Ischaemic Heart Disease Flashcards
What is angina ?
Chest pain
What is stable angina ?
CP that occurs with exertion & relieved w/rest. It can also be provoked by emotional stress or exposure to cold.
Or relieved with removal of stressful stimuli or use of GTN.
What is the pathogenic mechanism of unstable angina?
It is caused by an intracoronary platelet-rich thrombus on a eroded atherosclerotic plaque leading to partial coronary occlusion.
What is Accelerating angina?
It is an exercise or stress triggered rapidly worsening chest pain.
What is the definition of Myocardial infarction?
Myocardial necrosis due to myocardial ischemia causing reduction in cardiac function, increase in cardiac biomarkers and inducing pathological Q waves in ECG.
What is STEMI ?
MI with STE + raised cardiac biomarkers and Pathological Q waves.
What is NSTEMI ?
NSTE with increased cardiac biomarkers +/- pathologic Q waves.
What is the pathophysiology of atherosclerotic plaque formation ?
Initial stage- Endothelial dysfunction and inflammation causing macrophage mediated foam cell formation.
Fatty streak formation- due to intracellular lipid accumulation.
Intermediate lesion- At this stage there is intracellular and extracellular lipid pools.
The final stage- Atheroma formation which progress to calcified fibroatherma and will eventually become a complicated lesion capable of causing turbulent flow, ischemia, vessel wall injury and thrombosis due to plaque rupture.
What are the risk factors for IHD ?
- Age
- Male sex
- Family history
- Personal hx of
vascular disease– CVA, TIA, PAD - Genetics
What are the modifiable risk factors for IHD ?
- HTN, High cholesterol and Diabetes
- Smoking, Obesity and Sedentary
- Raised CRP and Homocysteinaemia
- Heavy alcohol consumption
- Medications: OCP, COX-2 inhibitors,
nucleoside analogues
What is the CVD risk classification based on family Hx ?
- Average risk = No family Hx or only one secondary relative is affected.
- Moderate risk= One first degree relative with disease onset at an avg age or two affected kins in the same side of the family.
- High risk = Premature disease in a 1st degree kin./ 2 or more first degree kins affected./ moderate risk on both sides of the family.
What are the Lipid & lipoprotein abnormalities that are associated with increased risk of CHD?
–Elevated total and LDL cholesterol
– Low HDL cholesterol
– Hypertriglyceridaemia
– Increased non-HDL cholesterol
– Increased Lp(a)
– Increased apolipoprotein C-III
– Small, dense LDL particles
– Certain genotypes of apolipoprotein E
What are the risk factors for CVD ?
- Diabetes and related metabolic derangements.
- Obesity
- Smoking- The incidence of MI is increased 6x in women
and 3x in men who smoke at least 20 cigarettes per day.
What is the clinical presentation of Angina ?
- Location – substernal, epigastrium, lower jaw, teeth, between
shoulder blades, upper extremities - Character – pressure, tightness, or heaviness; strangling,
constricting, or burning - Duration – brief (≤ 10 min) but not too brief as CP that lasts “seconds” is not likely cardiac in origin.
- Relationship to exertion – symptoms appear or worsen with increased levels of exertion.
How to classify angina based on symptoms to typical, atypical and non anginal CP ?
The criteria
* Constricting discomfort in the chest, jaw, neck shoulder or hand.
* Precipitated by exertion
* Relived by rest or NTG within 5 min.
Typical angina- Must meet all the criteria
Atypical angina- should meet at least 2 of the criteria
Non-anginal- Meets only one or none.
What is the Canadian Cardiovascular society grading of angina based on symptom severity ?
- Grade 01 - Angina only with strenuous exercise.
- Grade 02- Angina with moderate exertion.
- Grade 03- Angina with mild exertion.
- Grade 04- Angina at rest
What should be the focus of physical examination in Angina ?
- There are no specific physical examination findings for angina
- Look for signs of CVD.
- Auscultate the base to see if there is systolic crescendo-decrescendo murmur radiating to the carotid as it indicates Aortic stenosis.
What are the diagnostic lab studies in Angina ?
- FBC- Anemia exacerbating CHD, WBC elevation if recent MI.
- Lipid profile
- Creatinine & eGFR
- TFT to rule out CP secondary to hypothyroidism.
- Ankle brachial index - To rule out PAD.
- If angina at rest Troponin levels.
What are the ECG findings in angina?
- None for stable angina.
- Periods of active ischaemia will
show ST depression &/or T
wave inversion. - Tachyarrhythmias can worsen
myocardial ischaemia. - Look for evidence of prior MIs,
like pathologic Q waves or Lt
BBB.
What are the Echocardiography findings in Angina ?
- Regional wall motion
abnormalities due to ischemia or prior MI. - Low stroke volume &/or low
ejection fraction (EF) due to HF. - Evidence of valve disease or aortic stenosis causing CP.
What are the CXR findings in angina?
- Not always necessary
- Evidence of LVH
– Ex. Enlarged cardiac silhouette - Evidence of HF
– Ex. Pulmonary congestion - Evidence of pulmonary disease
that could exacerbate
underlying ischaemia
– Ex. Emphysema/COPD
What is the value of pre-test probability in diagnostic test choice making ?
- Intermediate likelihood increases the value to diagnostic testing.
- When the likelihood is high, a negative test can seldom rule out
the presence of obstructive CAD because negative predictive value is low. - When the likelihood is low increased risk of false positive results due to low positive predictive value.
- Hence at the extremes of probability deem the patients as having IHD or no having IHD respectively.
What are the pre- test probability based test choices in IHD work up
*Very low probability - No test
*Low to moderate probability- Coronary CTA with contrast.
* Intermediate to very high probability- Invasive angiography with instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR).
What is Coronary CTA ?
It is a non invasive anatomical evaluation of the coronary arteries to rule out stenosis. If there is 50 to 90% stenosis invasive coronary angiogrpahy will have to be done.
