Teaching cardiac auscultation: effectiveness of a patient-centered teaching conference on improving cardiac auscultatory skills

Onset of new diastolic murmur as a sign of bioprosthetic valve dysfunction: A case report

The diagnosis of prosthetic valve dysfunction remains challenging because visualization is limited due to artifacts on echocardiography. We herein report a case of bioprosthetic valve dysfunction, in which cardiac auscultation was useful as an initial clue to the diagnosis. An 81-year-old man, who had undergone bioprosthetic aortic valve replacement due to aortic stenosis 10 years earlier, presented to the emergency department with chest discomfort. Cardiac auscultation revealed a newly developed diastolic murmur, although no diastolic murmurs were previously detected on auscultation or phonocardiography. There were no notable changes in electrocardiography, chest radiograph, laboratory tests, or echocardiography except for trivial aortic regurgitation. His hemodynamic status progressively deteriorated due to prosthetic valve dysfunction, which was later confirmed on echocardiography, and aortic valve re-replacement was semi-urgently performed with success. The diastolic murmurs disappeared after surgery. <Learning objective: This case once again highlights the importance of cardiac auscultation for diagnosis even with the use of advanced imaging technology.>.

Simulation-based mastery learning in medical students: Skill retention at 1-year follow up

Context: Deficits in basic skill performance and long-term skill retention among medical students and novice doctors are a persistent problem. This controlled study tested whether the addition of a mastery learning component to simulation-based teaching is associated with long-term retention and performance of peripheral venous catheter insertion. Methods: Fourth-year medical students were assigned to receive either the control (simulation without mastery learning, n = 131) or the intervention (simulation + mastery learning, n = 133) instruction in peripheral venous catheter insertion. Performance was assessed at one year post-instruction. Eighty-four students from the control group and 71 from the intervention group participated in the assessment. Results: Students who received the mastery learning instruction achieved higher overall test scores than did controls (median mastery learning score: 20.0, IQR 2.0; median control score 19.0, IQR 3.0; Mann-Whitney U test, p < 0.001, effect size d = 0.82). Pass rates also differed significantly between the groups, with 74.5% (n = 53) of the intervention group passing compared with 33% (n = 28) of the control group (p < 0.001). Conclusions: Mastery learning is an effective means of teaching practical skills to medical students, and is associated with higher scores at a 1-year follow up.

Effect of Psychoacoustic Learning on Cardiac Auscultation Proficiency in Nurse Practitioner Students

BACKGROUND

Assessment is a vital role of all nurses, yet cardiac murmur identification remains difficult for students. Cardiac auscultation is a technical, not intellectual, skill, and a psychoacoustic approach to learning is recommended. A psychoacoustic approach involves repetition of cardiac sounds to facilitate auditory perceptual learning.

PURPOSE

The purpose of this study was to determine the effectiveness of a psychoacoustic learning modality for identification of cardiac murmurs by nurse practitioner (NP) students.

METHODS

A repeated-measures design was used. Following a pretest, NP students listened to repetitions of heart sounds, then took a posttest. Students were instructed to listen to the heart sounds weekly, then given posttests at 1 and 3 months.

RESULTS

All posttest scores were higher than pretest scores; no significant difference in scores was noted between posttests.

CONCLUSIONS

Psychoacoustic learning may improve cardiac assessment. Further research is recommended with prelicensure nursing and NP students.

Digital devices for teaching cardiac auscultation - a randomized pilot study

BACKGROUND

Competent cardiac auscultation is a declining skill. Digital stethoscopes and hand-held echocardiography (HHE) are modern devices which may improve the accuracy of heart murmur recognition and diagnosis. Their incremental value compared to conventional examination has not been evaluated in depth.

OBJECTIVES

Our aim was to quantify the utility of digital stethoscopes and HHE as teaching aids to improve medical students' diagnostic accuracy in the evaluation of heart murmurs using a novel clinically weighted scoring system.

DESIGN

This pilot study involved eight medical students and eight patients with heart murmurs. Four patients were examined at 2 sessions, 1 week apart. Medical students were randomised into two groups: the 'intervention group' examined patients with a standard and digital stethoscope, and then received demonstration of the valvular lesion with HHE to illustrate the diagnosis. The 'control group' used a standard stethoscope only and were taught using traditional methods. Students' scores were compared to a 'gold standard' derived from a consensus of auscultation findings of three cardiologists.

RESULTS

Overall the mean percent correct of total possible score was 65.4% (SD8.4). Using a mixed models ANOVA approach to repeated measures, the mean [95% CI] increase from training to validation period for the control group was 2.5% [-11.5, 16.5] P(Tukey) = 0.95 and 15.8% [1.7,29.8] P(Tukey) = 0.027 for the intervention group. Between the validation and training sessions for both groups, there was an increase of 9.1% [1.82, 16.4] in scores (p = 0.018). The mean [95% CI] difference in scores of the control and intervention groups was 1.9% [-5.4, 9.2] (p = 0.59). The Cohen's effect size estimate was 0.9.

CONCLUSION

Digital stethoscopes and hand-held echo may be useful devices for teaching cardiac auscultation. This pilot study provides a novel study design, a heart murmur grading system, and data that will help develop definitive studies to assess new teaching techniques for cardiac auscultation using digital technology.

Third and Fourth Heart Sounds and Myocardial Fibrosis in Hypertrophic Cardiomyopathy

BACKGROUND

The 4th heart sound (S4) is commonly heard in patients with hypertrophic cardiomyopathy (HCM). The 3rd heart sound (S3) is also audible in HCM patients regardless of the presence or absence of heart failure. These extra heart sounds may be associated with myocardial fibrosis because myocardial fibrosis has been suggested to affect left ventricular compliance.Methods and Results:The present retrospective study evaluated 53 consecutive HCM patients with sinus rhythm who had no symptoms of heart failure and underwent an initial assessment including phonocardiography, echocardiography, and late gadolinium enhancement (LGE) magnetic resonance imaging (MRI). S3 was detected on phonocardiography in 13% of all patients, and S4 was recorded in 75% of patients. Patients with S3 had a higher incidence of LGE and larger LGE volumes (86% and 11.5±2.4 g/cm, respectively) than patients without S3 (33% and 2.5±0.8 g/cm, respectively; P=0.02 and P=0.002). The presence of S4 was not associated with MRI findings, including the incidence of LGE and LGE volume. The diagnostic value of S3 for the detection of LGE was highly specific (97%), with a low sensitivity (29%).

CONCLUSIONS

Myocardial fibrosis, as assessed by LGE, was associated with S3 but not with S4 in patients with HCM. These results may contribute to the risk stratification of patients with HCM.

Development of a Smartphone App for Visualizing Heart Sounds and Murmurs

BACKGROUND

Auscultation is one of the basic techniques for the diagnosis of heart disease. However, the interpretation of heart sounds and murmurs is a highly subjective and difficult skill.

OBJECTIVES

To assist the auscultation skill at the bedside, a handy phonocardiogram was developed using a smartphone (Samsung Galaxy J, Android OS 4.4.2) and an external microphone attached to a stethoscope.

METHODS AND RESULTS

The Android app used Java classes, "AudioRecord," "AudioTrack," and "View," that recorded sounds, replayed sounds, and plotted sound waves, respectively. Sound waves were visualized in real-time, simultaneously replayed on the smartphone, and saved to WAV files. To confirm the availability of the app, 26 kinds of heart sounds and murmurs sounded on a human patient simulator were recorded using three different methods: a bell-type stethoscope, a diaphragm-type stethoscope, and a direct external microphone without a stethoscope. The recorded waveforms were subjectively confirmed and were found to be similar to the reference waveforms.

CONCLUSIONS

The real-time visualization of the sound waves on the smartphone may help novices to readily recognize and learn to distinguish the various heart sounds and murmurs in real-time.

Mastery learning improves students skills in inserting intravenous access: a pre-post-study

OBJECTIVE

Inserting peripheral venous catheters (PVCs) has been identified as a core competency for medical students. Because the performance - even of hygienic standards - of both students and novice physicians is frequently inadequate, medical faculties must focus on competence-based learning objectives and deliberate practice, features that are combined in mastery learning. Our aim was to determine the competency of students in inserting PVCs before and after an educational intervention.

DESIGN

This study comprised a skills assessment with pre- and post-tests of a group of third-year students who received a simulation-based intervention. A newly established curriculum involved one hour of practice at inserting PVCs on simulators. Students were required to pass a test (total 21 points, pass mark 20 points) developed on the concept of mastery learning. An unannounced follow-up test was performed one week (8 days) after the intervention.

SETTING

The simulation center of the medical faculty in Muenster.

PARTICIPANTS

Third-year students who received the intervention.

RESULTS

One hundred and nine complete data sets were obtained from 133 students (82.5%). Most students (97.2%) passed the test after the intervention (mean score increase from 15.56 to 20.50, P<0.001). There was a significant decrease in students' performance after one week (8 days): only 74.5% of participants passed this retest (mean score reduction from 20.50 to 20.06, P<0.001).

CONCLUSION

Mastery learning is an effective form of teaching practical skills to medical students, allowing a thorough preparation for the challenges of daily clinical practice.

International trial of online auditory training programme for distinguishing innocent and pathological murmurs

AIM

Recognition of normal and abnormal heart sounds and murmurs is an important but declining clinical skill among practitioners. Current teaching methods are often ineffective. This may result from inadequate repetition and normal-abnormal comparisons needed for auditory recognition. This paper describes a rapid new method of teaching murmur recognition using principles of auditory training.

METHODS

Participants were 120 Australian and 42 Canadian medical students. The medical students were randomised to intervention and control (no intervention) groups. The 1-h online programme structured like a computer game used auditory training methodology to teach students to distinguish between innocent and pathological murmurs. Participants underwent pre- and post-testing on 20 paediatric murmurs. Post-testing occurred immediately following training and after 2 months. Twenty-two Canadian medical students were retested 1 year later with a brief mastery-style reinforcement programme.

RESULTS

Median pre- and post-test scores improved in about 1 h from 75-95% (P < 0.001) for Australian students and 85-95% (P = 0.004) for Canadian students. Two-month post-test scores declined for Australian students to 85% (P = 0.001), and for Canadian students to 85% (P = 0.02). Australian controls had no significant change during the study period, whereas Canadian controls improved slightly. The group receiving reinforcement after 1 year had a median final score of 90%.

CONCLUSIONS

This auditory training programme rapidly teaches students to distinguish innocent and pathological murmurs with at least 90% accuracy. The skill declines within 2 months but can be restored with brief mastery reinforcement 1 year later.

Combining simulated patients and simulators: pilot study of hybrid simulation in teaching cardiac auscultation

Auscultation torsos are widely used to teach position-dependent heart sounds and murmurs. To provide a more realistic teaching experience, both whole body auscultation mannequins and torsos have been used in clinical examination skills training at the Medical Faculty of the University of Muenster since the winter term of 2008-2009. This training has since been extended by simulated patients, which are normal, healthy subjects who have undergone attachment of the electronic components of the auscultation mannequins to their chests to mimic pathophysiological conditions ("hybrid models"). The acceptance of this new learning method was examined in the present pilot study. In total, 143 students in their second preclinical year who were participating in auscultation training were randomized into an intervention group (hybrid models) and a control group (auscultation mannequins). One hundred forty-two (99.3%) of these students completed a self-assessment Likert-scale questionnaire regarding different teaching approaches (where 1 = "very poor" to 100 = "very good"). The questionnaire focused on the "value of learning" of different teaching approaches. Direct comparison showed that students evaluated the hybrid models to be significantly more effective than the auscultation mannequins (median: 83 vs. 64, P < 0.001). The cardiac auscultation training was generally assessed positively (median: 88). Additionally, verbal feedback was obtained from simulated patients and tutors (trained students who had successfully passed the course a few semesters earlier). Personal feedback showed high satisfaction from student tutors and simulated patients. Hybrid simulators for teaching cardiac auscultation elucidated positive responses from students, tutors, and simulated patients.

Simulation-guided cardiac auscultation improves medical students' clinical skills: the Pavia pilot experience

Clinical evaluation is the cornerstone of any cardiac diagnosis, although excessive over-specialisation often leads students to disregard the value of clinical skills, and to overemphasize the approach to instrumental cardiac diagnosis. Time restraints, low availability of "typical" cardiac patients on whom to perform effective bedside teaching, patients' respect and the underscoring of the value of clinical skills all lead to a progressive decay in teaching. Simulation-guided cardiac auscultation may improve clinical training in medical students and residents. Harvey(©) is a mannequin encompassing more than 50 cardiac diagnoses that was designed and developed at the University of Miami (Florida, USA). One of the advantages of Harvey(©) simulation resides in the possibility of listening, comparing and discussing "real" murmurs. To objectively assess its teaching performance, the capability to identify five different cardiac diagnoses (atrial septal defect, normal young subject, mitral stenosis with tricuspid regurgitation, chronic mitral regurgitation, and pericarditis) out of more than 50 diagnostic possibilities was assessed in 523 III-year medical students (i.e. at the very beginning of their clinical experience), in 92 VI-year students, and in 42 residents before and after a formal 10-h teaching session with Harvey(©). None of them had previously experienced simulation-based cardiac auscultation in addition to formal lecturing (all three groups) and bedside teaching (VI-year students and residents). In order to assess the "persistence" of the acquired knowledge over time, the test was repeated after 3 years in 85 students, who did not repeat the formal 10-h teaching session with Harvey(©) after the III year. As expected, the overall response was poor in the "beginners" who correctly identified 11.0 % of the administered cardiac murmurs. After simulation-guided training, the ability to recognise the correct cardiac diagnoses was much better (72.0 %; p < 0.001 vs. baseline). Rather unexpectedly, before the tutorial, the performance of VI-year students and of residents was not significantly different from their III-year colleagues, since the two groups correctly identified 14.2 and 16.2 % of the diagnoses, respectively. After the tutorial, the VI-year students and the residents also improved their overall performance (to 73.1 and 76.1 %, respectively; p < 0.001 for both when compared to before the tutorial). The persistence of this capability after 3 years was remarkable, since the 85 students who repeated the test without any further exposure to the 10-h teaching session with Harvey(©) correctly identified 68.4 % of the possible cardiac diagnoses (p < 0.001 vs. baseline). These data underscore the importance of clinical training in order to improve auscultation skills in our academic setting, prompting to redesign teaching curricula. Simulation-based cardiac auscultation should be considered as the "missing link" between formal lecturing and bedside teaching of heart sounds and murmurs.

Self-directed study using MP3 players to improve auscultation proficiency of physicians: a randomized, controlled trial

INTRODUCTION

Studies of physicians at all levels of training demonstrate significant deficiencies in cardiac auscultation skills. The best instructional methods to augment these skills are not known.

METHODS

This study was a randomized, controlled trial of 83 noncardiologist volunteers exposed to a 12-week lower cognitive load self-study group using MP3 players containing heart sound audio files compared to a group receiving a 1-time 1-hour higher cognitive load multimedia lecture using the same audio files. The primary outcome measure was change in 15-question posttest score at 4 and 12 weeks as compared to pretest on recognition of identical audio files introduced during training. In the self-study group, the association of total exposure and deliberate practice effort (estimated by standard deviation of files played/mean) to improvement in test score was measured as a secondary end point.

RESULTS

Self-study group participants improved as compared to pretest by 4.42 ± 3.41 answers correct at 12 weeks (5.09-9.51 correct, p < .001), while those exposed to the multimedia lecture improved by an average of 1.13 ± 3.2 answers correct (4.48-5.61 correct, p = .03). In the self-study arm, improvement in the posttest was positively associated with both total exposure (β = 0.55, p < .001) and deliberate practice score (β = 0.31, p = .02).

DISCUSSION

A lower cognitive load self-study of audio files improved recognition of cardiac sounds, as compared to multimedia lecture, and deliberate practice strategies improved study efficiency. More investigation is needed to assess transfer of learning to a wider range of cardiac sounds in both simulated and clinical environments.

Looking is not seeing and listening is not hearing: effect of an intervention to enhance auditory skills of graduate-entry nursing students

Inspection/observation and listening/auscultation are essential skills for health care providers. Given that observational and auditory skills take time to perfect, there is concern about accelerated students' ability to attain proficiency in a timely manner. This article describes the impact of music auditory training (MAT) for nursing students in an accelerated master's entry program on their competence in detecting heart, lung, and bowel sounds. During the first semester, a two-hour MAT session with focused attention on pitch, timbre, rhythm, and masking was held for the intervention group; a control group received traditional instruction only. Students in the music intervention group demonstrated significant improvement in hearing bowel, heart, and lung sounds (p < .0001). The ability to label normal and abnormal heart sounds doubled; interpretation of normal and abnormal lung sounds improved by 50 percent; and bowel sounds interpretation improved threefold, demonstrating the effect of an adult-oriented, creative, yet practical method for teaching auscultation.

Experienced clinicians improve detection of third and fourth heart sounds by viewing acoustic cardiography

BACKGROUND

Clinical assessment of diastolic heart sounds is challenging.

HYPOTHESIS

We sought to examine whether visual inspection of acoustic cardiographic tracings augments the accuracy of medical students' and physicians' detection of third and fourth heart sounds (S(3), S(4)) compared to auscultation alone.

METHODS

A total of 90 adults referred for left heart catheterization underwent digital precordial heart sound recordings by computerized acoustic cardiography. Two blinded, experienced readers using a consensus method determined the presence of the S(3)/S(4) on each file. There were 35 subjects from the following 5 groups participating in this study from 1 teaching institution: first-year medical students (n = 5), fourth-year medical students (n = 5), interns (n = 5), medicine residents (n = 5), cardiology fellows (n = 5), and attendings (n = 10). Using a computer module, each subject listened to the heart sounds alone and documented whether an S(3)/S(4) was present. Next, subjects listened to each recording in random order while viewing phonocardiographic tracings, and recorded S(3)/S(4) presence.

RESULTS

An S(3) was present in 21 patients (23%) and an S(4) in 31 patients (34%) by consensus overread in 90 recordings. Baseline accuracy for auscultation of S(3)/S(4) did not change with level of experience. While viewing the acoustic cardiogram, first-year medical students had minimal improvement in S(3) (2%) and S(4) (11%) accuracy. More experienced subjects improved S(3) accuracy by 8% to 18% and S(4) by 15% to 32% (P < .05). Accuracy was superior for S(3) compared to S(4) in all ausculatory groups.

CONCLUSIONS

While listening to heart sound recordings, viewing acoustic cardiography increased subjects' accuracy in detecting diastolic heart sounds, particularly among more experienced subjects. There was greater improvement for S(4) compared to S(3) detection.

Confidential testing of cardiac examination competency in cardiology and noncardiology faculty and trainees: a multicenter study

BACKGROUND

Many reported studies of medical trainees and physicians have demonstrated major deficiencies in correctly identifying heart sounds and murmurs, but cardiologists had not been tested. We previously confirmed these deficiencies using a 50-question multimedia cardiac examination (CE) test featuring video vignettes of patients with auscultatory and visible manifestations of cardiovascular pathology (virtual cardiac patients). Previous testing of 62 internal medical faculty yielded scores no better than those of medical students and residents.

HYPOTHESIS

In this study, we tested whether cardiologists outperformed other physicians in cardiac examination skills, and whether years in practice correlated with test performance.

METHODS

To obviate cardiologists' reluctance to be tested, the CE test was installed at 19 US teaching centers for confidential testing. Test scores and demographic data (training level, subspecialty, and years in practice) were uploaded to a secure database.

RESULTS

The 520 tests revealed mean scores (out of 100 ± 95% confidence interval) in descending order: 10 cardiology volunteer faculty (86.3 ± 8.0), 57 full-time cardiologists (82.0 ± 3.3), 4 private-practice cardiologists (77.0 ± 6.8), and 19 noncardiology faculty (67.3 ± 8.8). Trainees' scores in descending order: 150 cardiology fellows (77.3 ± 2.1), 78 medical students (63.7 ± 3.5), 95 internal medicine residents (62.7 ± 3.2), and 107 family medicine residents (59.2 ± 3.2). Faculty scores were higher in those trained earlier with longer practice experience.

CONCLUSIONS

Academic and volunteer cardiologists outperformed other medical faculty, as did cardiology fellows. Lower scores were observed in more recently trained faculty. Remote testing yielded scores similar to proctored tests in comparable groups previously studied. No significant improvement was seen after medical school with residency training.

Training auscultatory skills: computer simulated heart sounds or additional bedside training? A randomized trial on third-year medical students

BACKGROUND

The present study compares the value of additional use of computer simulated heart sounds, to conventional bedside auscultation training, on the cardiac auscultation skills of 3rd year medical students at Oslo University Medical School.

METHODS

In addition to their usual curriculum courses, groups of seven students each were randomized to receive four hours of additional auscultation training either employing a computer simulator system or adding on more conventional bedside training. Cardiac auscultation skills were afterwards tested using live patients. Each student gave a written description of the auscultation findings in four selected patients, and was rewarded from 0-10 points for each patient. Differences between the two study groups were evaluated using student's t-test.

RESULTS

At the auscultation test no significant difference in mean score was found between the students who had used additional computer based sound simulation compared to additional bedside training.

CONCLUSIONS

Students at an early stage of their cardiology training demonstrated equal performance of cardiac auscultation whether they had received an additional short auscultation course based on computer simulated training, or had had additional bedside training.

Cardiac physical diagnosis in the digital age: an important but increasingly neglected skill (from stethoscopes to microchips)

With the advent of readily available imaging modalities, the time-honored skills in physical examination of the cardiac patient have eroded and are no longer the hallmark of the expert cardiologist. Although auscultation continues to be the primary focus in the examination, this is a skill in which competency is only achieved through continuous exposure, and does not quantitate the physiologic status of the patient. Accuracy in the examination is best achieved by evaluating the physiologic variables that characterize cardiac function (pulse amplitude, blood pressure, jugular venous pressure, and makers of neurohumoral activation), and the identification of which cardiac chambers are involved using precordial motion and the electrocardiogram. Practical methods for the acquisition of these clinical observations are discussed. These clinical data are often more quantitative and easier to acquire for many clinicians than is proficiency in auscultation, and facilitate accurate diagnosis of cardiac conditions including murmur interpretation. In conclusion, even in the digital age, the physical examination remains uniquely relevant to patient care, particularly when focused on the physiologic status of the cardiac patent.

Heart sound and electrocardiogram recording devices for telemedicine environments

There is currently a worldwide trend to bring healthcare services as close as possible to the patient, either through home healthcare systems, or telemedicine. There is thus a general need for equipment that can capture patient data electronically for automated review or analysis by a medical practitioner. This paper presents prototype systems that were developed with the ultimate aim for use in telemedicine settings in rural Africa. These devices can be used to electronically capture data on patients from several sensors in a quick an easy manner. In our presented cases we focus on cardiovascular information. One of the main advantages of the proposed systems is that the data are captured simultaneously from multiple sensors. The data can be stored and sent electronically for review and analysis, and knowledge-based systems or neural network type models can be used in the future for semi-autonomous screening of the recordings, before a patient is referred to a specialist.

The prevalence of valvular abnormalities in patients who were referred for echocardiographic examination with a primary diagnosis of "heart murmur"

INTRODUCTION

The prevalence of valvular abnormality and innocent murmur in patients who are referred for echocardiographic evaluation with the diagnosis of "murmur" is not known. The goal of this study was to evaluate the prevalence of valvular abnormalities in such patients.

METHODS

We retrospectively reviewed the echocardiograms that were referred with the primary ordering diagnosis of "murmur," for the presence of valvular abnormalities. For comparison, we used other documented primary reasons for echocardiographic referral, such as chest pain, shortness of breath, etc.

RESULTS

In this cohort, 7,684 echocardiogram reports documented primary diagnostic reasons for echocardiographic referral. A total of 3,460 echocardiogram reports (45%) were coded "murmur" as the primary reason for the study referral. There was a higher prevalence of female patient referrals for heart murmur evaluation (61.8% vs. 38.2%). Although, patients with murmur had a higher prevalence of valvular abnormalities, compared to other reasons for echocardiographic examination, the prevalence of valvular abnormality was less than 50% (48.6% vs. 35.5%) in both groups. Despite the higher number of female patients referred with the diagnosis of murmur, the percentage of abnormal valves was lower in women (45.6% vs. 53.4% in men).

CONCLUSION

The prevalence of valvular abnormalities in patients who were referred with the diagnosis of murmur for echocardiographic examination was less than 50%, with a lesser degree found in women. Routine utilization of echocardiography for evaluation of all murmurs may be unwarranted.

Phono-spectrographic analysis of heart murmur in children

BACKGROUND

More than 90% of heart murmurs in children are innocent. Frequently the skills of the first examiner are not adequate to differentiate between innocent and pathological murmurs. Our goal was to evaluate the value of a simple and low-cost phonocardiographic recording and analysis system in determining the characteristic features of heart murmurs in children and in distinguishing innocent systolic murmurs from pathological.

METHODS

The system consisting of an electronic stethoscope and a multimedia laptop computer was used for the recording, monitoring and analysis of auscultation findings. The recorded sounds were examined graphically and numerically using combined phono-spectrograms. The data consisted of heart sound recordings from 807 pediatric patients, including 88 normal cases without any murmur, 447 innocent murmurs and 272 pathological murmurs. The phono-spectrographic features of heart murmurs were examined visually and numerically. From this database, 50 innocent vibratory murmurs, 25 innocent ejection murmurs and 50 easily confusable, mildly pathological systolic murmurs were selected to test whether quantitative phono-spectrographic analysis could be used as an accurate screening tool for systolic heart murmurs in children.

RESULTS

The phono-spectrograms of the most common innocent and pathological murmurs were presented as examples of the whole data set. Typically, innocent murmurs had lower frequencies (below 200 Hz) and a frequency spectrum with a more harmonic structure than pathological cases. Quantitative analysis revealed no significant differences in the duration of S1 and S2 or loudness of systolic murmurs between the pathological and physiological systolic murmurs. However, the pathological murmurs included both lower and higher frequencies than the physiological ones (p < 0.001 for both low and high frequency limits). If the systolic murmur contained intensive frequency components of over 200 Hz, or its length accounted for over 80 % of the whole systolic duration, it was considered pathological. Using these criteria, 90 % specificity and 91 % sensitivity in screening were achieved.

CONCLUSION

Phono-spectrographic analysis improves the accuracy of primary heart murmur evaluation and educates inexperienced listener. Using simple quantitative criterias a level of pediatric cardiologist is easily achieved in screening heart murmurs in children.

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.