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.