Accuracy of cardiac auscultation in the era of Doppler-echocardiography: A comparison between cardiologists and internists

A call to consider an aortic stenosis screening program

Aortic stenosis (AS) is the most common age-related valvular condition with a prevalence of 13.1% in patients older than 75 years of age. Based on the severity of AS and symptoms, current guidelines recommend interval monitoring with transthoracic echocardiogram (TTE). However, no guidelines exist regarding screening asymptomatic persons for AS. Prevalence of AS is comparable to conditions such as colorectal cancer, lung cancer, breast cancer, and abdominal aortic aneurysm where dedicated screening programs are offered resulting in reduction of overall morbidity and mortality. We review recent advancements in treatment options, and we propose an AS screening program for high-risk individuals without known history of AS including all persons over age 75 and persons aged 70 years and older with dialysis dependent end-stage renal disease (ESRD).

Artificial Intelligence-Based Stethoscope for the Diagnosis of Aortic Stenosis

BACKGROUND

The diagnostic accuracy of the stethoscope is limited and highly dependent on clinical expertise. Our purpose was to develop an electronic stethoscope, based on artificial intelligence (AI) and infrasound, for the diagnosis of aortic stenosis (AS).

METHODS

We used an electronic stethoscope (VoqX; Sanolla, Nesher, Israel) with subsonic capabilities and acoustic range of 3-2000 Hz. The study had 2 stages. In the first stage, using the VoqX, we recorded heart sounds from 100 patients referred for echocardiography (derivation group), 50 with moderate or severe AS and 50 without valvular disease. An AI-based supervised learning model was applied to the auscultation data from the first 100 patients used for training, to construct a diagnostic algorithm that was then tested on a validation group (50 other patients, 25 with AS and 25 without AS). In the second stage, conducted at a different medical center, we tested the device on 106 additional patients referred for echocardiography, which included patients with other valvular diseases.

RESULTS

Using data collected at the aortic and pulmonic auscultation points from the derivation group, the AI-based algorithm identified moderate or severe AS with 86% sensitivity and 100% specificity. When applied to the validation group, the sensitivity was 84% and specificity 92%; and in the additional testing group, 90% and 84%, respectively. The sensitivity was 55% for mild, 76% for moderate, and 93% for severe AS.

CONCLUSION

Our initial findings show that an AI-based stethoscope with infrasound capabilities can accurately diagnose AS. AI-based electronic auscultation is a promising new tool for automatic screening and diagnosis of valvular heart disease.

Using Point-of-Care Ultrasound in Heart Failure Diagnosis and Management in Rural and Resource-Limited Settings

•RHD is a common cause of heart failure in sub-Saharan Africa. •Task shifting by training rural providers in POCUS improves cardiac imaging access. •POCUS in low-resource settings can determine presence of structural heart disease. •There are specific POCUS device considerations for use in low-resource settings. •POCUS use in rural low-resource settings can lead to early heart failure management.

S2 Heart Sound Detects Aortic Valve Calcification Independent of Hemodynamic Changes in Mice

Background

Calcific aortic valve disease (CAVD) is often undiagnosed in asymptomatic patients, especially in underserved populations. Although artificial intelligence has improved murmur detection in auscultation exams, murmur manifestation depends on hemodynamic factors that can be independent of aortic valve (AoV) calcium load and function. The aim of this study was to determine if the presence of AoV calcification directly influences the S2 heart sound.

Methods

Adult C57BL/6J mice were assigned to the following 12-week-long diets: (1) Control group (n = 11) fed a normal chow, (2) Adenine group (n = 4) fed an adenine-supplemented diet to induce chronic kidney disease (CKD), and (3) Adenine + HP (n = 9) group fed the CKD diet for 6 weeks, then supplemented with high phosphate (HP) for another 6 weeks to induce AoV calcification. Phonocardiograms, echocardiogram-based valvular function, and AoV calcification were assessed at endpoint.

Results

Mice on the Adenine + HP diet had detectable AoV calcification (9.28 ± 0.74% by volume). After segmentation and dimensionality reduction, S2 sounds were labeled based on the presence of disease: Healthy, CKD, or CKD + CAVD. The dataset (2,516 S2 sounds) was split subject-wise, and an ensemble learning-based algorithm was developed to classify S2 sound features. For external validation, the areas under the receiver operating characteristic curve of the algorithm to classify mice were 0.9940 for Healthy, 0.9717 for CKD, and 0.9593 for CKD + CAVD. The algorithm had a low misclassification performance of testing set S2 sounds (1.27% false positive, 1.99% false negative).

Conclusion

Our ensemble learning-based algorithm demonstrated the feasibility of using the S2 sound to detect the presence of AoV calcification. The S2 sound can be used as a marker to identify AoV calcification independent of hemodynamic changes observed in echocardiography.

Cardiac auscultation skills in final year veterinary students and recent veterinary graduates, referral hospital veterinary surgeons and veterinary cardiologists or cardiology residents

BACKGROUND

Cardiac auscultation is an important part of the physical examination. This study evaluated cardiac auscultation skills in veterinary students and compared their abilities to recent veterinary graduates, referral hospital veterinary surgeons and veterinary cardiologists or cardiology residents. In addition it compared their self-predicted quiz scores to their actual scores, evaluating if they could accurately predict their own performance level.

METHODS

A digital recording device was used to record auscultation sounds from 12 different patients with a diagnosis confirmed by a board-certified veterinary cardiologist. The sound files and associated phonocardiograms were uploaded to a video sharing website. A cloud-based online multiple-choice quiz was generated and shared with final year veterinary students, recent veterinary graduates, referral hospital veterinary surgeons and veterinary cardiologists or cardiology residents.

RESULTS

There were 128 participants: 51 final year veterinary students, 62 recent veterinary graduates, and 10 referral hospital veterinary surgeons and five veterinary cardiologists or cardiology residents. No difference was found between the cardiac auscultation skills of recent veterinary graduates and final year veterinary students. Veterinary students' self-predicted scores were lower than actual scores.

CONCLUSIONS

Recent veterinary graduates did not perform better than final year veterinary students in this study, suggesting that auscultation skills do not continue to improve in the first few years after graduation. Efforts should be made to maximise students' learning in cardiac auscultation skills. Veterinary students show a lack of confidence in cardiac auscultation skills.

Pre-participation Cardiovascular Screening in Young Competitive Athletes

Purpose of Review

The purpose of this review was to highlight the current recommendations, data, and limitations for methods of cardiovascular screening in athletes.

Recent Findings

While the history and physical (H&P) alone remains the cornerstone for preparticipation cardiovascular screening (PPCS) in athletes, the advent of modern electrocardiographic (ECG) screening criteria has drastically increased sensitivity and decreased false positive rates for screening. Advanced imaging techniques remain an important component of secondary testing after an athlete has an abnormal initial screening exam, however, the use of imaging for universal screening has not been rigorously tested to date. Current disqualification guidelines have now begun to emphasize shared decision making between the provider and athlete in situations of clinical equipoise.

Summary

All major medical and sporting societies recommend PPCS using a focused medical history and physical examination for all competitive athletes, but there remains controversy about the role of ECG and advanced imaging in PPCS. Future research should focus on the creation of a randomized trial that is powered for mortality that can truly assess the utility of PPCS in athletes.

Do 'pathologic' cardiac murmurs in adolescents identify structural heart disease? An evaluation of 15 141 active adolescents for conditions that put them at risk of sudden cardiac death

OBJECTIVES

We assessed whether the presence and character of a cardiac murmur in adolescents were associated with structural heart disease that confers risk of sudden cardiac death (SCD).

METHODS

We performed a retrospective analysis of 15 141 adolescents age 12-19 who underwent a heart screen with history, physical examination and ECG. Participants with any screening abnormality underwent an echocardiogram for the assessment of structural heart disease. Murmurs were classified as physiological or pathological according to standard clinical criteria, and participants with murmurs were compared with a comparison group without murmurs. The primary outcome was echocardiogram-detected structural heart disease associated with SCD.

RESULTS

905 participants with a cardiac murmur (mean age 15.8; 58% male) and 4333 participants without a murmur (comparison group; mean age 15.8; 55% male) had an echocardiogram to detect structural heart disease. 743 (82%) murmurs were described as physiological and 162 (18%) as pathological. Twenty-five (2.8%) participants with murmurs and 61 (1.4%) participants without murmurs had structural heart disease. Three (0.3%) participants in the murmur group were diagnosed with hypertrophic cardiomyopathy (HCM) which was the only identified condition associated with SCD. Two participants with HCM had physiological murmurs, one had a pathological murmur, and all three had an abnormal ECG. The most common minor structural heart disease was bicuspid aortic valve in both the murmur (7; 0.8%) and comparison (20; 0.5%) groups. The positive predictive value of physiological versus pathological murmurs for identifying any structural heart disease was 2.4% versus 4.3% (p=0.21), respectively. The positive predictive value of having any murmur versus no murmur for identifying structural heart disease was 2.8% versus 1.4% (p=0.003), respectively.

CONCLUSIONS

In adolescents, the traditional classification of cardiac murmurs as 'physiologic' or 'pathologic' does not differentiate for structural heart disease that puts individuals at risk for SCD. We recommend ECG evaluation in all patients with a cardiac murmur found during preparticipation screening to increase detection of HCM.

Point-of-care ultrasound: Closing guideline gaps in screening for valvular heart disease

BACKGROUND

A linear increase in the number of valvular heart disease is expected due to the aging population, yet most patients with severe valvular heart disease remain undiagnosed.

HYPOTHESIS

POCUS can serve as a screening tool for valvular heart disease.

METHODS

We reviewed the literature to assess the strengths and limitations of POCUS in screening and diagnosing valvular heart disease.

RESULTS

POCUS is an accurate, affordable, accessible, and comprehensive tool. It has a fast learning curve and can prevent unnecessary and more expensive imaging. Challenges include training availability, lack of simplified screening protocols, and reimbursement. Large scale valvular screening data utilizing POCUS is not available.

CONCLUSION

POCUS can serve as a screening tool and guide the management of patients with valvular heart disease. More data is needed about its efficacy and cost-effectiveness in the screening of patients with valvular heart disease.

Concurrent Validity of Digital Vascular Auscultation for the Assessment of Blood Flow Obliteration on the Radial Artery in Healthy Subjects

This study aimed to determine the validity of digital vascular auscultation for the assessment of changes in the radial pulse in healthy subjects, using Doppler sonography as a validated test referent. Sixty-one non-symptomatic subjects (mean age of 52.5 ± 16.1 years) were assigned and evaluated under one of the following conditions: In condition 1, blood flow of the radial artery was not modified; for condition 2, blood flow of the radial artery was modified using a pressure sleeve around the humerus. The radial pulse was then measured three times with each diagnostic tool by three different blinded evaluators. Both instruments demonstrated a high association between the identification of blood flow modifications or not and the assigned condition (p < 0.001). A strong concordance between the two devices when detecting the “changes” or “no changes” in blood flow was demonstrated (k = 0.936, p < 0.001). Stethoscope sensitivity was 95%, and specificity was 99%. In conclusion, digital vascular auscultation seems to be a valid technique to examine blood flow changes of the radial artery in non-symptomatic subjects, and it could be useful for physical therapists when combined with provocative tests for the screening of possible thoracic outlet syndrome in patients.

Accuracy and Efficacy of Hand-Held Echocardiography in Diagnosing Valve Disease: A Systematic Review

In recent years, advances in technology have enabled hand-held echocardiography (HHE) to generate high-quality 2-dimensional and color Doppler images. As these devices become smaller, simpler, and more affordable, the question of whether HHE can augment or replace auscultation as the primary mode of cardiovascular diagnosis has become increasingly more relevant. If widely implemented, HHE has the potential for significant cost savings and better resource utilization. This review examines studies comparing the sensitivities of auscultation, HHE, and standard echocardiography in detecting various valvular lesions and discusses why current evidence supports the use of HHE to augment the physical examination, which can lead to more reliable and rapid bedside diagnoses, triage, and appropriate treatment of structural cardiac abnormalities.

Cardiac auscultation poorly predicts the presence of valvular heart disease in asymptomatic primary care patients

Objective

Cardiac auscultation is a key clinical skill, particularly for the diagnosis of valvular heart disease (VHD). However, its utility has declined due to the widespread availability of echocardiography and diminishing emphasis on the importance of clinical examination. We aim to determine the contemporary accuracy of auscultation for diagnosing VHD in primary care.

Methods

Cardiac auscultation was undertaken by one of two experienced general practitioners (primary care/family doctors) in a subset of 251 asymptomatic participants aged >65 years undergoing echocardiography within a large community-based screening study of subjects with no known VHD. Investigators were blinded to the echocardiographic findings. Newly detected VHD was classified as mild (mild regurgitation of any valve or aortic sclerosis) or significant (at least moderate regurgitation or mild stenosis of any valve).

Results

Newly identified VHD was common, with mild disease in 170/251 participants (68%) and significant disease in 36/251 (14%). The sensitivity of auscultation was low for the diagnosis of mild VHD (32%) but slightly higher for significant VHD (44%), with specificities of 67% and 69%, respectively. Likelihood ratios were not statistically significant for the diagnosis of either mild or significant VHD in the overall cohort, but showed possible value for auscultation in non-overweight subjects (body mass index <25 kg/m2).

Conclusion

Cardiac auscultation has limited accuracy for the detection of VHD in asymptomatic patients and is a poor diagnostic screening tool in primary care, particularly for overweight subjects. Ensuring easy access to echocardiography in patients with symptoms suggesting VHD is likely to represent a better diagnostic strategy.

Misconceptions and Facts About Aortic Stenosis

Aortic stenosis is the most common valvular heart disease leading to intervention, and it is typically a disease of the elderly. Recent clinical advances have expanded the role of transcatheter aortic valve intervention in patients with severe aortic stenosis, making aortic valve intervention feasible and effective even in patients at intermediate, high, and prohibitive surgical risk. With the rapid advances in treatment, proper diagnosis becomes crucial for a wide range of patients with aortic stenosis: from "concordant" high-gradient aortic stenosis to "discordant" low-gradient aortic stenosis. The latter group commonly presents a clinical challenge requiring thoughtful and comprehensive evaluation to determine eligibility for aortic valve intervention. Providers at all levels should be familiar with basic diagnostic caveats and misconceptions when evaluating patients with possible aortic stenosis.

AMSSM Position Statement on Cardiovascular Preparticipation Screening in Athletes: Current Evidence, Knowledge Gaps, Recommendations and Future Directions

Cardiovascular screening in young athletes is widely recommended and routinely performed prior to participation in competitive sports. While there is general agreement that early detection of cardiac conditions at risk for sudden cardiac arrest and death (SCA/D) is an important objective, the optimal strategy for cardiovascular screening in athletes remains an issue of considerable debate. At the center of the controversy is the addition of a resting electrocardiogram (ECG) to the standard preparticipation evaluation using history and physical examination. The American Medical Society for Sports Medicine (AMSSM) formed a task force to address the current evidence and knowledge gaps regarding preparticipation cardiovascular screening in athletes from the perspective of a primary care sports medicine physician. The absence of definitive outcomes-based evidence at this time precludes AMSSM from endorsing any single or universal cardiovascular screening strategy for all athletes, including legislative mandates. This statement presents a new paradigm to assist the individual physician in assessing the most appropriate cardiovascular screening strategy unique to their athlete population, community needs, and resources. The decision to implement a cardiovascular screening program, with or without the addition of ECG, necessitates careful consideration of the risk of SCA/D in the targeted population and the availability of cardiology resources and infrastructure. Importantly, it is the individual physician's assessment in the context of an emerging evidence-base that the chosen model for early detection of cardiac disorders in the specific population provides greater benefit than harm. AMSSM is committed to advancing evidenced-based research and educational initiatives that will validate and promote the most efficacious strategies to foster safe sport participation and reduce SCA/D in athletes.

Variation in effectiveness of a cardiac auscultation training class with a cardiology patient simulator among heart sounds and murmurs

BACKGROUND

Effectiveness of simulation-based education in cardiac auscultation training is controversial, and may vary among a variety of heart sounds and murmurs. We investigated whether a single auscultation training class using a cardiology patient simulator for medical students provides competence required for clinical clerkship, and whether students' proficiency after the training differs among heart sounds and murmurs.

METHODS

A total of 324 fourth-year medical students (93-117/year for 3 years) were divided into groups of 6-8 students; each group participated in a three-hour training session using a cardiology patient simulator. After a mini-lecture and facilitated training, each student took two different tests. In the first test, they tried to identify three sounds of Category A (non-split, respiratory split, and abnormally wide split S2s) in random order, after being informed that they were from Category A. They then did the same with sounds of Category B (S3, S4, and S3+S4) and Category C (four heart murmurs). In the second test, they tried to identify only one from each of the three categories in random order without any category information.

RESULTS

The overall accuracy rate declined from 80.4% in the first test to 62.0% in the second test (p<0.0001). The accuracy rate of all the heart murmurs was similar in the first (81.3%) and second tests (77.5%). That of all the heart sounds (S2/S3/S4) decreased from 79.9% to 54.3% in the second test (p<0.0001). The individual accuracy rate decreased in the second test as compared with the first test in all three S2s, S3, and S3+S4 (p<0.0001).

CONCLUSIONS

Medical students may be less likely to correctly identify S2/S3/S4 as compared with heart murmurs in a situation close to clinical setting even immediately after training. We may have to consider such a characteristic of students when we provide them with cardiac auscultation training.

AMSSM Position Statement on Cardiovascular Preparticipation Screening in Athletes: Current evidence, knowledge gaps, recommendations and future directions

Cardiovascular screening in young athletes is widely recommended and routinely performed prior to participation in competitive sports. While there is general agreement that early detection of cardiac conditions at risk for sudden cardiac arrest and death (SCA/D) is an important objective, the optimal strategy for cardiovascular screening in athletes remains an issue of considerable debate. At the centre of the controversy is the addition of a resting ECG to the standard preparticipation evaluation using history and physical examination. The American Medical Society for Sports Medicine (AMSSM) formed a task force to address the current evidence and knowledge gaps regarding preparticipation cardiovascular screening in athletes from the perspective of a primary care sports medicine physician. The absence of definitive outcome-based evidence at this time precludes AMSSM from endorsing any single or universal cardiovascular screening strategy for all athletes, including legislative mandates. This statement presents a new paradigm to assist the individual physician in assessing the most appropriate cardiovascular screening strategy unique to their athlete population, community needs and resources. The decision to implement a cardiovascular screening programme, with or without the addition of ECG, necessitates careful consideration of the risk of SCA/D in the targeted population and the availability of cardiology resources and infrastructure. Importantly, it is the individual physician's assessment in the context of an emerging evidence base that the chosen model for early detection of cardiac disorders in the specific population provides greater benefit than harm. AMSSM is committed to advancing evidenced-based research and educational initiatives that will validate and promote the most efficacious strategies to foster safe sport participation and reduce SCA/D in athletes.

The need for annual echocardiography to detect cabergoline-associated valvulopathy in patients with prolactinoma: a systematic review and additional clinical data

Present recommendations by the US Food and Drug Administration advise that patients with prolactinoma treated with cabergoline should have an annual echocardiogram to screen for valvular heart disease. Here, we present new clinical data and a systematic review of the scientific literature showing that the prevalence of cabergoline-associated valvulopathy is very low. We prospectively assessed 40 patients with prolactinoma taking cabergoline. Cardiovascular examination before echocardiography detected an audible systolic murmur in 10% of cases (all were functional murmurs), and no clinically significant valvular lesion was shown on echocardiogram in the 90% of patients without a murmur. Our systematic review identified 21 studies that assessed the presence of valvular abnormalities in patients with prolactinoma treated with cabergoline. Including our new clinical data, only two (0·11%) of 1811 patients were confirmed to have cabergoline-associated valvulopathy (three [0·17%] if possible cases were included). The probability of clinically significant valvular heart disease is low in the absence of a murmur. On the basis of these findings, we challenge the present recommendations to do routine echocardiography in all patients taking cabergoline for prolactinoma every 12 months. We propose that such patients should be screened by a clinical cardiovascular examination and that echocardiogram should be reserved for those patients with an audible murmur, those treated for more than 5 years at a dose of more than 3 mg per week, or those who maintain cabergoline treatment after the age of 50 years.

Present role of the precordial examination in patient care

Recent observations suggest that many physicians do not consider the bedside cardiac examination as a valuable tool in patient care. Internists, hospitalists, emergency department physicians, cardiologists, physician assistants, and nurse practitioners were interviewed to ascertain their current practice in completing the cardiac examination. In addition, we surveyed patients in a cardiology practice concerning their attitudes about the cardiac physical examination. The study found that a significant number of practitioners failed to carry out a basic cardiac examination. Most patients do not have their chest exposed. It is unusual for the patient to be examined in the lateral decubitus position or for maneuvers to be used to evaluate the significance of a murmur. Most patients were more confident in the physician when a bedside examination was carried out, and they expect to undress for the examination. Half of the patients were more secure when they were undressed if there was a attendant of the same gender in the room. Review of the medical literature suggests that when a skilled examiner completes the bedside cardiac examination, it has an excellent sensitivity and specificity to recognize clinically significant cardiac disorders. A thorough cardiac bedside examination can make an echocardiogram unnecessary in some patients and compliment the echo in every patient. In conclusion, the bedside cardiac examination is a valuable diagnostic aid for diagnosing heart disease. If on the teaching wards and in the medical journals more emphasis is placed on the importance of physical findings for diagnosing heart disease, more physicians will make the effort to perform a thorough examination.

Development of a diagnostic test set to assess agreement in breast pathology: practical application of the Guidelines for Reporting Reliability and Agreement Studies (GRRAS)

Background

Diagnostic test sets are a valuable research tool that contributes importantly to the validity and reliability of studies that assess agreement in breast pathology. In order to fully understand the strengths and weaknesses of any agreement and reliability study, however, the methods should be fully reported. In this paper we provide a step-by-step description of the methods used to create four complex test sets for a study of diagnostic agreement among pathologists interpreting breast biopsy specimens. We use the newly developed Guidelines for Reporting Reliability and Agreement Studies (GRRAS) as a basis to report these methods.

Methods

Breast tissue biopsies were selected from the National Cancer Institute-funded Breast Cancer Surveillance Consortium sites. We used a random sampling stratified according to woman’s age (40–49 vs. ≥50), parenchymal breast density (low vs. high) and interpretation of the original pathologist. A 3-member panel of expert breast pathologists first independently interpreted each case using five primary diagnostic categories (non-proliferative changes, proliferative changes without atypia, atypical ductal hyperplasia, ductal carcinoma in situ, and invasive carcinoma). When the experts did not unanimously agree on a case diagnosis a modified Delphi method was used to determine the reference standard consensus diagnosis. The final test cases were stratified and randomly assigned into one of four unique test sets.

Conclusions

We found GRRAS recommendations to be very useful in reporting diagnostic test set development and recommend inclusion of two additional criteria: 1) characterizing the study population and 2) describing the methods for reference diagnosis, when applicable.

Diagnostic utility and clinical usefulness of the pocket echocardiographic device

BACKGROUND

The pocket echocardiograph (PE) with color Doppler imaging belongs to a new class of diagnostic tools, the feasibility and accuracy of which is not well established. The aim of this study was to assess the feasibility and diagnostic value of transthoracic echocardiography (TTE) performed with the use of PE by a cardiology resident (2nd year of training) and by an experienced cardiologist.

METHODS

The study population comprised 220 consecutive patients (142 men, mean age 63 ± 8 years), 110 of whom were admitted to our intensive cardiac care unit (ICU) and 110 patients referred for TTE from the outpatient clinic. All patients had PE TTE performed by a resident (60 ICU patients, 60 outpatients) or a cardiologist (50 ICU patients, 50 outpatients). Within 24 h of PE TTE, all subjects had a standard TTE (sTTE) performed by an experienced echocardiographer.

RESULTS

96% of patients had echocardiographic measurements completed by both PE TTE and sTTE. The dimensions measured with PE TTE by the resident and the cardiologist showed good to excellent correlation with sTTE (r = 0.64-0.96, P < 0.001). The agreement in detection of various pathologies between PE TTE performed by the resident and sTTE examinations was moderate to very good, whereas it was good to excellent if PE TTE was performed by the experienced cardiologist.

CONCLUSION

The diagnostic accuracy of the PE in basic assessment of cardiac morphology and function as compared to standard echocardiography is moderate to very good for a cardiology resident and good to excellent for an experienced cardiologist. (Echocardiography 2012;29:1-6).