Angina & ACS Flashcards
______ is the underlying cause of CAD and 90% of cases of MI and most heart failure
Atherosclerosis
Atherosclerotic plaques in coronary arteries can undergo fissuring or erosion, which triggers _____ formation to cause ischemia to the myocardium
Thrombus
Risk factors for atherosclerosis
Hyperlipidemia (high LDL, low HDL)
Smoking
DM
HTN
Family hx
Obesity
Physical inactivity
Psychosocial stress
Sleep disturbance
Age and gender
Characteristics of metabolic syndrome
Insulin resistance, increased BG
HTN
High TG, low HDL
Hyperuricemia
Hypercoagulability
Central obesity (BMI >30) or overweight (BMI 25-29)
Most frequent presenting symptom of myocardial ischemia
Angina pectoris
Chronic stable angina is a consequence of imbalance between ____ supply and demand; there is a ____ risk of plaque rupture in these pts (meaning there is small lipid core and thick fibrous cap)
oxygen; low
Compare supply angina vs. demand angina
Supply angina = decreased delivery of O2 to tissues leads to ischemia (i.e., coronary vasoconstriction, stenosis, platelets release 5-HT and TA2)
Demand angina = increased myocardial O2 requirements and workload lead to ischemia (i.e., exercise, stress, emotion, fever, thyrotoxicosis, LVH d/t AS, anemia)
Mechanical consequences of myocardial ischemia
Heart failure (L or R or both)
Angina (if ischemia is prolonged ro develop coronary occlusion, may lead to myocardial necrosis)
Segmental akinesis, bulging (dyskinesis) — aka wall motion abnormalities
Biochemical consequences of myocardial ischemia
Fatty acids can’t be oxidized
Increased lactate production
Reduced pH with metabolic acidosis
Electrical consequences of myocardial ischemia
Inversion of T wave
Transient displacement of ST segment (ST Depression=subendocardial; ST elevation=subepicardial)
Electrical instability: VT, VF
Area and artery affected if ischemic changes are seen in V1-V6
LAD —> anterior wall infarction
Artery and area affected if ischemic changes are seen in leads II, III, and aVF
RCA —> inferior wall infarction
Area affected if ischemic changes are seen in leads V3R-V6R
RV infarct
Artery and area affected if ischemic changes are seen in I, aVL, V5-V6
Circumflex a.; lateral wall infarct
Artery and area affected if ischemic changes are seen in V1-V3
Posterior descending artery; Posterior wall infarct
What information can an ST elevation on ECG tell you that an ST depression cannot?
Location/artery involved in infarct
Symmetric T wave inversion in the anterior precordial leads that were upright in prior ECGs indicates what?
LAD dz, possible anterior infarct
NOTE that T wave inversion is only significant if it is a CHANGE from previous ECG
A 58 y/o male presents to the ED with a hx of chest discomfort described as heaviness and pressure in retrosternal region. Pain radiates into base of neck and into jaw, and has been going on for 20 minutes. On PE he has S3 gallop and systolic murmur over apex with radiation into left axilla.
What is the cause of the S3 and the murmur?
S3 gallop may be “impending” LV dysfunction leading to heart failure
Murmur is likely MR d/t dysfunction of papillary m. during chest pain; location is inferior or inferior-posterior d/t RCA lesion
CV causes of chest pain
IHD (angina, UA, ACS, MI)
VHD
Pericarditis
Myocarditis
Cardiomyopathy
Non-cardiac causes of chest pain
Pleuritis Costochondritis Pneumonia PE-pulm infarct Pneumothorax GERD, PUD Gallstones Esophageal spasm Lung cancer Aortic aneurysm
Non-chest pain symptoms of chronic IHD
Dyspnea Mid-epigastric or abd pain Diaphoresis Excessive fatigue and weakness Dizziness and syncope
[epigastric pain often associated with inferior ischemia]