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[Value of echocardiography and amplified atrial vectorcardiography for selecting the methods of therapy and prevention of paroxysmal atrial fibrillation].

Atrial and left-ventricular myocardial activity was assessed in 85 coronary patients with paroxysmal atrial fibrillation. Their age varied between 43 and 88 years. The methods used included ECG, amplified atrial vectorcardiography after I. T. Akulinichev's schedule (amplification: 1 mv = 100 mm) and M-scan echocardiography. The comparison of these methods has substantiated criteria for the selection of differential treatment and preventive measures in these patients, on the basis of the prevailing type of atrial myocardial changes ("arrhythmic", "hemodynamic" or "combined" ones). A supportive treatment with cardiotonic agents is advisable in cases of the "hemodynamic" type with apparent signs of the overstrain (dilation) of the left atrium or both atria. In the "arrhythmic" variant, where conductivity, automatism and excitation disorders are predominant, antiarrhythmic agents (cordaron, quinidine, adrenoblockers) are indicated while the "combined" type calls for combined treatment with cardiotonic and antiarrhythmic agents.

Adult↗

[Comparison of echocardiography, vectorcardiography, electrocardiography, coronarography and ventriculography in coronary heart disease].

Fifty patients (9 women, 41 men) with angina pectoris, aged from 22 to 59 years, were examined by means of one- and two-dimensional echocardiography (ECHO), vectorcardiography (VCG) using the McFee-Parungao system of leads, standard 12 lead electrocardiography (ECG), coronarography (CAG), and ventriculography (VG). I of isolated positivity of either of these methods ans considererl as patse positivity and presence or absence of positivity in combination of at least two methods (ECG exeluted) astme positivity, or true negativity then VCG was found to have the highest sensitivity (96%), negative predictive value (80%), as well as the highest overall predictivity (83%), while ECHO had the lowest values, i.e. 55%, 36%, 64%, respectively. On the other hand, ECHO was leading in specificity and positive predictive value with 100%, whereas VCG ranked lowest with 62% and 83% respectively. The combination of ECHO and VCG versus CAG and/or VG positivity exhibited and 80% specificity, 90% sensitivity, 90% positive predictive value and 86% overall predictivity when stenosis of over 50% was considered to be criterion. If obstruction was required the figures were to 75%, 94%, 83% and 86% respectively. ECHO and VCG are complementary noninvasive methods able to predict the results of CAG and VG and have a good predictive value when lowing for mere presence of focal myocardial injury.

Adult↗

[History and perspectives of electro-vectorcardiography].

A panoramic view of the development of electrovectorcardiography from its beginnings until the present is reported. The functional essence of this exploratory method is emphasized and the basic steps of its evolution are described: the bipolar or differential leads in the beginning, the distal unipolar leads and the initial vectorcardiography in the 30s, the proximal unipolar leads in the 40s, the His electrograms and intracavitary and thoracic mapping in the 60s and later, the continuous records on a magnetic band. The evolution from Einthoven's original electrocardiograph to the modern apparatus of direct inscription and cathode-ray oscillographs is also described. Finally, the contribution of the Mexican School to a rational approach to electrovectorcardiography and clarification of some aspects of myocardial electrophysiopathology is presented.

Electrocardiography↗

[Spatial ventricular gradient studied by computerized vectorcardiography. Normal and pathological values. Interpretation and clinical evaluation].

The ventricular gradient is a reflection of uneven ventricular repolarisation. Until recently is was only appreciated in the frontal plane of the classical electrocardiogramme and expressed as the sum of the vectors representing the surfaces under the QRS complex and T wave. We used computerised vectorcardiography to obtain a more exact evaluation of the size and spatial orientation of the vector gradient. The spatial vector gradient was calculated in a control group and in a number of pathological conditions. The reference values were established in 70 normal subjects with a mean age of 36 +/- 21 years: 0.092 +/- 0.016 m V.s for amplitude: 38.4 degrees +/- 6.1 for thesite and 21.6 degrees +/- 8.7 for the azimuth. The size and spatial orientation of the ventricular gradient can be used to define normal limits and to distinguish subgroups by using the values of the site and azimuth. The spatial ventricular gradient is a new approach to defining the limits of normality in poorly understood abnormalities of ventricular repolarisation. It may also be useful in the comprehension of certain forms of cardiac arrhythmia related to desynchronisation of ventricular repolarisation.

Adolescent↗

[Vectorcardiography in inferior infarction associated with left bundle-branch block].

The authors report a series of 13 patients, 8 men and 5 women, with an average age of 68 years (range 39 to 87 years) presenting with documented inferior infarction with anteroseptal extension in 2 cases. These patients developed LBBB (complete in 9 cases, incomplete in 4 cases). This complications occurred in the acute phase in 8 cases and 4 months to 9 years later (average 4,5 years) in the other 5 cases. The block was intermittent in 4 patients and became permanent in all cases. The diagnosis of inferior infarction with LBBB was made by vectorcardiography (VCG) in 5 out of the 13 patients (38,4 p. 100) on the criteria suggested by Starr. 3 of the 8 false negative results were directly related to the block which masked the ECG and VCG signs of inferior infarction. The VCG signs observed were an upwards displacement of the QRS loop with preservation of the superior orientation of the initial forces (5 cases). Atypical appearances of LBBB were observed in 2 cases with a posterior and right-sided shift of the efferent loop following the anterior and left-sided orientations of the initial forces. The sensitivity of the VCG and ECG is mediocre in inferior infarction with LBBB because the block may mask the electrical signs of inferior infarction. The specificity of the VCG could not be assessed because of the mode of selection of the patients and the small number of cases.

Adult↗

Estimation of size of infarcted focus by spatial quantitative vectorcardiography in patients with acute anterior myocardial infarction.

The study included 113 patients with acute myocardial infarction of the left ventricular anterior wall. The patients were repeatedly followed up from the first hours of the affection onward in the course of the individual stages of treatment (stage of intensive monitoring and therapy; intermediate stage; initial rehabilitation with application of active therapy; early mobilization, activation and rehabilitation). A new approach to the estimation of the size of the infarcted focus is described, namely, the method using spatial quantitative vectorcardiography. It was found that the spatial localization of the 40-ms vector, especially its azimuth, is a specific indicator, with the aid of which the localization, extent and depth of the lesion in the left ventricular anterior wall can be assessed with a high probability in most instances. The compensatory adaptive and reparative capacity of the affected myocardium, estimated on the basis of spatial quantitative VCG, is closely correlated with the size of the infarcted focus.

Humans↗

Octant vectorcardiography and its data basis.

The present communication is a continuation of the previous report published in this journal [Physiol. bohemoslov., 29: 481, 1980]. It presents further information on the practical use and evaluation of the octant vectorcardiography method. The description starts from the elementary table set up according to the Frank lead system. All cases may be classified alpha-numerically into the data bases by means of a newly introduced concept - the octant. The data include 250 cases after myocardial infarction, supplemented by further information on the integration of peaks. In this way, even widely different cases can be compared in general. In advanced cases of coronary artery disease, an octant labelled in our terminology as the fifth octant, has been defined. The method brings new information about cases after myocardial infarction and it helps to determine the progress of the disease.

Computers↗

Use of vectorcardiography for the detection of +Gz-related cardiac pathology in miniature swine.

Vectorcardiograms were recorded from anesthetized, adult miniature swine 1-2 weeks before high sustained +Gz exposure and 2-6 h after exposure. Each +Gz run consisted of one 60-s exposure, respectively, to 3, 5, 7, and 9 +Gz, with 3 min rest between each +Gz plateau. The full range, from severe to minor, of +Gz-induced cardiac pathology was observed in this group of miniature swine. In spite of the large variation in the amount and degree of cardiac pathology, there were no post-exposure vectorcardiographic changes which might be diagnostic of +Gz-induced cardiac pathology. The results of this study indicate that vectorcardiography, performed after +Gz exposure, is not a reliable technique for detecting the presence of +Gz-induced cardiac pathology in miniature swine.

Aerospace Medicine↗

[Myocardial infarct without Q wave in the elderly: diagnostic evaluation using vectorcardiography].

The diagnosis of previous non-Q wave myocardial infarction by standard electrocardiographic investigation is uncertain, particularly in elderly patients because of concomitant disease. We have studied 31 elderly patients (aged 63-72 years) with a diagnosis of non-Q wave myocardial infarction between 1-6 months after this acute event. The patients underwent clinical-anamnestic examination, standard electrocardiography, vectorcardiography according to the Frank system and M-mode and 2-D echo-cardiography with continuous and pulsated Doppler. The ECG showed ST-T anomalies in 12 patients (38.7%) whereas the VCG showed anomalies of QRS-loop normal convexity in 27 patients (87%) and 16 of these (51.6%) showed bites criteria (duration > or = 10 msec, voltage > or = 0.1 mV, present at least on two planes). By echocardiography, regional hypo-akinesia was observed in 19 patients (61.3%). Although bites are not only present in myocardial infarction, they indicate an interruption of myocardial gradual electric activation, compatible with fibrous areas, and should be evaluated as a part of the clinical-anamnestic, laboratory and instrumental data.

Age Factors↗

On-line computerized vectorcardiography monitoring of myocardial ischemia during coronary angioplasty: comparison with 12-lead electrocardiography.

BACKGROUND: With new interventions minimizing ischemic myocardial injury, accurate and reliable techniques for the detection and continuous monitoring of myocardial ischemia are essential. We compared two techniques used for the detection of myocardial ischemia during coronary angioplasty: on-line computerized vectorcardiographic (cVCG) monitoring and the standard electrocardiography (ECG) leads or the complete 12-lead ECG. METHODS: Thirty patients scheduled for routine angioplasty were included in the study. cVCG was recorded continuously. The electrodes were placed according to the lead system described by Frank and connected to a computerized system for on-line vectorcardiography. A 12-lead ECG was recorded simultaneously. The absolute variable spatial ST vector magnitude (ST-VM) and the relative variable spatial ST change vector magnitude (STC-VM) were calculated and compared with the standard 12-lead ECG for the detection of ischemia. RESULTS: The sum of deviation in ST segment in all 12 standard ECG leads correlated closely with STC-VM, irrespective of which artery was occluded. STC-VM indicated ischemia during the first balloon inflation in 87% of the patients and demonstrated ischemia in more patients than the standard 12-lead ECG. Myocardial ischemia was not demonstrated by ST-VM in five out of 26 patients with ischemia according to STC-VM. In these cases, mainly directional vector changes and fewer changes in magnitude were observed. CONCLUSION: Compared with 12-lead ECG, on-line cVCG is a more sensitive method of detecting myocardial ischemia during coronary angioplasty and the reading is easier and faster. Our results support STC-VM > or = 0.050 mV as the criterion for ischemia during angioplasty; ST-VM should be applied together with STC-VM.

Angina Pectoris↗