The Patient: Unfortunately, this is an old tracing, and we do not have patient information, other than the list of medications the patient has been taking, (Lasix, Capoten, Ntg, and Procardia). Lasix (furosemide) is a potassium – wasting diuretic. Capoten (captopril) is an ACE inhibitor. Ntg is presumably sublingual nitroglycerine used for angina. Procardia (nifedipine) is a calcium-channel blocker. So, we can assume the patient was probably being treated for angina, heart failure, and hypertension.
The ECG: The first impression is that is a regular WIDE COMPLEX TACHYCARDIA. The ventricular rate is 100 bpm (Starts a little faster at the beginning at 106, then is 100 by the end). The QRS duration is about 250 ms (.25 seconds) – VERY WIDE. There appear to be P waves outside the QRS complexes in V1 and aVL, but probably buried in the ST-T of other leads.
We were all taught to treat all wide complex tachycardia (WCT) as VENTRICULAR TACHYCARDIA (VT) until proven otherwise. This is a very good rule, especially in an emergency setting. It pays to take a moment to consider the possibility of REGULAR REALLY WIDE COMPLEX TACHYCARDIA (RRWCT) before making a treatment decision.
An extremely wide QRS can occur because of a number of very concerning reasons, most involving blockade of the sodium channels. Included in this category are: