HUBUNGAN ANTARA DURASI R’ PADA SANDAPAN V1 DENGAN FUNGSI SISTOLIK VENTRIKEL KANAN PADA PASIEN DENGAN POLA ELEKTROKARDIOGRAFI COMPLETE RIGHT BUNDLE BRANCH BLOCK (CRBBB) DI KOTA MAKASSAR = CORRELATION BETWEEN R' DURATION AT LEAD V1 WITH THE RIGHT VETRICULAR SYSTOLIC FUNCTION IN PATIENTS WITH COMPLETE RIGHT BUNDLE BRANCH BLOCK (CRBBB) IN MAKASSAR

Backgrounds: Hemodynamic disturbances in right ventricle may suppress the right bundle branch and existing Purkinje fibers, which will lead to conduction delays or block on electrocardiography. Right bundle branch block (RBBB) is often found in the Emergency Department, mostly incidentally and lamentably, is often ignored by the physician. We hypothesized that longer duration of R' in lead V1 could be an indicator of impaired right ventricular systolic function in patients with RBBB.
Methods: Patients with CRBBB electrocardiographic patterns in both the outpatient and inpatient clinics of Makassar Cardiac Center were screened and selected using inclusion and exclusion criteria. After being screened, 70 subjects were found to meet the criteria to participate in this study. Transthoracic echocardiography examination was performed on all subjects, and the echocardiographic parameters were measured on Tricuspid Annular Plan Systolic Excursion (TAPSE), S' lateral velocity, Right Ventricular Fractional Area Change (RVFAC), and RV Strains. The results were analyzed with Mann-Whitney U Test on subjects with or without impaired right ventricular systolic function. The correlation analysis was performed using Spearman. ROC curve was performed for each parameter to determine the optimal cut-off of duration R' at V1 for determining the presence of impaired right ventricular systolic function.
Results: We found a significant difference in R' duration in V1 between the normal RV (85.3 ± 9.5 ms) and group with RV dysfunction (107.1 ± 23.2 ms) with a significance value of p < 0.001. In our study, duration R' of 115 ms using the Youden Index was found as the optimal cut off to predict the right ventricular systolic dysfunction. Correlation between R’duration with TAPSE, S' lateral, RV Free wall strain, and FAC were -0.587, -0.623, -0.640, -0.691, respectively. Those three variables R' duration, QRS duration, and R/QRS ratio were statistically equivalent in sensitivity and specificity and could detect RV systolic dysfunction, with AUC (area under ROC curve: 0.73 (95% CI 0.60 – 0.86), p=0.001 for R' duration, AUC 0.71 (95% CI 0.59 – 0.84), p = 0.002 for QRS duration, and AUC 0.77 (95% CI 0.65 -0.89), p < 0.001 for R'/QRS ratio.
Conclusion: Longer R' duration in lead V1 in patients with CRBBB-electrocardiographic pattern could be used an indicator of impaired right ventricular systolic function. Longer R' duration of more than 115 ms in lead V1 might predict an impaired right ventricular systolic function

Keywords : EKG, Fungsi sistolik ventrikel kanan, CRBBB