Cardiogenic shock in a woman with a mitochondrial cardiomyopathy: a case report

Figures

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  Figure 1. Admission electrocardiogram. The patient was in sinus tachycardia with a heart rate = 102 beats/min. A large P wave (>2.5 mm) is present in Lead II, indicating right atrial enlargement. A large negative P wave is present in Lead V1 (>1 mm deep and >1 mm wide), indicating left atrial enlargement.

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  Figure 2. Cardiac magnetic resonance imaging of a 35-year-old female patient who presented with suspected cardiogenic shock. (A) Cine images demonstrated a dilated left ventricle (left ventricular end-diastolic dimension = 56 mm) with severe systolic dysfunction and severe secondary MR (yellow arrow indicates MR jet through the mitral orifice). (B) Inversion recovery images in short axis view at mid-ventricle level and (C) modified 4 chamber view demonstrating late gadolinium enhancement (red arrows) of the septal, inferior, and inferolateral walls in a midwall and subepicardial pattern, consistent with a non-ischaemic cardiomyopathy. The left ventricular walls in the septal, inferior, and inferolateral distributions are thinned.

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  Figure 3. Left deltoid muscle biopsy histopathology. (A) Ragged red fibers with an altered myofibrillar network consisting of increased positive subsarcolemmal staining (asterisk, Modified Gomori Trichrome Stain). (B) Type 1 myofiber predominance (tan) with Type 2 specific myofiber atrophy (brown) (Alkaline ATPase 10.2 Stain). (C) Myofibers with cytochrome oxidase (COX) stain absent (asterisk, COX stain). (D) Subsarcolemmal mitochondria accumulation with paracrystalline inclusions (PCIs, arrow), swollen mitochondria (Mit), and lipid droplets (L) between myofibrils (MF, electron microscopy original magnification ×13 000). Rectangular inset with higher magnification highlighting PCIs.

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  Figure 4. Left ventricular excisional core biopsy histopathology following LVAD placement. (A) Hematoxylin and Eosin stained, formalin-fixed paraformaldehyde-embedded section demonstrates dense fibrosis, myocyte hypertrophy, myofibrillar loss. (B) Periodic-Acid-Schiff-stained section showing blue, positively stained vacuoles indicative of glycogen accumulation. These features, in the appropriate clinical context, are suggestive of a mitochondrial cardiomyopathy. Blue scale bar = 50 µm.

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  Figure 5. Mitochondrial DNA deletions. The human mitochondrial genome is circular and encompasses a total 16 569 base pairs which code for 22 transfer ribonucleic acids (RNAs) (yellow), 2 ribosomal RNAs (green), and 13 polypeptides involved in the mitochondrial respiratory chain (purple; one polypeptide is encoded within MT-RNR2 and two polypeptides are encoded in MT-ATP6/8). The patient has mtDNA deletions denoted as ‘D1’ (m.2819 _16072del13254) and ‘D2’ (m.6342_14004del7663). The length of each associated red arc approximates the span of the deletions in kilobases (kb). Italicized genes in red are affected by these deletions.