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Infantile cardiomyopathy is a genetically heterogeneous disorder with significant morbidity and mortality.This study aimed to identify the mutation present in four unrelated patients who presented as infants with isolated hypertrophic cardiomyopathy.In all four, a novel mitochondrial m.8528T--C mutation was identified. This results in a change of the initiation codon in ATPase 6 to threonine and a concurrent change from a highly conserved hydrophobic amino acid, tryptophan, at position 55 of ATPase 8 to a highly basic arginine. To our knowledge, this is the first report of a mutation affecting both mitochondrial genome-encoded complex V subunit proteins. Testing of the relatives of one patient indicated that the mutation is heteroplasmic and correlated with disease.Mitochondrial genome sequencing should be considered in patients with infantile hypertrophic cardiomyopathy.

Objective Our purpose was to evaluate yield of tools commonly advocated for surveillance of tetralogy of Fallot (TOF). Methods All patients (pts) with TOF, seen at any time from 1/2008 to 9/2013 in an academic cardiology practice were studied. At the first and each subsequent outpatient visit, the use of tools including history and physical (H&P), ECG, Holter (HOL), echocardiogram (Echo), MR or CT (MR-CT) and stress testing (STR) were noted. Recommendations for intervention (INT) and for time to next follow-up were recorded; rationale for each INT with attribution to one or more tools was identified. Results There were 213 pts (mean 11.5 years, 130 male) who had 916 visits, 123 of which (13.4%) were associated with 138 INTs (47 surgical, 54 catheter-mediated, 37 other medical). Recommended follow-up interval was 9.44±6.5 months, actual mean follow-up interval was 11.7 months. All 916 (100%) patient visits had a H&P which contributed to 47.2% of INT decisions. Echo was performed in 652 (71.2%) of visits, and contributed to 53.7% of INTs. MR-CT was obtained in 129 (14.1%) of visits, and contributed to 30.1% of INTs. ECG was applied in 137 (15%) visits, and contributed to 1.6% of INTs. HOL was obtained in 188 (20.5%) visits, and contributed to 11.3% of INTs. STR was performed at 101 (11%) of visits, and contributed to 8.9% of INTs. Conclusions INTs are common in repaired TOF, but when visits average every 11–12 months, most visits do not result in INT. H&P, Echo and HOL were the most frequently applied screens, and all frequently yielded relevant information to guide INT decisions. STR and MR/CT were applied as targeted testing and in this limited, non-screening role had high relevance for INT. There was low utilisation of ECG and major impact on INT was not demonstrated. Risk stratification in TOF may be possible, and could result in more efficient surveillance and targeted testing.