Cardiac abnormalities in patients with mitochondrial DNA mutation 3243A>G

Abstract

BackgroundTissues that depend on aerobic energy metabolism suffer most in diseases caused by mutations in mitochondrial DNA (mtDNA). Cardiac abnormalities have been described in many cases, but their frequency and clinical spectrum among patients with mtDNA mutations is unknown.MethodsThirty-nine patients with the 3243A>G mtDNA mutation were examined, methods used included clinical evaluation, electrocardiogram, Holter recording and echocardiography. Autopsy reports on 17 deceased subjects were also reviewed. The degree of 3243A>G mutation heteroplasmy was determined using an Apa I restriction fragment analysis. Better hearing level (BEHL0.5–4 kHz) was used as a measure of the clinical severity of disease.ResultsLeft ventricular hypertrophy (LVH) was diagnosed in 19 patients (56%) by echocardiography and in six controls (15%) giving an odds ratio of 7.5 (95% confidence interval; 1.74–67). The dimensions of the left ventricle suggested a concentric hypertrophy. Left ventricular systolic or diastolic dysfunction was observed in 11 patients. Holter recording revealed frequent ventricular extrasystoles (>10/h) in five patients. Patients with LVH differed significantly from those without LVH in BEHL0.5–4 kHz, whereas the contribution of age or the degree of the mutant heteroplasmy in skeletal muscle to the risk of LVH was less remarkable.ConclusionsStructural and functional abnormalities of the heart were common in patients with 3243A>G. The risk of LVH was related to the clinical severity of the phenotype, and to a lesser degree to age, suggesting that patients presenting with any symptoms from the mutation should also be evaluated for cardiac abnormalities.

Myocardial glucose uptake in patients with the m.3243A > G mutation in mitochondrial DNA

“…The m.3243A>G mutation heteroplasmy, i.e. the proportion of the mutated mtDNA out of total mtDNA, was determined in the buccal epithelium (Majamaa-Voltti et al 2002). The heteroplasmy showed a good correlation (r=0.68, P= 0.021) with that in skeletal muscle in the 11 patients in whom the data were available.…”

Mitochondrial Mutations in Left Ventricular Hypertrophy

“…The hypothesis of biogenesis of LVH has been supported by plethora of mtDNA mutations. Majamaa-Voltti K et al [11] reported that 3243A>G mtDNA mutation is associated with LVH. Lin Z, et al [12] found G8584A mtDNA mutation may influence LVH in hypertensives.…”

Maternally-inherited diabetes with deafness (MIDD) and hyporeninemic hypoaldosteronism

“…Patients with MIDD also have considerable risk for cardiac disorders. Left ventricular hypertrophy, Wolff-Parkinson-White syndrome and other cardiac conduction abnormalities, as well as heart failure have been reported in these patients (1,(12)(13)(14). In addition to diabetes, short stature is the most common endocrine manifestation of MIDD, and a deficiency in the release of growth hormone has been reported (15).…”