phonocardiography

pho·no·car·di·o·graph

P0254800 (fō′nə-kär′dē-ə-grăf′)n. An instrument consisting of microphones and recording equipment used to monitor and record heart sounds and murmurs.

pho′no·car′di·o·graph′ic adj.pho′no·car′di·og′ra·phy (-ŏg′rə-fē) n.

phonocardiography

stethography, def. 2.See also: Medical Specialties

Phonocardiography

a diagnostic method of graphic registration of heart sounds and murmurs.

Phonocardiography supplements auscultation (listening). It is used to evaluate objectively the intensity, duration, nature, and origin of sounds and murmurs and to record the third and fourth sounds, which cannot be heard by auscultation. Polycardiography, the simultaneous registering of a phonocardiogram, electrocardiogram, and sphygmogram, is used to record the central pulse in order to determine the duration of the phases of the cardiac cycle, that is, in order to obtain indirect information on myocardial contractility.

A phonocardiograph, the instrument used for phonocardiography, consists of a microphone, an amplifier, a set of frequency filters, and a recording device. The microphone is applied to various points on the chest over the heart region. After amplification and filtration, the electrical oscillations enter separate registration channels to permit the selective recording of low, medium, and high frequencies. The recording is done in a soundproof room while the patient holds his breath at exhalation or, if necessary, at the point of deepest inhalation; the patient must be in a reclining position and must have rested for five minutes.

Figure 1. Phonocardiogram of a healthy person: (I) first sound, (II) second sound

The straight line on the phonocardiogram reflects the systolic and diastolic pauses. A normal first sound (Figure 1) consists of three groups of oscillations. The initial group, which is of low frequency, is produced by the contraction of the ventricular muscles. The central group is of greater amplitude and is produced by the closure of the mitral and tricuspid valves. The final group, which is of low amplitude, is produced by the opening of the aortic and pulmonary valves and the vibrations of the walls of large blood vessels. The second sound consists of two groups of oscillations. The first group, which is of greater amplitude, is produced by closure of the aortic valves; the second group is produced by closure of the pulmonary valves. The normal third sound is caused by muscle vibrations during rapid filling of the ventricles; the normal fourth sound, which is less common, is produced by the contractions of the atria. The normal third and fourth sounds are found chiefly in children and athletes.

Changes shown by the phonocardiograph help diagnose various disorders, including heart diseases. In addition to weakening, intensification, or split of the first or second sounds, such changes include the appearance of pathological third and fourth sounds or of systolic and diastolic murmurs.

REFERENCES

Fitileva, L. M. Klinicheskaia fonokardiografiia, 2nd ed. Moscow, 1968. (Contains bibliography.)
Kel’man, I. M. Elektrokardiografiia i fonokardiografiia, 2nd ed. Moscow, 1974.

phonocardiography

[fo″no-kahr″de-og´rah-fe] the graphic recording of heart sounds and murmurs; by extension, the term includes pulse tracings (carotid, apex, and venous pulse). adj., adj phonocardiograph´ic.
Phonocardiography involves picking up, through a highly sensitive microphone, sonic vibrations from the heart which are then converted into electrical energy and fed into a galvanometer, where they are recorded on paper. The procedure is most useful when there is evidence of heart murmurs or unusual heart sounds, such as gallops, that are difficult to discern by the human ear.

pho·no·car·di·og·ra·phy

(fō'nō-kar'dē-og'ră-fē), 1. Recording of the heart sounds with a phonocardiograph. 2. The science of interpreting phonocardiograms. [phono- + G. kardia, heart, + graphō, to record]

phonocardiography

Echophonocardiography Cardiology A non-invasive technique that amplifies faint, low frequency sounds of blood flowing through the heart and great vessels, displaying them graphically; PCG encompasses carotid, apex, and venous pulse tracings Applications Diagnose heart valve defects, ventricular hypertrophy, left heart failure; PCG is usually performed in synchrony with EKG, and M-mode echocadiography or Doppler echocardiography, to match changes heard by PCG with the point at which they occur in the heart beat

pho·no·car·di·og·ra·phy

(fō'nō-kahr'dē-og'ră-fē) 1. Recording of the heart sounds with a phonocardiograph. 2. The science of interpreting phonocardiograms. [phono- + G. kardia, heart, + graphō, to record]

单词	phonocardiography
释义	phonocardiography pho·no·car·di·o·graph P0254800 (fō′nə-kär′dē-ə-grăf′)n. An instrument consisting of microphones and recording equipment used to monitor and record heart sounds and murmurs. pho′no·car′di·o·graph′ic adj.pho′no·car′di·og′ra·phy (-ŏg′rə-fē) n. phonocardiography stethography, def. 2.See also: Medical Specialties Phonocardiography Phonocardiography a diagnostic method of graphic registration of heart sounds and murmurs. Phonocardiography supplements auscultation (listening). It is used to evaluate objectively the intensity, duration, nature, and origin of sounds and murmurs and to record the third and fourth sounds, which cannot be heard by auscultation. Polycardiography, the simultaneous registering of a phonocardiogram, electrocardiogram, and sphygmogram, is used to record the central pulse in order to determine the duration of the phases of the cardiac cycle, that is, in order to obtain indirect information on myocardial contractility. A phonocardiograph, the instrument used for phonocardiography, consists of a microphone, an amplifier, a set of frequency filters, and a recording device. The microphone is applied to various points on the chest over the heart region. After amplification and filtration, the electrical oscillations enter separate registration channels to permit the selective recording of low, medium, and high frequencies. The recording is done in a soundproof room while the patient holds his breath at exhalation or, if necessary, at the point of deepest inhalation; the patient must be in a reclining position and must have rested for five minutes. Figure 1. Phonocardiogram of a healthy person: (I) first sound, (II) second sound The straight line on the phonocardiogram reflects the systolic and diastolic pauses. A normal first sound (Figure 1) consists of three groups of oscillations. The initial group, which is of low frequency, is produced by the contraction of the ventricular muscles. The central group is of greater amplitude and is produced by the closure of the mitral and tricuspid valves. The final group, which is of low amplitude, is produced by the opening of the aortic and pulmonary valves and the vibrations of the walls of large blood vessels. The second sound consists of two groups of oscillations. The first group, which is of greater amplitude, is produced by closure of the aortic valves; the second group is produced by closure of the pulmonary valves. The normal third sound is caused by muscle vibrations during rapid filling of the ventricles; the normal fourth sound, which is less common, is produced by the contractions of the atria. The normal third and fourth sounds are found chiefly in children and athletes. Changes shown by the phonocardiograph help diagnose various disorders, including heart diseases. In addition to weakening, intensification, or split of the first or second sounds, such changes include the appearance of pathological third and fourth sounds or of systolic and diastolic murmurs. REFERENCES Fitileva, L. M. Klinicheskaia fonokardiografiia, 2nd ed. Moscow, 1968. (Contains bibliography.) Kel’man, I. M. Elektrokardiografiia i fonokardiografiia, 2nd ed. Moscow, 1974. phonocardiography phonocardiography [fo″no-kahr″de-og´rah-fe] the graphic recording of heart sounds and murmurs; by extension, the term includes pulse tracings (carotid, apex, and venous pulse). adj., adj phonocardiograph´ic. Phonocardiography involves picking up, through a highly sensitive microphone, sonic vibrations from the heart which are then converted into electrical energy and fed into a galvanometer, where they are recorded on paper. The procedure is most useful when there is evidence of heart murmurs or unusual heart sounds, such as gallops, that are difficult to discern by the human ear. pho·no·car·di·og·ra·phy (fō'nō-kar'dē-og'ră-fē), 1. Recording of the heart sounds with a phonocardiograph. 2. The science of interpreting phonocardiograms. [phono- + G. kardia, heart, + graphō, to record] phonocardiography Echophonocardiography Cardiology A non-invasive technique that amplifies faint, low frequency sounds of blood flowing through the heart and great vessels, displaying them graphically; PCG encompasses carotid, apex, and venous pulse tracings Applications Diagnose heart valve defects, ventricular hypertrophy, left heart failure; PCG is usually performed in synchrony with EKG, and M-mode echocadiography or Doppler echocardiography, to match changes heard by PCG with the point at which they occur in the heart beat pho·no·car·di·og·ra·phy (fō'nō-kahr'dē-og'ră-fē) 1. Recording of the heart sounds with a phonocardiograph. 2. The science of interpreting phonocardiograms. [phono- + G. kardia, heart, + graphō, to record]
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