Table 4 New Insights Provided by CMR

Early Changes

PA stiffens before pulmonary artery pressure increase at rest

Distensibility of pulmonary arteries

[42]

Ventricular Remodeling and Dysfunction

LV mass is lower in patients with chronic thromboembolic disease but normalizes post-pulmonary endarterectomy

LV mass

[62]

Interventricular dyssnchrony and septal bowing in PAH is due to slower contraction for the RV than LV

Tagging

[63]

Cardiac Ischemia

Both ventricles display attenuated vasoreactivity proportional to mPAP

Adenosine Stress Perfusion

[64]

RV Metabolism

Bosentan improves RV energetics

31P-NMR spectroscopy

[65]

Ventricular-arterial Decoupling in PH

Disconnect occurs since increases in arterial load are far greater than those in contractility

Volumes combined with invasively derived pressure loops/pressures

[66, 67]

Changes with Exercise

Stroke volume in PAH fails to augment - increases in cardiac output are mediated by heart rate alone

Bicycle exercise

[68]

Inaccuracy of Catheter-Laboratory Measurements

Pulmonary vascular resistance derived from the Fick method is inaccurate in conditions of vasodilatation

Flow combined with invasively derived pressure

[69]