Figure 6.
Panel A has six bar graphs: In Fractional Shortening, the vertical axis represents Percent (percentage) from 0 to 40 in increments of 10. The horizontal axis represents W T and Ttn Delta A164-167. W T is at 23 percent, and Ttn Delta A164-167 is at 22 percent. A bracket labeled ns indicates no significant difference. In I V R T over R R Interval: The vertical axis represents metres per second from 0 to 150 in increments of 50. The horizontal axis represents W T and Ttn Delta A164-167. W T is at 78 metres per second, and Ttn Delta A164-167 is at 91 metres per second. A bracket with a p-value of 0.0782 indicates no statistical significance. In M P I: The vertical axis represents arbitrary units from 0.0 to 0.6 in increments of 0.2. The horizontal axis represents W T and Ttn Delta A164-167. W T is at 0.41 a.u., and Ttn Delta A164-167 is at 0.46 a.u. A bracket with a p-value of 0.0824 indicates no statistical significance. In M V E Decel. Time: The vertical axis represents milliseconds from 0 to 50 in increments of 10. The horizontal axis represents W T and Ttn Delta A164-167. W T is at 31 milliseconds, and Ttn Delta A164-167 is at 24 milliseconds. A bracket labeled with two asterisks indicates a significant difference. In M V E over A: The vertical axis represents the Ratio from 0.0 to 2.5 in increments of 0.5. The horizontal axis represents W T and Ttn Delta A164-167. W T is at 1.2, and Ttn Delta A164-167 is at 1.4. A bracket with a p-value of 0.0789 indicates no statistical significance. In M V A wave: The vertical axis represents millimeters per second from 0 to 800 in increments of 200. The horizontal axis represents W T and Ttn Delta A164-167. W T is at 580 millimeters per second, and Ttn Delta A164-167 is at 490 millimeters per second. A bracket with a p-value of 0.1036 indicates no statistical significance. Panel B has four bar graphs: In Whole Heart: The vertical axis represents H W over B W (milligrams per gram) from 0 to 8 in increments of 2. The horizontal axis represents W T and Ttn Delta A164-167. W T is at 4.8 milligrams per gram, and Ttn Delta A164-167 is at 5.6 milligrams per gram. A bracket with two asterisks indicates a significant difference. In Left Ventricle: The vertical axis represents L V weight over B W (milligrams per gram) from 0 to 5 in increments of 1. The horizontal axis represents W T and Ttn Delta A164-167. W T is at 3.1 milligrams per gram, and Ttn Delta A164-167 is at 3.7 milligrams per gram. A bracket with four asterisks indicates a highly significant difference. In the Right Ventricle: The vertical axis represents R V weight over B W (milligrams per gram) from 0.0 to 2.0 in increments of 0.5. The horizontal axis represents W T and Ttn Delta A164-167. WT is at 0.95 milligrams per gram, and Ttn Delta A164-167 is at 1.15 milligrams per gram. A bracket with two asterisks indicates a significant difference. In Atria: The vertical axis represents Atrial weight over B W (milligrams per gram) from 0.0 to 0.6 in increments of 0.2. The horizontal axis represents W T and Ttn Delta A164-167. W T is at 0.26 milligrams per gram, and Ttn Delta A164-167 is at 0.38 milligrams per gram. A bracket with three asterisks indicates a significant difference. Panel C consists of two side-by-side micrographs of cardiac tissue. W T histology shows a microscopic view of heart tissue sectioned longitudinally. Muscle fibers appear as organized, pink-stained parallel structures with dark purple nuclei. A scale bar at the bottom right indicates 100 micrometers. Ttn Delta A164-167 Histology shows a microscopic view of heart tissue with fibers running diagonally. The tissue displays similar striated pink muscle fibers and purple nuclei, appearing slightly denser than the W T section. All values are approximate.
Cardiac function and morphology. (A) Fractional shortening, isovolumic relaxation time normalized to RR time interval (IVRT/RR interval), myocardial performance index (MPI), mitral valve E-wave deceleration time (MV E decel. time), mitral valve E/A ratio, and mitral valve A-wave, as measured by echocardiography. 9 WT and 12 TtnΔA164–16 mice were used in echocardiography studies. (B) Muscle weight-to-BW ratio for the whole heart, left ventricle, right ventricle, and combined atrial weights. 12–16 WT and 13–17 TtnΔA164–167 mice were used. Statistical significance for A and B was determined by an unpaired t test. (C) Representative images of WT (left) and TtnΔA164–167 (right) Masson’s trichrome-stained heart sections. Three mice of each genotype were used (one representative image from each genotype is shown). BW, body weight. ns, p≥0.05; **p ≤ 0.01; ***p ≤ 0.001; ****p ≤ 0.0001.