Handheld echocardiographic screening for rheumatic heart disease by non-experts.

OBJECTIVES: Handheld echocardiography (HAND) has good sensitivity and specificity for rheumatic heart disease (RHD) when performed by cardiologists. However, physician shortages in RHD-endemic areas demand less-skilled users to make RHD screening practical. We examine nurse performance and interpretation of HAND using a simplified approach for RHD screening. METHODS: Two nurses received training on HAND and a simplified screening approach. Consented students at two schools in Uganda were eligible for participation. A simplified approach (HAND performed and interpreted by a non-expert) was compared with the reference standard (standard portable echocardiography, performed and interpreted by experts according to the 2012 World Heart Federation guidelines). Reasons for false-positive and false-negative HAND studies were identified. RESULTS: A total of 1002 children were consented, with 956 (11.1 years, 41.8% male) having complete data for review. Diagnoses included: 913 (95.5%) children were classified normal, 32 (3.3%) borderline RHD and 11 (1.2%) definite RHD. The simplified approach had a sensitivity of 74.4% (58.8% to 86.5%) and a specificity of 78.8% (76.0% to 81.4%) for any RHD (borderline and definite). Sensitivity improved to 90.9% (58.7% to 98.5%) for definite RHD. Identification and measurement of erroneous colour jets was the most common reason for false-positive studies (n=164/194), while missed mitral regurgitation and shorter regurgitant jet lengths with HAND were the most common reasons for false-negative studies (n=10/11). CONCLUSIONS: Non-expert-led HAND screening programmes offer a potential solution to financial and workforce barriers that limit widespread RHD screening. Nurses trained on HAND using a simplified approach had reasonable sensitivity and specificity for RHD screening. Information on reasons for false-negative and false-positive screening studies should be used to inform future training protocols, which could lead to improved screening performance.

Usefulness of intravenously administered fluid replenishment for detection of patent foramen ovale by transesophageal echocardiography.

Patent foramen ovale (PFO) is associated with cryptogenic stroke, migraine headache, decompression sickness, and platypnea-orthodeoxia syndrome. Patients undergoing transesophageal echocardiography are often hypovolemic from preprocedural fasting and might not demonstrate right to left shunting owing to insufficient right atrial pressure generation, despite provocative maneuvers. We hypothesized that volume replenishment with saline loading could potentially unmask a PFO by favorably modulating the interatrial pressure gradient. Our study sought to examine the role of pre- or intraprocedural intravenous fluid replenishment on PFO detection during transesophageal echocardiography. A total of 103 patients were enrolled. An initial series of bubble injections was performed unprovoked and then with provocative maneuvers such as the Valsalva maneuver and coughing. The patients were then given a rapid 500 ml saline bolus, and the same sequence of bubble injections was repeated. The presence, type, and magnitude of the right to left shunts were noted before and after the saline bolus. The detection rate of PFO increased from 10.6% to 26.2% after saline loading without any provocative maneuvers. When combined with provocative maneuvers (Valsalva or cough), saline loading improved the detection rate from 17.4% to 32.0%. Overall, from amongst the 103 enrolled patients, saline bolusing resulted in a de novo diagnosis of PFO in 15 patients, atrial septal aneurysm in 15, PFO coexisting with an atrial septal aneurysm in 10, and pulmonary arteriovenous fistula in 5 patients. In conclusion, saline infusion in appropriately selected patients during transesophageal echocardiography significantly enhances the detection of PFOs and pulmonary arteriovenous fistulas.