Does artificial intelligence and deep learning architecture system accurately measure left ventricular systolic function? [Meeting Abstract]
Background: Left ventricular ejection fraction (LVEF) is the most used measurement in the assessment of cardiac function. However, human error and image quality are among several factors contributing to inaccuracies of this measurement. The purpose of this study was to establish the correlation between LVEF measured by expert ultrasound cardiac sonographers and by a system based on a deep learning architecture and geometry processing algorithms. Methods: We developed a system based on a novel deep learning architecture and geometry processing algorithms for building a computational pipeline. Input was from a stream of cardiac ultrasound images that automatically calculated the ejection fraction of the left ventricle (LV). The system analyzes each image, identifies the viewing direction, segments the left ventricle, identifies systolic/diastolic frames and reconstructs 3D models of the LV at different times (see Figure 1). It then computes robust estimation of the ejection fraction. Echocardiographic images from of 114 patients were used. Each case contains cardiac ultrasound clips from two and four-chamber views fed to the system as a single stream with no additional data. We created the ground truth ejection fraction (EF) value for each case by taking the median of 8 estimators: 4 expert cardiologists eye-ball estimations, 3 computations using Simpson formula and 3D reconstructions based on marked LV segmentations of an expert technician, and the original medical report. Results: Figure 2 depicts error histograms comparing EF values and the ground-truth EF values. We compared the error histogram of our algorithm (right) and that of one of the experts (left ). The mean and variance of histograms is comparable indicating our algorithm is comparable in accuracy to an expert cardiologist. Conclusions: An excellent correlation was found between LVEF measured by expert Ultrasound cardiac sonographer and the LVEF measured by a system based on a deep learning architecture and geometry processing algorithms (Figure presented)
Right ventricular systolic function in patients with hypoplastic left heart syndrome following norwood operation: A novel method using doppler dP/dT across the sano shunt [Meeting Abstract]
Background: Hypoplastic left heart syndrome (HLHS) is of the highest risk lesions in congenital heart disease. The initial surgery typically involves the Norwood procedure, frequently with Sano modification. Despite surgical advances, interstage mortality remains approximately 10%, with diminished right ventricular (RV) systolic function a risk factor for death. Tricuspid regurgitation (TR) derived dP/dT has been shown to correlate with catheter derived dP/dT in patients with HLHS, and is frequently used in assessment of RV systolic function. However, in patients without an adequate TR Doppler signal, this modality cannot be used. The purpose of this study was to evaluate the correlation between a Sano derived RV dP/dT and TR derived RV dP/dT in the assessment of RV systolic function following Norwood operation with Sano modification. Methods: An echocardiographic retrospective review was performed in patients following a Norwood/Sano operation, and assessed for the presence of a continuous wave Doppler tracing across the tricuspid valve and Sano shunt. 46 studies met this criteria. A dP/dT for both methods was measured between 1 and 3 m/s, and a qualitative assessment of function was also assigned to each study. Results: The mean value of TR derived dP/ dT and Sano derived dP/dT was 979.9 mmHg/s and 1102.89 mmHg/s respectively. A linear relationship exists between a Sano and TR derived RV dP/dT, where the TR derived RV dP/dT = 387+0.73x, (p=0.001). There was also a statistically significant relationship between the Sano derived dP/dT and the qualitative analysis of RV systolic function, particularly in the higher values. Moderately diminished function was found to have a Sano derived dP/dT of 860 to 1093, mildly diminished 732 to 1325, and normal function 866 to 2048. Conclusions: Sano derived RV dP/dT can be effectively used as a surrogate for TR derived RV dP/dT, which may be of use in patients with inadequate TR. There is a statistically significant correlation between the Sano dP/dT and the qualitative assessment of function (Figure presented)
Cardiopulmonary stress testing in children and adults with congenital heart disease
Cardiopulmonary exercise stress testing (CPET) is a vital tool used to assess patients with a history of congenital heart disease. There are several tests in the cardiologist's armamentarium that allow for assessment of cardiac anatomy and function. The majority of these tests are only performed with the body at rest and some even require sedation. Exercise stress testing is unique in allowing assessment of the hemodynamic status of a patient in motion. In addition to providing all the information obtained during an exercise stress test, such as heart rate, rhythm, ST-segment analysis, and blood pressure, the CPET provides critical metabolic information. Parameters such as VO2, oxygen pulse, and VE/VCO2 slope help to detail the patient's physiology in a dynamic state. Decisions can then be better made regarding follow-up plans, acceptable exercise recommendations, and future interventions, if necessary. It allows insight into the patient's exercise capacity and quality of life. Norms for both children and adults with many forms of congenital heart disease are now available allowing appropriate comparisons to be made. This review will discuss in detail the CPET and its application in congenital heart disease.