Which Combination of Signs and Symptoms Would Indicate Cardiac Arrest? Select Two Answers

The two signs that indicate cardiac arrest are unresponsiveness and not breathing or only gasping. A person who does not respond to stimulation and has no normal breathing — or shows occasional irregular gasps — is in cardiac arrest until proven otherwise. Headache, dizziness, chest pain, and high fever can accompany a heart attack or other illness, but none of them defines cardiac arrest. The arrest is a pumping failure, not a pain syndrome, and the distinction drives every decision that follows.

The Pump Stops, and Breathing Fails With It

Cardiac arrest is a mechanical event. The heart's electrical system misfires into a chaotic rhythm, most often ventricular fibrillation, and the ventricles stop ejecting blood. Cerebral blood flow falls to near zero within seconds. Without oxygen delivery, the cortex loses function quickly: consciousness disappears, and the respiratory centers in the brainstem stop issuing rhythmic commands to the diaphragm.

That sequence explains why the two correct answers pair so tightly. Unresponsiveness is the brain's report that perfusion has failed. Abnormal breathing — absent breaths or agonal gasps — is the brainstem's failure to drive the lungs. Agonal gasps deserve special attention because they fool witnesses. They are slow, irregular, snoring or sighing sounds produced by a dying brainstem reflex, not by effective breathing. They appear in a large share of witnessed arrests during the first minutes and are often mistaken for normal respiration.

Chest pain belongs to a different physiology. It signals myocardial ischemia, a supply-demand mismatch in heart muscle that may precede an arrest by minutes, hours, or days. Most people with chest pain are not in arrest. Headache and dizziness reflect other pathways entirely, from migraine to stroke to dehydration. High fever indicates infection or inflammation. Each symptom can coexist with arrest, but coexistence is not definition.

How the Numbers Separate the Two Signs

The epidemiology draws a sharp line between arrest and the look-alikes. Sudden cardiac arrest causes roughly 300,000 to 450,000 deaths in the United States each year, and out-of-hospital survival sits near 10 percent overall, with wide regional variation. Survival falls by an estimated 7 to 10 percent for every minute that CPR and defibrillation are delayed, which is why recognition speed matters more than diagnostic precision.

Breathing assessment performs well as a screening tool when witnesses are trained. Agonal gasps are present in a substantial minority of out-of-hospital arrests at the time of recognition, and bystanders who mistake gasps for breathing delay compressions. Unresponsiveness is even more reliable: a person in arrest cannot speak, move purposefully, or react to a shoulder shake. Combining the two observations — no response plus no normal breathing — captures the great majority of true arrests while excluding most other emergencies.

By contrast, chest pain as a lone discriminator would miss the majority of arrests, because many arrests occur without preceding chest pain, and most chest pain never progresses to arrest. Headache and dizziness have essentially no diagnostic value for arrest. High fever predicts sepsis or infection, a different pathway with different treatment.

Edge Cases That Confuse the Picture

Several scenarios blur the classic presentation. Opioid overdose produces unresponsiveness and slow, shallow, or absent breathing that mimics arrest; the pulse may persist, so rescue breathing and naloxone change the response. Drowning victims often arrest after hypoxia, and the breathing abnormality may precede circulatory collapse. Hypoglycemia can cause unresponsiveness with preserved breathing, and it reverses with glucose rather than compressions.

Seizures create a counterintuitive trap. A convulsing patient is not in arrest, but after the seizure stops, postictal unresponsiveness with noisy breathing can resemble arrest. The professional caveat: check for a pulse only if trained and only for up to 10 seconds, and when uncertain, begin compressions. A pulse check that takes too long costs more lives than a rare compression on a beating heart.

Trauma adds another layer. Arrest after hemorrhage usually follows a period of shock, and the mechanism of arrest differs from primary cardiac causes. In all these cases, the two-sign combination still identifies who needs CPR now; it does not identify why the arrest happened.

Misconceptions That Cost Minutes

The most damaging misconception is that a gasping patient is breathing. Witnesses hear noise, assume air is moving, and wait. In reality, agonal gasps move little or no air and predict arrest with high specificity. Another misconception holds that chest pain must precede arrest. It does not; arrest is often the first sign of coronary disease, and a substantial fraction of victims have no prior warning symptoms.

A third error treats responsiveness as all-or-nothing. A person who briefly rouses but cannot stay awake is not safe, and a person who responds only to pain needs urgent evaluation. The practical test is simple: tap the shoulders and shout. No response plus no normal breathing means start CPR.

Red flags that should trigger immediate action:

No response to shouting and shoulder tapping. No breathing, or only occasional gasps, for 10 seconds of observation. Sudden collapse in a person who was speaking or moving moments earlier. Blue lips or face with unresponsiveness. A seizure that stops but leaves the person unresponsive and not breathing normally.

One plain-language rule covers all of it: if the person will not wake up and will not breathe normally, treat it as cardiac arrest.

What to Do in the First Minutes

Recognition should take seconds, not minutes. Shout for help, tap the shoulders, and scan the chest for rise and fall. If the person is unresponsive and not breathing normally, call emergency services on speaker and start chest compressions at 100 to 120 per minute, 2 to 2.4 inches deep, allowing full recoil. Push hard and fast, and do not stop to search for a pulse if you are untrained.

Send someone for the nearest automated external defibrillator and use it as soon as it arrives; the device analyzes the rhythm and delivers a shock only when appropriate. Continue CPR until responders take over, the person starts breathing normally, or you are physically unable to continue. For suspected opioid overdose with absent breathing, give rescue breaths and naloxone if available while waiting for help. The threshold is not a diagnosis; it is the two-sign combination, and acting on it early is the single strongest predictor of survival.

The Limits of Symptom-Based Recognition

No symptom checklist replaces assessment in context. The two-sign combination performs well because it reflects the underlying physiology, but it cannot distinguish cardiac arrest from other causes of unresponsiveness with apnea, such as opioid toxicity, drowning, or profound hypoglycemia. That ambiguity is acceptable because the immediate action — CPR and defibrillation — is the same, while reversible causes are addressed by responders.

The thresholds in this article come from consensus resuscitation guidance rather than a single trial, and survival statistics vary by region, bystander training, and response times. What holds steady is the mechanism: when the pump stops, the brain and brainstem fail within seconds, and the two observable consequences are unresponsiveness and abnormal breathing. Any explainer that ranks chest pain or dizziness above those two signs is describing a heart attack, not an arrest.

This article is general educational information, not a diagnosis or treatment plan. It cannot substitute for evaluation by a qualified clinician or for your local emergency protocol. If you witness someone who is unresponsive and not breathing normally, call your local emergency number immediately and follow dispatcher instructions.