A 50ish Man whose Wide Tachycardia was Treated

===================================MY Comment by KEN GRAUER, MD (5/22/2020):===================================The ECG in Figure-1 was obtained from a 50-ish year-old man, who was found by the EMS team to be in a wide tachycardia. The patient was treated on the scene with medication. ECG #1 shows the results of such treatment.Is this patient now in sinus tachycardia (RED arrow)?Figure-1: The 12-lead ECG and long lead II rhythm strip obtained after medication converted a wide tachycardia (See text).My THOUGHTS on ECG #1: It is tempting to accept the RED arrow in Figure-1 as highlighting an upright sinus P wave in lead II.The “good news” — is that this patient had been in a wide tachycardia prior to administration of medical treatment. The QRS complex in ECG #1 is now narrow — so the patient is in a regular SVT ( = SupraVentricular Tachycardia) rhythm at a rate of ~115/minute.QUESTION: Is there extra atrial activity in Figure-1?HINT: Using calipers makes it much easier to answer this question!ANSWER: Although tempting to accept the RED arrow in Figure-1 as pointing to a sinus P wave — several factors should make you skeptical of this conclusion:IF the rhythm in Figure-1 was sinus tachycardia — the ventricular rate of ~115/minute is fairly fast ...Several leads...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs