In myocardial excitation, the delay between the excitation of the atria and ventricles is determined by the sum of atrial and atrioventricular nodal conduction. This delay, measured in milliseconds, ...

The rhythm is irregularly irregular (ie no consistency to the RR intervals). There are three supraventricular rhythms that are irregularly irregular: Sinus arrhythmia, in which there is one P wave ...

A 68-year-old male with morbid obesity and no past medical history comes to the office complaining of fatigue and shortness of breath. He does not feel dizzy and has never passed out. He takes no ...

Current methods for assessing perinatal hypoxic conditions did not improve infant outcomes. Various waveform-based and interval-based ECG markers have been suggested, but not directly compared. We ...

Second Degree Type I AV Block 2:1 AV block Some P waves conduct to the ventricles on this ECG tracing, however it is clear that some do not. There does appear to be a prolonging PR interval before ...

A common electrocardiogram finding that has largely been considered insignificant may actually signal an increased risk of atrial fibrillation, the future need for a permanent pacemaker and an ...

QRS interval widening appears to be highly specific for the diagnosis of hyperkalemia in patients with end-stage kidney disease. ECG changes, in general, have poor sensitivities for hyperkalemia in ...