Late gadolinium enhancement cardiovascular magnetic resonance in genotyped hypertrophic cardiomyopathy with normal phenotype

A 35 year-old asymptomatic Caucasian female with a family history of hypertrophic cardiomyopathy (HCM) was referred for cardiologic evaluation. The electrocardiogram and transthoracic echocardiogram were normal. Cardiovascular magnetic resonance (CMR) was performed for further assessment of myocardial function and presence of myocardial scar. CMR showed normal left ventricular systolic size, measurements and function. However, there was extensive, diffuse late gadolinium enhancement (LGE) throughout the left ventricle. This finding was consistent with extensive myocardial scarring and was highly suggestive of advanced, non-ischemic cardiomyopathy. Genotyping showed a heterozygous mis-sense mutation (275G>A) in the cardiac troponin T (TNNT2) gene, which is causally associated with HCM. There have been no previous reports of such extensive, atypical pattern of myocardial scarring despite an otherwise structurally and functionally normal left ventricle in an asymptomatic individual with HCM. This finding has important implications for phenotype screening in HCM

Interatrial block: correlation with P-terminal force

BACKGROUND AND HYPOTHESIS: Interatrial block (IAB: P-duration \u3e 100 ms) is poorly recognized in hospital populations. In addition to reduced left atrial function and left atrial enlargement it predicts atrial fibrillation and other arrthymias. P-terminal force (Ptf): +/- biphasic P in lead V(1) \u3e or = area of 1 small square on the electrocardiogram (ECG) grid also indicates left atrial abnormality, particularly left atrial enlargement. These 2 should be related. We determined the intercorrelation. METHODS AND RESULTS: Two blinded observers evaluated 500 consecutive patients\u27 ECGs for both Ptf and IAB utilizing all 12 leads for IAB and V(1) for Ptf. Measurement differences were resolved in a consensus conference. Among 482 usable ECGs, IAB and Ptf were strongly and significantly correlated (chi(2) = 68.041; P \u3c or = .001). CONCLUSION: IAB and Ptf are significantly and strongly correlated and one should be expected in the majority of cases when the other is recognized