A young man with tachycardia. Should We Try Adenosine?

A young man presented with weakness and fever.  His pulse was 186.  An ECG was recorded:What do you think?There is a regular narrow complex tachycardia. Thus, it is supraventricular tachycardia.  It is important to remember thatSVT includes Sinus Tachycardia!  That is why I like to call re-entrant SVT " Paroxysmal " SVT, or PSVT).  The sinus node is " supraventricular " and in young people it can beat VERY fast.  Especially when there is fever.You must look closely for P-waves, and if you do, the P-waves are obvious (if you look at the leads most likely to reveal P-waves: leads II and V1).  In lead II, the P-wave is always upright and has the greatest amplitude because the atrium depolarizes towards the apex (lead II).  Lead V1 because it should be biphasic, up-down (the positive deflection is the right atrium and the negative deflection is the left atrium.)So scrutinize this ECG for P-waves:lead II has an extra little bump before every QRS, and lead V1 has an up-down P-wave (the negative deflection is the easiest to see).Other strategies for discerning sinus tach:1. A heart rate that is not perfectly constant.  See if it changes gradually with fluids or antipyresis or just spontaneously.  Sinus tach will rarely remain exactly constant, while PSVT or flutter will always have the same re-entrant rate2. TryLewis Leads.  This is using the Monitor leads,not the 12-lead electrodes!See many cases with use of Lewis Lea...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs