Cardiac Emergencies Flashcards

A patient presents with palpitations and the ECG shows a narrow-complex tachycardia at 160 bpm with no visible P waves. Vagal maneuvers are ineffective. What is the next treatment?

Answer: Adenosine 6 mg rapid IV push

For stable SVT unresponsive to vagal maneuvers, adenosine 6 mg IV rapid push is the first pharmacological treatment per ACLS.

Which ECG finding is most consistent with right ventricular infarction complicating an inferior STEMI?

Answer: ST elevation in right-sided lead V4R

ST elevation in right-sided lead V4R is the most sensitive and specific indicator of right ventricular infarction.

A patient with inferior STEMI and RV infarction develops hypotension. Which intervention is contraindicated?

Answer: Nitroglycerin administration

Nitroglycerin is contraindicated in RV infarction because the RV is preload-dependent, and reducing venous return can precipitate severe hypotension.

Torsades de pointes is most commonly associated with which electrolyte abnormality?

Answer: Hypomagnesemia

Hypomagnesemia is the most common electrolyte cause of Torsades de pointes, and IV magnesium sulfate is the treatment of choice.

A patient with a history of Wolff-Parkinson-White (WPW) syndrome develops atrial fibrillation with a rapid ventricular response. Which drug is contraindicated?

Answer: Diltiazem

AV nodal blocking agents like diltiazem, verapamil, digoxin, and adenosine are contraindicated in WPW with AF as they can accelerate conduction through the accessory pathway.

A patient presents 2 hours after cocaine use with chest pain and diaphoresis. ECG shows ST elevation in V1-V4. Which medication should be avoided?

Answer: Non-selective beta-blockers

Non-selective beta-blockers are contraindicated in cocaine-induced coronary spasm because they can cause unopposed alpha-adrenergic stimulation, worsening vasospasm.

Which finding on a 12-lead ECG indicates posterior MI?

Answer: Tall R waves and ST depression in V1-V2

Posterior MI presents as a mirror image on standard leads, showing tall R waves, ST depression, and upright T waves in V1-V2, which represents posterior ST elevation when viewed from the back.