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PubMed1982

[Left ventricular hypertrophy in hypertensive and athlete's hearts: echocardiographic and vectorcardiographic characteristics].

The difference in the patterns of left ventricular hypertrophy (LVH) between the athlete's heart (Judo player: Judo-Ath group) and the hypertensive heart (HT group) was studied using vectorcardiography and echocardiography. The both groups were classified into two types based on the pattern of a QRS loop vector in the horizontal plane, respectively. One type (type II) satisfied the vectorcardiographic criteria of LVH by Upshaw, and the other (type I) did not satisfy it. The subjects composed of 12 Ath-I, 18 Ath-II, 10 HT-I and 16 HT-II. In the Ath-I, the characteristic vectorcardiogram was demonstrated in the horizontal plane, where an increased amplitude of an initial QRS vector was in the right and anterior direction. A mean ratio of the thickness of the interventricular septum to left ventricular posterior wall (IVSTd/PWTd) was 1.20 (p less than 0.001) in their echocardiograms. In HT-I, on the other hand, a decreased amplitude of an initial anterior vector and an increased amplitude of a posterior vector were observed in the horizontal plane. IVSTd and PWTd did not increase in these patients. These results indicated that an increased amplitude of an initial QRS vector in Ath-I is a reflection of the increased IVSTd. In type II, both IVSTd and PWTd were symmetrically increased. Concerning a spatial maximum QRS magnitude and left ventricular mass (LV mass), there was a significant correlation between the two only in HT-II (r = 0.75, p less than 0.01). It was concluded that there was some vectorcardiographic and echocardiographic differences between the left ventricular hypertrophic patterns of the athlete's heart and the hypertensive heart.

Adult↗

PubMed1984

[A contribution to the electrogenetic interpretation of left ventricular hypertrophy caused by volume overload].

The purpose of the present study is to make a contribution to the understanding of the electrogenetic interpretation of left ventricular hypertrophy caused by volume overload. Thirty-two cases of isolated aortic valve regurgitation with electrocardiographic evidence of left ventricular hypertrophy were studied by vectorcardiography in order to measure the 20 msec vector both in the spatial and horizontal plane, and by M-Mode echocardiography to obtain the interventricular septal and posterior wall thickness and the end diastolic dimension of the left ventricle. The following relations were analyzed: a) between the interventricular septal thickness and the amplitude of the 20 msec vector in the spatial and horizontal plane; b) between the end diastolic dimension of the left ventricle and the amplitude of the 20 msec vector. We also explored the possibility to distinguish by means of the 20 msec vector amplitude between patients with and without disproportionate septal thickening. We found no correlation either between interventricular septal thickness and amplitude of the 20 msec vector, or between left ventricular end diastolic dimension and amplitude of the 20 msec vector. It was not possible to distinguish by means of the amplitude of the 20 msec vector between the cases of left ventricular hypertrophy with disproportional septal thickening and those without it.

Adolescent↗

PubMed1983

[Investigation of the preexcitation syndromes].

Assessment of the localization and function of accessory atrioventricular pathways may be undertaken with noninvasive and invasive examination techniques. Noninvasive methods, however, such as electrocardiography, vectorcardiography, precordial mapping, echocardiography and scintigraphy do not enable exact delineation of the site of the accessory pathway since, in general, their use requires maximal preexcitation; moreover, they are of less value in the presence of septal bundles, multiple accessory pathways or intraventricular conduction disturbances. Accordingly, localization of accessory atrioventricular pathways is based on data obtained from intracardiac electrography such as the interval between stimulus and delta wave during atrial pacing, retrograde atrial sequence, VA conduction time at onset of right or left bundle branch block as well as responses to programmed ventricular stimulation during orthodromic reciprocating tachycardia. The most exact method for determination of the localization of the Kent bundle employs intraoperative endocardial and epicardial mapping with analysis of VA and AV conduction times during reciprocating tachycardia, ventricular stimulation and atrial pacing. The conduction properties of the accessory atrioventricular bundle may be estimated noninvasively based on the persistence of a delta wave as a function of the heart rate, the influence of antiarrhythmic agents on the anterograde conduction via the normal pathway as well as the shortest interval between two consecutive QRS complexes with delta waves during atrial fibrillation. Functional assessment is carried out invasively through recording the anterograde and retrograde refractory periods of the Kent bundle as well as observations during programmed atrial and ventricular stimulation or induced atrial fibrillation.

Anti-Arrhythmia Agents↗

PubMed1983

[Relation between the vectorcardiogram and mean pulmonary arterial pressure in pulmonary pathology].

Mean pulmonary artery pressure (PAP) is considered to be a valuable indicator of the severity of disease in patients with chronic lung damage. Its measurement requires minicatheterisation, an invasive technique associated with some morbidity. This study was undertaken to establish a relationship between PAP and vectorcardiography (VCG) in 76 patients with chronic lung disease. The patients were divided into three groups: Group I, PAP less than 19 mmHg; Group II, PAP between 19 and 30 mmHg; Group III, PAP greater than 30 mmHg. The patients presented with an obstructive pulmonary syndrome in 67,1% of cases, and an emphysematous syndrome in 32,9% of cases. The ECG tracing was suggestive of chronic cor pulmonale in 20 patients. The three VCG planes were analysed. The direction and amplitude of the 0,01 sec, 0,02 sec, 0,04 sec, 0,06 sec and maximum vector over each QRS loop were measured; the direction of rotation of the QRS loop and, in the horizontal plane, the duration of the terminal forces were also determined. Treatment of the angular data by Down's centre of gravity method allowed definition of the preferential direction of the vectors and of an index of precision. The statistical significance of the results was checked by the usual methods (chi-square, F test). The results confirmed the importance of the right posterior quadrant of the horizontal plane in assessing the degree of electrical overload and for evaluating the repercussions on the pulmonary circulation. In this plane, all angular positions of the 0,06 sec vector beyond -125 degrees corresponded in 9 out of 10 cases to higher than normal PAP (greater than 19 mmHg). A voltage of over 0,80 MV was always associated with higher than normal PAP. The predictive value of this method was 92%, with a specificity of 88% and a sensitivity of 39%. The VCG was also more sensitive than the ECG in assessing PAP of 19 to 30 mmHg; 25,6% of patients had deviation of the 0,06 sec vector of beyond -125 degrees in the horizontal plane whilst only 6,3% of cases had ECG criteria of chronic cor pulmonale. This study shows that simple and reliable non-invasive VCG criteria may be used to assess mean pulmonary artery pressure.

Adolescent↗

PubMed1980

[The heart in myotonic dystrophy. Clinical and instrumental study in 17 patients (author's transl)].

17 patients with myotonic dystrophy have been studied. The skeletal muscle disease has been assessed by history, physical examination, electro-myography and muscle biopsy. Cardiac evaluation has been obtained by history, physical examination, chest X-ray, ecg at rest and after exercise, vectorcardiography and echocardiography. Only two patients presented symptoms and clinical findings of cardiac disease, otherwise conduction disturbances have been founded in 15 cases, pseudoinfarct pattern in 5 cases and loss of anterior vectors in 2 cases. Has to be remembered that in myotonic dystrophy sudden death has a very high incidence, which could be explained by the development of complete a-v block, because of the impairment of the conduction system. Therefore, in those patients with bifascicular blocks (3 cases), the electrophysiological study may be useful in order to evaluate the opportunity to put on a permanent pace-maker, to prevent sudden death.

Adolescent↗

PubMed1981

[Non-invasive methods of investigation cardiology (author's transl)].

Non-invasive assessment of heart and chamber size employs various techniques which yield different information. Overall size as estimated by biplane chest roentgenogram in the upright or - better - supine position is a valuable quantitative method. Correlation with individual chamber size is, however, only fair. Information on wall thickness can currently be obtained only by ultrasound echocardiography. ECG and vectorcardiography as a means for determining ventricular hypertrophy have remained semi-quantitative techniques, but can probably be developed into more quantitative information by means of computer analysis. A method of predicting left ventricular muscle mass using the Frank orthogonal lead system is described. Regional disorder of contraction and contractility have been difficult to assess non-invasively. Kymographic techniques describe only motion of the lateral wall. Ultrasound techniques, even using a two-dimensional approach, rarely include the ventricular apical region. Systolic time intervals and radionuclide minimal transit times have remained of limited importance. The value of ECG-gated computertomography cannot be assessed as yet. The greatest promise can be expected from radionuclide techniques with gated blood pool scanning and myocardial scintigraphic techniques.

Angiocardiography↗

PubMed1984

Delayed initial QRS forces of intraventricular pacing: unreliability of the scalar ECG in their diagnosis.

Delta waves, similar to those observed in the Wolff-Parkinson-White syndrome, are currently observed in the ECG tracings of patients with endocardial pacing. With the aid of standard ECG and vectorcardiography (VCG), we studied the initial QRS forces during right endocardial pacing in 20 patients. More details were obtained by VCG concerning the amplitude duration, electrical axis and shape of the delta waves of paced ventricular beats, than by ECG. It is remarkable that delayed initial QRS forces, diagnosed by VCG analysis, were present in only 9 of 20 patients with delta waves in their ECG. In other patients, the slurring or thickening at the onset of the R waves in the ECG resulted from the perpendicular direction of the initial QRS vectors to the lead axis, or from multiple changes in the direction of the early, nondelayed QRS vectors. The superiority of VCG in the study of the initial QRS forces, particularly in the diagnosis of delayed initial QRS forces, is discussed.

Cardiac Pacing, Artificial↗

PubMed1982

[Dependence of myocardium function on the degree of coronary bed involvement in chronic ischemic heart disease patients with and without previous myocardial infarct].

A total of 104 patients with chronic ischaemic heart disease were examined. The left ventricle myocardial function was studied by determining the signs of overload of the atria by the method of enhanced atrial vectorcardiography, which were compared to the data of heart catheterization, and of left ventriculography. This showed the reliability of the non-invasive methods of investigation. The degree of lesions of the coronary bed was determined in the bicycle ergometric tests and by selective coronarography. A group of patients who had not suffered myocardial infarction showed trends of progressing signs of myocardial insufficiency corresponding to the degree of the damage of the coronary bed. In a group of patients, who had suffered myocardial infarction, myocardial insufficiency was more manifest, however, even in them the degree of myocardial lesion was closely associated not only with the presence of the scar changes but also with the degree of the damage of the coronary bed.

Adult↗

PubMed1980

[Ebstein's anomaly in adult patients: diagnostic and prognostic profile with regard to two cases (author's transl)].

Two cases of Ebstein's anomaly in apparently asymptomatic adult patients are described. The chances of non invasive recognition of the malformation by means of electro-vectorcardiography and echocardiography are discussed. Unlike their useful diagnostic contribution, their prognostic valve seems to be negligible. For this purpose clinical course of malformation would remain very important, even if some unusual electrocardiographic and radiological features can provide interesting informations.

Carotid Arteries↗

PubMed1980

Localization and interruption of accessory conduction pathway in the Wolff-Parkinson-White syndrome.

We operated upon 36 patients with Wolff-Parkinson-White (WPW) syndrome between 1969 and July, 1979. The relationship between the electrocardiogram (ECG), particularly the delta wave, and localization of the accessory conduction pathway (ACP) was analyzed, and the value of preoperative examinations such as vectorcardiography, echocardiography, body surface mapping, intracavitary potential study, and cardiac pacing were demonstrated. Epicardial mapping was indispensable as an intraoperative study and represented the most effective method for localizing the ACP. In some cases, endocarial potential study was found to be efficacious. Detachment of the atrium from the ventricle by an incision along the anulus at the area of earliest pre-excitation, resulted in complete correction in 26 of 28 patients operated upon between 1973 and July, 1979. In five patients multiple ACPs was corrected, although four of them required a second operation. The surgical indications in the WPW syndrome should be expanded in view of the high success rate and the safety of the operation.

Adolescent↗

PubMed1994

Addition of sodium to iohexol. A vectorcardiographic study.

The addition of sodium to nonionic contrast media has reduced the incidence of arrhythmias in animal models. The influence on cardiac function and safety of sodium addition to the nonionic contrast medium iohexol (Omnipaque) was studied in a randomized, double-blind trial in patients undergoing cardioangiography. Fifty-nine patients received iohexol 350 mg I/ml with NaCl 28 mmol/l and 58, iohexol only. ECG changes after contrast injections were evaluated with continuous computerized dynamic vectorcardiography (VCG). QRS-vector difference (QRS-vd), which reflects changes in the QRS-complex, was chosen as the main parameter. Both contrast media caused changes in the QRS-complex, but there was no significant difference between the two. No serious arrhythmias were observed. Both contrast media were well tolerated. No beneficial effects from enriching iohexol with sodium were found. VCG was found to be a valuable tool in the study of contrast medium-induced ECG changes.

Adult↗

PubMed1993

Changes in QRS segments during exercise in relation to scintigraphic myocardial perfusion defects: a multivariate analysis.

BACKGROUND: The relation between QRS changes during exercise and ischemic heart disease is controversial. The present investigation addressed whether exercise QRS changes are related 1) to myocardial ischemia or necrosis, 2) to possibly confounding factors such as baseline QRS size and changes in heart rate and ST magnitude during exercise, and 3) to the location of scintigraphic defects. METHODS: Advanced computerized vectorcardiography (MIDA1000, Ortivus Medical AB, Sweden) was recorded in 71 consecutive patients referred for 201TI exercise myocardial scintigraphy. Maximal exercise tests were performed in the sitting position on a bicycle ergometer. Planar scintigraphic images were obtained immediately after exercise and 4 hours later in three projections, and were evaluated blindly. RESULTS: Exercise QRS changes correlated to baseline QRS size (X, Y, and Z leads; P < 0.005), change in heart rate (X and Y leads; P < 0.01), and ST change at J + 20 ms (X, Y, and Z leads; P < 0.0001). Increased QRS magnitudes in the Y and Z leads correlated to late perfusion defects (P < 0.0001). These correlations remained after correction for baseline QRS size and changes in heart rate and ST magnitude at J+20 ms during exercise (P < 0.0001). No consistent relationships were observed between the location of myocardial perfusion defects and the stress-induced alterations in QRS. CONCLUSIONS: Baseline QRS size and changes in heart rate and ST magnitude may have important confounding effects on the QRS response to exercise. However, even after consideration of these factors, the QRS response to exercise was related to late (4 h) scintigraphic myocardial perfusion defects. The findings suggest that the presence of myocardial infarctions or long-lasting ischemia after exercise is associated with increased QRS magnitudes during exercise.

Adult↗

PubMed1977

Reassessment of the diagnostic value of the vectorcardiogram in cystic fibrosis (correlation with clinical score, pulmonary function tests and echocardiogram).

In 21 children with cystic fibrosis, the vectorcardiogram (VCG) was correlated with various indices of the severity of the disease. The best correlation was found between (1) the azimuth angle of the spatial QRS loop area, representing the rightward and posterior shift of the main electrical forces, and pulmonary function tests (PFT): FEV1 % predicted (r = -0.671, P less than 0.005) and VC% predicted (r = -0.607, P less than 0.005), and (2) the right ventricular anterior wall index measured echocardiographically (r = 0.472, P less than 0.05). More VCG parameters correlated significantly with PFT than with the echocardiogram. This shows the major influence of pulmonary changes on the VCG of those patients. In several subgroups with different clinical scores, the VCG were analyzed and compared to normal limits of age- and sex-matched controls. In this small series, the VCG was a specific but not very sensitive method for predicting the degree of severity of the disease. Echocardiography and vectorcardiography can be considered as two complementary techniques in the evaluation of cystic fibrosis.

Adolescent↗

PubMed1976

Display of the vectorcardiograms with a new complementary loop of formula Z = f (square root X2 + Y2).

It is important in vectorcardiography to be able to determine the position and magnitude of a given vector, e.g., the left maximum spatial vector, or the vector occurring 20 ms after beginning of QRS, etc. In this aim the authors present besides the three classical planar projections , a fourth curve of Lissajous, known asthe "modulus curve" and which corresponds to the formula Z = f (square root X2 + Y2). In general applications, this curve is very simple to use, and several examples of application are given. The technical realization, which involves no great modification of standard equipment, is described.

Computers, Analog↗

PubMed1978

Transmural myocardial infarction in the absence of coronary arterial luminal narrowing in a young man with single coronary arterial anomaly.

Reported is a case of single coronary arterial anomaly (SCAA) with its origin from the right sinus of Valsalva as demonstrated by selective coronary arteriography. No branches coursed between the great vessels. Electrocardiography and vectorcardiography were consistent with inferior wall myocardial infarction, although subsequent coronary arteriograms were free of luminal narrowing. While this is an infrequently recognized isolated coronary anomaly, it may carry significant risk of myocardial ishcemia. This risk may not depend alone upon the passage of a branch of SCAA between the great vessels. Evidence of precocious ischemic heart disease should alert the angiographer to look for anomalous coronary anatomy.

Adult↗

PubMed1991

Localization of cardiac arrhythmias: conventional noninvasive methods.

Noninvasive localization of the accessory pathway (AP) in patients with the Wolff-Parkinson-White syndrome and of the site of origin of ventricular tachycardia (VT) is reviewed. 12-lead electrocardiography (ECG) is the most readily available method for localization of both the AP and the site of VT origin. Many published ECG criteria are introduced. The application of body surface potential mapping, vectorcardiography, nuclear phase imaging, echocardiography, computed tomography, nuclear magnetic resonance, and signal-averaged ECG in the localization of these arrhythmogenic substrates is also described. We believe that ECG is the most sensitive noninvasive method for AP localization as well as being convenient and simple; it may be used as the only noninvasive method for the initial evaluation. The left lateral AP, which occurs with an incidence of more than 40%, could be localized preoperatively by noninvasive methods only. For localization of the site of VT origin, none of the noninvasive methods is accurate enough for guiding the surgical and catheter-mediated ablative therapies so far.

Action Potentials↗

PubMed1996

Nucleoside transport inhibition by draflazine in unstable coronary disease.

OBJECTIVES: In a randomised, double-blind, placebo controlled study, we evaluated the tolerability and safety of draflazine, a nucleoside transport inhibitor, in the treatment of patients with unstable angina and non-Q-wave infarction. METHODS: Twenty-one patients were randomised to treatment with draflazine 3.5 mg or matching placebo given as an i.v. infusion and haemodynamic and symptomatic tolerability were investigated. Myocardial ischaemia was evaluated by means of vectorcardiography and blood analysis of the MB fraction of creatine kinase. RESULTS: The study drug was well tolerated by all patients and it did not cause any adverse haemodynamic effects, nor other serious adverse events. Three patients in the placebo group reported five adverse events, as compared to a single adverse event in the draflazine group. Cardiovascular events were detected in 7 patients in the placebo group and in 5 patients receiving draflazine. The mean duration of chest pain during the 24 hour observation period was 91.4 min in the placebo group compared to 75.5 min in draflazine treated patients. Neither the vectorcardiographic nor biochemical measures of ischaemia differed between treatment groups. CONCLUSION: Nucleoside transport inhibition by draflazine was well tolerated by patients with unstable coronary disease. It seems to be a promising method of adenosine enhancement in acute myocardial ischaemia. The potential cardioprotective effect of the drug needs further evaluation in larger trials.

Aged↗

PubMed1981

Planar curve analysis of three-channel auditory brain stem response: a preliminary report.

Recording of auditory brain stem responses (ABRs) were made in guinea pigs by means of far-field computer averaging from three orthogonal electrode pairs. The 'Y' locations were mouth and nuchal ridge, 'X' locations left and right mastoids, and 'Z' locations vertex and throat. Three-dimensional models were constructed to plot simultaneous points from the three averages in a voltage-voltage-voltage space. In all five animals tested, at least three subsets of sequential data points lie in separate planes. The data points in each plane roughly correspond to waves I to III in the guinea pig ABR as recorded from the vertex-throat electrode pair. The planarity of data points is a new observation and is not predicted from the single-channel recordings. Three-dimensional planes are also found by means of vectorcardiography, which suggests some underlying principle, such as synchrony and homogeneity of anatomical position of the generators. Planar analysis of ABRs may be useful in analyzing and utilizing the additional information obtainable from 'non-standard' electrode pairs.

Acoustic Stimulation↗