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The electrogram of the turtle's heart
tonic contraction in “resting’ ’ muscle. .2fter treatment with an excess of ealcium ions the responses are followed by oscillatory changes in tension. The tonus changes and the local potentials are probably manifestations of a The mechanical more fundamental process, a fluctuation in resting metabolism. changes are weak and hardly play any role as such. Their chief interest lies in their relation to the automaticity am! rhythmicity of the muscle. It may be assumed that an increase in metabolism causes a rise in tonus and a decreased surface polarization. The decrease in polarization in turn may be considered as the last. link in the chain of processes leading to the discharge of an impulse. AIJTHOR.
Rosenblueth, Ventricular
A., and Del Pozo, E. C.: The Changes of Impedance of the Turtle’s Muscle During Contraction. Am. J. Physiol. 139, 514, 1943.
The changes of electrical impedance during the activity of the turtle’s ventricle were measured by means of an alternating current bridge and recorded from a cathode-ray oscillograph. The impedance to alternating currents of 30 to 10,000 cycles per second and of The increase begins approximateIy at 0.04 to 0.06 ma. increases during activity. the same time as contraction, but it outlasts the mechanical events. There is no parallelism between the impedogram and the electrogram. Brief electrical and mechanical responses involve a brief impedance variation. Upon repetitive stimulation a long enduring impedance change may ensue. The early part of the ventricular electrogram is not attended by any striking change of impedance. AUTHORS.
Kosupkin, J. M., and Olmsted, J. M. D.: Slowing of the Heart as a Conditioned Reflex in the Rabbit. Am. J. Physiol. 139: 550, 1943. It is possible so to condition a rabbit tion of ammonia as the unconditioned conditioned stimulus.
as to slow its heart rate stimulus and the ringing
by using inhalaof a bell as the AUTHORS.
Nahum, L. I-I., Hamilton, W. F., and Hoff, H. E.: trocardiogram. Am. J. Physiol. 139: 202, 1943.
The Injury
Current in the Elec-
Injury to the right ventricle causes an upward displacement of the diastolic base line in the three standard leads of the electrocardiogram. Injury to the left ventricle produces a downward displacement of the diastolic base line. During systole there is a return of the string to the isopotential level which constitutes the S-T segment. In reality, therefore, elevated S-T segments must be interpreted as due to an injury potential resulting from left ventricular damage, which produces in the electrocardiogram a downward displacement of the diastolic base line. Depressed S-T segments must be interpreted as due to an injury potential resulting from right ventricular damage, which produces in the electrocardiogram an upward displacement of the diastolic base line. AUTHORS.
Rosenblueth,
fr&
A., Daughaday,
Turtle’s
Heart.
Am.
Evidence ‘leads
is presented on an intact
W., and Bond,
J. Physiol.
139:
464,
D. D.:
The Electrogram
of the
1943.
which indicates that the electric and an injured region of the turtle’s
phenomena ventricle
recorded are due to
SELECTED
ABSTRACTS
131
changes which occur in the intact, not the injured part of the muscle. may be called monotopic, to avoid the use of other ambiguous terms. trogram exhibits several components which may vary independently. nificance of some of these components is discussed.
This record This elecThe sig-
The records with leads from intact to intact tissue are influenced by the position of the leads with respect to the stimulated region. They may also be modified in the course of a series of responses. These records may be called ditopic, since they represent the algebraic summation of two monotopic records. The electric dependent.
and
the
mechanical
phenomena
of
the
ventricle
are
largely
in-
AUTHORS.
Garvin, C. F.: Gallop Rhythm-Incidence Sex. Am. J. M. SC. 205: 814, 1943.
and the Influence
of Age, Race, and
Of 790 consecutive, adult, autopsied patients dead of heart disease, 199 (25.2 per cent) had had gallop rhythm due either to auricular contraction or a third heart sound. Gallop rhythm occurred most frequently in hypertensive heart disease and coronary artery disease; one out of every three patients had this type of rhythm. Cor pulmopale was associated with gallop rhythm in about one case in five. Only one of ten patients who died of rheumatic heart disease or syphilitic heart disease had gallop rhythm. The average age of death of 93 patients with hypertensive heart disease and gallop rhythm was 49.5 years, of 171 patients with hypertensive heart disease and no gallop rhythm, 58.8 years. Patients with coronary artery disease and gallop rhythm (55) averaged 57.3 years at death; 122 patients with coronary heart disease and no gallop rhythm averaged 64.4 years. Both of these differences seem Even if patients with auricular fibrillation to be statistically highly significant. are excluded (such patients rarely have gallop rhythm and are apt to be older), it still appears that the average age at death of cardiac patients with gallop rhythm is less than the average age of cardiac patients without gallop rhythm. When patients with hypertensive and/or coronary heart disease were grouped together, it was found that, of 326 white patients, 100 (30.7 per cent) had a gallop rhythm, while of the 115 colored patients, 48 (41.7 per cent) had a gallop rhythm. This seems to indicate that colored patients with fatal hypertensive heart disease and/or coronary heart disease, show a higher incidence of gallop rhythm than white patients. It is thought that this is really a manifestation of the influence of age, for the average age at death of the colored patients was less than that of the white patients. No
association
between
gallop
rhythm
and
sex was
demonstrable. AUTHOR.
Mazer, M., and Reisinger, J. A.: Criteria for Differentiating Deep Q, Electrocardiograms From Normal and Cardiac Subjects. Am. J. M. SC. 206: 48, 1943. A series of 102 electrocardiograms with significantly deep analyzed. Criteria have been suggested to aid in differentiating mal and diseased hearts.
Q3 waves those
has been from nor-
AUTHORS.
Evans, W., and Hunter,
A.:
Chest Lead
CR, in Cardiac
Infarction.
Brit.
Heart
J. 5: 73, 1943. A new chest nosis of cardiac
lead, CR, infarction.
is described
and
has been
tested
in the differential
diag-
Rosenblueth, Ventricular
A., and Del Pozo, E. C.: The Changes of Impedance of the Turtle’s Muscle During Contraction. Am. J. Physiol. 139, 514, 1943.
The changes of electrical impedance during the activity of the turtle’s ventricle were measured by means of an alternating current bridge and recorded from a cathode-ray oscillograph. The impedance to alternating currents of 30 to 10,000 cycles per second and of The increase begins approximateIy at 0.04 to 0.06 ma. increases during activity. the same time as contraction, but it outlasts the mechanical events. There is no parallelism between the impedogram and the electrogram. Brief electrical and mechanical responses involve a brief impedance variation. Upon repetitive stimulation a long enduring impedance change may ensue. The early part of the ventricular electrogram is not attended by any striking change of impedance. AUTHORS.
Kosupkin, J. M., and Olmsted, J. M. D.: Slowing of the Heart as a Conditioned Reflex in the Rabbit. Am. J. Physiol. 139: 550, 1943. It is possible so to condition a rabbit tion of ammonia as the unconditioned conditioned stimulus.
as to slow its heart rate stimulus and the ringing
by using inhalaof a bell as the AUTHORS.
Nahum, L. I-I., Hamilton, W. F., and Hoff, H. E.: trocardiogram. Am. J. Physiol. 139: 202, 1943.
The Injury
Current in the Elec-
Injury to the right ventricle causes an upward displacement of the diastolic base line in the three standard leads of the electrocardiogram. Injury to the left ventricle produces a downward displacement of the diastolic base line. During systole there is a return of the string to the isopotential level which constitutes the S-T segment. In reality, therefore, elevated S-T segments must be interpreted as due to an injury potential resulting from left ventricular damage, which produces in the electrocardiogram a downward displacement of the diastolic base line. Depressed S-T segments must be interpreted as due to an injury potential resulting from right ventricular damage, which produces in the electrocardiogram an upward displacement of the diastolic base line. AUTHORS.
Rosenblueth,
fr&
A., Daughaday,
Turtle’s
Heart.
Am.
Evidence ‘leads
is presented on an intact
W., and Bond,
J. Physiol.
139:
464,
D. D.:
The Electrogram
of the
1943.
which indicates that the electric and an injured region of the turtle’s
phenomena ventricle
recorded are due to
SELECTED
ABSTRACTS
131
changes which occur in the intact, not the injured part of the muscle. may be called monotopic, to avoid the use of other ambiguous terms. trogram exhibits several components which may vary independently. nificance of some of these components is discussed.
This record This elecThe sig-
The records with leads from intact to intact tissue are influenced by the position of the leads with respect to the stimulated region. They may also be modified in the course of a series of responses. These records may be called ditopic, since they represent the algebraic summation of two monotopic records. The electric dependent.
and
the
mechanical
phenomena
of
the
ventricle
are
largely
in-
AUTHORS.
Garvin, C. F.: Gallop Rhythm-Incidence Sex. Am. J. M. SC. 205: 814, 1943.
and the Influence
of Age, Race, and
Of 790 consecutive, adult, autopsied patients dead of heart disease, 199 (25.2 per cent) had had gallop rhythm due either to auricular contraction or a third heart sound. Gallop rhythm occurred most frequently in hypertensive heart disease and coronary artery disease; one out of every three patients had this type of rhythm. Cor pulmopale was associated with gallop rhythm in about one case in five. Only one of ten patients who died of rheumatic heart disease or syphilitic heart disease had gallop rhythm. The average age of death of 93 patients with hypertensive heart disease and gallop rhythm was 49.5 years, of 171 patients with hypertensive heart disease and no gallop rhythm, 58.8 years. Patients with coronary artery disease and gallop rhythm (55) averaged 57.3 years at death; 122 patients with coronary heart disease and no gallop rhythm averaged 64.4 years. Both of these differences seem Even if patients with auricular fibrillation to be statistically highly significant. are excluded (such patients rarely have gallop rhythm and are apt to be older), it still appears that the average age at death of cardiac patients with gallop rhythm is less than the average age of cardiac patients without gallop rhythm. When patients with hypertensive and/or coronary heart disease were grouped together, it was found that, of 326 white patients, 100 (30.7 per cent) had a gallop rhythm, while of the 115 colored patients, 48 (41.7 per cent) had a gallop rhythm. This seems to indicate that colored patients with fatal hypertensive heart disease and/or coronary heart disease, show a higher incidence of gallop rhythm than white patients. It is thought that this is really a manifestation of the influence of age, for the average age at death of the colored patients was less than that of the white patients. No
association
between
gallop
rhythm
and
sex was
demonstrable. AUTHOR.
Mazer, M., and Reisinger, J. A.: Criteria for Differentiating Deep Q, Electrocardiograms From Normal and Cardiac Subjects. Am. J. M. SC. 206: 48, 1943. A series of 102 electrocardiograms with significantly deep analyzed. Criteria have been suggested to aid in differentiating mal and diseased hearts.
Q3 waves those
has been from nor-
AUTHORS.
Evans, W., and Hunter,
A.:
Chest Lead
CR, in Cardiac
Infarction.
Brit.
Heart
J. 5: 73, 1943. A new chest nosis of cardiac
lead, CR, infarction.
is described
and
has been
tested
in the differential
diag-