What is the critical management approach for a patient experiencing a heart attack, including diagnosis and treatment options?

Critical Management of Heart Attack (STEMI)

Immediate reperfusion therapy is the cornerstone of STEMI management and must be initiated within 90-120 minutes of first medical contact, with primary percutaneous coronary intervention (PCI) as the preferred strategy when available, or fibrinolytic therapy if PCI cannot be performed timely. 1

Immediate Recognition and Triage

• Activate emergency medical services (EMS) immediately rather than self-transport, as EMS arrival is associated with significantly shorter treatment times and early access to life-saving interventions including defibrillation if cardiac arrest occurs 1
• Obtain 12-lead ECG within 10 minutes of arrival to identify ST-segment elevation and initiate the appropriate reperfusion pathway 1
• Place patient on continuous cardiac monitoring with emergency resuscitation equipment and defibrillator immediately available 1, 2
• Transfer patients directly to the catheterization laboratory, bypassing the emergency department when primary PCI is planned 1

Reperfusion Strategy Selection

Primary PCI (Preferred Method)

• Perform primary PCI for all STEMI patients with symptoms <12 hours duration and persistent ST-elevation (Class I, Level A recommendation) 1
• Target door-to-balloon time of <90 minutes for patients presenting directly to PCI-capable centers, or <120 minutes for transferred patients 3, 4
• EMS field activation of the catheterization laboratory reduces door-to-balloon times by approximately 43 minutes compared to emergency department activation 5, 4, 6

Fibrinolytic Therapy (When PCI Unavailable)

• Administer fibrinolytic therapy within 12 hours of symptom onset if primary PCI cannot be performed within 120 minutes (Class I, Level A recommendation) 1
• Initiate treatment as soon as possible after diagnosis, preferably in the pre-hospital setting (Class I, Level A recommendation) 1
• Use fibrin-specific agents: tenecteplase, alteplase, or reteplase (Class I, Level B recommendation) 1
• Transfer all patients to PCI-capable center immediately after fibrinolysis for angiography and PCI of the infarct-related artery between 2-24 hours post-fibrinolysis (Class I, Level A recommendation) 1

Immediate Pharmacotherapy

Antiplatelet Therapy

• Administer aspirin 75-100 mg orally or IV immediately to all patients without contraindications (Class I, Level B recommendation) 1
• Add a potent P2Y12 inhibitor before or at the time of PCI: prasugrel or ticagrelor preferred over clopidogrel, continued for 12 months unless excessive bleeding risk (Class I, Level A recommendation) 1, 3
• For fibrinolytic therapy, add clopidogrel in addition to aspirin (Class I, Level A recommendation) 1

Anticoagulation

• For primary PCI: Use unfractionated heparin as weight-adjusted IV bolus followed by infusion 1, 3
• For fibrinolytic therapy: Enoxaparin IV followed by subcutaneous (preferred over unfractionated heparin, Class I, Level A recommendation) or unfractionated heparin as weight-adjusted IV bolus with infusion (Class I, Level B recommendation) 1
• Continue anticoagulation until revascularization or for duration of hospital stay up to 8 days 1
• Do NOT use fondaparinux for primary PCI (Class III, Level B recommendation) 1

Pain Management

• Administer morphine sulfate 4-8 mg IV with additional 2 mg doses at 5-15 minute intervals for pain control and anxiety reduction (Class I recommendation) 2
• Morphine provides dual benefit of reducing sympathetic drive and myocardial oxygen demand while addressing patient distress 3, 2
• Avoid nitrates if patient has taken phosphodiesterase-5 inhibitors (e.g., tadalafil) within 48 hours due to risk of severe, potentially fatal hypotension 3

Critical Time-Dependent Interventions

Rescue PCI Indications

• Perform rescue PCI immediately when fibrinolysis fails (<50% ST-segment resolution at 60-90 minutes) (Class I, Level A recommendation) 1
• Emergency angiography and PCI indicated for: hemodynamic instability, electrical instability, worsening ischemia, heart failure/shock, or recurrent ischemia after initial successful fibrinolysis (Class I, Level A/B recommendations) 1

Beta-Blocker Therapy

• Initiate metoprolol tartrate in early phase: Three IV bolus injections of 5 mg each at 2-minute intervals during hemodynamically stable period, followed by oral metoprolol 50 mg every 6 hours starting 15 minutes after last IV dose 7
• Oral beta-blockers indicated for patients with heart failure and/or LVEF <40% unless contraindicated (Class I, Level A recommendation) 1
• Avoid IV beta-blockers in patients with hypotension or acute heart failure 1

Post-Reperfusion Management

Imaging and Monitoring

• Perform routine echocardiography during hospital stay to assess LV and RV function, detect mechanical complications, and exclude LV thrombus (Class I, Level B recommendation) 1, 3

Long-Term Therapy

• Continue dual antiplatelet therapy (aspirin plus ticagrelor/prasugrel/clopidogrel) for 12 months after PCI unless excessive bleeding risk (Class I, Level A recommendation) 1
• Add proton pump inhibitor with dual antiplatelet therapy in patients at high gastrointestinal bleeding risk (Class I, Level B recommendation) 1
• Initiate or continue high-intensity statin therapy for all STEMI patients 3

Secondary Prevention

• Enroll in cardiac rehabilitation program (Class I, Level A recommendation) 1
• Provide smoking cessation counseling with pharmacotherapy (nicotine replacement, varenicline, or bupropion) and follow-up support (Class I, Level A recommendation) 1

Critical Pitfalls to Avoid

• Do NOT delay reperfusion therapy for administrative procedures such as insurance verification 1
• Do NOT perform routine PCI of occluded infarct-related artery >48 hours after STEMI onset in asymptomatic patients (Class III, Level A recommendation) 1
• Do NOT use benzodiazepines for anxiety as they can cause respiratory depression, hypotension, and obscure clinical signs of ongoing ischemia 2
• Do NOT delay transfer to PCI-capable center after fibrinolysis; transfer should occur immediately 1

The greatest mortality benefit occurs within the first 3 hours of symptom onset, with every minute of delay increasing myocardial necrosis and worsening outcomes 3. Systems that integrate EMS field activation of catheterization laboratories demonstrate 38% reduction in door-to-balloon times and 21.9% reduction in total symptom-onset-to-reperfusion times 4.