This nice example of atrial flutter offers many teaching opportunities. "Sawtooth" flutter waves are readily visible in Leads II, III, avF, and V1, typically good "P wave" leads. Other leads show small, discreet P waves that the beginning student might not recognize as flutter waves because they don't produce the sawtooth pattern. The P waves' rate, approximately 360/min., gives them away as atrial flutter. This is also a good example of a constant 4:1 conduction, resulting in a regular QRS rhythm and regular pulse, at a rate of about 90/min. This demonstrates that not all narrow-complex rhythms between 60 and 100 bpm are "NSR". The low voltage in the limb leads makes this a good ECG to demonstrate that the flutter waves are regular and do not pause when the QRS happens, illustrating the separate actions of the atria and the ventricles. For students just learning 12-lead interpretation, this ECG serves to show that acute ST elevation M.I. is not the only valuable information that can be obtained from a 12-Lead, and that some leads are better than others for showing dysrhythmias.
Pacemaker Mediated Tachycardia
PACEMAKER MEDIATED TACHYCARDIA is a term for several different mechanisms that cause inappropriately fast rates in a paced patient. It is a very interesting topic, which I will not attempt to discuss here, because it has been done to perfection by DR. KEN GRAUER, MD, with assistance from JASON ROEDIGER, CCT, CRAT in Dr. Grauer's ECG Consult #13 Please follow this link to a concise, complete, and illustrated discussion of PMT.
Do you ever feel confused by pacemaker rhythms? You are not alone! Pacemakers are electronic devices, and have rapidly evolved in their capabilities. Often, we call the manufacturer's representative to come and interrogate a patient's pacemaker to determine if it is behaving as it was programmed. Without knowing the programming of the individual pacemaker, it can be hard to evaluate the patient's rhythm.