PURPOSE: For optimization of the pump setting, there is currently a lack of non-invasive diagnostic methods capable to sensitively reflect the altered right-to-left ventricle relationship following the Left Ventricle Assist Device (LVAD) implantation. It was hypothesized that novel measures derived from the re-breath diffusing lung capacity for carbon monoxide (DLCO) technique may become a viable alternative to invasive hemodynamic studies. The present pilot study demonstrates feasibility and quantification of dynamic pulmonary variables including lung blood flow (Q) in the face of a device derived and clinical data. METHODS: 6 patients with LVAD participated in the present study (tab 1). Oxygen consumption and DLCO with its components were assessed pre- and during 12-15 min of low intensity (0.3 Watts/kg) exercise on a semi-recumbent ergometer. At constant LVAD speed, nitric oxide analyzer and mass spectrometer connected to a subject via a mouthpiece were used. RESULTS: During exercise, each patient demonstrated different patterns and magnitude of alterations in respiratory gas exchange (fig 1A). Moreover, variability of alteration in DLCO measures among patients was more prominent after correction for Q (fig 2B). CONCLUSION: Distinct inter-personal responses in DLCO components and respiratory gas exchange to low intensity exercise may indicate that the re-breath DLCO technique can be utilized for a non-invasive LVAD speed optimization.
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Cardiology and Cardiovascular Medicine