Changes in the body's QRS surface potentials produced by alterations in certain compartments of the nonhomogeneous conducting model

Bayley, Robert H.; Kalbfleisch, John M.; Berry, Paul M.

doi:10.1016/0002-8703(69)90161-6

Cited by 40 publications

(7 citation statements)

References 12 publications

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“…An earlier attempt to do so (Bayley and Berry, 1966;Bayley et al, 1969), which was based on a comprehensive model similar to the one used here, was found in error (Rudy and Plonsey, 1979).…”

mentioning

confidence: 80%

The effects of variations in conductivity and geometrical parameters on the electrocardiogram, using an eccentric spheres model.

Rudy¹,

Plonsey²,

Liebman³

1979

Circulation Research

120

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SUMMARY The effects of variations in the volume conductor properties of the torso on the electrocardiogram were studied by means of a theoretical eccentric spheres model. The model includes a blood cavity, cardiac muscle layer, pericardium, lung region, skeletal muscle layer, and subcutaneous fat. The source of the field is a double-layer spherical cap located within the myocardium. The following effects regarding the electrocardiogram (ECG) potentials were determined: (1) blood augments the potential, but less than predicted by simpler published models; (2) in anemia, high potentials are expected, whereas in polycythemia, voltages are reduced; (3) abnormally low lung conductivity (emphysema) causes low surface potentials whose magnitude is controlled by the low conductivity skeletal muscle layer; (4) low voltages result both from low and high pericardial conductivities; (5) the surface potential increases with increasing myocardial conductivity; (6) low skeletal muscle conductivity (Pompe's disease) causes high surface potentials; (7) obesity lowers the potential only slightly; (8) a thick myocardium, protruding into the lung region, slightly augments the potential; (9) an increase in the thickness of the myocardium at the expense of the blood cavity causes a decrease in potential; (10) the potential increases with increasing heart size; and (11) the location of the heart within the torso has a very significant effect on the surface potential distribution. Ore Res 104-111, 1979

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mentioning

confidence: 80%

The effects of variations in conductivity and geometrical parameters on the electrocardiogram, using an eccentric spheres model.

Rudy¹,

Plonsey²,

Liebman³

1979

Circulation Research

120

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“…epicardial ECG QRS amplitudes increased in three dogs and decreased in five during the saline infusion, but the mean change was not significant (figs. 3 …”

Section: Increased Ventricular Sizementioning

confidence: 99%

Effects of changes in ventricular size on regional and surface QRS amplitudes in the conscious dog.

Battler¹,

Froelicher²,

Gallagher³

et al. 1980

Circulation

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Eight conscious dogs instrumented with wall thickness sonomicrometers and 11 subcutaneous electrodes in a modified McFee vectorcardiographic array were studied during changes in ventricular volume. Simultaneous measurements were made of QRS amplitudes of the endocardial and epicardial ECG, QRS spatial vector magnitudes (SVM), end-diastolic wall thickness (EDT), end-systolic wall thickness (EST) and the amount of systolic thickening (zAWT). Ventricular size was decreased by atropine and infulsion of 0.02 gg/kg/min of isoproterenol to increase the mean heart rate from 81 ± 5 beats/min (mean ± SEM) to 174 10 beats/min (p < 0.001), and was reflected by an increased mean EDT (9.06 ± 0.64 mm to 9.94 i 0.61 mm, p < 0.005). The endocardial QRS amplitude increased in each dog (mean increase 21.55 ± 1.36 mV to 25.13 ± 1.35 mV, p < 0.001), whereas the SVM decreased from 7.69 ± 0.75 mV to 6.18 ± 0.48 mV (p < 0.02). Ventricular size was then increased by rapid saline infusion and was reflected by a decrease of EDT from 9.65 ± 0.66 mm to 9.09 ± 0.66 mm (p < 0.001), while heart rate remained unchanged. Endocardial amplitude decreased in each dog (average decrease 3.59 ± 0.25 mV, p < 0.001), while the SVM increased in each dog (average increase 0.81 ± 0.18 mV, p < 0.005). The mean epicardial amplitudes did not change significantly during either increases or decreases in ventricular volume. In each dog, there was a linear relation between EDT and endocardial amplitudes (r values > 0.88) and an inverse linear relation between EDT and SVM (r values > -0.80). The relations between EST or AWT and regional and QRS surface amplitudes were nonlinear. We conclude that in the conscious dog changes in endocardial QRS amplitudes and SVM respond in an opposite manner to changes in ventricular volume. In this experimental model, alterations in endocardial QRS amplitudes were related directly to changes in diastolic wall thickness; changes in body surface QRS amplitudes were inversely related to wall thickness, a finding that may relate in part to alterations in the distance of the heart from the chest wall. THE MECHANISMS underlying regional and surface QRS amplitude changes during acute forms of stress are unclear, and it has not been established whether changes in left ventricular volume are directly or inversely related to QRS amplitudes. In model systems 14 and in animal experiments,5' 6 an increase in ventricular volume produces an augmentation of the initial portions of the QRS potentials in the body surface ECG and vectorcardiogram (VCG), but in human subjects the direction of such changes has been controversial.7' 8 Lekven et al. recently reported that the endocardial QRS amplitude decreased during volume increases in open-chest dogs,9 an effect opposite to that described in the surface ECG.5' 6 It has also been proposed that changes in the ventricular ejection fraction relate to surface QRS-amplitude changes.10 11 However, clear relations between left ventricular ejection fractions, left ventricular volumes and alterations in surface...

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“… Electroconduction of tissues located between the heart and the electrodes; 1,2 , 9 , 11 , 14 , 19 , 33 Electroconduction of myocardium. This depends on electroconduction of cardiac fibers, and on the amount of blood in myocardium and in the ventricles; 1‐8 , 10 , 13,14 , 34‐36 Distances between the heart and electrodes as a consequence of the heart position, form, volume changes, and changes of chest form; 1,2 , 9 , 12‐14 , 33,34 , 37,38 Nonhomogeneity of the heart, which changes with variations of the heart volume (Brody effect) 9 , 11‐13 , 36 …”

Section: Discussionmentioning

confidence: 99%

“…On the one hand, it takes place in most cases and, on the other, small and steady ECG voltage variations (0.1–0.2 mV) are taken into consideration in this monitoring 15 . But many researchers 2‐8 have shown the importance of thorax electroconduction using analytical models and in experiments on animal opened chest. But there are large problems in the estimation of the influence of this factor on human ECG in clinical conditions; it is very difficult to distinguish the influence of electroconduction from other factors.…”

mentioning

confidence: 99%

Variations of Intrathoracic Amount of Blood as a Reason of ECG Voltage Changes

Saltykova

Capderou

Atkov

et al. 2003

Noninvasive Electrocardiol

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Blood redistribution during gravity change leads to changes of QRS voltage, which is more expressed and steady on R in Z lead: an average near 0.2 mV. It is due to the balance between two factors: (a). changes of degree of short circuiting by variations in the amount of blood in thorax (b). changes of distance between heart and electrodes as a result of change in the position, form, and volume of the heart.

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Changes in the body's QRS surface potentials produced by alterations in certain compartments of the nonhomogeneous conducting model

Cited by 40 publications

References 12 publications

The effects of variations in conductivity and geometrical parameters on the electrocardiogram, using an eccentric spheres model.

The effects of variations in conductivity and geometrical parameters on the electrocardiogram, using an eccentric spheres model.

Effects of changes in ventricular size on regional and surface QRS amplitudes in the conscious dog.

Variations of Intrathoracic Amount of Blood as a Reason of ECG Voltage Changes

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