RecruitingDevice studyQuantaFlo HD Clinical Validation StudyThe primary aim of this validation protocol is to assess cardiovascular function through transthoracic echocardiography ("Echo") measurements and the QuantaFlo HD test measuring blood flow at the finger during a forced expiration ("FE"). The study examines whether Echo-measured GLS values greater than -16% correlate with abnormal responses during FE as measured by QuantaFlo HD.