What does rsr' in v1 or v2 mean on an ecg?

Likely normal. Rsr', pronounced 'r s r-prime' can be a normal finding in leads v1 and v2. This pattern is often found in young healthy people. An rsr' with widening of the qrs and characteristic findings in other leads is due to a right bundle branch block. This is when the electrical pathway to the right ventricle is slower than the pathway to the left venricle (typically several milliseconds).