Studying for ACLS comes down to mastering a handful of algorithms, recognizing cardiac rhythms quickly, and proving you can lead a team through a simulated code. The course itself runs 13 to 16 hours depending on format, but the real preparation happens before you walk in the door. The AHA requires you to pass a precourse self-assessment with at least 70% before attending, and you’ll need to print that score report and bring it to class. Here’s how to break down the material so nothing catches you off guard.
Start With the Cardiac Arrest Algorithm
This is the backbone of ACLS and the scenario you’re most likely to face on the megacode exam. The sequence begins with starting CPR, initiating bag-mask ventilation with oxygen, and attaching a monitor/defibrillator. From there, the algorithm splits into two pathways based on one question: is the rhythm shockable?
Shockable rhythms are ventricular fibrillation (V-Fib) and pulseless ventricular tachycardia (pulseless V-Tach). Non-shockable rhythms are asystole and pulseless electrical activity (PEA). Every two minutes you do a rhythm check, and between checks you’re delivering high-quality CPR, establishing IV or IO access, and administering medications. Learn this flowchart until you can talk through it from memory without looking at notes. Draw it out by hand repeatedly. That single exercise will carry you further than passive reading.
Memorize High-Quality CPR Standards
CPR metrics show up everywhere in the course, and the megacode evaluator is specifically watching for them. The numbers you need to know cold:
- Depth: At least 2 inches (5 cm)
- Rate: 100 to 120 compressions per minute
- Chest compression fraction: Greater than 80% (meaning compressions are happening at least 80% of the time)
- Compression-to-ventilation ratio without an advanced airway: 30:2
- Ventilation rate with an advanced airway: 1 breath every 6 seconds (10 breaths per minute) with continuous compressions
- Compressor switches: Every 2 minutes, or sooner if fatigued
Allow complete chest recoil between compressions and avoid excessive ventilation. These details sound simple, but they’re critical performance steps on the skills test. Failing to maintain them can result in a “needs remediation” designation.
Know the Key Medications and Doses
ACLS pharmacology is more focused than most people expect. You don’t need to memorize a pharmacy textbook. For cardiac arrest, there are really only three drugs to know:
- Epinephrine: 1 mg IV/IO every 3 to 5 minutes. Used in all cardiac arrest rhythms.
- Amiodarone: First dose 300 mg bolus, second dose 150 mg. Used for shockable rhythms (V-Fib and pulseless V-Tach) that persist after defibrillation.
- Lidocaine (alternative to amiodarone): First dose 1 to 1.5 mg/kg, second dose 0.5 to 0.75 mg/kg.
For bradycardia with a pulse, atropine is first-line: 1 mg bolus, repeated every 3 to 5 minutes, up to a maximum of 3 mg. If atropine doesn’t work, the next steps are transcutaneous pacing or a dopamine or epinephrine drip. You don’t need to memorize infusion calculations for the exam, but know the order of interventions.
Learn to Recognize the Core Rhythms
Rhythm recognition is where many people feel least confident, but ACLS only tests a limited set of rhythms. Focus your study time on identifying these quickly:
V-Fib looks like chaotic, disorganized waves with no identifiable pattern. There’s no heart rate, no distinct complexes, and no pulse. Ventricular tachycardia shows wide, bizarre-looking complexes at a rate above 100 per minute, usually regular. There are no normal P waves. Three or more of these wide beats in a row at that rate qualifies as V-Tach. Asystole is a flatline, with a ventricular rate of zero. Occasional P waves may still appear, but there are no ventricular complexes.
For heart blocks, focus on the relationship between P waves and the QRS complexes. In a first-degree block, every P wave is followed by a QRS, but the interval between them is prolonged (greater than 0.20 seconds). In second-degree Type I (Wenckebach), the interval gets progressively longer with each beat until one P wave fails to produce a QRS, and the cycle repeats. In second-degree Type II, that interval stays consistent, but some P waves simply don’t conduct. This is the more dangerous one. In third-degree (complete) heart block, the P waves and QRS complexes fire independently of each other, with no relationship between them.
Use free online rhythm trainers or flashcard apps to drill these until identification becomes automatic. On the exam, you won’t have time to puzzle through a strip for 30 seconds.
Commit the H’s and T’s to Memory
During both the cardiac arrest algorithm and the megacode exam, you’ll be expected to verbalize reversible causes of arrest. These are the H’s and T’s, and evaluators specifically check that you mention them for asystole and PEA scenarios.
The seven H’s: hypovolemia, hypoxia, hydrogen ion excess (acidosis), hypoglycemia, hypokalemia, hyperkalemia, and hypothermia. The five T’s: tension pneumothorax, cardiac tamponade, toxins, pulmonary embolism (thrombosis), and heart attack (thrombosis). Create a mnemonic or write them out from memory ten times. During the megacode, simply stating “I’m considering the H’s and T’s” and listing them out loud scores you a critical performance point.
Understand the Bradycardia and Tachycardia Pathways
These algorithms handle patients who have a pulse but are symptomatic. For bradycardia, the threshold is a heart rate typically below 50 beats per minute. The key question is whether the slow rate is causing problems: low blood pressure, altered mental status, signs of shock, chest pain, or heart failure. If the patient is stable, you monitor. If they’re compromised, you follow the atropine-then-pacing sequence described above.
For tachycardia, the critical decision point is stability. An unstable patient with a rapid heart rate gets immediate synchronized cardioversion. A stable patient gets a more measured workup to determine whether the rhythm is narrow or wide complex, regular or irregular, which guides medication choices. Study these two algorithms as mirror images: both start with identifying the rhythm and assessing for symptoms, then branch based on how sick the patient is.
Prepare for the Megacode Exam
The megacode is a simulated cardiac arrest scenario where you’re evaluated as the team leader. You won’t be doing chest compressions yourself. Instead, you’re directing a team, assigning roles, calling for rhythm checks, ordering medications, and making real-time decisions as the patient’s condition changes.
A typical megacode scenario walks through multiple rhythm changes. You might start with a tachycardia case that deteriorates into V-Fib, then transitions to PEA or asystole, and eventually achieves return of spontaneous circulation (ROSC). At each transition, the evaluator checks whether you recognized the new rhythm, chose the correct intervention, maintained high-quality CPR, and communicated clearly with your team.
After ROSC, you’ll need to demonstrate knowledge of post-arrest care. This means ordering a 12-lead ECG, monitoring oxygen saturation (target 90% to 98%), maintaining blood pressure with a minimum mean arterial pressure of 65 mmHg, and verbalizing the need for advanced airway confirmation with waveform capnography. You should also mention considering targeted temperature management.
Practice by talking through scenarios out loud, even alone. Say the words: “Let’s do a rhythm check. I see V-Fib. Charge to 200 joules. Everyone clear. Shock delivered. Resume CPR immediately. Push 1 mg epinephrine.” Verbalizing builds the muscle memory that written study alone cannot.
Airway Confirmation Details
Once an advanced airway is placed, the most reliable way to confirm correct positioning is continuous waveform capnography, which measures exhaled carbon dioxide. You’ll also assess by watching for bilateral chest rise and listening for breath sounds over both lungs while confirming no sounds over the stomach. Know that waveform capnography is the gold standard. If it’s unavailable, a non-waveform CO2 detector or an esophageal detector device is an acceptable alternative. This comes up on both the written assessment and during megacode scenarios.
Build a Study Schedule
Most people need one to two weeks of focused preparation before the course, studying 30 to 60 minutes per day. If you’re a first-time ACLS student, the full provider course runs approximately 15.5 to 16.5 hours of classroom time (or 13.25 to 14.25 hours if you complete video prework in advance). The update course for recertification is shorter, around 8.5 to 9.5 hours.
A practical study plan looks like this: spend the first few days learning the cardiac arrest algorithm and CPR standards. Next, tackle rhythm recognition, drilling with flashcards or online simulators daily. Then layer in the bradycardia and tachycardia pathways. Dedicate a session to medications and the H’s and T’s. In your final days before the course, practice talking through megacode scenarios from start to finish, including post-arrest care. Complete the AHA precourse self-assessment early enough that you have time to restudy weak areas before your class date.
The precourse self-assessment covers ECG recognition and pharmacology. If you score well above 70% on your first attempt, your foundation is solid. If you’re hovering near the cutoff, focus your remaining study time on whatever categories you missed.