L19- CVS Pathology II Flashcards
list the 4 consequences of IHD
- angina pectoris (AP)
- MI
- chronic IHD w/ CHF
- sudden cardiac death (SCD)
define AP and name its 3 types
angina pectoris: intermittent chest pain / discomfort due to transient / reversible (<30 mins) myocardial ischemia (severe with radiation of pain, but not quite an infarction)
- Stable, typical
- Prinzmental, variant
- Unstable, crescendo
alternate names for:
(1) stable AP
(2) variant AP
(3) unstable AP
1- typical
2- prinzmetal
3- crescendo
how does age, gender, and race relate to incidences of MIs
Age: at any age, but incidences inc w/ age
Gender: M:F
- (45-54 y/o) 5:1
- (55-80 y/o) 2:1
- (>80 y/o) 1:1
Race: equal among black and white people
list the 4 major contributing factors for MI
- hypercholesterolemia
- smoking (vasoconstriction, atherosclerosis, microvascular disease, high [CO])
- HTN
- DM (exaggerates atherosclerosis + microangiopathy affecting small BVs/capillaries)
90% of MIs are a result of (1), usually involves (2)
the other 10% are a result of (3), (4), (5)
1- acute thrombosis (–> coronary artery occlusion)
2- disruption of pre-existing plaque
3- vasospasm (isolated, intense, prolonged w/ or w/o coronary atherosclerosis)
4- emboli (via L sided mural thrombus)
5- unexplained (disease of small intramural coronary vessels or hematological abnormalities)
describe the biochemical events in the heart during MI, indicate timing
i) stop aerobic metabolism –> dec ATP, inc lactic acid (accumulates in myocytes), seconds
ii) ATP at 50% normal levels, 10 mins
iii) ATP at 10%, 40 mins
describe the changes in heart function during MI, indicate timing
loss of contractility, <2 mins
describe the (cellular) morphological events in the heart during MI, indicate timing
- reversible injury (cell swelling), <20 mins
- irreversible injury (coagulative necrosis), 20-50 mins
- microvascular injury, >1 hr
list the 3 morphological types of MIs
i) transmural
ii) subendocardial
iii) microscopic
(1) type of MI involves the full thickness of the ventricular wall in the disruption of (2), termed (3). It is usually associated with (4) and (5). It can also occur in (6) abuse.
1- transmural
2- single coronary artery (regional)
3- STEMI
4- acute plaque changes
5- superimposed / completely occlusive thrombosis
6- cocaine (inc catecholamines => severe vasospasm)
(1) type of MI is limited to affecting the inner 1/3 (or at most inner 1/2) of ventricular wall, termed (2). It is associated with (3) or (4). It may occur due to (5) type of obstruction.
(less serious than transmural)
1- subendocardial
2- NSTEMI
3- diffuse stenosing coronary atherosclerosis
4- prolonged hypotension
5- transient/partial arterial obstruction (regional)
describe the essential sequence of events in MI (4)
1) coagulative necrosis
2) inflammation, then resorption of necrotic myocardium
3) granulation tissue forms
4) granulation tissue organizes into collagen rich scar tissue
Describe heart histology / events post-MI at the following days:
- day 1
- day 3
- days 7-10
- step 1 after day 10 (day 11-14 –> 2-8 wks)
- step 2 after day 10 (2 mos+)
1- coagulative necrosis + wavy fibers
2- dense PMN leukocyte infiltration
3- removal of necrotic myocytes by phagocytosis
4- granulation tissue: loose collagen, abundant capillaries
5- healed MI, necrotic tissue replaced with dense collagenous scar + residual cardiac muscle hypertrophy
The initial goal during a MI is to initiate (1) either through (2) or (3). Although it is important and useful, (4) is a potentially dangerous outcome.
1- reperfusion
2- thrombolysis via enzymes: streptokinase, tissue plasminogen activator (<30-40 min onset)
3- angioplasty, CABG
4- reperfusion injury
describe the 4 (cellular) factors that lead to Reperfusion Injury (in terms of MI)
i) mitochondrial dysfunction => apoptosis (promotion)
ii) high extracellular [Ca] / impaired Ca cycling –> myocyte hypercontracture –> cytoskeletal damage (=> dark constriction band necrosis)
iii) free radical production after reperfusion => myocardial damage
iv) leukocyte aggregation + platelet activation –> microvasculature injury / occlusion (no reflow phenomenon)
describe the 2 morphologies of reperfusion injury post-MI
1) hemorrhage: vascular injury, leakiness
2) contraction band necrosis: hypercontracted sarcomeres show hyper-eosinophilic transverse bands via high extracellular [Ca] due to leaky plasma membrane + low ATP leaves actin-myosin interactions stuck
list the clinical features (presentation) of a MI
- CHEST PAIN: retrosternal, crushing, with radiation to neck, jaw, epigastrium, shoulder, L arm; persistent for >30 mins; no relief from vasodilators or rest
- dyspnea
- rapid weak pulse
- diaphoresis, n/v
25% of MI cases are (1), where they are discovered through (2). This is more common in (3) patients, usually with (4).
1- silent MIs (neuropathy)
2- EKG changes + lab tests
3- elderly
4- DM, HTN
list the 5 categories of post-MI complications
- ischemic
- arrhythmic
- embolic
- mechanical
- inflammatory