Tunggulah hingga depolarisasi nodus sinoatrial. Carilah gelombang P yang diikuti dengan interval PR. Identifikasi kompleks QRS. Pelajari cara merekam hasil EKG. Gunakan hasil EKG untuk menentukan laju denyut jantung.

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
The normal cardiac cycle starts with depolarization of the sinus node. This occurs in a specialized tissue that is located in the right atrium (RA).  The electrical activity (depolarization) commences from the right atrium through the inter-atrial septum to the left atrium (LA). The atrium and ventricles are separated by the atrioventricular node (AV). The AV node delays the electrical activity for a short while and then it spreads down through the interventricular septum into the right (RV) and