This is commonly described as varying RR intervals. This means an ECG showing atrial fibrillation will have no visible P waves and an irregularly irregular QRS complex. The ventricular rate is ...

If no P waves can be seen and the QRS complexes ... Hypokalemia causes U waves in the ECG seen as a positive wave just after the T wave. Hyperkalemia causes peaked T waves initially, then an ...

A new study shows that SCD is linked to prolonged P-wave duration, even in individuals with no coincident cardiovascular ... avoided using electrocardiogram (ECG) for early detection of prolonged ...