Quantifying Cardiothoracic Variation with Posture and Respiration to Inform Cardiac Device Design.

Purpose: With extravascular implantable cardioverter defibrillator leads placed beneath the sternum, it is important to quantify heart motion relative to the rib cage with postural changes and respiration.

Methods: MRI scans from five males and five females were collected in upright and supine postures at end inspiration [n = 10 each]. Left and right decubitus [n = 8 each] and prone [n = 5] MRIs at end inspiration and supine MRIs at end expiration [n = 5] were collected on a subset.