ISCHEMIC HEART DISEASE

Definition

• Chronic Stable Angina = Angina during activity (Work, Exercise, etc.)
• Angina/Angina Pectoris = Secondary pain due to myocardial ischemic
• Stable = Decrease/Absent of pain after arrest activity (<5 min) without Nitroglycerin

Pathophysiology of stable angina

• In stable angina, atherosclerotic plaque volume will increase due to the accumulation of the LDL cholesterol molecules in the plaque
• The large plaque creates a tight stenosis hemodynamic inducing ischemia during exercise
• In stable angina, there are no plaque rupture, unlike acute coronary syndromes (ACS)
• Stable angina is differentiated from acute coronary syndrome (Non-ST-Segment elevation and myocardial infarction (MI)) by characteristics of pain (Occurring during exercise, time <30 minutes, no change in the frequency and duration of seizures) and the absence of electrocardiographic abnormalities or increased biomarkers of myocardial injury
► Acute Coronary Syndrome (ACS) = Total consequences of plaque rupture
1. ACS Non ST-segment elevation include:
• Unstable angina: No ST-segment elevation, Normal cardiac enzymes
• Non ST-segment elevation myocardial infarction (NSTEMI): No ST-segment elevation, Increased cardiac enzymes
• Non Q-wave infarction: Significant enzyme elevation, ST segment initially not elevate
• ACS without ST-elevation: Sub-occlusive thrombosis → Unstable angina or non-transmural MI
2. ACS with ST-segment elevation: Initial ST-elevation, elevation of cardiac biomarkers and appearance of Q-waves necrosis (Q-wave > 1/2 R, > 1/3 complex QRS height)
• ACS with ST-segment elevation (STEMI): Occlusive thrombosis transmural → myocardial infarction

Pathophysiology

• Evolution of plaque: Rupture/Break → Activation of coagulation cascade → Thrombus formation: brutal ↓ diameter of the coronary
• As long as incomplete obstruction: ACS No ST-segment elevation; if complete obstruction: ACS with ST-segment elevation (STEMI): Myocardial

Dx	Stable Angina	Unstable Angina	ACS without ST-Elevation	ACS with ST-Elevation
Plaque Obstruction	Minimal Ischemia	Subtotal		Total
Trigger Factor	Exercise	At rest or Exercise		Usually at rest
Duration	< 5mn	5-30mn		≥ 30mn
EKG	Normal if no symptome	+/- ST-segment depression or T-wave Invert No Q-wave necrosis		ST-segment elevation, Q-wave necrosis
Troponin	-	-	+	++