The following is a summary of “Predicting factors for unresolved premature ventricular complexes in healthy children,” ...

Note that intermittent 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 some dropped beats ...

Of course, such an approach requires more than a single ECG tracing. Incorporation of these ideas in one's "routine" is not cumbersome, necessary information derives from ubiquitously available ...