Clinical, echocardiographic and echophonocardiographic characteristics of the atrial myxomas in 22 years period

INTRODUCTION

Atrial myxomas are the most frequent benign tumors of the heart. Left atrial myxomas are about 3-4 times more frequent then right. Clinical findings reveal atrioventricular obstruction symptoms and signs, symptoms and signs of peripheral arteries or pulmonary artery embolisation and/or nonspecific symptoms.

AIM

Review of atrial myxomas diagnosed at the Clinic of Cardiology in 20 years period and analysis of clinical characteristics, transthoracic echocardiographic (TTE), transesophageal echocardiographic (TEE), and M-mod echophonographic findings.

METHODS

TTE is performed in all, but TEE in 16 patients. Simultaneous M-mod echophonocardiographic examination were performed in 11 patients, when optional equipment was applicable.

RESULTS

We found 24 atrial myxomas: 19 (79.2%) in left and 5 (20.810%) in right atrium. 21(87.5%) patients had some of the symptoms, but 3 (12.5%) were asymptomatic. TTE was performed in all patients, but we found 1 (2.4%) false negative result. TEE was performed in 14 (58.3%) patients. Echophonocardiographic recordings showed early diastolic tumor "plop" in 10 patients and unusual late diastolic tumor "plop" in one right atrial myxoma, which has not yet been described.

CONCLUSIONS

TTE is a reliable method in diagnosis of atrial myxomas, but not in all cases, while TEE has been found as always reliable. Echophonocardiographic recording is useful for confirmation and understanding of auscultatory finding when applicable.

[Application and comparison of continuous wavelet transform and matching pursuit method in analyzing phonocardiographic signals]

Heart sounds are highly valuable to the clinical diagnoses of most cardiovascular diseases, so the analysis of phonocardiographic signals is helpful to diagnosing cardiovascular diseases clinically. Phonocardiographic signals are non-stable, so it is necessary to choose appropriate method in time-frequency analysis. The traditional method such as Fourier Transform is dissatisfactory. Continuous Wavelet Transform (CWT) and Matching (MPM) Pursuit Method are both effective methods. They can be used to extract and cluster the characteristics of the signals. By analysis and comparison, the two methods showed the advantages over traditional methods. Additionally, their respective merits and demerits are indicated.

Generalized blind delayed source separation model for online non-invasive twin-fetal sound separation: a phantom study

The fetal phonocardiogram, which is the acoustic recording of mechanical activity of the fetal heart, facilitates the measurement of the instantaneous fetal heart rate, beat-to-beat differences and duration of systolic and diastolic phases. These measures are sensitive indicators of cardiac function, reflecting fetal well-being. This paper provides an algorithm to non-invasively estimate the phonocardiogram of an individual fetus in a multiple fetus pregnancy. A mixture of fetal phonocardiograms is modeled by a generalized pure delayed mixing model. Mutual independence of fetal phonocardiograms is assumed to apply blind source separation based techniques to extract the fetal phonocardiograms from their mixtures. The performance of the algorithm is verified through simulation results and on experimental data obtained from a phantom that is used to simulate a twin pregnancy.

First heart sound and opening snap in patients with mitral valve disease. Phonocardiographic and pathomorphologic study

We investigated correlation between mitral valve morphology and first heart sound (S(1)) and opening snap (OS) amplitude. The analysis revealed negative correlation between the OS amplitude and the area of calcification and the mitral orifice area. We also found negative correlation between the S(1) intensity and the area of calcification.

The third heart sound for diagnosis of acute heart failure

Dyspnea is a common presenting complaint in the emergency department (ED). Rapid identification of heart failure as the etiology leads to early implementation of targeted therapies. Although having only intermediate sensitivity, the S3 is a highly specific finding among older adults with heart failure. Identification of an S3 by routine auscultation can be problematic given the chaotic and noisy ED environment, patient comorbid conditions, and intolerance of ideal positioning for auscultation. Technologies using computerized analysis of digitally recorded heart tones have recently been developed to aid the clinician with bedside detection of abnormal heart sounds. Data using these technologies and their applications in the ED are reviewed as well as implications for future use and research.

Computerized acoustic cardiographic insights into the pericardial knock in constrictive pericarditis

BACKGROUND

One of the clinical hallmarks of constrictive pericarditis is the pericardial knock, a high-pitched early diastolic heart sound. Making the clinical diagnosis of constrictive pericarditis is challenging, as is accurate auscultation of the pericardial knock.

HYPOTHESIS

We sought to assess the utility of a computerized acoustic cardiographic device in the assessment of the pericardial knock in patients with constrictive pericarditis.

METHODS

We report a case series in which computerized acoustic cardiography (Audicor, Inovise Medical Inc., Portland, OR) is performed in patients with constrictive pericarditis.

RESULTS

Three patients with constrictive pericarditis underwent computerized acoustic cardiographic recordings at the time of cardiac catheterization. In each case, initial physical examination by the internist and referring cardiologist did not appreciate a pericardial knock. Acoustic cardiography demonstrated a high-pitched early diastolic sound in each case. Time-frequency representation analyses showed the high-frequency components of the pericardial knock sound. Repeat acoustic cardiography demonstrated resolution of the pericardial knock after pericardiectomy in two patients.

CONCLUSIONS

Non-invasive computerized acoustic cardiography can demonstrate the high-pitched pericardial knock in patients with constrictive pericarditis. This may aid the bedside assessment of patients with diastolic heart failure, improving the clinician's ability to appreciate the ausculatory findings in constrictive pericarditis.

Relationship between cardio-ankle vascular index (CAVI) and carotid atherosclerosis in patients with essential hypertension

Aortic stiffness measured by aorta-iliac or carotid-femoral pulse wave velocity (PWV) predicts all-cause and cardiovascular mortality. Brachial-ankle PWV (baPWV) has been developed as a more convenient assessment of arterial stiffness. However, the problem with clinical use of baPWV is that the index itself is closely dependent on blood pressure. Recently, a new method, termed the cardio-ankle vascular index (CAVI), has been proposed in Japan to overcome the disadvantages associated with measuring PWV. However, its clinical usefulness has not yet been fully clarified. In the present study, we compared the usefulness of CAVI with that of ultrasound for evaluating atherosclerosis in patients with essential hypertension. CAVI was measured in 70 hypertensive patients. The intima-media thickness (IMT), cross-sectional distensibility coefficient (CSDC), stiffness parameter beta, and mean diastolic (V(d)) and systolic (V(s)) flow velocities were evaluated by carotid ultrasound. The V(d)/V(s) ratio, an index of peripheral arterial resistance, was also calculated. CAVI was positively correlated with IMT (r=0.360, p=0.0022) and stiffness beta (r=0.270, p=0.0239) and negatively correlated with V(d)/V(s) (r=-0.471, p<0.0001) and CSDC (r=-0.315, p=0.0079). Stepwise regression analysis revealed that age (r=0.475, p<0.0001) and pulse pressure (r=0.492, r<0.0001) were independent determinants of CAVI. These results suggest that CAVI is a useful clinical marker for evaluating atherosclerosis and arteriolosclerosis in patients with essential hypertension.

Detection of cardiac pathology: time intervals and spectral analysis

AIM

To develop an objective diagnostic method that facilitates detection of noncyanotic congenital heart diseases.

METHODS

Heart sounds and murmurs were recorded from 60 healthy children and 173 children with noncyanotic congenital heart disease. Time intervals were measured and spectrum of the systolic murmurs analyzed. Stepwise logistic regression analysis was used to distinguish physiological from pathological signals. The receiver operating characteristic (ROC) curve was plotted to show the classification performance of the model and the area under the curve (AUC) was calculated. The probability cut-off points for calculation of sensitivities and specificities were estimated.

RESULTS

The distinguishing variables were the interval from the end of the first heart sound (S(1)) and the beginning of the systolic murmur, respiratory variation of the splitting of the second heart sound, intensity of the systolic murmur, and standard deviation of the interval from the end of the S(1) to the maximum intensity of the murmur. The AUC was 0.95, indicating an excellent classification performance of the model. The sensitivity of 95% and specificity of 72% was achieved at a probability cut-off point of 0.45. Significant cardiac defects were correctly classified.

CONCLUSION

Interval measurements and spectral analysis can be used to confirm significant noncyanotic congenital heart diseases. Further development of the method is necessary to detect also insignificant heart defects.

Systolic Dysfunction: Correlation of Acoustic Cardiography With Doppler Echocardiography

For detection of left ventricular (LV) systolic dysfunction in the outpatient setting, simultaneous electrocardiographic and heart sound data have been shown to be helpful. In 161 patients with suspected or known cardiac disease, echocardiography and acoustic cardiography were performed. Acoustic cardiographic parameters correlated to echocardiography included: presence or absence of S3, electromechanical activation time (EMAT), LV systolic time (LVST), and EMAT/LVST. LV ejection fraction was >or=50% in 82 patients (S3 present in 9.8%) and <50% in 79 patients (S3 present in 30.4%; the <50% group also had a greater EMAT, EMAT/LVST, and lower mean LVST [p<0.05]). Patients with an S3 had a lower ejection fraction, larger mean left atrial and LV dimensions, and an increased proportion of diastolic dysfunction. Acoustic cardiography allows reliable detection of the S3, which correlates with echocardiographic evidence of impaired LV function, and the EMAT/LVST ratio reflects reduced ejection fraction, providing an affordable, accessible means to assess LV dysfunction in the outpatient setting.

Optimization of Cardiac Resynchronization Devices Using Acoustic Cardiography: A Comparison to Echocardiography

Optimization of pacemaker settings for cardiac resynchronization therapy (CRT) remains challenging and problematic. Several noninvasive methods are offered to customize the programmed parameters for individual patients, but so far only echocardiographic imaging has established itself as an accepted method. The authors examined the value of acoustic cardiography as a fast and more cost-efficient alternative to established echocardiographic imaging techniques for the optimization of CRT devices. The atrioventricular delay in 22 subjects with implanted CRT devices was independently optimized using echocardiography (Doppler transmitral flow) as well as acoustic cardiography, and the recommended settings from each method were later compared. Doppler echocardiography and acoustic cardiography recommendations matched within a mean value +/- SD of 17+/-16 milliseconds and gave a correlation coefficient of r=0.90 (p<0.001). In 17 of the 22 cases (77.3%), the difference between echocardiographic and acoustic cardiogram CRT optimization results was <or=20 milliseconds. Furthermore, the echocardiographic transmitral flow pattern was not significantly different for the setting independently chosen by the echocardiographic expert and the acoustic cardiographer for the cases with a difference of >20 milliseconds (22.7%). In addition, it took less time for the acoustic cardiogram to collect sufficient information to make a recommendation, and it was found that the acoustic cardiogram data trend is easier to interpret.

Diagnostic characteristics of combining phonocardiographic third heart sound and systolic time intervals for the prediction of left ventricular dysfunction

BACKGROUND

The third heart sound (S3) and systolic time intervals (STIs) are validated clinical indicators of left ventricular (LV) dysfunction. We investigated the test characteristics of a combined score summarizing S3 and STI results for predicting LV dysfunction.

METHODS AND RESULTS

A total of 81 adults underwent computerized phonelectrocardiography for S3 and STI (Audicor, Inovise Medical Inc), cardiac catheterization for LV end-diastolic pressure (LVEDP), echocardiography for LV ejection fraction (LVEF), and B-type natriuretic peptide (BNP) testing. LV dysfunction was defined as both an LVEDP >15 mm Hg and LVEF <50%. The STI measured was the electromechanical activation time (EMAT) divided by LV systolic time (LVST). Z-scores for the S3 confidence score and EMAT/LVST were summed to generate the LV dysfunction index. The LV dysfunction index had a correlation coefficient of 0.38 for LVEDP (P = .0003), -0.53 for LVEF (P < .0001), and 0.35 for BNP (P = .0008). This index had a receiver operative curve c-statistic of 0.89 for diagnosis of LV dysfunction; a cutoff >1.87 yielded 72% sensitivity, 92% specificity, 9.0 positive likelihood ratio, and 88% accuracy.

CONCLUSIONS

In this preliminary study, the LV dysfunction index combined S3 and STI data from noninvasive electrophonocardiography, and yielded superior test characteristics compared to the individual tests for the diagnosis of LV dysfunction.

Wavelet-based segmentation and feature extraction of heart sounds for intelligent PDA-based phonocardiography

OBJECTIVES

Many pathological conditions of the cardiovascular system cause murmurs and aberrations in heart sounds. Phonocardiography provides the clinician with a complementary tool to record the heart sounds heard during auscultation. The advancement of intracardiac phonocardiography combined with modern digital signal processing techniques has strongly renewed researchers' interest in studying heart sounds and murmurs. The aim of this work is to investigate the applicability of different spectral analysis methods to heart sound signals and explore their suitability for PDA-based implementation.

METHODS

Fourier transform (FT), short-time Fourier transform (STFT) and wavelet transform (WT) are used to perform spectral analysis on heart sounds. A segmentation algorithm based on Shannon energy is used to differentiate between first and second heart sounds. Then wavelet transform is deployed again to extract 64 features of heart sounds.

RESULTS

The FT provides valuable frequency information but the timing information is lost during the transformation process. The STFT or spectrogram provides valuable time-frequency information but there is a trade-off between time and frequency resolution. Wavelet analysis, however, does not suffer from limitations of the STFT and provides adequate time and frequency resolution to accurately characterize the normal and pathological heart sounds.

CONCLUSIONS

The results show that the wavelet-based segmentation algorithm is quite effective in localizing the important components of both normal and abnormal heart sounds. They also demonstrate that wavelet-based feature extraction provides suitable feature vectors which are clearly differentiable and useful for automatic classification of heart sounds.

[Heart sound recognition algorithm based on PNN for evaluating cardiac contractility change trend]

This paper discusses the recognition of heart sound for evaluating the cardiac contractility change trend, which includes heart sound samples recorded at different exercise condition. Especially, focused on the recognition of heart sound recorded after high intensity exercise workload. The algorithm proposed consisted of two correlative methods. The first was to recognize heart sound recorded at rest and after low intensity exercise workloads by probabilistic neural network and the second was to recognize heart sound recorded after high intensity exercise workloads based on the characteristic of heart sound. Both methods have two consecutive phases. Firstly, all peaks, including the peaks of both heart sounds and noise, are marked by a repetitive threshold detecting algorithm. Secondly, probabilistic neural network is employed to classify the peaks detected in the first phase into Si, S2, and noise. Finally, the performance of the algorithm was evaluated using 45 digital heart sound recordings including normal and abnormal heart sound, which were recorded at rest and after low intensity exercise workloads, and 28 digital heart sound recordings recorded after high intensity exercise workloads. The results showed that over 94% of heart sound samples were classified and recognized correctly. Moreover, the reasons for the wrong classification, of which omitting and misdetection are two main problems, are also discussed and solutions are proposed. So this method can be improved and refined in following studies. In conclusion, this algorithm is a reliable approach to detect and classify heart sounds, providing a solid basis for further heart sound analysis.

[Cardiovascular syphilis: diagnosis, treatment]

Cardiovascular tertiary syphilis may lead to aortitis, aortic aneurism, coronary stenosis, aortic insufficiency and, rarely, to myocarditis. The physician must be familiar with the clinical presentations of this process, including the asymptomatic variety and must be able to have an organized plan for the diagnosis and evaluation to establish or exclude the presence of cardiovascular pathology and the differential diagnosis with other entities. Once the etiologic and topographic diagnosis is established, the patient should be treated with penicillin, doxicycline and other antibiotics, and the consequences of the disorder, both actual and potential, should be considered before deciding weather to recommend surgical intervention. Although late syphilis can be prevented by appropriate therapy of early syphilis, this is a cardiovascular disease that most likely will continue to be diagnosed lately. Understanding of the pathology and pathophysiology of the disease, is most important for its prompt recognition and subsequent management. This paper reviews the natural history, diagnosis and therapy of cardiovascular syphilis.

Analysis and study of the variation of splitting in the second heartbeat sound of wavelet transform

The second heart sound, S2, consists of two acoustic components, A2 and P2. The former is due to the closure of the aortic valve and the latter is due to the closure of the pulmonary valve. The aortic valve usually closes before the pulmonary valve, introducing a time delay known as the 'split'. A technique based on discrete wavelet transform (DWT) and continuous wavelet transform (CWT) is developed in this paper to measure the split. To quantify splitting, two components in S2 (i.e. A2 and P2) are identified, and the delay between the two components can be estimated. One normal case and three pathological cases (mitral stenosis, pulmonary stenosis and atrial septal defect) are considered in this study. The split is measured for each S2 sound of the considered signals. The split normally varies in duration over the cardiac cycle. In certain pathologies such as ASD (atrial septal defect) or PS (pulmonary stenosis), the split becomes fixed over the cardiac cycle. The main part of this paper consists of the identification and measurement of the S2 split. The study confirms the notion of 'variable splitting' for normal phonocardiogram and 'fixed splitting' for ASD and PS cases. This paper relates also to the establishment of statistical parameters to make a distinction between normal and pathological cases of phonocardiogram signals.

Occasional single beat regurgitation observed with the medtronic advantage bileaflet heart valve

BACKGROUND

The purpose of this clinical study was to obtain further evidence of the underlying mechanism causing the echocardiographically detected phenomenon of single beat regurgitation in a new bileaflet heart valve. As part of a prospective multicenter trial at our institution, 63 patients received the Advantage bileaflet mechanical heart valve (Medtronic, Minneapolis, Minnesota) in aortic position. During routine follow-up performed at discharge and annually after the operation, intermittent moderate transvalvular regurgitation was detected by echocardiography in 5 patients.

METHODS

Fluoroscopy of leaflet motion (n = 4), invasive blood pressure measurements in the ascending aorta (n = 3) and digital phonocardiography (n = 5) was obtained in the patients showing an intermittent regurgitation during echocardiography.

RESULTS

Valve thrombosis, sutures, or pannus ingrowth impairing valve closure was not detected. Fluoroscopy of leaflet motion showed intermittent incomplete closure of either one of the two leaflets in the same prosthesis. This could be correlated with a distinct diastolic blood pressure drop in the same cardiac cycle. Digital phonocardiography showed pathologic closure sounds in those cycles in which echocardiographically the intermittent regurgitation was observed.

CONCLUSIONS

Some patients with the Medtronic Advantage prosthesis in the aortic position show an intermittent inability of complete valve closure that leads to a single beat transvalvular regurgitation. As thrombotic or other material that might cause a disturbance of leaflet motion could not be detected, and the patients seem not to be exposed to any risk except for some chronic regurgitant volume, we decided not to replace the prostheses.