Assessment of Pulmonary Congestion During Cardiac Hemodynamic Stress Testing

The aim of this study is to utilize lung ultrasound to detect the development of extravascular lung water in patients undergoing clinically indicated invasive hemodynamic exercise stress testing for symptomatic shortness of breath. The study will correlate the lung ultrasound findings with cardiac hemodynamics and measurements of extravascular lung water in an effort to better understand the pathophysiology of exertional dyspnea.

Exercise induced elevation of left ventricular (LV) filling pressures can be the source of chronic dyspnea. Ultimately, high LV filling pressure leads to the development of extravascular lung water (EVLW) which can cause symptoms of dyspnea. Lung ultrasound (LUS) is a highly feasible, non-invasive procedure that is extremely sensitive for detecting EVLW. The sonographic signature of EVLW is a reverberation artifact called a "B-Line". The study will evaluate the etiology of sonographic B-Lines using invasive hemodynamic catheterization while simultaneously measuring the amount of EVLW present during exercise stress testing using transpulmonary thermodilution. The study aim is to demonstrate that the severity of EVLW, assessed by number of B-Lines, will correlate with LV filling pressures. In addition, the study will test the hypothesis that patients demonstrating dynamic increases in sonographic B-Lines with exercise will also display more severe symptoms of dyspnea, altered ventilatory mechanics (higher ratio of minute ventilation to carbon dioxide production (VE/VCO2)), and reduced aerobic capacity (lower peak oxygen consumption (VO2)).

dyspnea, heart failure with preserved ejection fraction, pulmonary edema, lung ultrasound, extravascular lung water

All patients undergoing a clinically indicated invasive cardiac hemodynamic exercise test will be eligible for enrollment into the study.

Subjects scheduled for standard-of-care, clinically indicated, invasive hemodynamic stress test will undergo lung ultrasound and assessment of extravascular lung water by pulmonary thermodilution technique.

Lung ultrasound will be performed at baseline (resting), prior to exercise with passive leg elevation, after 1.5 minutes of 20 Watts exercise, during each subsequent stage, at peak workload and at 1 minute recovery. Pulmonary thermodilution will be performed at rest, peak stress and at 1 minute recovery.

Lung ultrasound will be performed during invasive stress testing. The number of B-lines visible during stress testing will be correlated with synchronous measurements of intra-cardiac filling pressures .

Lung ultrasound imaging for B-Lines and assessment of intracardiac hemodynamics will be performed during the scheduled invasive stress test (initial visit, day #1).

Lung ultrasound will be performed during invasive stress testing. The number of B-lines visible during stress testing will be correlated with synchronous measurements ventilatory mechanic parameters measured using expiratory gas.

Lung ultrasound imaging and assessment of ventilatory mechanics (using analysis of expired gas) will be performed during the scheduled invasive stress test (initial visit, day #1).

Correlation of the Number of Lung Ultrasound B-Lines Developed During Invasive Stress Testing With Measurement of Extravascular Lung Water.

Lung ultrasound will be performed during invasive stress testing. The number of B-lines visible during stress testing will be correlated with synchronous measurements extravascular lung water using transpulmonary thermodilution.

Lung ultrasound imaging and assessment of the amount of extravascular lung water using transpulmonary thermodilution will be performed during the scheduled invasive stress test (initial visit, day #1).

Lung Ultrasound B-Lines Developed During Invasive Stress and the Calculated Amount of Extravascular Lung Water Will be Correlated With Changes in the Levels of Serum Protein, Hemoglobin and Brain Natriuretic Peptide Levels.

Lung ultrasound will be performed during invasive stress testing. The number of B-lines visible during stress testing will be correlated with synchronous measurements extravascular lung water using transpulmonary thermodilution. In addition, serum levels of hemoglobin, protein and brain natriuretic peptide will be collected, synchronously, during the stress test.

Serum biomarkers, lung ultrasound and assessment of extravascular lung water will be performed during the scheduled invasive stress test (initial visit, day #1).

Correlation of the Number of Lung Ultrasound B-Lines Developed During Invasive Stress Testing With Clinical Outcomes.

Lung ultrasound will be performed during invasive stress testing. The number of B-lines visible during stress testing will be correlated with patient clinical outcomes defined as a composite outcome of hospital readmission, non-fatal myocardial infarction, or cardiovascular death.

Inclusion Criteria: All adult patients (≥18 years) who are referred for invasive cardiac hemodynamic assessment Patients who have the capacity to understand and consent for the research study Exclusion Criteria: Patients with known interstitial lung disease or pulmonary fibrosis