Chapter 3 Cardiac atrophy & Remodeling © 2014, Elsevier Inc., Willis, et.al., Cellular and Molecular Pathobiology of Cardiovascular Disease

FIGURE 3.1 Cardiac remodeling involves increased and decreased growth mediated by an imbalance between protein synthesis and degradation. (A) In atrophic remodeling, protein degradation is favored to produce smaller cardiomyocytes and reduced myocardial size. (B) In the healthy heart, protein synthesis is balanced by protein degradation such that they occur equally and simultaneously. (C) In the hypertrophic heart, protein synthesis outweighs protein degradation to increase cardiomyocyte and myocardial size. Adapted from Willis et al., New Engl J Med (2013).119 © 2014, Elsevier Inc., Willis, et.al., Cellular and Molecular Pathobiology of Cardiovascular Disease

FIGURE 3. 2 (A) Schematic of heterotopic heart transplant FIGURE 3.2 (A) Schematic of heterotopic heart transplant. To reduce cardiac load, a donor heart is transplanted into a recipient. Blood is shunted from the abdominal aorta or the recipient through the ascending aorta associated with the donor heart and through the donor heart. The donor heart returns blood through its associated pulmonary artery to the recipient inferior vena cava, thus reducing workload in both the donor and recipient hearts. (B) Schematic of left ventricular assist device. A prosthetic left ventricular pump is implanted that receives blood from the left ventricle and returns it via peristaltic or continuous pressure to the aorta. A battery pack attached to a harness is worn externally by the patient. © 2014, Elsevier Inc., Willis, et.al., Cellular and Molecular Pathobiology of Cardiovascular Disease

FIGURE 3.3 Electron micrographs of atrophic remodeling in feline papillary muscles after transaction of the chordae tendineae. Longitudinal sections of (A) healthy papillary muscles, and (B) after one week on ventricular unloading. Adapted from Kent el al., JMCC (1985).30 © 2014, Elsevier Inc., Willis, et.al., Cellular and Molecular Pathobiology of Cardiovascular Disease

FIGURE 3.4 Structure of t-tubules in adult cardiomyocytes isolated from healthy rat (left) and from rat receiving heterotopically transplanted heart for four weeks (right). Images were obtained using confocal microscopy after staining with membrane-binding dye. Inset is 40 μm long. Binary image is shown below. Adapted from Ibrahim et al., FASEB J (2010).88 © 2014, Elsevier Inc., Willis, et.al., Cellular and Molecular Pathobiology of Cardiovascular Disease