Acute Coronary Syndrome (ACS)

ACS refers to a spectrum of urgent cardiac conditions caused by myocardial ischemia due to diminished blood flow in the coronary arteries. The primary underlying mechanism is the rupture of an unstable atherosclerotic plaque, leading to partial or complete coronary occlusion, which compromises myocardial perfusion. ACS encompasses ST-segment elevation myocardial infarction (STEMI), non–ST-segment elevation myocardial infarction (NSTEMI), and unstable angina, distinguished by ECG findings, cardiac biomarker levels and clinical symptom. Common symptoms include chest pain, shortness of breath, and diaphoresis. Early recognition and prompt treatment—including antithrombotic therapy and timely percutaneous coronary intervention (PCI)—are crucial to limiting myocardial damage.

ACS includes 3 related clinical conditions that exist along a continuum of severity

• ST-segment elevation myocardial infarction (STEMI)
• Non–ST-segment elevation myocardial infarction (NSTEMI)
• Unstable angina

Acute chest discomfort is the leading presenting symptom

• May be described as sudden chest pain or discomfort, pressure, squeezing, or fullness
• Pain may radiate to the arm, neck, jaw, or back
• Shortness of breath
• Nausea, sweating, or dizziness

Atypical symptoms 

• More common in older adults, women, and patients with diabetes
• Include fatigue, indigestion, or general weakness instead of chest pain

Red Flag signs

• Prolonged chest pain (>15 min)
• Recurrent pain within 1hr

ACS is primarily caused by acute coronary atherothrombosis, which is usually triggered by disruption of an atherosclerotic plaque—either through rupture or erosion. This process often leads to partial or complete thrombosis of the coronary artery, resulting in reduced blood flow to the heart muscle.

Risk Factors

Comorbidity: Hypertension, dyslipidemia, diabetes mellitus, chronic kidney disease

Lifestyle Factors:

Smoking, Obesity 

Healthy Behaviors: 

regular physical activity, balanced diet, weight control, smoking cessation

Control of risk factors:

Blood pressure, blood glucose, and cholesterol management

Medication adherence

Adherence to prescribed medications (e.g., statins, antihypertensives)