Cardiac massage is the rhythmic compression of the heart to force blood through the body when someone’s heart has stopped. The version you can perform as a bystander is external cardiac massage, better known as chest compressions or hands-only CPR. You push hard and fast on the center of the chest, at least 2 inches deep, at a rate of 100 to 120 compressions per minute. No special equipment is needed, and you don’t need to give rescue breaths to make a difference.
Step-by-Step Chest Compressions
If you find someone who has collapsed and isn’t breathing normally, here’s exactly what to do:
- Check the scene. Make sure the area is safe for you to approach. Tap the person on the shoulder and ask loudly if they’re okay. Look for normal, rhythmic breathing. Gasping or no breathing at all means you need to act.
- Call 911. If there’s no response, call emergency services immediately or ask someone nearby to call. Every minute without blood flow reduces the chance of survival.
- Position the person. Make sure they’re on their back on a firm, flat surface. A soft bed or couch absorbs your compression force, so move them to the floor if possible.
- Kneel beside them. Position yourself next to their chest with your knees about shoulder-width apart for stability.
- Place your hands. Put the heel of one hand in the center of the chest, right on the breastbone. Place your other hand on top and interlace your fingers. Keep your fingers lifted off the chest so all the force goes through the heel of your hand.
- Lock your arms. Position your shoulders directly above your hands and lock your elbows straight. You want to compress using your body weight, not your arm muscles. This keeps you from tiring out quickly.
- Push hard and fast. Compress at least 2 inches deep at 100 to 120 compressions per minute. A common trick: push to the beat of “Stayin’ Alive” by the Bee Gees, which runs at about 104 beats per minute.
- Let the chest recoil. After each compression, let the chest return fully to its normal position before pushing again. Leaning on the chest between compressions prevents the heart from refilling with blood.
Keep going without stopping until paramedics arrive or an automated defibrillator (AED) is available. If another bystander is present, switch off every two minutes. Effective compressions are physically exhausting, and compression quality drops significantly once fatigue sets in.
Where Exactly to Place Your Hands
Hand placement has been refined over the years. The current guideline is simple: place the heel of your hand over the center of the chest on the lower half of the breastbone. One reliable method is to feel for the small notch at the top of the breastbone (where the collarbones meet), then place the heel of your dominant hand one heel-width below that notch, centered on the breastbone. This positions your force over the heart’s pumping chambers rather than the upper chest or the soft area below the breastbone.
An older rule of thumb suggested lining up your hands with the nipple line, which works reasonably well for many adults. Either landmark gets you to roughly the same spot. The key principle is to stay on the breastbone itself, not off to one side over the ribs.
Compression Depth and Speed
The target is at least 2 inches of depth for an adult, but not deeper than about 2.4 inches. That range generates enough pressure to squeeze blood out of the heart and into the brain and other organs, without unnecessarily increasing the risk of injury. For reference, 2 inches is roughly the depth of stacking two golf balls. It feels like a lot when you’re doing it, and most untrained rescuers compress too shallowly rather than too deeply.
The rate of 100 to 120 compressions per minute is faster than most people expect. Counting “one-and-two-and-three” at a brisk pace gets you close. Compressions that are too slow fail to maintain blood pressure. Compressions faster than 120 per minute tend to become shallow because there isn’t enough time for full recoil between pushes.
Injuries From Chest Compressions
Effective compressions require significant force, and injuries to the chest wall are common. A large meta-analysis found that about 60% of patients who receive CPR sustain some type of compression-related injury. Rib fractures are the most frequent, occurring in roughly 55% of cases. Breastbone fractures happen in about 24%. Lung bruising occurs in around 20% of patients.
These numbers can sound alarming, but the context matters. A person in cardiac arrest will die without compressions. A cracked rib heals; an oxygen-starved brain does not. If you feel or hear a crack while performing compressions, keep going. You’re doing it right. Mechanical CPR devices, which are sometimes used by paramedics, carry an even higher injury rate than manual compressions, so the force involved is inherent to the procedure regardless of who or what delivers it.
What About Internal Cardiac Massage?
The term “cardiac massage” can also refer to open-chest cardiac massage, where a surgeon opens the chest and compresses the heart directly by hand. This is a hospital procedure, typically performed during surgery when the chest is already open, after penetrating chest trauma like a stab wound, or when fluid trapped around the heart (pericardial tamponade) prevents it from beating effectively. It is not something a bystander would ever perform.
In the open-chest technique, the surgeon places one flat hand behind the heart and the other on the front surface, then gently squeezes from the bottom of the heart upward at the same 100-beats-per-minute rate used in external compressions. Fingertips are avoided because they can puncture or bruise the heart muscle. An assistant may clamp the large artery below the heart to redirect blood flow toward the brain and coronary arteries.
Interestingly, open-chest massage generates better blood pressure than standard chest compressions. However, a systematic review comparing the two approaches found no overall difference in survival. In non-trauma cardiac arrests, open-chest massage was associated with about three times higher odds of restoring a heartbeat compared to closed-chest compressions. In trauma-related cardiac arrests, standard external compressions actually performed better. The takeaway is that open-chest massage is reserved for very specific clinical scenarios, not used as a default approach.
Why Hands-Only CPR Works
For the first several minutes of cardiac arrest, there is still oxygen dissolved in the blood. The problem isn’t a lack of air in the lungs; it’s that blood has stopped moving. Chest compressions alone can keep that oxygenated blood circulating to the brain and vital organs. This is why current guidelines for bystanders emphasize continuous compressions without pausing for rescue breaths. Each time you stop pushing, blood pressure drops to near zero and takes several compressions to build back up.
Hands-only CPR removes the barriers that used to keep people from helping: the hesitation about mouth-to-mouth contact, the confusion about compression-to-breath ratios, the fear of doing something wrong. The simplicity of “push hard and fast on the center of the chest” makes it more likely that bystanders will actually step in, and that alone saves lives.