The relationship between angiotensin converting enzyme gene I/D polymorphism and QT dispersion in patients with hypertrophic cardiomyopathy

Introduction: Hypertrophic cardiomyopathy (HCM) is characterized by disorganized myocardial architecture, and may cause ventricular arrhythmias and sudden death. The angiotensin-converting enzyme (ACE) with two deletion alleles (DD genotype) has been proposed to be associated with increased myocardial collagen content. We evaluated QT dispersion (QTd), which reflects regional differences in ventricular repolarization, in HCM patient and controls among the three different ACE genotypes. Materials and methods: Sixty-three patients with HCM and 20 healthy subjects were included in the study. QT parameters were measured from 12 lead electrocardiograms. ACE genotypes were determined from the DNA extracted from peripheral blood by a polymerase chain reaction (PCR) method. QT parameters were compared among the three ACE genotypes both in HCM patients and controls. Results: Median ages were similar in HCM and control groups. QTd and corrected QTd (QTcd) were significantly greater in the HCM group compared with the controls. The frequencies of each genotype were similar in both groups. Although QTd and QTcd did not differ among the three genotypes in the control subjects, they were significantly greater in patients with DD genotype compared with other genotypes in the HCM group. Conclusion: QTd and QTcd are increased in patients with HCM, especially in those with the DD genotype.