Is There any Relationship Between Myocardial Repolarization Parameters and the Frequency of Ventricular Premature Contractions?
Background: Ventricular premature contractions (VPCs) may trigger lethal ventricular arrhythmias in patients with structural heart disease. However, this role of VPCs in healthy people remains controversial once that not enough clinical trials are available. Recently, some myocardial repolarization markers, such as Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios, have been reported to be useful for predicting lethal ventricular arrhythmias in various clinical disorders without structural heart disease.
Objective: In this study, we aimed to investigate the relation between VPC frequent and myocardial repolarization markers in individuals without structural heart disease.
Methods: This study included 100 patients who had complaints of dizziness and palpitations. Twelve lead electrocardiography and 24-hour ambulatory Holter recordings were obtained from all patients. VPC burden was calculated as the total number of VPCs divided by the number of all QRS complexes in the total recording time. P-values < 0.05 were considered significant.
Results: Tp-e interval and Tp-e/QTc ratio were significantly higher in patients with higher VPC burden than in patients with lower VPC burden, and a positive correlation was found between these markers and VPC burden. Tp-e (β = 1.318, p = 0.043) and Tp-e/QTc (β = -405.136, p = 0.024) in the lead V5 were identified as independent predictors of increased VPC burden.
Conclusions: Tp-e interval and Tp-e/QTc ratio increased in patients with high VPC number. Our study showed that VPCs may have a negative effect on myocardial repolarization. This interaction may lead to an increased risk of malignant arrhythmias. (Arq Bras Cardiol. 2018; 110(6):534-541)
Keywords: Ventricular Premature Complexes; Arrhythmias, Cardiac; Electrocardiography / methods; Cardiovascular Diseases; Obesity; Ventricular Dysfunction, Left.