Learn ECGs Fast | JMD Medical Ed on Instagram: "27-year-old is found confused at home. Sweaty. Tachycardic. Known history of depression and chronic pain. This ECG lands on your screen. Chase the rate, but look at the width. The QRS is wide. The QT is stretched. This isn’t a simple SVT and it’s not just “fast” - this is a myocardium under chemical attack. Tricyclic antidepressants like amitryptilline block fast sodium channels. That single mechanism explains the whole ECG: a widening QRS, QT prol