalities of the Q wave varies among different ethnic groups, present a high risk for future cardiovascular events in healthy Hispanic men [2]. Most clinicians believe that isolated minor deviations of the ST segment and the T wave are random, transient and benign changes in healthy individuals. In a transverse, one-stage US study, individuals 40 to 90 years of age without CVD who are participants in the NHANES III study studied the association of small ST-T abnormalities with CVD. The data from this study show that minor deviations in the ST segment and in the T wave are associated with an increased risk of cardiovascular and total mortality [3], which is confirmed by a study in Finland [4].
Among the small changes, the most common pathology is the IRBBB, whose prevalence in the general population is estimated to be about 10%, is more often recorded in men, especially among athletes [5,6]. Some researchers believe that IRBBB is benign and does not affect the cardiovascular prognosis in individuals with and without CVD [7]. So, Lerecouvreux and the co-authors note that the prognosis of IRBBB in the absence of CVD is usually favorable, but it may have an unfavorable prognosis in the presence of CVD [8]. Work of BakalliA. and co-authors discovers an association between IRBBB and the aneurysm of the interatrial septum [9]. Along with this, it is suggested that IRBBB in combination with anomalies of the T wave predict a presence of an atrial septal defect [10]. ILBBB is characterized by blockade of the anterior or posterior branch of LBBB. Posterior branch of LBBB occurs much less frequently than the blockade of the anterior branch and is often combined with RBBB [11]. In one of the prospective cohort studies, the dynamics of anterior branch of LBBB is studied. The study involved 1664 patients, 39 of whom had anterior branch of LBBB. Over a 10-year follow-up, 16 patients with an initial anterior branch of LBBB have AF, 17 have congestive heart failure, and 33 have a fatal outcome. Thus, according to the results of this study, anterior branch of LBBB is a risk factor for AF, heart failure and overall mortality [12]. Most foreign studies show that in people with risk factors for CVD, ECG deviations occur more often. In addition, it was found that both large and small ECG changes play an important role in the development and progression of CVD. Along with this, there are data suggesting that some types of ECG deviations do not represent any significance in the development of CVD. All this is of great interest and requires further study of CVD and the contribution of electrocardiographic changes in the development of diseases of the cardiovascular system.
References 1. Peter W. Minnesota coding and the prevalence of ECG abnormalities.j Heart, 2000. 2. Li Y., Dawood F.Z., et al. Minor isolated Q waves and cardiovascular events in the MESA study. Am J Med., 2013. 3. Badheka A.O., Rathod A., et al. Isolated nonspecific ST-segment and T-wave abnormalities in a cross-sectional United States population and Mortality (from NHANES III). Am J Cardiol., 2012. 4. Tikkanen J.T., Kenttа T., et al. Electrocardiographic T Wave Abnormalities and the Risk of Sudden Cardiac Death: The Finnish Perspective. Ann Noninvasive Electrocardiol., 2015. 5. Corrado D., Pelliccia A., et al. Recommendations for interpretation of 12- lead electrocardiogram in the athlete. Eur Heart J., 2009. 6. Swiatowiec A., Król W., et al. Analysis of 12-lead electrocardiogram in top competitive professional athletes in the light of recent guidelines. Kardiol Pol., 2009. 7. Haataja P., Anttila I., et al. Prognostic implications of intraventricular conduction delays in a general population: the Health 2000 Survey. Ann Med., 2015. 8. Dijk G.P., van der Kooi E., et al. High prevalence of incomplete right bundle branch block in facioscapulohumeral muscular dystrophy without cardiac symptoms. Funct Neurol., 2014. 9. Bakalli A, Kamberi L, Pllana E, Gashi A. Atrial septal aneurysm associated with additional cardiovascular comorbidities in two middle age female patients with ECG signs of right bundle branch block: two case reports. Cases J., 2008. 10. Wang M.X., Wu G.F., et al. Defective T wave combined with incomplete right bundle branch block: a new electrocardiographic index for diagnosing atrial septal defect. Chin Med J., 2012. 11. http//lifeinthefastlane.com/ecg-library/basics/left-posterior-fascicular-block/
12. Ms. Mala C. Mandyam, et al. Long-term Outcomes of Left Anterior Fascicular Block in the Absence of Overt Cardiovascular Disease. JAMA, 2013.