When you arrive at a hospital with a heart attack, the medical team works on a tight timeline. The first priority is diagnosing the type of heart attack, because that determines everything that follows. Most patients receive an electrocardiogram (EKG) within 10 minutes of walking through the door and a blood draw immediately after. From there, treatment splits into two paths depending on the severity of the blockage, with the most dangerous cases heading to a catheterization lab within 90 minutes.
What Happens in the First 10 Minutes
The emergency team starts with an EKG, a quick test that reads your heart’s electrical activity and reveals whether a major artery is completely blocked. They also draw blood to measure a protein called troponin, which leaks from damaged heart muscle cells. High-sensitivity troponin tests can detect or rule out heart damage with roughly 99.5% accuracy for serious outcomes over the next 30 days. These two tests, combined with your symptoms and medical history, tell the team which type of heart attack you’re having.
Not everyone shows up with classic crushing chest pain. Women, older adults, and people with diabetes often have less obvious symptoms like shortness of breath, upper back pain, or stomach discomfort. Emergency teams are trained to factor this in during their initial assessment, which is why the blood tests and EKG matter so much: they catch heart attacks that symptoms alone might not make obvious.
STEMI vs. NSTEMI: Two Different Urgencies
The EKG divides heart attacks into two categories that dictate the speed and type of treatment. A STEMI (ST-elevation myocardial infarction) means a coronary artery is completely blocked, and heart muscle is actively dying. An NSTEMI (non-ST-elevation myocardial infarction) means the artery is partially blocked or was briefly blocked, causing damage but with some blood still flowing.
STEMI is the more dangerous scenario. The goal is to restore blood flow within 120 minutes of when symptoms started. In practice, hospitals track “door-to-balloon time,” the minutes between your arrival and the moment a catheter opens the blocked artery. Guidelines set the target at 90 minutes or less, and this is treated as the highest-priority recommendation in cardiology. Every minute of delay means more heart muscle lost.
NSTEMI patients face a less immediate but still serious situation. Treatment starts with medications to prevent the clot from growing, reduce the heart’s workload, and manage pain. The medical team then decides whether you need a catheterization procedure within 48 hours or whether medication alone can stabilize you while further testing guides the next step. If chest pain continues, your heart rhythm becomes unstable, or blood pressure drops, the team moves toward catheterization sooner.
Opening the Blocked Artery
The primary procedure for opening a blocked artery during a heart attack is percutaneous coronary intervention, commonly called angioplasty with stenting. An interventional cardiologist threads a thin, flexible tube called a catheter through a blood vessel in your wrist or thigh, guided by X-ray imaging and contrast dye. Once the catheter reaches the blockage, a tiny balloon at its tip inflates to push the plaque against the artery wall and restore blood flow.
In most cases, the cardiologist then places a stent, a small mesh tube that holds the artery open permanently. Modern stents are coated with medication that slowly releases into the artery wall to prevent scar tissue from narrowing it again. The whole procedure typically takes 30 minutes to two hours, depending on how extensive the blockage is. You’re awake during the procedure but sedated, and most people feel pressure but not sharp pain.
When Stenting Isn’t Possible
If the blockage is too complex for a stent, if multiple arteries are severely diseased, or if a complication occurs during the catheterization (such as a tear in the artery wall or a stent that can’t be placed properly), the team may recommend coronary artery bypass surgery. This is open-heart surgery where a surgeon uses a blood vessel from your chest, leg, or arm to reroute blood flow around the blocked section. Bypass surgery is also more likely to be recommended for patients with diabetes or weakened heart function, even in the acute setting, because long-term outcomes tend to be better with surgery in those groups.
Rare but serious mechanical complications of a heart attack, such as a tear in the wall between the heart’s chambers or a rupture of the heart muscle itself, almost always require emergency surgery to repair the damage.
Clot-Busting Drugs as a Backup
Not every hospital has a catheterization lab, and not every patient can reach one in time. When the expected delay to angioplasty exceeds 120 minutes, doctors use clot-dissolving medications called thrombolytics instead. These drugs are delivered through an IV and work by breaking down the blood clot that’s blocking the artery. They’re less effective than angioplasty at fully restoring blood flow, but they can save heart muscle when time is running out.
Thrombolytics carry a risk of serious bleeding, so they can’t be given to everyone. Patients who have had a recent stroke, brain surgery, or head injury, or who have active internal bleeding or a possible aortic tear, are not eligible. Severe uncontrolled high blood pressure, recent major surgery, pregnancy, and current use of blood thinners are also factors that may rule out this option. In those cases, transferring the patient to a hospital with catheterization capability becomes the priority.
Medications You’ll Receive
Regardless of the type of heart attack, you’ll be started on aspirin almost immediately. Aspirin blocks one of the pathways that causes blood to clot, and a low daily dose (75 to 100 milligrams) provides the maximum anti-clotting benefit. Higher doses don’t add protection but do increase the risk of bleeding.
A second anti-clotting medication is typically paired with aspirin. This combination, called dual antiplatelet therapy, targets a different clotting mechanism. The specific medication and dose depend on whether you’re heading to the catheterization lab or being managed with medication alone. Blood thinners are also used during the acute phase to prevent new clots from forming while the underlying blockage is being treated. Beyond anti-clotting drugs, the team may use medications to lower your heart rate, reduce blood pressure, relieve chest pain, and decrease the heart’s oxygen demand.
Monitoring in the Hospital
After treatment, you’ll be connected to continuous heart monitoring (telemetry) that tracks your rhythm around the clock. For heart attack patients who undergo angioplasty, the American Heart Association recommends at least 12 to 24 hours of monitoring after a successful procedure where all significant blockages were treated, and 24 to 48 hours if some blockages remain. The monitors watch for dangerous rhythm changes: abnormally slow or fast heart rates, pauses in electrical activity, and ventricular tachycardia or fibrillation, which can be life-threatening and trigger an automatic alert to the emergency response team.
Serious rhythm disturbances requiring intervention are uncommon. In a study of over 1,300 patients monitored after angioplasty at the Mayo Clinic, prolonged pauses occurred in about 0.6% of patients and significant heart block in about 0.9%. When these events do happen, treatment ranges from adjusting medications to implanting a temporary or permanent pacemaker.
How Long You’ll Stay
Hospital stays after a heart attack vary considerably. A straightforward NSTEMI treated successfully with angioplasty may mean two to three days in the hospital. A STEMI, especially one involving complications, bypass surgery, or significant heart muscle damage, can mean a week or longer. Before discharge, you need to demonstrate stable vital signs, the ability to get out of bed and walk (with assistance if needed), adequate pain control, and tolerance of food and fluids.
Recovery Starts Before You Leave
Cardiac rehabilitation begins during your hospital stay. Phase 1, the inpatient phase, is as simple as walking down the hallway with a nurse or physical therapist. The goal is to safely start moving again and to begin the education process: understanding your medications, recognizing warning signs, and making a plan for the weeks ahead. After discharge, outpatient cardiac rehab continues with supervised exercise sessions, typically on a stationary bike or treadmill, along with stress management, nutrition counseling, and help managing conditions like high blood pressure or diabetes that contributed to the heart attack in the first place.