Successful Improvement of Cardiac Function in Late-Onset Dilated Cardiomyopathy Due to the SLC25A20 c.199-10T>G Mutation

Figures

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  Figure 1. Chest X-Ray, Coronary Angiography, and Cardiac Magnetic Resonance Imaging Findings (A) Posteroanterior chest X-ray demonstrating an increased cardiothoracic ratio (>0.6). (B and C) Invasive coronary angiography revealing nonsignificant stenosis in the right and left coronary arteries. (D-I) Cardiac magnetic resonance imaging findings. (D) Four-chamber view showing dilation of all 4 cardiac chambers and a small pericardial effusion. (E and F) Late gadolinium enhancement in the subendocardial region of the interventricular septum and basal-to-mid inferior wall, with midmyocardial enhancement in the midseptal region. The total fibrosis burden was 9 g, accounting for 7% of the total left ventricular mass. (G) Increased native T1 time (1,010 ms). (H) Increased native T2 time (63 ms). (I) Increased extracellular volume fraction (45%).

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  Figure 2. Genetic Findings and Family Pedigree (A) Family pedigree. The patient (indicated by an arrow) had 7 offspring, 3 of whom died in the neonatal period. (B) Sanger sequencing of the patient and family members identified a heterozygous intronic mutation in the SLC25A20 gene (NM_000387.6: c.199-10T>G). DCM = dilated cardiomyopathy; HF = heart failure; m = months; mut = mutation; VT = ventricular tachycardia; wt = wild-type; y.o. = years old. Pedigree symbols: squares for males, circles for females, diagonal lines represent deceased, black-filled symbols denote affected individuals, gray-filled symbols for uncertain cardiac phenotype, and white-filled symbols denotes healthy individuals.

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  Figure 3. Imaging-Based Assessment of Heart Failure Treatment Response (A and B) 12-lead electrocardiogram (ECG) before and after cardiac resynchronization therapy with defibrillator (CRT-D) implantation. Pre-CRT-D implantation, ECG demonstrated complete left bundle branch block, whereas after CRT-D implantation, ECG showed reduced QRS duration. (C to E) Speckle-tracking echocardiography at admission, after 2 months of guideline-directed medical therapy, and after CRT-D implantation demonstrated improvements in left ventricular ejection fraction from 32% to 39% to 46% and in global longitudinal strain from –7% to –14.7% to –16%. (F and G) M-mode echocardiography assessing left ventricular ejection fraction using the Teichholz method showed systolic dyssynchrony between the interventricular septum (arrowhead) and posterior left ventricular wall (arrow) before CRT-D implantation, with restoration of synchrony after CRT-D implantation.