Syncope, Hypotension, and a Large Right Ventricle -- What is the ECG Diagnosis?

CaseA 60-something woman had syncope and was unconscious for a few minutes. It was not a seizure. EMS found her lethargic and short of breath but without chest pain. Pulse was 103, BP 100/60, and O2 saturation on room air 98%.She was brought to the ED, where her SpO2 was 93%, BP 88/48, pulse 100.On arrival in the ED, she underwent an immediate bedside cardiac ultrasound:What do you see?There is a very large RV and very poor LV filling; the LV ejection fraction is nearly 100%. It is easy to jump to the conclusion that this patient has a pulmonary embolism (hypotension, tachycardia, low O2 saturations, syncope, large RV).An ECG was recorded:What do you see?At first glance, this ECG also suggests pulmonary embolism. It shows an S1Q3T3. One might think this is then highly specific for pulmonary embolism. However, S1Q3T3 has a very limited (+) and (-) likelihood ratio for PE; it is seen in only 8.5% of patients with PE and 3.3% of patients who are evaluated for PE but do not have it. See this post for detailed information.This ECG has quite a bit more information: it shows sinus tachycardia with right axis deviation, alarge wide R-wave in V1 (but without complete RBBB), and ST depression with T-wave inversion in V2-V6. This is a typical ECG of right ventricular hypertrophy.Further historyFurther history revealed that the patient had poor po intake and vomiting.  Review of records revealed " chronic cor pulmonale " and a review of a...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs