week 4 Flashcards
(101 cards)
Coronary artery disease CAD
It results from damage to, and the death of, cells in the heart as a consequence of inadequate blood flow (ischaemia) and reduced oxygen delivery (hypoxia) to meet the workload of the heart.
angina pectoris
where the myocardial cells experience a temporary ischaemic state
myocardial infarction
when the cells experience anoxia and die.
aeitology of CAD
multifactorial condition caused by a combination of nonmodifiable and modifiable risk factors
Nonmodifiable Risk Factors for CAD
Age: CAD risk increases with age, particularly in men over 45 years and women over 55 years
Gender: Men are generally at higher risk than premenopausal women, though the risk equalises postmenopause.
Genetics and Family History: A positive family history of premature CAD increases an individual’s risk
Modifiable Risk Factors of CAD
HTN- contributes to endothelial damage
Dyslipidaemia: Elevated LDL and reduced HDL levels promote plaque formation
Tobacco use damages blood vessels and increases oxidative stress and inflammation
Obesity and sedentary lifestyle
diabetes
dietary factors
inflammatory markers
psychological stress
Epidemiology of CAD
estimated 600,000Links to an external site. Australians aged 18 and over (3.0% of the adult population) have CAD.
types of CAD/Clinical Manifestations of CAD
Stable Angina (Exertional Ischaemia)
Acute Coronary Syndromes (ACS)
Atypical Symptoms (More common in women, elderly, diabetics)
Silent Ischaemia
Silent Ischaemia
No symptoms; detected via ECG or stress testing in diabetics or elderly patients
- Acute Coronary Syndromes (ACS)
Unstable Angina: Chest pain at rest or increasing in frequency
NSTEMI: Ischemia with myocardial injury (elevated troponins) but no ST elevation
STEMI: Complete coronary occlusion with ST elevation on ECG
Atypical Symptoms (More common in women, elderly, diabetics) of cad
Dyspnoea (SOB), fatigue, dizziness, epigastric pain or nausea without chest pain
- Stable Angina (Exertional Ischaemia)
Predictable chest discomfort with exertion, relieved by rest or nitroglycerin
chest discomfort is thought to be attributable to?
myocardial ischaemia.
Stable Angina pathophysiology
(atherosclerosis) Accumulation of lipid-laden plaques in the coronary arteries reduces blood flow, leading to ischaemia and a predictable chest pain with exertion or stress, relieved by rest or medication such as nitroglycerin
Unstable Angina caused by
Caused by a sudden worsening of coronary blood flow.
Plaque rupture and thromboembolism (unstable angina) mechanism and cause
Mechanism: Clot formation (thrombosis) or embolisation leads to sudden coronary artery occlusion. Causes: Atrial fibrillation
Sudden Coronary Artery Dissection (SCAD) mechanism and common in who
Mechanism: A tear in the coronary artery wall creates a false lumen, obstructing blood flow. Common in: Young women, pregnancy, connective tissue disorders
Variant Angina (Prinzmetal Angina) caused by
Caused by Coronary Vasospasm.
Pathophysiology of angina
myocardial oxygen demand exceeds oxygen supply
Biochemical & Cellular Changes in Ischaemia
When blood supply is insufficient, the heart switches to anaerobic metabolism eg:
reduced ATP production
increase lactate,
Accumulation of ischaemic metabolites
Impaired nitric oxide (NO) release → Reduced vasodilation, worsening ischaemia
Clinical manifestations of stable angina
chest pain or discomfort, often triggered by exertion or emotional stress and relieved by rest or nitroglycerin
where is pain w stable angina
Retrosternal discomfort radiating to the left arm, jaw, neck or back
Clinical manifestations of unstable angina
Recent onset of chest discomfort
One or more prolonged episodes (more than 20 minutes)
Chest discomfort occurring with less exertion and/or at rest compared with prior episodes of stable angina
Acute coronary syndrome
spectrum of conditions caused by acute myocardial ischaemia due to a sudden reduction in coronary blood flow. It includes:
Unstable Angina (UA)
Non-ST-Elevation Myocardial Infarction (NSTEMI)
ST-Elevation Myocardial Infarction (STEMI)