PMT, Johnston - CAD: Angina-Stable/Unstable Flashcards
What is the major underlying cause of CAD (and the cause of 90% of MI and most HF)
Atherosclerosis
What is angina pectoris?
Chest discomfort, the most frequent expression of myocardial ischemia.
What is Chronic Stable Angina?
A consequence of imbalance between oxygen supply-demand.
Examples of supply angina
Decreased oxygen delivery to tissue leading to ischemia»_space; coronary vasoconstriction, platelets releasing 5HT and TXA2.
Examples of demand angina
Increase myocardial ocygen requirement and workload can lead to ischemia»_space; exercise, stress, emotion, fever, LVH due to AS, Anemia (low O2 carrying capacity).
The three disturbances/effects of ischemia.
1) Mechanical consequences
2) Biochemical consequences
3) Electrical consequences
Examples of MECHANICAL consequences caused by ischemia (3).
1) HF (LVF and/or RVF)
2) Angina, if ischemia is prolonged or develop coronary occlusion, may lead to myocardial necrosis.
3) Segmental akinesis, bulging (dyskinesis)
Examples of BIOCHEMICAL consequences caused by ischemia (3).
1) FA can’t be oxidized
2) Increased lactate production
3) Reduced pH with metabolic acidosis
Higher lactate is associated with what?
Higher mortality
Examples of ELECTRICAL consequences caused by ischemia (5).
1) T wave inversion
2) Transient displacement of ST segment
3) ST Depression - subendocardial (only inner infarcted)
4) ST Elevation - subepicardial (all infarcted)
5) Electrical instability - VT, Vfib
What will angina look like on ECG?
50% of the time the ECG will look normal.
See T wave inversion, think what?
Diffuse ischemia.
Dx?
Heaviness in retrosternal region. Pain radiates to base of neck and into jaw. Radiates to L shoulder and arm. Crescendo/decrescendo for 20 minutes.
Angina
MI
PE in angina:
S3 gallop means what?
Systolic murmur over apex with radiation into left axilla means what?
S3 indicates LV dysfunction leading to HF
Murmur is likely mitral regurgitation due to impaired blood supply to papillary muscles.
Anginal systolic murmur in what locations is due to lesion of what vessel?
Inferior and inferior-posterior due to RCA impairment.
What are non-chest pain symptoms of chronic IHD (5)?
- Dyspnea
- Non chest locations of discomfort (exertional or at rest), mid-epigastric or abdominal
- Diaphoresis
- Excessive fatigue and weakness
- Dizziness and syncope.
Why does the threshold of activity level that provokes angina attacks vary among patients?
Fixed CA stenosis/fixed O2 supply; produces ischemia because of increased oxygen demand.
What is Levine’s Sign - description and what it means.
Substernal discomfort, clinched fist - discomfort that goes along with ANGINA.