Clinical Mnemonics · Pharmacology & Electrolytes
IDEA
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Lists four drugs that can raise the heart rate in symptomatic bradycardia — Isoproterenol, Dopamine, Epinephrine, Atropine — as a memory aid, NOT the ACLS treatment algorithm.
The college version
Status: current, with caveats. The source library flags this one as still taught but qualified — read the safety notes on each component before relying on it.
Lists four drugs that can raise the heart rate in symptomatic bradycardia — Isoproterenol, Dopamine, Epinephrine, Atropine — as a memory aid, NOT the ACLS treatment algorithm.
I — Isoproterenol
Historical nonselective beta-agonist
Nonselective beta-agonist that increases rate and conduction but causes hypotension (peripheral vasodilation), increases myocardial oxygen demand, and is proarrhythmic; not in the current ACLS bradycardia algorithm.
Physiology. Beta-1 stimulation increases SA/AV nodal automaticity and conduction; beta-2 stimulation dilates peripheral vessels, dropping blood pressure.
Safety. Treat isoproterenol as historical for routine bradycardia; modern practice favors atropine, transcutaneous pacing, and epinephrine/dopamine.
D — Dopamine
Second-line infusion (5–20 mcg/kg/min)
Accepted second-line agent for atropine-refractory symptomatic bradycardia, providing chronotropic and inotropic support while pacing is arranged.
Physiology. Beta-1 stimulation increases heart rate and contractility; at higher doses alpha stimulation raises blood pressure via vasoconstriction.
Safety. Infuse via pump; titrate to rate and BP; monitor for tachyarrhythmias and extravasation.
E — Epinephrine
Second-line infusion (2–10 mcg/min)
The other accepted second-line drug for atropine-refractory symptomatic bradycardia, increasing rate, contractility, and vascular tone while awaiting transcutaneous pacing.
Physiology. Beta-1 (chronotropy/inotropy) and alpha (vasoconstriction) agonism supports both heart rate and blood pressure.
Safety. Titrate carefully; watch for hypertension, tachyarrhythmias, and ischemia.
A — Atropine
First-line drug (0.5 mg IV, max 3 mg)
First-line drug for symptomatic bradycardia: 0.5 mg IV q3–5 min up to 3 mg (0.04 mg/kg); works best for vagally mediated rhythms (sinus bradycardia, first-degree, Mobitz I).
Physiology. Blocks muscarinic (vagal) tone at the SA and AV nodes, increasing sinus rate and AV conduction.
Safety. May worsen infranodal block (Mobitz II, third-degree); do not delay pacing for repeated atropine.
Memory aids
- I = Isoproterenol
- D = Dopamine
- E = Epinephrine
- A = Atropine
Quick review
- I = Isoproterenol — Historical nonselective beta-agonist
- D = Dopamine — Second-line infusion (5–20 mcg/kg/min)
- E = Epinephrine — Second-line infusion (2–10 mcg/min)
- A = Atropine — First-line drug (0.5 mg IV, max 3 mg)
Eli explains
The same idea, in plain words
Explain it like I’m 10
A memory trick to remember the names of the 'speed-up-the-heart' medicines — but the letter order is not the do-this-first order.
I — Isoproterenol. Isoproterenol is a 'gas pedal' drug that revs the heart, but it also makes the heart burn more fuel and skip dangerously, so doctors rarely use it now.
D — Dopamine. Dopamine is a pump-booster medicine that, at higher doses, makes the heart beat faster and squeeze harder so blood pressure climbs.
E — Epinephrine. Epinephrine (adrenaline) is the body's fight-or-flight medicine — it speeds the heart and squeezes vessels to raise blood pressure.
A — Atropine. Atropine releases the vagus 'brake' on the heart so it can speed up — it's the quick first step.
Study tools & related lessonsKey vocabulary · Related
Key vocabulary
- I
- Isoproterenol
- D
- Dopamine
- E
- Epinephrine
- A
- Atropine
Sources & references
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