Patient Presentation: 85 year old male had sudden onset shortness of breath and chest tightness while taking his dog out for a walk. The chest tightness is consistent with his usual angina discomfort but is far worse 9/10. PMHx: Angina, hypertension, CABG, hyperlipidemia. Meds: NitroDur patch, Altace, Lipitor, ASA.
What is YOUR interpretation?
ECG Interpretation: Ventricular Tachycardia Medical Council Notes: The most obvious thing about this ECG is that the QRS complexes are broad, and the rate is fast. The differential for a regular wide complex tachycardia includes ventricular tachycardia, supraventricular tachycardia with either aberrancy (bundle branch block) or pre-excitation, paced rhythm, or artifact. There are criteria that can be used to differentiate VT from SVT (those interested can look up Brugada criteria), however there are also some general rules that can be followed. For example, wide complex tachycardias that don’t have a RBBB or LBBB pattern are more likely to be VT. As well, those with a extreme axis (upright QRS in aVR, negative in I and aVF) are also more likely to be VT. Signs of AV dissociation (Ps and QRS complexes with no relation to each other) as well as fusion beats (a hybrid QRS between a sinus and ventricular originating QRS) and capture beats (an impulse from the SA node actually ‘gets through’ between the AV dissociation and produces a normal QRS) all lead to the diagnosis of VT. As well, positive or negative concordance in the precordial leads (all QRS complexes going up or down) is suggestive of VT. There are a few other criteria that can help, but the above are the most telling. This is a very difficult ECG to interpret. The above ECG certainly isn’t a slam dunk VT, indeed there are some features of RBBB in there. However, there are some features suggestive of VT. For example, if you look at the length of time between the R wave and S wave (look at V3-4), it seems to be greater than 100 ms, which is more convincing for VT. As well, there are some subtle findings of AV dissociation. If you look at the first complex in lead III, you’ll notice the overall morphology is different from the other complexes in the ECG. This is likely related to a P wave that has no relation to the QRS complex. If you look closely, there are a few other complexes that are suggestive of AV dissociation. As well, the patient factors in this case make the diagnosis to be more likely VT. VT is typically seen in the older population with pre-existing structural or ischemic heart disease, previous MIs, and cardiomyopathy of CHF. When in doubt, the rule is to treat a wide complex tachycardia as VT.