Arrhythmogenic right ventricular cardiomyopathy/dysplasia on the basis of the revised diagnostic criteria in affected families with desmosomal mutations

Aims To evaluate arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) in affected families with desmosome mutations on the basis of the recently revised Task Force Criteria (TFC).Methods and results One hundred and three consecutive carriers of pathogenic desmosome mutations and 102 mutation-negative relatives belonging to 22 families with dominant and 14 families with recessive ARVC/D were evaluated according to the original and revised TFC. Serial cardiac assessment with 12-lead, signal-averaged, and 24 h ambulatory ECG and two-dimensional echocardiography was performed. Clinical events and outcome were prospectively analysed up to 24 years (median 4 years). With the revised criteria, 16 carriers were newly diagnosed on the basis of ECG abnormalities in 100%, ventricular arrhythmias in 79%, and functional/structural alterations in 31%, increasing diagnostic sensitivity from 57 to 71% (P=0.001). Task Force Criteria specificity improved from 92 to 99% (P=0.016). In dominant mutation carriers, penetrance changed significantly (61 vs. 42%, P=0.001); no changes were observed in recessive homozygous carriers (97 vs. 97%, P=1.00). Affected carriers according to the revised TFC (n=73) had 12-lead ECG abnormalities in 96%, ventricular arrhythmias in 91%, and functional/structural alterations fulfilling echocardiographic criteria in 76%. Cumulative and event-free survival did not differ significantly between dominant and recessive affected carriers, being at 78.6 vs. 76 and 51.7 vs. 55.4%, respectively, by the age of 40 years.Conclusion Revised TFC increased diagnostic sensitivity particularly in dominant ARVC/D. Serial family evaluation may rely on electrocardiography which seems to have the best diagnostic utility particularly in early disease that is not detectable by two-dimensional echocardiography

Phenotype reveals genotype in a Greek long QT syndrome family

We aimed to verify the tong QT syndrome (LQTS) genotype in a family with strong evidence of LQTS type 1 (LQT1) on the basis of so far established genotype-phenotype correlations. Genetic testing for mutations in the KCNQ1 potassium channel gene revealed an A341V mutation in three generations of the family. Existing genotype-phenotype correlations were correctly predictive of the genotype in the case of this family, despite the fact that there are no previously reported data for the Greek LQTS genetic pool. Thus, genotype-phenotype correlations are often a helpful tool in the management of LQTS patients and their families

Phenotype reveals genotype in a Greek long QT syndrome family

We aimed to verify the tong QT syndrome (LQTS) genotype in a family with strong evidence of LQTS type 1 (LQT1) on the basis of so far established genotype-phenotype correlations. Genetic testing for mutations in the KCNQ1 potassium channel gene revealed an A341V mutation in three generations of the family. Existing genotype-phenotype correlations were correctly predictive of the genotype in the case of this family, despite the fact that there are no previously reported data for the Greek LQTS genetic pool. Thus, genotype-phenotype correlations are often a helpful tool in the management of LQTS patients and their families

ST Segment “Hump” during Exercise Testing and the Risk of Sudden Cardiac Death in Patients with Hypertrophic Cardiomyopathy

Background: The appearance of a discrete upward deflection of the ST segment termed “the ST hump sign” (STHS) during exercise testing has been associated with resting hypertension and exaggerated blood pressure response to exercise. Objective: We investigated the prevalence and clinical significance of this sign in a population of patients with hypertrophic cardiomyopathy. Methods: Eighty-one patients with hypertrophic cardiomyopathy (HCM) who underwent cardiopulmonary exercise testing were followed in a retrospective cohort study for a mean period of 5.3 years. Results: The appearance of the STHS at the peak of exercise testing was observed in 42 patients (52%), particularly in the inferior and the lateral leads. Patients with the STHS had higher fractional shortening and maximum left ventricular wall thickness and exhibited more frequently outflow tract gradient > 30 mmHg at rest. Furthermore, the presence of STHS was a strong independent predictor of the risk of sudden cardiac death (SCD), as the latter occurred in eight of the patients with this sign (8/42, 19%) and in none of the patients without it (0/39, 0%) (P < 0.001). Conclusion: The appearance of a “hump” at the ST segment during exercise testing appears to be a risk factor for SCD in patients with HCM. However, further studies are necessary to validate this finding in larger populations and to elucidate the mechanism of the appearance of the “hump.” Ann Noninvasive Electrocardiol 2009;14(2):158-164