10.1 Sudden Cardiac Arrest, High-Performance CPR & AED

Quick Answer: Any collapsed and unresponsive athlete is sudden cardiac arrest (SCA) until proven otherwise (NATA-sponsored Inter-Association Task Force, Drezner et al., Journal of Athletic Training 42(1):143–158, 2007; restated in NATA 2012 Preventing Sudden Death in Sports and secondary-school best practices). Do not wait for a long pulse check or for ‘funny breathing’ to stop. Start high-quality CPR and apply an automated external defibrillator (AED) immediately. Adult high-performance CPR (American Heart Association 2020, unchanged as the 2025 adult rate/depth numbers): 100–120 compressions/min, depth about 5–6 cm (2–2.4 in), full recoil, minimize pauses. Survival from untreated ventricular fibrillation (VF) falls about 7–10% per minute without defibrillation.

Practice Analysis, 8th Edition (PA8) Domain III, task 0303, asks the athletic trainer (AT) to provide evidence-based emergent care, including airway, SCA, and other emergent conditions. Chapter 9 built the emergency action plan (EAP) and 3-minute AED retrieve-and-use window. This chapter is the clinical algorithm once the athlete is down.

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SCA until proven otherwise

The Inter-Association consensus is unambiguous: SCA should be suspected in any collapsed and unresponsive athlete, and an AED should be applied as soon as possible for rhythm analysis and a shock if indicated. Provide CPR while the AED is coming. Do not spend the first minute debating hypertrophic cardiomyopathy versus a ‘faint’ versus a seizure.

Do not wait for a ‘definitive’ pulse check. AHA adult basic life support has long warned that pulse assessment is unreliable. Healthcare providers who check a pulse should take no more than 10 seconds; if there is no definite pulse, start compressions. Lay coaches on your staff should not hunt for a carotid artery at all. If the athlete is unresponsive and not breathing normally, it is SCA.

Exam trap: ‘He’s breathing funny—let’s wait.’ Agonal gasps are irregular, slow, snoring or snorting breaths in the first minutes of arrest. They are not effective ventilation and they do not mean the heart is pumping. Occasional chest or abdominal movement with the eyes open and rolled back can also follow SCA on the field of play (Resuscitation Council UK field-of-play guidance, 2024). Myoclonic jerking or brief seizure-like activity occurs in about 50% of young athletes with SCA and must not be treated as a primary epileptic seizure. Inaccurate pulse or respiration checks, agonal gasping, and myoclonus are the three recognition barriers the 2007 task force named. Activate the EAP, start compressions, put the AED on.

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Chain of Survival and the clock

The 2025 AHA Guidelines consolidated the four 2020 chains (adult/pediatric, in-hospital/out-of-hospital) into one 6-link Chain of Survival for pediatric and adult arrest:

1. Recognition of cardiac arrest and activation of the emergency response.
2. Early high-quality CPR (compressions first).
3. Rapid defibrillation.
4. Advanced resuscitation (EMS/ACLS).
5. Post–cardiac arrest care.
6. Recovery (rehabilitation and survivorship).

Prevention and preparedness sit before the chain (venue EAP, AED staging, rehearsal). The writing group considered adding prevention as a seventh link and did not in 2025.

Time numbers you must not mix:

CARES 2024 data cited in the 2025 AHA BLS part: EMS-treated adult out-of-hospital arrest survival to discharge about 10.5%, favorable neurologic survival about 8.2%. Those community numbers are why your 3-minute AED, not the city ambulance, is the intervention that changes an athlete’s outcome.

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High-performance CPR

‘High-performance’ is not a slogan. It is a measurable set of metrics. AHA high-quality CPR components (2020 adult BLS, still the 2025 bedside numbers in adult rate and depth summaries):

• Rate: 100–120/min. Slower starves coronary perfusion; faster usually becomes shallow.
• Depth (adults): about 5–6 cm (2–2.4 in)—at least 50 mm (2 in) and avoid >6 cm (2.4 in). Pediatrics: about one-third the anterior–posterior chest diameter.
• Recoil: full chest recoil every compression; do not lean. Recoil fills the heart.
• Pauses: keep rhythm and shock pauses under about 10 seconds. Target chest compression fraction (CCF) >80%.
• Surface and position: firm surface; patient’s torso roughly at the rescuer’s knee height (2025 adult BLS positioning language).
• Ratio: 30:2 compressions to breaths before an advanced airway for a single rescuer and for two healthcare rescuers on adults. After a supraglottic airway or endotracheal tube, continuous compressions with about 1 breath every 6 seconds (10/min).
• Switch compressors about every 2 minutes (or sooner if depth falls). Depth decays after roughly 90–120 seconds of continuous work.
• CAB, not ABC, for SCA: compressions first. Rescue breaths still matter for ATs (healthcare-professional CPR), especially in drowning, lightning, and pediatric arrest, but do not delay the first compression cycle to find a bag.

After a shock, resume CPR immediately beginning with compressions. Do not pause for a pulse or a ‘look for ROSC’ until the AED reanalyzes at about 2 minutes. Many victims have pulseless electrical activity for minutes after a successful shock; they need blood flow, not a hopeful pause.

Two-person bag-valve-mask (BVM) is preferred when breaths are given: one rescuer opens the airway and seals with two hands; the other squeezes the bag during the 30:2 pause. That is 2025 AHA adult BLS language, not a clinic preference.

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AED: apply it, do not decorate with it

Turn the AED on, bare the chest, dry sweat, shave dense hair if pads will not stick, and place pads as the diagram shows (typically upper-right chest and lower-left lateral chest; anterior–posterior is acceptable if the chest is small or pads would overlap). Analyze only when the device tells you to stop touching the patient. If it advises shock, clear and shock, then compressions back on.

Equipment-laden football (and similar pads): chest access is the priority for SCA. Cut the jersey in a T (collar to waist and sleeve to sleeve), cut or open shoulder-pad straps, and get pads onto bare skin. Some pad sets can be opened so adult pads sit around or under the shoulder-pad shell. Do not delay a shock until every piece of equipment is in a gear bag if a shock can be delivered on exposed skin. Keep a kit with heavy shears, a towel, a razor, and spare pads. Wet or hairy chests fail pad contact; that is a preparedness problem, not a reason to wait for EMS.

If SCA is not the problem and you are protecting a suspected cervical spine, facemask off for airway and leave helmet and shoulder pads as a unit if you cannot remove both—that airway access rule is 10.2. For true SCA, CAB outranks cosmetic equipment etiquette: you cannot compress a chest you cannot reach.

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Differential: HCM vs primary arrhythmia vs commotio vs trauma

You will not make a pathology diagnosis during compressions. You will be asked to recognize the story so you do not withhold the AED.

Hypertrophic cardiomyopathy (HCM) is the classic structural cause of sudden death in young U.S. athletes in registry series (on the order of ~25% of SCD cases in older U.S. series; coronary anomalies ~14%). The heart is structurally abnormal; VF/VT can be harder to convert if defibrillation is delayed even briefly. Family history, exertional syncope, and a murmur that rises with Valsalva belong in the preparticipation file—not in the first 10 seconds of a collapse.

Primary electrical disease (long QT, catecholaminergic polymorphic VT, Wolff–Parkinson–White, Brugada) can arrest a structurally normal heart. Screening ECG is not the sideline test. The sideline test is the AED.

Commotio cordis is VF from a blunt, non-penetrating blow to the precordium (baseball, lacrosse ball, hockey puck, a punch or collision) timed to a narrow window on the T-wave upstroke, about 10–30 milliseconds before the peak of the T wave (Link et al., NEJM 1998; subsequent swine work). That window is a few percent of the cardiac cycle, which is why commotio is rare—and why it is not ‘just the wind knocked out.’ Collapse may be instant or after a few steps. The heart is structurally normal. Treat as SCA. Early AED changes survival; AHA public teaching now cites commotio survival above 50% with prompt CPR and AED, versus historically grim numbers when defibrillation was late. Animal data: defibrillation at 1–2 minutes rescued nearly all; at 4 minutes ~46%; at 6 minutes ~25%.

Traumatic collapse (cervical spine, intracranial bleed, tension pneumothorax, massive hemorrhage) can also drop an athlete. If the athlete is unresponsive after a chest blow or unexplained collapse, you still apply the AED while you manage airway and bleeding. The machine will not shock a pulsatile rhythm. Withholding it because ‘this looked traumatic’ is how commotio dies on the infield.

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After ROSC

Return of spontaneous circulation (ROSC) is a pulse, purposeful movement, or an organized rhythm with signs of life—not a single gasp. Keep the AED attached. Support airway and breathing, give oxygen per protocol (many SCA survivors are hypoxemic), avoid hyperventilation, and transport to a facility capable of post-arrest cardiac care. Do not sit a just-resuscitated athlete on the bench ‘to see if they come around.’ Do not clear them because they talk. They leave on a stretcher with EMS, not in a parent’s car.

Document collapse time, CPR start, first rhythm/shock times, number of shocks, ROSC time, and who did what. That record is clinical care and quality improvement, not paperwork after the fact.