L’électrocardiogramme de la brebis

Noseda, V.; Aguggini, G.; Santi, Aura Daniella; Bettini, V; Oberosler, R

doi:10.1159/000167117

Cited by 2 publications

(1 citation statement)

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“…Noseda et al 11 gave the path of ventricular excitation of the lamb as follows: trabecular zone, central zone of right ventricle, apex, areas near the auriculoventricular sulcus, apical, central and posterior areas of the left ventricle and finally the upper zones of both ventricles and the pulmonary conus. Borgatti and Mavrulis 14 found a shift in axis for the lamb from -152° to -95° in going from the standing to the decubitus dorsal positions, and a shift in the dog axis from 57° to 75°.…”

Section: Circulation Research Vol XVII August 1965mentioning

confidence: 99%

Dipole Moments of Dog, Monkey, and Lamb Hearts

Nelson

Angelakos

Gastonguay

1965

Circulation Research

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A method of measuring the resultant dipole moment of the human or animal heart from body surface potentials has been published. 1 ' 2 Recently, a detailed exposition of the theory has been presented, together with values of the maximum vectors for a dog, lamb, monkey and four human beings. 3 The purpose of this paper is to give complete data on the resultant vectors as a function of time during the cardiac cycle for the three animals, as well as details of the potential distributions on the thorax of each animal. MethodsIn the three animals, unipolar potentials were measured around the thorax at a number of horizontal transverse levels. Electrocardiograms at each point were recorded simultaneously with limb lead n; the peak of lead n was used as the time reference. Limb leads and a head lead were also measured simultaneously with lead n. The dipole components were then determined from the following equations.where M x , M v and M z are the left-right, foot-head, and back-front components of the resultant dipole, k = average thorax conductivity, V = potential at each point, 0 = angle between the normal to the body at each point and the +X axis, A = average thorax cross-sectional area, V f -V h = p.d. between left hind limb and head. 3 The right hind limb was grounded. ' Potentials were measured by means of two Grass P-5 preamplifiers, a Dumont model 333 dual-beam oscilloscope, and a Grass C4E camera. Film speeds of 250 or 500 mm/sec were used in order to obtain adequate resolution. For P and T wave studies, high amplification was used so that the QRS peaks were off the oscilloscope screen. In studying the monkey, the outputs of the preamplifiers were applied to two channels of an Ampex FR-1100 magnetic tape recorder and replayed at lower speed to a two-channel Sanborn model 320 direct-writer.The anesthetic used was pentobarbital (Nembutal) in the following amounts: Dog (weight 17.2 kg) 32 mgAg and mephenesin to reduce muscle tremor; monkey (weight 4.5 kg) 35 mgAg; lamb (weight 27 kg) 50 mgAg plus subsequent injections of 10 mg/kg when necessary. During the lamb experiment, artificial respiration was applied by means of a Harvard animal respirator. After anesthesia, the animal was placed supine inside a screened cage. Needle electrodes were inserted subcutaneously. Up to 20 electrodes were connected to a telephone steppingrelay so that measurements could be made very quickly. For the dog, 212 torso points were measured for the P and T waves, and 330 points for QRS. For the monkey, 139 points were used, and for the lamb, 87 points. Limb and head leads were also taken. In the final records, the amplitude of each complex was measured at a number of equal times. For each time value, averages of two to five measurements from successive records were taken. ResultsThe results are given in terms of the spatial magnitude of the resultant dipole moment vector, M, and angles a and /3 defining the direction of M ( fig. 1, left). The sequence of 168

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Section: Circulation Research Vol XVII August 1965mentioning

confidence: 99%