The utility of handheld echocardiography for early diagnosis of rheumatic heart disease

Background: Rheumatic heart disease (RHD) remains endemic in most of the developing world. Echocardiography has proved highly sensitive for early detection of RHD, but it remains too costly for most low-income settings. Handheld ultrasound machines used to perform handheld echocardiography (HAND) are both less expensive and more portable, possibly making them ideal screening tools. HAND has never been tested for the early diagnosis of RHD. The aim of this study was to evaluate the performance of focused HAND compared with focused standard portable echocardiography for the diagnosis of subclinical RHD.

Methods: HAND and standard portable echocardiography were performed on 125 Ugandan children, 41 with borderline or definite RHD, and 84 healthy controls. Images were blindly reviewed according to the 2012 World Heart Federation guidelines.

Results: HAND was highly sensitive (90.2%) and specific (92.9%) for distinguishing between normal patients and those with RHD, but it performed best with definite RHD. HAND overestimated mitral valve morphologic valve abnormalities, being only 66.7% specific for anterior leaflet thickness > 3 mm and 79.0% specific for restricted leaflet motion. False-negative results (n = 4) were due primarily to underestimation of mitral regurgitation length.

Conclusions: In this population, HAND was highly sensitive and specific for early detection of RHD. HAND functions best as a screening tool with confirmation of positive screening results by fully functional echocardiography machines. Technical advances may enable one-step RHD screening using HAND. The performance of HAND should be studied across diverse populations and in field tests before recommending it for widespread screening.