Ischemic Heart Disease Overview

Ischemic Heart Disease

• Ischemic heart disease occurs when there is insufficient blood and oxygen supply to a portion of the myocardium.
• Atherosclerosis plaque rupture and thrombus formation in the coronary arteries are the primary causes of ischemic heart disease.

Acute Coronary Syndrome

• A group of potentially life-threatening conditions resulting from a thrombus formation in the coronary arteries.

Risk Factors for Plaque Formation

• Hypertension
• BMI over 30
• Alcohol consumption
• Age over 65
• Increased LDL levels
• Diabetes
• Family history of coronary artery disease
• Tobacco use

Categories of Ischemic Heart Disease: Clinical Features

• Substernal chest pain described as “squeezing, tight choking.”
• Chest pain occurring with exertion and can disappear with rest.

Categories of Ischemic Heart Disease: ACS - Clinical Features

• Chest pain occurring at rest and worsens with exertion.

Right Ventricular Myocardial Infarction vs Left Ventricular Myocardial Infarction

• Right ventricular MI: Mostly affects the right ventricle.
• Left ventricular MI: Involves the left ventricle.

Complications of Ischemic Heart Disease

• First 24 hours: Arrhythmias (ventricular fibrillation, atrial fibrillation), cardiogenic shock, heart failure.
• 24 hours to 3 days: Pericarditis, papillary muscle rupture, mitral valve regurgitation.
• 3 days to 14 days: Ventricular aneurysm, mural thrombus formation.
• 14 days to 1 month: Dressler's syndrome, late ventricular rupture.

Diagnosis: EKG & Biomarker

• Electrocardiogram (EKG): Used to identify ST-segment elevation (STEMI) or ST-depression (NSTEMI).
• Biomarkers: Troponin I (elevated levels indicate myocardial damage), creatine kinase (CK), and creatine kinase MB (CK-MB) are common biomarkers used.

Diagnostic Feature: Cardiac Troponin I

• Levels rise 2-4 hours after myocardial injury.
• Peak levels are reached in 12-48 hours.
• Remains elevated for 4-15 days.

Diagnostic Feature: Coronary Angiography

• Visualizes coronary arteries to identify blockages.

Diagnostic Feature: Echocardiogram

• Uses sound waves to image the heart and determine the extent of damage.

TIMI Score

• Used to stratify patients with NSTEMI or unstable angina and determine the need for catheterization based on the risk of mortality.

Stress Testing

• Pharmacologic Stress Testing: Uses medication to simulate exercise and evaluate heart function.
• Exercise Stress Testing: Evaluates heart function during exercise.

Epidemiology of Acute Coronary Syndrome

• Prevalent in males (67%) with a median age of 61 years.
• Common risk factors include hypertension (77.1%), diabetes (39%), and smoking history (33.4%).

Risk Factors for ACS

• Non-modifiable risk factors: Aging, male sex, family history, genetic predisposition, ethnicity (Caucasians).
• Modifiable risk factors: Smoking, hypertension, poor diet, dyslipidemia, obesity, sedentary lifestyle, diabetes.

Goal of Treatment for Acute Coronary Syndrome

• Short-term goals: Restoration of blood flow to the affected artery, prevention of infarct expansion (in case of MI), prevention of death and complications, prevention of coronary artery reocclusion, relief of ischemic chest discomfort.
• Long-term goals: Control of CAD risk factors, prevention of additional MACE (major adverse cardiac events), improvement in quality of life.

General Approach to Treatment

• Patients with STEMI require urgent PCI to restore blood flow.
• Patients with NSTEMI may need PCI or medical management based on their risk level.
• All patients must receive antithrombotic therapy, pain relief, and medication to prevent MACE and complications.

Acute Supportive Care: MONA

• Morphine: Relief of pain
• Oxygen: Improves oxygen delivery to the heart.
• Nitrate: Reduces chest pain and workload of the heart.
• Aspirin: Prevents further clot formation.

Acute Supportive Care: THROMBINS2

• Thienopyridine: Antiplatelet therapy.
• Heparin: Prevents clot formation.
• RAAS inhibitors: Reduce blood pressure and workload of the heart.
• Oxygen: Improves oxygen delivery.
• Morphine: Pain relief.
• Beta-blocker: Reduces heart rate and workload.
• Percutaneous Coronary Intervention (PCI): To open blocked coronary arteries.
• Nitroglycerin (NTG): Dilates coronary arteries.
• Statins & Salicylates: Reduce cholesterol levels and prevent further clot formation.

Acute Supportive Care: Beta-blockers

• Metoprolol, Propranolol, Atenolol, Esmolol: Reduce heart rate and workload of the heart.

Acute Supportive Care: Calcium Channel Blockers (CCBs)

• Non-dihydrophyridine (non-DHP) CCBs: Reduce heart rate and workload.
• Dihydropyridine (DHP) CCBs: Can cause harm and should be avoided in ACS.

Management Strategies for STEMI

• Primary percutaneous coronary intervention (PCI): Preferred for patients with cardiogenic shock, increased bleeding risk, or symptoms present for at least 2-3 hours.
• Fibrinolytic therapy: Uses medications like alteplase, reteplase, or tenecteplase to dissolve clots.