though atrial flutter with variable conduction of the P waves can also occur. In this situation, there may be three P waves to one QRS complex, then a quick change to two P waves to one QRS ...

When atrial flutter is seen with such a slow ventricular response (in this case, 9:1 conduction), there is concern for underlying complete heart block should the patient be restored to normal ...

Complete AV or bundle branch block or other severe intraventricular conduction defects ... abnormal rhythms due to escape mechanisms. Atrial flutter; digitalize first. Incomplete AV block.