Philip A Corrado1, Gregory P Barton2, Christopher J François3, Oliver Wieben1, and Kara N Goss2
1University of Wisconsin-Madison, Madison, WI, United States, 2University of Texas Southwestern, Dallas, TX, United States, 3Mayo Clinic, Rochester, MN, United States
1University of Wisconsin-Madison, Madison, WI, United States, 2University of Texas Southwestern, Dallas, TX, United States, 3Mayo Clinic, Rochester, MN, United States
We used 4D flow MRI before & during acute pharmacological intervention to reduce afterload or heart rate in young adults born very to extremely premature.
We found improved cardiac function and increased direct flow in the right ventricle (RV) after RV afterload reduction with sildenafil.
Figure 2: Flow compartment visualization in a typical example before and after sildenafil administration. The
fraction of right ventricular pathlines in the direct flow compartment (green
pathlines) increases after sildenafil administration (white arrows). Direct
Flow: Blood that enters the ventricle and leaves in the same heartbeat. Retained Inflow: Blood that enters the ventricle
during diastole and stays for >=1 beat. Delayed Ejection Flow:
Blood that starts in the ventricle and leaves during
systole. Residual Volume: Blood that resides within the ventricle for >=2 beats.
Figure 1: Overall study design. On the first visit, each subject
was randomly assigned to receive either intravenous metoprolol tartrate or oral
sildenafil citrate. Each subject received the other drug on the second visit,
so that all 9 subjects received both drugs. On each visit, the subject received
2 cardiac MRI scans: one baseline and one after drug administration.