Geeth A Kondaveeti1, Varun A Bhatia2, Ryan P Lahm2, Megan L Harris2, James P Gaewsky1,3, F Scott Gayzik1, John F Greenhalgh4, Craig A Hamilton1, R Brandon Stacey5, Ashley A Weaver6. 1. Department of Biomedical Engineering, Wake Forest School of Medicine, 575 N. Patterson Ave. Suite 530, Winston-Salem, NC, 27101, USA. 2. Cardiac Rhythm Management, Medtronic Inc., 8200 Coral Sea Street NE, Mounds View, MN, 55112, USA. 3. Elemance LLC, 3540 Clemmons Rd #127, Clemmons, NC, 27012, USA. 4. FONAR Corporation, 110 Marcus Drive, Melville, NY, 11747, USA. 5. Department of Cardiology, Wake Forest University School of Medicine, Winston-Salem, NC, 27157, USA. 6. Department of Biomedical Engineering, Wake Forest School of Medicine, 575 N. Patterson Ave. Suite 530, Winston-Salem, NC, 27101, USA. asweaver@wakehealth.edu.
Abstract
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. Four cardiothoracic measurements, six cardiac measurements, and six cardiac landmarks were collected to measure changes across different postures and stages of respiration. RESULTS: The relative location of the LV apex to the nearest intercostal space was significantly different between the supine and decubitus postures (average ± SD difference: - 15.7 ± 11.4 mm; p < 0.05). The heart centroid to xipho-sternal junction distance was 9.7 ± 7.9 mm greater in the supine posture when compared to the upright posture (p < 0.05). Cardiac landmark motion in the lateral direction was largest due to postural movement (range 23-50 mm) from the left decubitus to the right decubitus posture, and less influenced by respiration (5-17 mm). Caudal-cranial displacement was generally larger due to upright posture (13-23 mm caudal) and inspiration (7-20 mm cranial). CONCLUSIONS: This study demonstrates that the location of the heart with respect to the rib cage varies with posture and respiration. The gravitational effects of postural shifts on the heart position are roughly 2-3 times larger than the effects of normal respiration.
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. Four cardiothoracic measurements, six cardiac measurements, and six cardiac landmarks were collected to measure changes across different postures and stages of respiration. RESULTS: The relative location of the LV apex to the nearest intercostal space was significantly different between the supine and decubitus postures (average ± SD difference: - 15.7 ± 11.4 mm; p < 0.05). The heart centroid to xipho-sternal junction distance was 9.7 ± 7.9 mm greater in the supine posture when compared to the upright posture (p < 0.05). Cardiac landmark motion in the lateral direction was largest due to postural movement (range 23-50 mm) from the left decubitus to the right decubitus posture, and less influenced by respiration (5-17 mm). Caudal-cranial displacement was generally larger due to upright posture (13-23 mm caudal) and inspiration (7-20 mm cranial). CONCLUSIONS: This study demonstrates that the location of the heart with respect to the rib cage varies with posture and respiration. The gravitational effects of postural shifts on the heart position are roughly 2-3 times larger than the effects of normal respiration.
Authors: Walter Richard Schwertner; Anett Behon; Eperke Dóra Merkel; Márton Tokodi; Attila Kovács; Endre Zima; István Osztheimer; Levente Molnár; Ákos Király; Roland Papp; László Gellér; Luca Kuthi; Boglárka Veres; Annamária Kosztin; Béla Merkely Journal: Europace Date: 2021-05-25 Impact factor: 5.214
Authors: Ashley R Hayes; F Scott Gayzik; Daniel P Moreno; R Shayn Martin; Joel D Stitzel Journal: Comput Math Methods Med Date: 2013-03-27 Impact factor: 2.238