Relationship between quantitative and descriptive methods of studying blood flow through intrapulmonary arteriovenous anastomoses during exercise

• Published in: Respiratory physiology & neurobiology Vol. 243; pp. 47 - 54
• Main Authors: Duke, Joseph W., Elliott, Jonathan E., Laurie, Steven S., Voelkel, Thomas, Gladstone, Igor M., Fish, Mathews B., Lovering, Andrew T.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.09.2017
• Subjects: Adult; Arteriovenous Anastomosis - diagnostic imaging; Arteriovenous Anastomosis - physiology; Contrast echocardiography; Echocardiography; Exercise; Exercise - physiology; Hemodynamics - physiology; Humans; Intrapulmonary shunt; Male; Medical Education; Pulmonary circulation; Pulmonary Circulation - physiology; Pulmonary/Respiratory; Regional Blood Flow - physiology; Respiratory; Respiratory Function Tests; Spirometry; Technetium Tc 99m Aggregated Albumin - metabolism; Tomography Scanners, X-Ray Computed; Tomography, Emission-Computed, Single-Photon; Young Adult; Respiratory; Pulmonary circulation; Exercise; Contrast echocardiography; Intrapulmonary shunt
• ISSN: 1569-9048; 1878-1519; 1878-1519
• DOI: 10.1016/j.resp.2017.05.006

•Macroaggregates and bubble scores are used to study intrapulmonary shunt in humans.•These methods have not been investigated simultaneously in the same subjects.•We used both methods and investigated whether they were related during exercise.•There was a positive and significant relationship between these methods.•Large bubble scores during exercise correspond to a meaningful magnitude of shunt. Several methods exist to study intrapulmonary arteriovenous anastomoses (IPAVA) in humans. Transthoracic saline contrast echocardiography (TTSCE), i.e., bubble scores, is minimally-invasive, but cannot be used to quantify the magnitude of blood flow through IPAVA (QIPAVA). Radiolabeled macroaggregates of albumin (99mTc-MAA) have been used to quantify QIPAVA in humans, but this requires injection of radioactive particles. Previous work has shown agreement between 99mTc-MAA and TTSCE, but this has not been tested simultaneously in the same group of subjects. Thus, the purpose of this study was to determine if there was a relationship between QIPAVA quantified with 99mTc-MAA and bubble scores obtained with TTSCE. To test this, we used 99mTc-MAA and TTSCE to quantify and detect QIPAVA at rest and during exercise in humans. QIPAVA significantly increased from rest to exercise using 99mTc-MAA and TTSCE and there was a moderately-strong, but significant relationship between methods. Our data suggest that high bubble scores generally correspond with large QIPAVA quantified with 99mTc-MAA during exercise.