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Biomedical subjects

I E Katzeff

Publications and source records attributed to I E Katzeff.

28 records · Page 2Linked to original sources
PubMed1981

Dynamic electrocardiography. III. The "imaginary cardiac vector" hypothesis: theoretical basis.

The "imaginary cardiac vector" hypothesis states that the "cardiac vector" is not a "real" vector entity. The hypothesis arises from the fact that voltage is not a vector but a scalar quantity. Nevertheless, in classical electrocardiographic analysis and teaching, the ECG voltage is treated as a vector. These voltages are used as "vector" components--first, to calculate a "resultant manifest potential difference", represented by the "cardiac vector" arrow in electrocardiography, and second, to draw the "cardiac vector" loop in vectorcardiography. The resultant "cardiac vector" is usually considered to be a "real" vector quantity describing the electrical activity of the heart. It is also widely believed that this "vector" was first described by Einthoven in 1913. To evaluate the hypothesis, we have utilised the actual values and methods presented by Einthoven, and demonstrated that the theoretical basis of the "cardiac vector" is false. It appears that Einthoven followed scalar and not vector procedures and that he did not describe a vector.

Electrocardiography↗
PubMed1980

A psychophysiological hypothesis on the aetiology of duodenal ulceration.

A previously undescribed explanation for the development of duodenal ulcer is advanced. Stressful situations and avoidance-avoidance conflicts in individuals with a dependant compliant personality incapable of appropriate "stimulus-seeking behaviour" lead to an immobilised state. This predicament is denied. Helplessness develops. This state is associated with an autonomic imbalance in which a central monoamine depletion results in uncompensated parasympathetic overactivity which facilitates the development of duodenal ulceration. Denial often invalidates superficial psychological investigations into the aetiology of duodenal ulceration and may explain the contradictory findings in the literature.

Adult↗
PubMed1979

Creatine phosphokinase and lactate dehydrogenase levels after ultra long-distance running. An analysis of iso-enzyme profiles with special reference to indicators of myocardial damage.

Blood samples obtained from 20 runners on completion or partial completion of a 160-km marathon were assayed for total serum creatine kinase (CK) and lactate dehydrogenase (LD), as well as for the respective iso-enzymes. Total CK was significantly elevated in all subjects, the mean value (2 243 U/l) constituting a 24-fold increase above the normal upper limit. In 65% of these cases, the cardiac-specific iso-enzyme of CK, MB, was present. The mean LD level (1 220 U/l) also exceeded the upper limit of normal significantly, 5 subjects presenting a 'flipped' LD pattern (LD1 greater than LD2). Three subjects exhibited the MB iso-enzyme in the presence of a flipped LD pattern. No electrocardiographic evidence of irreversible cardiac 'damage' could, however, be established after the race, nor any significant decrease in the Bruce protocol stress test rating. It is concluded that the MB iso-enzyme of CK, even in conjunction with a flipped LD pattern, may not represent unequivocal evidence of myocardial damage under all circumstances.

Adult↗
PubMed1979

Dynamic electrocardiography. II. A crucial test of the electromechanical QRS wave theory.

The dynamic electromechanical electrocardiogram hypothesis, that QRS voltage fluctuations can be used as a simple noninvasive transducer of cardiac mechanical function, has been subjected to a crucial experiment. Under direct vision, transient modifications of the end-diastolic volume of the baboon heart were produced and photographed. Sequential obstructions to filling (by vena caval compression) and to emptying (by aortic compression), and vice versa, significantly distorted the size and shape of the heart. The instantaneous effects of these manipulations on the amplitudes of the R and S waves were evaluated in electrocardiograms recorded from electrodes glued to selected pericardial and epicardial sites. Major QRS voltage deviations occurred in the perircardial leads. Manipulations increasing the left ventricular volume increased the S wave and reduced the R wave, while those decreasing heartsize had the opposite effect. These findings refute the null hypothesis, that the electrocardiogram is not an indicator of mechanical function. No changes of the QRS waves in the epicardial lead were detected, supporting the concept that displacement relative to the recording electrode is the basis of the QRS CHANGEs due to heartsize variation. The results negate the classical concept that the electrocardiogram does not reflect cardiac mechanical function, and strongly corroborate the dynamic electromechanical electrocardiogram hypothesis.

Animals↗
PubMed1975

Exercise stress testing and an electromechanical S wave of the electrocardiogram. Does the S-wave voltage change with increasing work rate?

A new view of the electrocardiogram, first proposed by Posel and arising from Craib's travelling dipole concept, predicts an electromechanical relationship between S-wave amplitude changes and cardiac mechanical function changes. In an attempt to determine whether the S-wave voltage changes with increasing work rate, 10 male subjects were tested at rest and at maximum exercise. A statistically significant increase in the S wave occurred with increased mechanical work. The theoretical prediction of an electromechanical S wave is thus validated and a request is extended to other workers to verify or refute its existence.

Electrocardiography↗
PubMed1975

Electrocardiographic measurement of cardiac function. Are the amplitude changes of the S wave indicative of changes in the size of the heart?

Preliminary tests to determine whether there is an electromechanical link between the electrocardiogram and cardiac function have been done by means of echocardiography. Three different haemodynamic manipulations which alter cardiac function, viz. nitroglycerin, intravenous digoxin and exercise-induced angina, were used. The changes in the S-wave amplitude, in selected leads, appear to be directionally related to the changes in the left ventricular enddiastolic volume. It is thus suggested that the S-wave changes may be indicative of changes in cardiac function.

Angina Pectoris↗
PubMedDate not supplied

Dynamic electrocardiography, the electromechanical S wave: the problem of the contradictory converse.

Two basic hypotheses concerning an electromechanical S wave of the electrocardiogram during exercise have been expanded to five to include the effect of recovery which should produce converse changes. Four hypotheses have been supported and the fifth contradicted. An attempt has been made to analyse the ensuing dilemma and a conclusion is reached that either the electromechanical hypothesis is in error or a new hypothesis, which predicts an increase in the cardiac end-diastolic volume after exhaustive exercise, must be proposed. This new hypothesis is commonly accepted by physical educationalists but appears to be rarely discussed in physiological texts.

Adult↗