SEARCH · PubMed Health

Results for “PHONOCARDIOGRAPHY”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

PubMed1989

Phonocardiography as a monitor of cardiac performance during anesthesia.

The usefulness of phonocardiography as a monitor of cardiac performance during anesthesia was investigated in six dogs. Anesthetic depression by halothane, isoflurane and nitrous oxide was demonstrated by the phonocardiogram. Likewise, the stimulating effect of dopamine clearly showed in the recordings. Changes in the amplitude of the first heart sound were found to correlate closely with changes in the maximum rate of rise of left ventricular pressure (r = 0.9551, 0.001). P less than 0.001). Simultaneous changes in cardiac output and arterial pressure also occurred. Cardiac depression from anesthetics and/or disease is a major concern during anesthesia. Perioperative phonocardiography, a simple and noninvasive procedure, merits further investigation as a possible monitor of cardiac performance.

Anesthesia↗

PubMed1985

[Pulsed Doppler echocardiography and pharmacodynamic phonocardiography in the diagnosis of silent aortic regurgitation: a correlative study].

To determine the usefulness of pulsed Doppler echocardiography (PDE) in diagnosing aortic regurgitation (AR), the following two studies were performed. PDE and phonocardiography (PCG) were evaluated for the diagnosis of AR in 36 patients for whom angiography was performed. In 24 patients with grade 2 to 4 by Sellers' classification, all PDE studies were positive for AR (sensitivity of 100%) and PCG studies were positive in 21 patients (sensitivity of 88%). Among 10 patients of grade 1, PDE studies were positive for eight (sensitivity of 80%) and PCG studies were positive for seven (sensitivity of 70%). Angiography was negative for AR in two PCG-proven cases, and PDE also proved AR in one of these. Thus, in all patients, the sensitivity of PDE and PCG were 94 and 82%, respectively. These results indicate that AR may be missed during auscultation, or even when using the latest type PCG. The ability of detecting silent AR was studied in 160 consecutive patients with AR. PDE was positive for AR in 156 of 160 consecutive patients who were diagnosed as having AR by PDE or PCG. In the remaining four patients, three were diagnosed by PCG alone and one by pharmacodynamic phonocardiography using methoxamine (ME-PCG). On the other hand, in 137 of 160, Ar was proven by PCG, and the remaining 23 were so-called "silent AR". ME-PCG was performed for 11 cases of silent AR, but an unequivocal AR murmur was detected in only five. Therefore, the sensitivity of PDE in diagnosing silent AR was 96 percent, while that of ME-PCG was only 45 percent. Thus, compared to PCG and even pharmacodynamic PCG, PDE is a much more sensitive method of diagnosing AR. However, in mild AR cases, angiography, PDE and PCG, all have some limitations in diagnosing AR.

Adult↗

PubMed1978

Origin of the basal systolic murmurs in mitral stenosis. A study with intracardiac phonocardiography.

In order to study the origin of the basal systolic murmurs in mitral stenosis, left and right heart catheterization was performed in 18 patients with mitral stenosis using intracardiac phonocardiography. Our data revealed that the basal systolic murmurs originated in the aorta, the pulmonary artery, and the outflow tract of the right ventricle. In 14 cases, we noted the maximal ejection systolic murmur in the aorta near the aortic valve. However, in two cases, there was a loud systolic murmur in the pulmonary artery. These murmurs occurred in early to mild-systole and were crescendo-decrescendo in configuration. The pitch of the murmur ranged from low to medium frequency in the majority of cases. They are produced by the turbulence of blood flow in the aorta and the pulmonary artery. A late systolic murmur was also recorded in the outflow tract of the right ventricle in two patients. This is thought to occur due to functional or relative infundibular stenosis of the right ventricle. It differs in location and timing from those in the aorta and the pulmonary artery. The outflow tract of the right ventricle is regarded as the third origin of the basal systolic murmur in mitral stenosis.

Adult↗

PubMed1979

Clinical study on the right-sided Austin Flint murmur using intracardiac phonocardiography.

Right heart catheterization was carried out on 14 patients with pulmonic regurgitation using intracardiac phonocardiography. All the patients showed pulmonic regurgitant murmur in the right ventricular outflow tract. In addition, seven out of the 14 patients showed mid-diastolic and presystolic murmurs maximally in the outflow tract of the right ventricle. Furthermore, inspiration increased the loudness of these diastolic murmurs in four patients. These findings were compatible with those of right-sided Austin Flint murmur due to functional tricuspid stenosis in pulmonic incompetence. Ten out of the 14 patients had pulmonary hypertension and all the subjects with a rightsided Austin Flint murmur showed elevated pulmonary arterial pressure. Thus, pulmonic regurgitation with pulmonary hypertension is thought to be closely related to the right-sided Austin Flint murmur and the turbulence resulting from antegrade flow across a closing tricuspid valve may be responsible for the genesis of the murmur.

Adolescent↗

PubMed1980

Intracardiac phonocardiography in experimental left ventricular cavity obliteration: potential clinical applicability for the distinction of obliterating left ventricle from hypertrophic obstructive cardiomyopathy.

Intracardiac sound was measured in six dogs, four with left ventricular cavity obliteration induced by isoproterenol, and two with catheter entrapment. In left ventricular cavity obliteration, no murmur occurred within the left ventricle. Whenever a systolic murmur occurred, it was distal to the aortic valve. In entrapment, no murmur occurred within the left ventricle or distal to the aortic valve. Previous studies in patients with hypertrophic obstructive cardiomyopathy showed that the systolic murmur was of greatest intensity within the left ventricular outflow tract. Therefore, intracardiac phonocardiography may assist in differentiating these conditions which produce an intraventricular pressure gradient.

Animals↗

PubMed1990

Follow-up in mitral valve prolapse by phonocardiography, M-mode and two-dimensional echocardiography and Doppler echocardiography.

To assess the serial phonocardiographic and echocardiographic change in patients with mitral valve prolapse (MVP), phonocardiograms and echocardiograms were reviewed retrospectively in 116 patients (48 men and 68 women, mean age 27 years) who had been determined to have MVP and were reexamined 4.3 years (range 1 to 14) later by phonocardiography and echocardiography between 1971 and 1988. Follow-up phonocardiograms showed periods when 5 of 18 patients with silent MVP developed mid- or late systolic clicks. Of 57 patients with mid- or late systolic clicks, 15 had silent MVP, 6 developed a late systolic murmur with or without systolic clicks and 1 developed a pansystolic murmur. Two of 9 patients with an isolated late systolic murmur developed a pansystolic murmur. M-mode echocardiograms showed that left atrial and left ventricular dimensions at end-diastole and end-systole increased in patients with systolic murmur (33 +/- 10 vs 35 +/- 11, 46 +/- 6 vs 50 +/- 7 and 29 +/- 4 vs 31 +/- 5 mm, respectively, all p less than 0.001) and no statistically significant changes in any of these dimensions were found in patients without a systolic murmur. The degree of MVP evaluated by the anteroposterior mitral leaflet angle on the 2-dimensional echocardiogram was more severe in patients with a systolic murmur than in patients without systolic murmur (157 +/- 12 vs 131 +/- 16 degrees, p less than 0.001). The degree of prolapse did not change during the follow-up periods. The number of patients with mitral regurgitation detected by pulsed Doppler echocardiography increased from 21 of 72 (29%) to 31 of 72 (43%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Differences in foetal heart rate variability from phonocardiography and abdominal electrocardiography.

The agreement of the phonocardiographic method to provide foetal heart rate variability (FHRV) indices equivalent to those derived from abdominal electrocardiography was tested. 15 pregnant women were recruited in order to obtain antepartum foetal phonocardiograms and abdominal electrocardiograms three minutes long. From the respective sound (SS) and electric (RR) time series, typical temporal and spectral indices of FHRV were computed and compared. Means of the SS and RR intervals were not significant (P> 0.05) and these showed a correlation r=0.98. However, the temporal indices, P(TOT), HF and LF/HF presented differences (P< 0.05), since SS values were higher. Spectral coherence decreased below 0.5 for frequencies above 0.28+ 0.07 Hz, where bands resembling maternal and foetal breathing movements were noted. Particularly above 0.28Hz, temporal and spectral FHRV indices derived from phonocardiography and electrocardiography show differences. Quality of the signal, processing techniques, and maternal and foetal respiratory factors could account to explain these.

Adult↗

PubMed1977

Clinical study on the acoustic phenomena in coronary venous system with intracardiac phonocardiography.

In order to study the intracardiac murmurs in coronary venous system, right heart catheterization was carried out on 35 patients with or without mitral regurgitation. The double-lumen phonocatheter of A. E. L. was used for 33 cases but for 2 the microtip phonocatheter of Millar was employed. As a rule, simultaneous recording of intracardiac and external phonocardiograms was made with the pressure tracing in the majority of cases. The examined subjects were divided into 3 groups; 9 cases with mitral regurgitation confirmed by left ventriculography (Group I), 20 without mitral regurgitation (Group II), and 6 with functional systolic murmur (Group III). In Group I, a loud systolic murmur was recorded in 7 cases (MR 5, MR + AR 1, ECD 1), but in none of IHSS in the coronary sinus or great coronary vein. In Group II, no systolic bruit was noted in VSD and other lesions except ASR in the coronary venous system. The same was true in patients with functional systolic murmur (Group III). Intracardiac phonocardiography is thought to be useful to record mitral regurgitant murmurs in the coronary venous system, since the latter is in the close proximity to the mitral posterior commissure or mitral annulus.

Adult↗

PubMedDate not supplied

Application of phonocardiography for detecting hypoxia-induced cardiovascular adaptation in the chicken.

Phonocardiography was evaluated as a noninvasive technique for diagnosis of cardiovascular adaptation and disease in broiler chickens. Heart sounds (HSs) were compared in a fast-growing (FG) commercial broiler line that is highly susceptible to chronic right heart failure resulting from pulmonary hypertension syndrome (PHS) and in a non-selected slow-growing (SG) broiler line that is resistant to PHS. HSs were analyzed in broilers reared in hypobaric hypoxia (HYP) and normobaric (CON) conditions. PHS was induced by a combination of embryonic hypoxia and HYP exposure. HSs were recorded with a microphone placed at the thoracic inlet of each chicken. Electrocardiograms were used to mark the sampling interval for the first, second, and total HS. Digitized HS signals were analyzed for peak frequency, mean peak frequency, and band width. Birds were examined for PHS lesions when 6 wk of age, at the end of each experiment. HSs were compared by line and treatment (Experiment 1) or by treatment and week (Experiment 2). In addition, HS frequencies were analyzed within the HYP treatment group for differences between birds with severe or no gross PHS lesions. HS frequencies generally decreased with age and were also lower in the FG than the SG line. Hypobaric exposure decreased all HS frequencies in the SG line and components of the first HSs in the FG line. The SG line did not develop gross lesions of PHS. In the FG line, significant differences in HS frequencies were observed between HYP and CON groups but not between PHS- and PHS+ broilers. Frequency changes described in humans with PHS were not observed. Further development to maximize the resolution of the HS waveforms and improved matching of the sampling interval to the electrical or hemodynamic output of the chicken heart may allow its use as a diagnostic tool for differentiating broilers with normal cardiac function or physiologic adaptation from those with cardiovascular disease.

Acclimatization↗

PubMed1975

[Importance of electro- and phonocardiography in diagnosis of pulmonary hypertension in pregnant women with mitral valve stenosis].

The possibilities of electro- and phonocardiography in detecting the extent of pulmonary hypertension are elucidated. Taking as a basis pertinent changes in the electro- and phonocardiograms made it possible to objectively estimate the degree of risk that involves labour at early terms of pregnancy. This is of importance in solving the problem of its preservation and also in deciding on the management of gestation and labour.

Adult↗

PubMed1975

[Intracardiac phonocardiography in young persons with congenital heart defects].

Thirty nine persons 17 to 22 years old with mild forms of an interatrial defect, stenosis and congential dilation of the pulmonary artery were examined. During catheterization of the right heart intracardiac phonocardiography and characteristic systolic murmurs in the pulmonary artery and in the right ventricle were recorded, all this being of help in precisely diagnosing these minor and, therefore, atypical clinical forms of the malady.

Adolescent↗

PubMed2001

[Fetal phonocardiography with a novel approach].

The long-term recording of the fetal heart rate (FHR) variability is one of the most frequently used tools of routine fetal diagnostics which is usually carried out by the means of ultrasound cardiography. Frequent measurement of FHR is recommendable, however the cost of high quality ultrasound devices is unfortunately so high that this technology is not viable for low-cost devices used in the home-care sector. An alternative approach of FHR recording can be based on the fully non-invasive, passive acoustic recording, called phonocardiography. The evaluation of fetal phonocardiograms is complicated by various internal and external noise factors. The development of accurate and robust fetal phonocardiographs has been studied by biomedical researchers since long. This paper presents a novel two-channel phonocardiographic device and an advanced signal processing method, which provides a performance comparable to that of ultrasound cardiography. The proposed system offers an optimal trade-off between complexity and feasibility and it is viable in low-cost, stand-alone, battery-powered FHR monitoring devices. The developed system provided 83% accuracy compared to the simultaneously recorded reference ultrasound records.

Artifacts↗

PubMed1988

[Time analysis of mitral regurgitation in patients with mitral valve prolapse: a study by phonocardiography and Doppler techniques].

To assess the timing and duration of mitral regurgitation (MR) in patients with mitral valve prolapse (MVP), 20 subjects with mid-systolic click(s) and/or a late systolic murmur were studied using phonocardiography, two-dimensional echocardiography (2DE) and Doppler techniques including pulsed Doppler (PD), high pulse repetition frequency Doppler (HPRF), continuous wave Doppler (CW) and M-mode color Doppler (MD) methods and two-dimensional Doppler color flow mapping (2DD). The results were compared with those of 16 patients with a pansystolic murmur having late systolic accentuation. MVP with MR was observed in 15 of the 20 patients with mid-systolic clicks and/or a late systolic murmur and in all of the 16 patients with a pansystolic murmur. Using MD, MR signals were seen throughout systole and isovolumic relaxation period in all but one of these patients, and they were not related to the patterns of the systolic murmur. In only one, an MR signal was recorded just after the click. Five patients with a mid-systolic click lacked the findings of MVP, but two of them had MR signal only in early systole. Using PD and HPRF techniques, the timing and duration of MR signals in patients with mid-systolic clicks and/or a late systolic murmur were varied by changing the sites of the sample volume. Similarly, the timing and duration of MR signals in these patients were dependent on the ultrasonic beam direction by the CW method. In most patients with a pansystolic murmur having late systolic accentuation, however, MR signals throughout systole and the isovolumic relaxation period were demonstrated by each Doppler method. Therefore, PD, HPRF, and CW were not so efficiently sensitive or adequate techniques for investigating the timing and duration of MR, especially in patients with mid-systolic clicks and/or a late systolic murmur, who had mild or eccentric MR jets. In conclusion, 1) MR in MVP involves the entire systole and isovolumic relaxation period, 2) PD, HPRF and CW methods are not adequate for detecting mild or eccentric MR jets in patients with mid-systolic clicks and/or a late systolic murmur, and 3) MD is useful for the time analysis of MR in these patients.

Adolescent↗

PubMed1986

Clinical significance of early or mid-systolic apical murmurs: analysis by phonocardiography, two-dimensional echocardiography and pulsed Doppler echocardiography.

The records of 2,000 consecutive patients who had been examined by auscultation, phonocardiography (PCG), two-dimensional echocardiography and pulsed Doppler echocardiography (PDE) were reviewed to assess the clinical significance of apical systolic murmurs which cease well before the aortic closure sound. Fifty-five patients were verified to have early or mid-systolic apical murmurs. Mitral regurgitation (MR) was detected in 32 patients by PDE (29/32) and/or PCG with methoxamine test (27/32). The degree of MR was judged to be mild by PDE in all cases. Apical systolic murmurs due to MR began mainly with the first heart sound (27/32), were confined to the apex (27/32), and high-pitched (25/32). Their intensity was grade III/VI or less in all cases. Mitral valve prolapse (12 patients) was the most common cause of MR. Other causes were rheumatic mitral involvement in seven patients, dilated or ischemic cardiomyopathy in five, mitral annular calcification in three, and hypertrophic cardiomyopathy in two. The causes of the MR in the remaining three patients could not be identified. Thus, early or mid-systolic apical murmurs are mainly attributable to mild MR which can be diagnosed by careful auscultation, PDE and/or PCG with the methoxamine test.

Adult↗

PubMed1987

[From phonocardiography to phonoanalysis].

We report on a new system for the examination and presentation of heart sounds, the phonoanalysis (PHA). It gives automatically a complete, objective physically founded picture of heart sounds and murmurs by registering the frequency spectrum graphically, as well as presenting in a numeric format, as a whole and as a function of time; in addition, the usual phonocardiographic and electrocardiographic leads may be obtained. A further function is to measure--probably for the first time--quantitatively the "roughness" of heart murmurs. This factor is also essential for the quality of murmurs and independent of the pitch. Therefore, the quantitative assessment of roughness has been proposed as an essential part of the physically founded description of heart murmurs in the auscultation, in addition to the determination of the dominating frequency (pitch). The term 'roughness' should not been confined to the extremely rough low-pitched heart murmurs e.g. in typical aortic stenosis. The PHA gives a better insight into the hemodynamic basis of heart murmurs and discloses properties of murmurs not recognized by auscultation and phonocardiography. The PHA can also be used for the examination of vascular, lung, bronchial and abdominal murmurs and also in connection with a stethoscope using an airborne sound microphone.

Computers↗

PubMed1979

[Technical and methodological aspects concerning the application of Fourier's analysis to phonocardiography (author's transl)].

The frequency spectrum analysis (Fourier's analysis) has recently been applied to phonocardiography. Using this mathematical approach instead of the current empirical analysis, it is possible to obtain -- on a less subjective basis -- more precise pathophysiological and diagnostic information from the acoustic cardiac phenomena. On the other hand, this refinement of the method of analysis stresses the need for better technical and methodological solutions, in order to reach the standardization of both the transduction and the recording of the acoustic signal at higher level of sensibility, fidelity and reproducibility. With this in mind, and on the basis of their experience, the Authors suggest the adoption of devices with specific technical characteristics, and propose a suitable method of application of Fourier's analysis to the phonocardiogram.

Fourier Analysis↗

PubMed1978

[Possibilities of intracardiac phonocardiography in congenital defects with left-right shunt].

The author shares his experience from intracardial phonocardiography of 48 patients with congenital heart defects with leftright shunt. The importance of the method is stressed upon, particularly in cases with interauricular and interventricular defect, not only for the diagnosis of the disease but for the differential diagnosis in difficult cases as well. The characteristic murmurs are presented, recorded intracardially in the three of the basic congenital heart defect with left-right shunt--interauricular defect, interventricular defect, and open Botal's duct.

Adolescent↗

PubMed1998

[Fetal phonocardiography: new application of an old method].

Cardiotocography plays an important role in the assessment of the fetal condition. Phonocardiography, abdominal electrocardiography and ultrasound cardiography are the three methods for external fetal cardiography. The authors summarize their observations in the analysis of 980 antepartum cardiotocograms made by a phonocardiograph. They conclude, that this phonocardiograph is cheap, reliable, handling can easily attach, and makes possible twenty-four hours home-monitoring.

Cardiotocography↗