Chronological change of left ventricular global longitudinal strain in patients with maternally inherited diabetes and deafness: A case series

Abstract

Rationale: Maternally inherited diabetes and deafness (MIDD) is a rare genetic disorder arising from mitochondrial DNA mutations, characterized by a combination of diabetes mellitus and sensorineural deafness. It is known that MIDD patients with cardiomyopathy have a poor prognosis, but there are no established guidelines for the diagnosis and follow-up of cardiomyopathy in MIDD patients.

Patient concerns: Patient 1 was a 48-year-old woman who visited the hospital with cardiomegaly and had been taking oral hypoglycemic agents for 8 years. Patient 2 was a 21-year-old man, the son of patient 1, who visited the hospital for genetic screening. Patient 2 was also diagnosed diabetes mellitus 2 years ago.

Diagnosis: Patient 1 was found to have restrictive cardiomyopathy on echocardiography and underwent endomyocardial biopsy and genetic testing to determine the etiology. The m.3243A>G mutation was confirmed and she was diagnosed with MIDD accompanied with diabetes and hearing loss. Additionally, patient 2 had m.3243 A>G mutation and was diagnosed with MIDD due to diabetes and hearing loss.

Interventions: Because MIDD does not have a specific treatment, patient 1 took ubidecarenone (coenzyme Q10), acetylcarnitine, and multivitamin along with the treatment for diabetes control and heart failure. Patient 2 was taking ubidecarenone (coenzyme Q10), acetylcarnitine, and multivitamin along with treatment for diabetes.

Outcomes: She subsequently underwent routine transthoracic echocardiography, and a progressive decline in global longitudinal strain (GLS) was first observed, followed by a worsening of the patient's clinical situation. Patient 2 had concentric remodeling and decreased GLS. On periodic echocardiography, GLS decreased at a very slow rate, and the patient's clinical course was stable.

Lessons: The findings of this report contribute to the understanding of the clinical course of MIDD-associated cardiomyopathy and highlight the potential of GLS as a sensitive marker for disease progression.

Figure 1.

Transthoracic echocardiograms of Patient 1. (A) Parasternal long axis. (B) Parasternal short axis. (C) Mitral inflow. (D) Septal mitral annulus tissue Doppler image.

Figure 2.

Chronological change of the global longitudinal strain of Patient 1. (A) Initial (B) 1-year follow-up. (C) Two-year follow-up. (D) Three-year follow-up. (E) Four-year follow-up. (F) Five-year follow-up.

Figure 3.

Delayed gadolinium enhancement of the cardiac magnetic resonance images of Patient 1. (A) Left ventricular (LV) base, (B) mid LV, and (C) LV apex.

Figure 4.

Microscopic findings of Patient 1. (A) Hematoxylin and eosin staining, magnification ×400. (B) Periodic acid–Schiff staining, magnification ×400. (C) Masson trichrome staining, magnification ×400. (D) Nicotinamide adenine dinucleotide staining, magnification ×400.

Figure 5.

Transmission electron microscopic findings of Patient 1. (A) Magnification ×4000. (B) Magnification ×25,000. (C) Magnification ×30,000. (D) Magnification ×40,000.

Figure 6.

Chronological change of the global longitudinal strain of Patient 2. (A) Initial. (B) 2-year follow-up. (C) Four-year follow-up. (D) Six-year follow-up.