Handheld ultrasound: accurate diagnosis at a lower cost?

Insonation versus Auscultation in Valvular Disorders: Is Aortic Stenosis the Exception? A Systematic Review

BACKGROUND

Handheld echocardiography is being proposed as the fifth pillar of bedside physical cardiovascular examination (PE) and is referred to as insonation. Although there is emerging consensus that insonation is superior to PE for diagnosis of various cardiac conditions, superiority has not been consistently demonstrated for various valvular heart disease (VHD) lesions. The objective of this review is to systematically review the accuracy of insonation and auscultation in published literature for detection of common VHD.

METHODS

An extensive literature search across three commonly used public databases allowed comparison of diagnostic characteristics of insonation and auscultation for common VHD including aortic stenosis, mitral regurgitation, aortic regurgitation, tricuspid regurgitation. Sensitivity, specificity, and accuracy of insonation and auscultation for the detection of these VHD lesions were extracted for further analysis. The quality of evidence was assessed according to Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

RESULTS

Eight hundred eighty studies were screened, and seven observational studies were selected for full analysis. Due to heterogeneity of data, this study was not amenable to meta-analysis. Insonation was superior to auscultation for the detection of all regurgitant lesions, but there was no significant difference in diagnostic ability of the two strategies for detection of aortic stenosis.

CONCLUSIONS

Compared to auscultation, insonation, in its currently available form, is a superior diagnostic tool for regurgitant lesions. However, insonation fails to improve upon auscultation for recognition of aortic stenosis. This limitation is likely due to absence of spectral Doppler and inability of HE to assess transvalvular velocity and gradient.

A systematic review of pocket-sized imaging devices: small and mighty?

Introduction

Hand-held imaging devices are widely used in clinical practice and are a useful tool. There is no published review examining the diagnostic parameters achieved with these devices in clinical practice.

Methods

We searched three online medical literature databases (PubMed, EMBASE and MEDLINE) for all literature published up until January 2018. We selected studies that (1) were conducted in the adult population; (2) used a truly hand-held device; (3) featured sensitivities and/or specificities on the use of the hand-held scanner. We extracted and summarised the diagnostic metrics from the literature.

Results

Twenty-seven articles were excluded from the initial 56 relevant articles, as the device featured was not truly hand-held. Ultimately a total of 25 studies were analysed. Sixteen studies were carried out by experienced users, seven by users with little previous experience and two studies by nurses. High diagnostic parameters were achieved by all three groups when scanning cardiac pathology and intra-abdominal structures. Training of non-expert users varied, taking a mean of 21.6 h. These hand-held devices can change diagnoses at the bedside and be used as gate-keepers to formal echocardiography. Individual studies show them to be cost-effective.

Conclusion

Hand-held echocardiography is a useful tool in the hands of experts and novices alike. Studies conducted are highly heterogeneous making it difficult to pool data for the diagnostic metrics. Further studies with rigorous methodology are needed to evaluate the true diagnostic potential in the hands of non-experts and in the community as well as to validate training protocols.

Utility of physical examination and comparison to echocardiography for cardiac diagnosis

Objective

To find out the accuracy of cardiac auscultation using non-digital stethoscope in physical diagnosis of cardiac diseases.

Methods

We enrolled 104 consecutive patients with abnormal cardiac auscultatory findings attending cardiology clinic and not previously evaluated by echocardiography. One time detailed cardiac physical examination followed by echocardiography within 1 month was undertaken. Agreement between two methods was calculated using mean pair percentage agreement, kappa statistics (κ) and calculation of 95% confidence interval (CI) for kappa statistics.

Results

Using kappa statistics, there was almost perfect agreement between cardiac auscultation and echocardiography for the detection of mitral stenosis (κ = 0.865; CI 0.76–0.97) and ventricular septal defect (κ = 0.872; CI = 0.73–1.01). Substantial agreement was noted for aortic stenosis (κ = 0.752; CI = 0.56–0.94), pulmonary stenosis (κ = 0.647; CI = 0.33–0.97) and atrial septal defect (κ = 0.646; CI = 0.32–0.97), while moderate agreement was found for mitral regurgitation (κ = 0.470; CI = 0.30–0.64), aortic regurgitation (κ = 0.456; CI = 0.25–0.66) and tricuspid regurgitation (κ = 0.575; CI = 0.38–0.77).

For combined mitral stenosis and mitral regurgitation lesions, almost perfect agreement was found for mitral stenosis (κ = 0.842; CI = 0.691–0.993) while fair agreement noted for mitral regurgitation (κ = 0.255; CI = −0.008 to 0.518).

Conclusion

Careful clinical auscultation using a stethoscope remains a valuable tool for cardiac diagnosis. Decision on initial diagnosis and management of valvular and congenital heart diseases should be based on clinical examination and integrating such information with echocardiography as required.