Diagnostic value of abnormal Q waves for identification of preclinical carriers of hypertrophic cardiomyopathy based on a molecular genetic diagnosis

Aims There are currently no established diagnostic criteria for the identification of abnormal Q waves in patients with hypertrophic cardiomyopathy (HCM), resulting in various definitions being applied in each previous study. The aim of this study was to determine the most accurate diagnostic definition of abnormal Q waves for HCM based on a molecular genetic diagnosis, and also to apply abnormal Q waves to the identification of preclinical carriers. Methods and results We applied three different criteria used in previous reports for abnormal Q waves in 148 genotyped subjects. Of the three criteria, Criterion 3 (Q wave >3 mm in depth and/or >0.04 s in duration in at least two leads except aVR) showed the highest sensitivity (50% in the young, 29% in adults) while retaining a high specificity (90% in the young, 97% in adults), resulting in the highest accuracy (69% in the young, 52% in adults). Using Criterion 3, abnormal Q waves were present 27.6% of preclinical carriers, and in 5.4% of non-carriers (P<0.01). Conclusions These findings suggest that Criterion 3 may be the most accurate diagnostic definition for HCM. Understanding the diagnostic value of abnormal Q waves may be useful in screening preclinical carriers of HCM. (C) 2003 The European Society of Cardiology. Published by Elsevier Ltd. ALL rights reserved.