Chest pain Flashcards
ST elevation in II, III, aVF
location
blood supply
Inferior
RCA
ST elevation: I, aVL, V6
location
blood supply
Lateral wall
LCX
ST elevation: V1-V4
location
blood supply
Anterior wall
LAD
ST elevation in V1-V2
locaiton
blood supply
Antero-septum
LAD
Gross appearance of MI: <12 ;
12-24 hrs ;
1-14 days ;
> 2 weeks
hrs not apparent, tetrazolium stain shows pale areas 2-3 hrs post-occurrence
dark red-blue mottling
sharply defined yellow-tan area then hyperemic peripheral zone
gray-white scar
Histology of MI:
4-12 hours wavy fibers;
12 hrs - 7 days coagulative necrosis ongoing, neutrophils, by 7 days macrophages;
7-14 days granulation tissue, collagen begins to deposit;
>14 days more collagen, dense fibrous scar
- usually an atherosclerotic narrowing that only causes problems during exercise when demand for O2 is increased.
Stable angina
change in the frequency of angina, change in the amount of activity that provokes angina, change in the duration of angina, no longer relieved by nitroglycerin
Unstable angina-
-> degradation product of cross-linked fibrin, usually elevated with acute DVT
High sensitivity for PE, but low specificity
D-dimer
Virchow’s triad:
stasis, hypercoaguable state, endothelial injury
Difference between true and false aneurysm
Aneurysm: True -> involves all 3 layers, False (pseudoaneurysms) -> wall defect leading to extravascular hematoma
Pathogenesis of aneurysm
loss of smooth muscle cells - thickening of intima due to atherosclerosis -> ischemia of inner media; systemic HTN narrows vasa vasorum -> ischemia of outer media
Common -> location of aneurysms:
atherosclerosis -> _____;
HTN -> _____
abdominal aorta
ascending aorta
-> intimal tear w/in 10 cm of aortic valve, occurs betw middle and outer third of wall, in media, usually extends anterograde, ruptures “out”, may re-enter and form a double-barrel, ascending aorta most common
Aortic dissection
Aortic dissection: type A always involves the
ascending aorta
sudden onset of severe pain. Pain is constant, distressing, life threatening, unrelenting
aortic dissection:
Where is the dissection: hypotension, pulse deficits in upper extremities, aortic regurg, cardiac tamponade as late complication
Proximal dissection
Where is the dissection: hypertension, pulse deficits in lower extremities
Distal dissection ->
What is our first line tx for aortic dissection?
Beta blockers are first line treatment for aortic dissection: Goals: 60 bpm, SBP 100-120.
How do we manage type A and type B aortic dissectin differently
Type A dissection: surgery. Type B dissection- medically managed. Elective aneurysm repair at > 6cm.
Failure to increase blood pressure or HR w/ exercise is
a bad prognostic sign
imbalance betw supply and demand for O2 and nutrients & removal of metabolites
IHD:
Why is ischemia worse then hypoxia?
Ischemia worse than hypoxia b/c lack of perfusion prevents removal of metabolites
Cuases of decreased blood flow to heart
1.) fixed atherosclerotic narrowing, 2.) acute plaque change, 3.) thrombosis overlying ruptured plaque, 4.) Vasospasm
1.) Fixed obstruction: narrowing > 70% =
; >90% =
symptomatic ischemia w/ exercise
isch at rest
Difference between Total and Incomplete Occlusion
3.) Coronary thrombosis: TOTAL occlusion -> acute transmural MI or sudden cardiac death,
INCOMPLETE occlusion (mural thrombus) -> unstable angina, acute subendocardial infarction, sudden death, emboli
Difference between Transmulra and subendocardial infarct
MI:
- *- transmural** -> ST elevation, full thickness, confined to distribution of 1 vessel
- *- subendocardial infarct** -> ST depression, necrosis limited to inner 1/3, may extend beyond perfusion of 1 vessel
Elevations in ____- and _____ after acute MI persist up to 10 days, peak ____ values OR the 72-96 hr values correlate with infarct size
cTnl and cTnT
cTnT
____ begins to rise 4-6 hrs after onset of infarct (at 12 hrs elevation seen in all pts), return to baseline w/in 36-48 hrs
CK-MB
_____is more specific to MI than CK-MB, but CK-MB is useful to determine if a second MI occured as it returns to normal much quicker
Troponin
Chronic ischemic heart dz often seen in elderly, what do we see?
elderly pts w/ progressive heart failure due to ischemic myocardial damage, enlarged heart w/ LV hypertrophy and dilation
Complications of MI:
cardiogenic shock (w/ damage to 40% or more of LV), arrhythmia (early in course), myocardial rupture (3-7 days; tamponade, aneurysm, VSD, papillary muscle), pericarditis (2-3 days)
