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Intracardiac phonocardiography
INTRACARDIAC
l’HONOCARDIOGRAF’HY
KUNIO YAMAKAWA, M.D., YASUO SHIONOYA, TOICHI NAGAI, M.D., TAK.~Y,Z YAMAMOTO, TOKYO,
M.D., KAZUO KITAMUKA, M.D., AND SATOSHI OHTA,
M.D., M.D.
JAPAN
P
HONOCARDIOGRAMS are usually recorded from the chest wall but when picked up from the esophagus, some components are obtained more clearly, such as the auricular sound. L\ vibration that is perceived like the heart sound is assumed to receive a certtiin amount of damping, such as absorption and reflection, on its way from the heart to the chest wall, and is distorted to some extent. It seemed of physiological and clinical significance to pick up the prototype of the heart sounds from the esophagus, or better still, from the cardiac cavity itself, rather than from the chest wall. It would also be of clinical interest to obtain a phonocardiogram from various parts of the heart to which a catheter could be introduced in the case of congenital malformation of the heart. This purpose would necessitate the use of a miniature microphone that could be attached to the tip of a catheter, but since such a device was unavailable, the following method was employed. A condenser microphone, using the body as one pole and devised by Koizumi’ and Hinohara2 for picking up the heart sounds from the esophagus, was adapted with some modifications. To the tip of a plastic tubing (FS), a small metal stick (Fig. 1) was attached and well insulated. A fine, shielded wire was used for the lead wire between the metal stick at the tip of the catheter and the grid of the oscillator circuit. The wiring diagram of our circuit is shown in Fig. 2. The frequency of the carrier wave is 480 kc. It was assumed that the dielectric change that must occur at the tip of the catheter by the vibration, which is thought to be the cause of the heart sounds, would then be transferred by frequency modulation to an oscillogram The use of a fine and be perceived directly as a sound through a loud-speaker. shielded wire, as lead wire, in the catheter, limited the conversion of frequency to By this means, it became possible to record more selecthe tip of the catheter. tively the vibratidn in the desired portion of the heart cavity. By a similar method, Tomomatsu and Takasaki3B4 obtained the slow vibration especially from the right auricle. They discussed the mechanism of venous return with their slow vibrati0ns.j Moreover, they did not use a shielded wire for the lead in the catheter and their apparatus is said to be entirely insensible to sound waves when the catheter is left in the air.4 From the First Medical Clinic, Tokyo University School OPMedicine, Director: Received for publication Aug. 25, 1953. 424
Prof. S. Tasaka.
YAMAKAW.4
Fig.
l.-The
tip of the catheter.
6ZPl
3.-Wave
form
:
INTRACARDIAC
A, Metal C, Plastic
stick; tube:
2.-The
of Japanese
wiring
diagram
voiced
vowel
“a”
42.5
PHONOCARDIOGRAPHY
B. Electrode D, Insulator.
6s:”
6SJP -
Fig.
Fig.
ET AL.
of the unipolar
,!:,
,
of our circuit.
(Second
articulated
by an adult
electrocardiogram;
6ZPl
model.)
man.
Time:
l/100
sec.
426
AMERICAN
HEART
JOURNAL
The apparatus used in our experiment, as long as the tuning was perfect, is extremely sensitive to sound waves when the catheter is left in the air, showing that the catheter could act as an extremely small microphone which could not have been manufactured to date. An oscillogram of vowel “a”, taken with our apparatus, is shown in Fig. 3. It follows, therefore, that the apparatus and the object of research by Tomomatsu and Takasaki are a great deal different from those of our present study.
Fig.
4.-Roentgenogram
of a dog, in which one catheter microphone was introduced pulmonary artery and another in the left ventricle.
in the left
Under fluoroscopic observation, the catheter microphone was introduced into the heart cavity. Using over twenty adult healthy dogs, the catheter was introduced into the right heart through the cervical vein, or to the left side of the heart through the carotid artery. Venous catheterization was also carried out on three human beings, in one of which the catheter microphone reached the pulmonary artery and then heart sounds at various parts in the heart were recorded on the tape recorder. RESULTS Results and
obtained
with
dogs
1. Fig. 5, A is the recording 5, B, that from the common
are
described
in the
following.
obtained from the descending pulmonary artery. Both
are
limb of the left pulmonary high-pitched murmurs
artery, of holo-
YA4MAKAWA systolic phase, and stenosis. The time 0.03 sec., shorter in of blood flow at the
ET
AL. :
INTRACARDIAC
PHONOCARDIOGRAPHY
427
the contour is oval or ellipsoidal, similar to the murmur of semilunar valve elapsed from Q of the electrocardiogram to the beginning of the murmur is 5, B than 5, A. This means that the record obtained is that of a whirlpool tip of the catheter.
2. Fig. 6, A shows the wall of the left ventricle by from the chest wall made at first sound complex of this is
recording obtained by contacting the tip of the catheter on the inner its introduction through the carotid artery, and 6, B, the recording the same time. The former shows the auricular sound clearly. The very similar to the first sound from the chest wall. A.
B.
Fig. 5.-Upper tracing is electrocardiogram. is phonocardiogram with filter. A is the tracing and B, from the common pulmonary artery.
middle is phonocardiogram from the descending limb
without filter, and lower of the left pulmonary artery.
3. Fig. 7, A and B are the recordings of various points in the left ventricle of the same dog as in Fig. 6. Presystolic ellipsoidal murmur is especially well shown in 7, A. It is not clear whether this resulted from a temporary mitral stenosis caused by the tip of the catheter having pushed on the mitral valve, or whether such a whirlpool of blood flow exists in the left ventricle. This presystolic murmur cannot be observed from the chest wall at the same time. 4. Fig. 8 is the recording obtained from a point near the aortic valve in the left ventricle. It shows the auricular sound and a murmur of small amplitude that follows it. The first sound is either prolonged or split and follows a rough systolic murmur. The second sound is in some cases split, and a large third sound follows.
428
.\MERIChN
HEART
JOUKNAI,
5. Fig. 9A, B, and C are records whrll the tip of the catheler is placed in the blood stream in the aortic arch. A holosystolic, high-pitched murmnr is present, as in the case of the pulmonary artery, and it is very similar to the findings of auscultation of aortic stenosis. When the tip of the catheter is in contact with the aortic wall, the first and second sounds become more clear, as can be seen in Fig. 9, B. In this instance, this strong systolic murmur cannot be seen in the cardiograph taken from the chest wall at the same time. The whining of a dog is extremely damaging to the recording from the chest wall, but it does have as much effect on the cardiograph taken from the left ventricle or aorta. These results show that the myocardium and aortic wall exert an extreme damping effect on vibration, especially that of higher frequency.
R
,.
i
‘*:‘
i
i B. Fig. 6.--A is the tracing from the inner wall of the left, ventricle. obtained at the same t,ime as is auricular sound. Note the fluctuation with the respiration.
13 is a tracing from of AS-7 interval
the chest wall in accordance
SUMMr\RY
1. by
means
The intracardiac of
a condenser
2. Intracardiac recorder.
phonocardiography microphone
using
the
was obtained from dogs and men body as one pole.
heart sounds of men and dogs were recorded on the tape
YAMAKAWA
ET
AL. :
INTRACARDIAC
429
PHONOCARDIOGRAPHY
B.
Fig.
7.-Tracings
Fig.
S.-Tracing
from the cavity of the left ventricle of the same Note the presystolic ellipsoidal murmur.
from
cavity
of the left
ventricle
near the aortic
dog of Fig.
valve.
6.
430
AMERICAN
HEART
JOURNAL
3. The data obtained to date indicate that there exists a certain amount of blood whirlpooling inside the heart cavities and arteries. Although this whirlpool is mostly in audible range, the damping effect of heart and arterial walls makes it impossible to hear these sounds upon the chest wall in a normal healthy person.
arch
Fig. Q.-A is recording and 0 from the chest
B is from the inner wall of aortic from the blood stream of the aortic arch. The whining of a dog is shown only in 0. wall obtained at the same time.
YAMAKAWA
ET
AL.:
INTRACARDIAC
PHONOCARDIOGRAPHY
431
4. When the catheter tip is placed in the blood stream, chiefly course sounds due to a blood whirlpool are recorded, and when the tip is contacted with the inner wall of the heart, chiefly vibrations of a solid structure are recorded. These latter are thought to be similar to the heart sounds obtained from the chest wall. REFERENCES
1.
Koizumi,
H.: Eine neue Methode der Registrierung des Spitzenstosses und Herztons, J. Clin. Angiocardiology, 4:137, 1938. Hinohara, S.: Studies on the Heart Sounds. I. A New Method for the Recording of Heart Sounds and Murmurs, Jap. J. Clin. Angiocardiology, 6:117, 1940. Tomomatsu, T., and Takasaki, H.: Heart Sounds Obtained From Heart Cavity (Japanese language), Jap. J. Clin. Angiocardiology 13:122, 1949. Tomomatsu, T., and Takasaki, H.: On the Condenser Microphone (Japanese language), Jap. J. Clin. Angiocardiology, 14:183, 19.50. Tomomatsu, T.: Clinical Studies on Heart Failure (Japanese language), Jap. J. Clin. Angiocardiology 14:2.54, 1951. Jap.
2. 3. 4. 5.
l’HONOCARDIOGRAF’HY
KUNIO YAMAKAWA, M.D., YASUO SHIONOYA, TOICHI NAGAI, M.D., TAK.~Y,Z YAMAMOTO, TOKYO,
M.D., KAZUO KITAMUKA, M.D., AND SATOSHI OHTA,
M.D., M.D.
JAPAN
P
HONOCARDIOGRAMS are usually recorded from the chest wall but when picked up from the esophagus, some components are obtained more clearly, such as the auricular sound. L\ vibration that is perceived like the heart sound is assumed to receive a certtiin amount of damping, such as absorption and reflection, on its way from the heart to the chest wall, and is distorted to some extent. It seemed of physiological and clinical significance to pick up the prototype of the heart sounds from the esophagus, or better still, from the cardiac cavity itself, rather than from the chest wall. It would also be of clinical interest to obtain a phonocardiogram from various parts of the heart to which a catheter could be introduced in the case of congenital malformation of the heart. This purpose would necessitate the use of a miniature microphone that could be attached to the tip of a catheter, but since such a device was unavailable, the following method was employed. A condenser microphone, using the body as one pole and devised by Koizumi’ and Hinohara2 for picking up the heart sounds from the esophagus, was adapted with some modifications. To the tip of a plastic tubing (FS), a small metal stick (Fig. 1) was attached and well insulated. A fine, shielded wire was used for the lead wire between the metal stick at the tip of the catheter and the grid of the oscillator circuit. The wiring diagram of our circuit is shown in Fig. 2. The frequency of the carrier wave is 480 kc. It was assumed that the dielectric change that must occur at the tip of the catheter by the vibration, which is thought to be the cause of the heart sounds, would then be transferred by frequency modulation to an oscillogram The use of a fine and be perceived directly as a sound through a loud-speaker. shielded wire, as lead wire, in the catheter, limited the conversion of frequency to By this means, it became possible to record more selecthe tip of the catheter. tively the vibratidn in the desired portion of the heart cavity. By a similar method, Tomomatsu and Takasaki3B4 obtained the slow vibration especially from the right auricle. They discussed the mechanism of venous return with their slow vibrati0ns.j Moreover, they did not use a shielded wire for the lead in the catheter and their apparatus is said to be entirely insensible to sound waves when the catheter is left in the air.4 From the First Medical Clinic, Tokyo University School OPMedicine, Director: Received for publication Aug. 25, 1953. 424
Prof. S. Tasaka.
YAMAKAW.4
Fig.
l.-The
tip of the catheter.
6ZPl
3.-Wave
form
:
INTRACARDIAC
A, Metal C, Plastic
stick; tube:
2.-The
of Japanese
wiring
diagram
voiced
vowel
“a”
42.5
PHONOCARDIOGRAPHY
B. Electrode D, Insulator.
6s:”
6SJP -
Fig.
Fig.
ET AL.
of the unipolar
,!:,
,
of our circuit.
(Second
articulated
by an adult
electrocardiogram;
6ZPl
model.)
man.
Time:
l/100
sec.
426
AMERICAN
HEART
JOURNAL
The apparatus used in our experiment, as long as the tuning was perfect, is extremely sensitive to sound waves when the catheter is left in the air, showing that the catheter could act as an extremely small microphone which could not have been manufactured to date. An oscillogram of vowel “a”, taken with our apparatus, is shown in Fig. 3. It follows, therefore, that the apparatus and the object of research by Tomomatsu and Takasaki are a great deal different from those of our present study.
Fig.
4.-Roentgenogram
of a dog, in which one catheter microphone was introduced pulmonary artery and another in the left ventricle.
in the left
Under fluoroscopic observation, the catheter microphone was introduced into the heart cavity. Using over twenty adult healthy dogs, the catheter was introduced into the right heart through the cervical vein, or to the left side of the heart through the carotid artery. Venous catheterization was also carried out on three human beings, in one of which the catheter microphone reached the pulmonary artery and then heart sounds at various parts in the heart were recorded on the tape recorder. RESULTS Results and
obtained
with
dogs
1. Fig. 5, A is the recording 5, B, that from the common
are
described
in the
following.
obtained from the descending pulmonary artery. Both
are
limb of the left pulmonary high-pitched murmurs
artery, of holo-
YA4MAKAWA systolic phase, and stenosis. The time 0.03 sec., shorter in of blood flow at the
ET
AL. :
INTRACARDIAC
PHONOCARDIOGRAPHY
427
the contour is oval or ellipsoidal, similar to the murmur of semilunar valve elapsed from Q of the electrocardiogram to the beginning of the murmur is 5, B than 5, A. This means that the record obtained is that of a whirlpool tip of the catheter.
2. Fig. 6, A shows the wall of the left ventricle by from the chest wall made at first sound complex of this is
recording obtained by contacting the tip of the catheter on the inner its introduction through the carotid artery, and 6, B, the recording the same time. The former shows the auricular sound clearly. The very similar to the first sound from the chest wall. A.
B.
Fig. 5.-Upper tracing is electrocardiogram. is phonocardiogram with filter. A is the tracing and B, from the common pulmonary artery.
middle is phonocardiogram from the descending limb
without filter, and lower of the left pulmonary artery.
3. Fig. 7, A and B are the recordings of various points in the left ventricle of the same dog as in Fig. 6. Presystolic ellipsoidal murmur is especially well shown in 7, A. It is not clear whether this resulted from a temporary mitral stenosis caused by the tip of the catheter having pushed on the mitral valve, or whether such a whirlpool of blood flow exists in the left ventricle. This presystolic murmur cannot be observed from the chest wall at the same time. 4. Fig. 8 is the recording obtained from a point near the aortic valve in the left ventricle. It shows the auricular sound and a murmur of small amplitude that follows it. The first sound is either prolonged or split and follows a rough systolic murmur. The second sound is in some cases split, and a large third sound follows.
428
.\MERIChN
HEART
JOUKNAI,
5. Fig. 9A, B, and C are records whrll the tip of the catheler is placed in the blood stream in the aortic arch. A holosystolic, high-pitched murmnr is present, as in the case of the pulmonary artery, and it is very similar to the findings of auscultation of aortic stenosis. When the tip of the catheter is in contact with the aortic wall, the first and second sounds become more clear, as can be seen in Fig. 9, B. In this instance, this strong systolic murmur cannot be seen in the cardiograph taken from the chest wall at the same time. The whining of a dog is extremely damaging to the recording from the chest wall, but it does have as much effect on the cardiograph taken from the left ventricle or aorta. These results show that the myocardium and aortic wall exert an extreme damping effect on vibration, especially that of higher frequency.
R
,.
i
‘*:‘
i
i B. Fig. 6.--A is the tracing from the inner wall of the left, ventricle. obtained at the same t,ime as is auricular sound. Note the fluctuation with the respiration.
13 is a tracing from of AS-7 interval
the chest wall in accordance
SUMMr\RY
1. by
means
The intracardiac of
a condenser
2. Intracardiac recorder.
phonocardiography microphone
using
the
was obtained from dogs and men body as one pole.
heart sounds of men and dogs were recorded on the tape
YAMAKAWA
ET
AL. :
INTRACARDIAC
429
PHONOCARDIOGRAPHY
B.
Fig.
7.-Tracings
Fig.
S.-Tracing
from the cavity of the left ventricle of the same Note the presystolic ellipsoidal murmur.
from
cavity
of the left
ventricle
near the aortic
dog of Fig.
valve.
6.
430
AMERICAN
HEART
JOURNAL
3. The data obtained to date indicate that there exists a certain amount of blood whirlpooling inside the heart cavities and arteries. Although this whirlpool is mostly in audible range, the damping effect of heart and arterial walls makes it impossible to hear these sounds upon the chest wall in a normal healthy person.
arch
Fig. Q.-A is recording and 0 from the chest
B is from the inner wall of aortic from the blood stream of the aortic arch. The whining of a dog is shown only in 0. wall obtained at the same time.
YAMAKAWA
ET
AL.:
INTRACARDIAC
PHONOCARDIOGRAPHY
431
4. When the catheter tip is placed in the blood stream, chiefly course sounds due to a blood whirlpool are recorded, and when the tip is contacted with the inner wall of the heart, chiefly vibrations of a solid structure are recorded. These latter are thought to be similar to the heart sounds obtained from the chest wall. REFERENCES
1.
Koizumi,
H.: Eine neue Methode der Registrierung des Spitzenstosses und Herztons, J. Clin. Angiocardiology, 4:137, 1938. Hinohara, S.: Studies on the Heart Sounds. I. A New Method for the Recording of Heart Sounds and Murmurs, Jap. J. Clin. Angiocardiology, 6:117, 1940. Tomomatsu, T., and Takasaki, H.: Heart Sounds Obtained From Heart Cavity (Japanese language), Jap. J. Clin. Angiocardiology 13:122, 1949. Tomomatsu, T., and Takasaki, H.: On the Condenser Microphone (Japanese language), Jap. J. Clin. Angiocardiology, 14:183, 19.50. Tomomatsu, T.: Clinical Studies on Heart Failure (Japanese language), Jap. J. Clin. Angiocardiology 14:2.54, 1951. Jap.
2. 3. 4. 5.