Hi skep,
my 2 cents:
if I'm reading this right, the short run of 5 beats is a run of supraventricular ectopics. Supraventricular = atrial. I don't believe that is ventricular tachycardia, to my knowledge V-tach is a sequence of at least 3 PVC's at a rate greater than 100.
Please don't take me wrong, I am no doctor, nor am I a specialist at interpreting ecg's , I've just read quite a lot about arrhythmias lately.
the other thing, even if say those 5 beats were v-tach, that would be non-sustained v-tach (meaning that it lasted less than 30 seconds) and I've been told by a cardiologist that I should not worry about anything like that.
A nonconducted ectopic P wave could be an early PAC (ectopic beat) that isn't conducted to the heart chambers. This is completely normal.
A nonconducted sinus P wave (normal P wave) does imply something called an AV block. This is also normal during sleep to some extent. Based on what I've been reading this becomes concerning only if it happens a lot, isolated episodes are usually dismissed as "normal".
I'm quite sure Dr. Rane will get back to you and you'll get a better picture of what goes on.
Best,
Alex

Okay, isolated supraventricular ectopics is simply a fancy way of stating atrial premature atrial contraction. Supraventricular means above the ventricles.

Multifocal ventricular ectopics simply defines multiple myocardial tissues being excited simultaneously within the ventricles. It would be analogous to an electrical shock from an outlet causing other proximal tissues to respond aside from those in direct contact with the current source.  

A non-conducted P wave is simply a measured P wave that is not followed by the standard QRS wave pattern. In other words, it constitutes a dropped beat. This does not necessarily mean that your heart stopped receiving signals from the sino-atrial node or pacer, but merely that the P wave conductivity itself was merely abhorrent. The beat could have been superimposed upon, creating a canceling effect but in all instances constitutes a variant of normal cardiac rhythm over the course of time.

Bradycardia is classified and measured as any rhythm below 55bpm and unless associated with persistence by underlying causes, is entirely normal, particularly during sleep.

People are often approximating the general clinical rule of 5 beats constituting an arrhythmia, but the characterization is largely incorrect from the point of specificity. We often use the rule to more closely examine patterns consisting of five or greater abnormal heartbeats which in certain instances may be suggestive of fibrillation. While certain instances may reveal a period of accelerated atrial or ventricular rhythm, it takes far more evidence than a general rule of thumb to classify it as a cardiac arrhythmia. In your instance in particular, it was recorded as a limited run of 5 atrial beats, or what is more commonly known as paroxysmal atrial tachycardia if you try to hold it to the general rule of thumb. Again, however, it is not the case and no mention was made of PAT.

Five abnormally fast beats does not characterize an arrhythmia and if you are person who exercises, your sinus rhythm regularly extends beyond the range of 100bpm and is clinically defined as tachycardia, with the exception that it is present under exertion rather than at rest.

Lastly, remember that your heart is part of a biological phenomenon and variability is one of the classic features of normality, not the expectation of absolute perfection. If that were actually the case, then we'd have no illness, disease or even death. Setting expectations of performance well beyond the actual true nature of biological function will only set one up for constant disappointment.

I'm going to call the description of your study to be entirely normal and within the accepted range for an entirely normal, healthy human heart.

Best regards,

Rutheford Rane, MD (ret.)