Abstract
Background
Early repolarization pattern (ERP) has been generally described as a benign electrocardiographic (ECG) sign despite it is associated with the development of malign ventricular arrhythmias. Although the pathophysiological mechanism of malign ventricular arrhythmias in ERP has been explained only electrophysiologically, whether the presence of structural changes in myocardium has not been known yet.
Purpose
We hypothesized that ERP is not only an ion channel disease. The structural changes in myocardium begin in individuals with ERP sign on 12 lead surface ECG even if a young person. The aim of the present study was to determine myocardial dysfunction due to early decaying in myocardial structure in individuals with ERP sign by the use of 2D- speckle tracking echocardiography (STE).
Method
We prospectively included 99 individuals who admitted to our clinic between 01.04.2018 and 01.09.2018. 48 individuals had ERP. 12 lead surface ECG was taken from all individuals at admission, all individual's ECG were further analysed for presence of ERP and ERP was divided into three groups which were defined as presence of ST elevation, J wave and QRS slurring. 2D-STE (Philips Epiq 7C Ultrasound System for Cardiology (Andover, USA)) was performed in all individuals. All strain echocardiographic recordings were further analysed off- line by the use of associated software.
Results
ERP had significantly lower left ventricular (LV) global longitudinal strain (GLS), circumferential peak systolic strain rate (CPSSr) in basal segments of LV and left ventricular ejection fraction compared to controls. In addition, LV diastolic function especially in LV basal segments were significantly impaired in individuals with ERP when assessed by circumferential peak diastolic strain rate (CPDSr) compared to controls. GCS, LV- longitudinal peak systolic Sr (LPSSr) and LV- longitudinal peak diastolic Sr (LPDSr) in all of the apical chambers were similar between two groups (Table 1). There was not a relationship between type of ERP and all of these parameters including GLS, GCS, LPSSr, CPSSr, LPDSr, CPDSr. Finally, ST elevation pattern had higher GCS value while QRS slurring pattern had higher GLS value (Figure 1).
Figure 1 and Table 1
Conclusion
Our study firstly demonstrated ERP can be combined of structural and electrical heart disease. LV-GLS can be more closely associated with ERP than LV-GCS. In addition, the either of impaired of circumferential systolic and diastolic function in LV basal segments can be detected in individuals with ERP.
Sudden cardiac death and inherited channelopathy: the basic electrophysiology of the myocyte and myocardium in ion channel disease