Right bundle branch block (RBBB) can be identified by changes in the electrocardiogram (ECG).
Features of RBBB:
(1) duration of QRS >= 0.12 seconds (120 milliseconds) with slurring in the middle to late portions
(2) V1 and/or V2 show a secondary R wave (R') with ST segment depression and T wave inversion
(3) V5 and V6 show wide slurring of the S wave
(4) lead I shows wide slurring of the S wave
