[The diagnostically significant indices of the corrected axial ECG system in the differentiation of ischemic heart disease and dilated cardiomyopathy]. / Diagnosticheski znachimye pokazateli korrigirovannoi aksial'noi sistemy EKG v differentsiatsii ishemicheskoi bolezni serdtsa i dilatatsionnoi kardiomiopatii.

The common uniformity of electrocardiographic changes in coronary heart disease (CHD) and dilated cardiomyopathy (DCMP) in the lead XII, namely low QRS complex voltage, T-wave inversion, cardiac arrhythmias, atrioventricular and intraventricular conduction disturbances, served as the basis for searching for individual or combined lesion signs quantitatively diagnostically significant for CHD and DCMP. For this purpose, 217 patients were examined. Out of them 83 were included into a group of healthy persons and 134 were patients who were divided into two groups: 60 with chronic CHD and 74 with DCMP. The authors identified a complex of diagnostically significant ECG parameters of the McPhi-Parungao system. SX > 4 mm, SZ > 12 mm, RX + SZ > 27 mm, sigma RXYZ + sigma SXYZ > 45 mm, sigma RXYZ/sigma SXYZ < 1.5, which permits differentiation of DCMP and CHD in case of lowered QRS voltage on ECG-12.

[Computer visualization of three-dimensional vectorcardiographic loops in the diagnosis of the enlargement of cardiac segments]. / Komp'iuternaia vizualizatsiia prostranstvennykh vektorkardiograficheskikh petel' i diagnostika uvelicheniia otdelov serdtsa.

A nontraditional method was proposed for computed visualization of three-dimensional vectorcardiographic loops in the projections on the two-dimensional planes the least departing from the appropriate loops in terms of root-mean-square deviation. The proposed visualization makes it possible to make a differential diagnosis of isolated forms of enlarged cardiac portions, including those of enlarged atria with high certainty.

[Vector electrocardiographic features in patients with hypertrophic cardiomyopathy]. / Vektor-élektrokardiograficheskie osobennosti u bol'nykh s gipertroficheskoi kardiomiopatiei.

The examination indicated that abnormal Q and QS waves recorded along the azes Z and Y in the adjusted lead system far clearly reflected a predominant site of suspected focal and scarring lestoh in hypertrophic cardiomyopathy (HCM) as in coronary heart disease (CHD) (the anterior site in the Z lead and inferior one, in the Y lead), however, the difference in their quantitative characteristics do not fulfil the goals of the electrocardiographic differentiation between HCM and CHD. To differentiate HCM and CHD in the presence of Q and QS waves, a characteristic complex of signs was identified: elevated waves Rx (greater than or equal to 17.5 mm), Sy (greater than or equal to 7.3 mm) of the total value, sigma Rxyz + sigma Sxyz (greater than or equal to 48.3 mm) at the anterior site of "scarring" myocardial lesion and increased waves Sz (greater than or equal to 20.4 mm), sigma Sxyz (greater than or equal to 21.4 mm) at the inferior site. Only "indirect" signs remained on VECG in the presence of scarring myocardial lesion concurrent with arterial hypertension in CHD patients.

[The ECG in dilated cardiomyopathy with different degrees of the manifestation of cardiosclerosis]. / EKG pri dilatatsionnoi kardiomiopatii s raznoi stepen'iu vyrazhennosti kardioskleroza.

ECG of 46 patients who had died from dilated cardiomyopathy were retrospectively examined in order to evaluate characteristic ECG changes in relation to myocardial sclerotic severity according to autopsy findings. It was found that 1) one of ECG features in this disease is QRS complex morphology in left chest leads in the form of "rS", "RS" as being independent of cardiosclerotic severity. The deep wave S V5-V6 was due not only to rotation shifts during left ventricular hypertrophy (dilatation), which was typical of dilated cardiomyopathy right ventricle mass; 2) as cardiosclerosis progresses, the frequency and severity of intraventricular conduction disturbances progressively increase; 3) ectopic arrhythmias and atrioventricular block are not caused only by cardiosclerosis and likely to be induced by drug therapy (cardiac glycosides); 4) despite cardiosclerotic development in patients with dilated cardiomyopathy, ECG retains voltage criteria of enlarged cardiac cavities; 5) enlarged cardiac cavities can be determined by standard 12 ECG leads in 73.9% of cases.

[Evaluation of the risk of fatal outcome in patients with stable stenocardia over a 5-year period]. / Otsenka riska letal'nogo iskhoda u bol'nykh stabil'noi stenokardiei na 5-letnii period.

The results have been analyzed of the 5-year prospective observation over patients with associated coronary heart disease (CHD) and stable angina pectoris without grave concomitant diseases and heart failure signs. A rule of prediction has been elaborated enabling one to distinguish on the basis of the clinical data a group of patients in whom the disease runs a favourable course. It is unlikely that in the future such a group of patients would require any combined instrumental examination or surgical intervention. The use of the common therapeutic measures (long-acting nitrates, beta-blockers, and calcium antagonists) can be recognized as quite sufficient and effective. The clinical observation can be limited by the patient's attendance of the health center for repeated examination and specification of the further prognosis, which is to be made once a year. The above-said confirms the importance of defining CHD prognosis, since the properly chosen tactics of such patients' management makes it possible to attain the maximal efficacy of the diagnostic and treatment measures and to save costs as well.

[Electrovectorcardiographic characteristics of shifting repolarization phase curves in patients with hypertrophic cardiomyopathy and ischemic heart disease with arterial hypertension]. / Elektrovektorkardiograficheskie osobennosti v sdvigakh repoliarizatsionnoi fazy krivykh u bol'nykh s gipertroficheskoi kardiomiopatiei i ishemicheskoi bolezn'iu serdtsa s arterial'noi gipertoniei.

Possible electrovectorcardiographic approaches to the diagnosis of hypertrophic cardiomyopathy (HCMP) are considered on the basis of a study of 85 HCMP patients, 44 coronary patients with postinfarction cardiosclerosis and arterial hypertension (CD + AH), and 83 normal subjects. Particular attention was paid to cases where myocardial scary changes and left-ventricular hypertrophy were detected electrocardiographically as their interpretation was difficult because of similar changes in the QRS complex being typical for postinfarction cardiosclerosis. An analysis of quantitative and qualitative changes in the end segment of the QRS complex demonstrated a specific pattern of repolarization shift in patients with HCMP and CD + AH. The demonstrated changes can be useful in differential diagnosis of these conditions, facilitating the interpretation of infarction-like curves that are quite common in HCMP patients.

[Cartogram of 35 ECG leads in hypertrophy of the right ventricle of the heart]. / Kartogramma 35 otvedenii EKG pri gipertrofii pravogo zheludochka serdtsa.

Automatedly-reproduced cartograms of 35 electrocardiographic leads in 27 cases of isolated right-ventricular hypertrophy (RVH) were analysed in relation to the latter's roentgenocardiometric markedness, and the obtained results were substantiated in terms of spacial vectorcardiography. A direct correlation was established between cartographic and roentgenocardiometric data in cases of moderate RVH that was absent in marked RVH. The correlation between cartographic and vectorcardiographic parameters was, on the contrary, only slightly expressed in moderate RVH and high in marked RVH cases. These results can be attributed to specific anatomical structure of the hypertrophic myocardium at different stages of RVH formation, with either the outflow-pathway hypertrophy proper prevailing at early stages of hypertrophic development, or the right-ventricular free wall hypertrophy prevailing at later stages which result in irregular thickening of individual compartments and distortion of cavity size characteristics and geometrical properties of the right ventricle proper, as well as the displacement of the center of gravity and heart rotation round its own axes.

[Approaches to electro- and vectorcardiographic differentiation of the signs of focal and cicatricial myocardial lesions in left-ventricular hypertrophy]. / Podkhody k elektrovektorkardiograficheskoi differentsiatsii priznakov ochagovo-rubtsovogo porazheniia miokarda na fone gipertrofii levogo zheludochka.

Electro- (12 and 35 ECG leads) and vectorcardiographic (3 orthogonal leads) examination of 75 patients with arterial hypertension and left-ventricular hypertrophy (LVH), 28 of which also had documented stenosis of one or more coronary arteries, was carried out using an automatic system of graphic registration and quantification of ECG-35 and VCG parameters. Electro- and vectorcardiographic signs of "pure" LVH and LVH accompanied by CHD relevant for their differential diagnosis were established. The principal singled out difference criteria include NQ (Q registration zone) and SQRSxyz (space QRS loop area), while Q (Q-wave sum), H0QRSxyz 0.08-0.10 s (QRS end vector azimuth), Gxyz (space ventricular gradient) and V0Gxyz (ventricular gradient elevation) are complementary, determined by the degree of the principal parameter shifts.

[Correlation of myocardial scintigraphy findings with 201Tl and electrocardiography in evaluation of the state of the myocardium in patients with ischemic heart disease]. / Sopostavlenie dannykh stsintigrafii miokarda s 201Tl i élektrokardiografii v otsenke sostoianiia miokarda u bol'nykh ishemicheskoi bolezn'iu serdtsa.

One hundred and twenty-seven coronary heart disease patients with angina of effort and at rest were examined, using myocardial scintigraphy with 201Tl. The results obtained were compared with the ECG findings recorded at 12 conventional leads. Myocardial scintigraphy with 201Tl was shown to be a highly sensitive (91% sensitivity) and accurate method of detecting and locating the local impairments of the myocardial blood supply. However it was not specific for diagnosing the post-infarction cicatricial changes (specificity was less than 10%). As compared to ECG with a sensitivity of 60% and specificity of 90%, myocardial scintigraphy with 201Tl makes it possible to diagnose more accurately the focal changes in the posterior wall which could be hardly detected by ECG. Myocardial scintigraphy may serve as a method of choice in cases where the clinical symptoms of myocardial infarction are not confirmed by the ECG findings as to the presence of focal changes as well as in cases of intraventricular conductivity irregularities and combined focal myocardial impairments of various localization which makes it difficult to differentiate one from another.

[Spatial parameters of the automatically reproduced QRS loop of the VCG in healthy subjects]. / Prostransrtvennye parametry avtomaticheski vosproizvedennoi petli QRS VKG u zdorovykh lits.

The findings of the VCG automatic construction in 55 healthy subjects with different axial and positional variants of ECG were analyzed . The applied method of the automatic corrected VCG construction has shown that QRS loop morphology coincides with the classical forms of VCG described before in healthy persons. The data of the automatic calculations of spatial characteristics demonstrated the orientation stability according to the angle--azimuth, max QRSxyz , S/2 QRSxyz and the integral vector-- AQRSxyz , i. e. independence of the azimuth value on the ECG axial and positional variants. The positional and rotational shifts regularly change the azimuth value in the spatial orientation of the initial (0.01"--0.02') and end (0.06") moment vector of depolarization, and the value of the angles of spatial vector elevation max QRSxyz , S/2 QRSxyz , AQRSxyz . In the normal intraventricular conduction, the orientations of max QRSxy , yz , xz are sufficiently informative in order to reveal the integral vector directions. The coincidence of S/2 QRSxy , yz , xz direction with that of AQRSxy , yz , xz in the two-polar loops indicates that S/2 QRSxy , yz , xz should be calculated to determine AQRSxy , yz , xz orientation. Indeed, in case of intraventricular conduction disorders, the AQRSxy , yz , xz calculation alone gives an idea of a resultant vector projection.

[Criteria of myocardial ischemia in bicycle ergometry of patients with stenosing arteriosclerosis of the cardiac coronary arteries depending on the initial ECG at rest]. / Kriterii ishemii miokarda pri veloérgometrii u bol'nykh stenoziruiushchim aterosklerozom venechnykh arterii serdtsa v zavisimosti ot iskhodnoi EKG v pokoe.

The sensitivity of various criteria of the physical exercise test in revealing myocardial ischemia was studied in 2 groups of patients with ischemic heart disease: 1st group of 64 patients with normal ECG at rest, 2nd group of 96 patients with cicatricial changes in the myocardium. Selective coronography demonstrated atherosclerotic narrowing (stenosis of more than 70%) of one or more coronary arteries of the heart in all patients. During physical exercise an attack of angina pectoris without "ischemic" changes on the ECG occurred in 36.1% of patients of the 1st group and in 22.4% of patients of the 2nd group. The frequency of other clinical signs of cessation of the exercise (dyspnoea, change of arterial pressure, extrasystole and others) was three and a half times higher in patients with cicatricial changes in the myocardium. It is concluded that the frequency with which signs of myocardial ischemia are revealed during physical exercise depends not only on the pronounced character of the pathological coronary condition and the development of collateral circulation but also by the sensitivity of the separate ECG leads and the presence and localization of cicatricial changes in the myocardium.

[Comparative diagnostic importance of 2 triaxial electrocardiographic systems (the Neba and McPhee-Parungao systems) in focal-cicatricial myocardial lesion of varying localization]. / Sravnitel'naia diagnosticheskaia znachimost' dvukh trekhosevykh élektrokardiograficheskikh sistem (sistema Néba i Mak Fi-Parungao) pri ochagovo--rubtsovom porazhenii miokardo raznoi lokalizatsii.

Comparison of two triaxial systems of an ECG record--the Neba system and the corrected McFee--Parungao system--showed that the second system possesses a greater number of informative signs than the first for differentiating the localization of a focal-cicatricial affection of the myocardium and comes close to the 12-axial system in informativeness: in focal-cicatricial lesion of the myocardium of a low localization they are recorded from lead Y, in anterior septal localization from lead Z, in anterolateral localization from lead X, in extensive affection (anterior septal, apico-lateral regions) from leads Y and Z. The Neba system proved unsuitable in the diagnosis of focal-cicatricial affection of low (postero-diaphragmatic) localization.

[Changes in the electro- and vectorcardiograms in primary vascular pulmonary hypertension]. / Izmeneniia élektro- i vektorkardiogramm pri pervichnoi sosudistoi gipertonii malogo kruga krovoobrashcheniia

A progressive elevation of the blood pressure in the pulmonary circulation in patients with primary vascular pulmonary hypertension results in isolated hypertrophy of the right-ventricle. According to electro- and vectorcardiographic data of the McFee--Parungao system, a significant predominance of the right vetricular potentials is noted, distinct reorientattion observed in those sections of the vectors that may reflect the process of hypertrophy and dilatation of the outflow tracts of the right ventricle.