pathology of ischemic heart disease Flashcards
What is leading cause of death for men and women in US and other industrialized nations
- ischemic heart disease
what are the risk factors for IHD
- DM
- HTN
- smoking
- lipids
what is general cause of IHD, and what are seom things that can cause this?
- imbalance of O2 supply and demand
MOST due to atheroscleortic CAD
- hypotenstion
- coronary artery vasospam (cocaine abuse)
what are some exacerbating conditions of IHD?
- myocardial hypertrophy
- shock
- hypoxemia/anemia
- increased HR
Name four clinical manifestations of IHD
- angina pectoris
- myocardial infarction
- chronic IHD
- sudden cardiac death
What is angina pectoris caused by?
- ischemia… results in cellular necrosis and metabolic spil
what are the 3 causes of angina pectoris
- stable (most common) due to reduced perfusion and ischemia with increased oxygen demand
- prinzmetal – uncommon, episodic, occurs at REST… coronary artery vasospasm is involved
- Unstable – pain that is progressively more frequent and intense; occurs progressively with less effort
what are the 3 acute coronary syndromes
- unstable angina
- acute mI
- sudden death
what are the three coronary artery perfusion zones?
- LAD (40-50% of MI – anteiror lv wall; anterior ventricular septum, apex
- RCA (30-40% of MI – inferoposterior lv wall; posterrior ventricular septum, and inferoposterior rv
- LCX (15-20 percent) – lateral wall of LV expect apex
What is the difference in EKG reading between transmural and subendocardial
transumral: q waves and st abnormal
subendocardial (not full thickness) ; non q wave
name some chest pain etiologies
- IHD
- pericarditis
- MSK
- PE
- peptic ulcer
- IHD
What is time frame of rise of CK-MB? when does it peak and when does it go to normal?
- rises 4-8 hrs after injury; peaks at 18 hours and normal by day 3
what is troponin biomarker of? what does it regulate?
describe elevation in relaetion to MI and how long does it remain high?
- biomarker of myocardial dmage
- regulates ca-mediated mediated contraciton of muscle
- elevation occurs within 4 hours after MI; levels remain high for 7-14 days
name some causes of non-mi troponin elevations
- pericarditis
- hert faiulre
- extreme physical exertion
- sepsis
- shock
- renail failure
- PE (due to right heart strain)
- cerebrovascular accident
name some characteristice events in MI
- inciting factor = sudden disruption of atheromatous plaque
- platelet adhesion and activation
- activaiton of coag pathway to give
- lumen occlusion
what two things happen in coronary thrombosis?
- thinning of atherosclerotic fibrous cap
2. endothelial dysfunction/disruption
what are some examples of endotherlial dysfunciton
- exposure of platelet adhesion factors
- complex of glycoproteins and vwf
- platelet activation/aggregation
- activation of coag cascade
Name 3 causes of non-atherosclerotic MI
- secondary ischemia (anemia, hypotension, arrhythmia, coronary artery emboli)
- cardiac intervention/CABG
- thrombosis of coronary artery stent
what are factors associated with MI onset/severity
- rate of thrombus development
- size of vascular bed involved (main coronary artery, or branch)
- duration of vascular occlusion
- metabolic demands of myocardium
- extent of collateral circulation to help out when needed
Give order of cellular ischemic events
- onset of ATP depletion in seconds
- loss of contractility in less than 2 min at area that is infarcted
- ATP reduced to 50 percent in 10 min, then 105 in 40 min
- irreversible cell injury in 20-40 min
- microvascular injury takes more than an hour
why are there no macroscopic/microscopic changes with sudden death for MI
- because there’s no time for inflammatory response that will bring on the damage
macroscopic/microscopic changes to heart at:
24 hours 1-3 days 3-10 days - 14 days > 3 months
- dark mottling; coag necrosis
- yellow center due to neutrophils
- red border with yellow center due to macrophags and neutrophils
- red-gray due to granulation tissue
white. .. scarring
Name complications of MI
- RV infarction
- infarct extension (new necrosis spreading adjacently to infarct region)
- infarct expansion – DILATION of infarct region, not new necrosis… no new cells dying, just spread out a bit
- contractile dysfunction
- arrythimas
- pericarditis
- myocardial rupture
- ventricular aneurysm
- mural thrombus
- papillary muscle dysfunciton
- progressive late heart failure
what is time frame for highest risk of myocardial rupture? what regions can be ruptured?
what is the most common site of myocardial rupture?
Where else can we see myocardial rupture?
4-7 days post MI
- ventricular free wall
- ventricular septum, causing left to right shunt
- papillary muscle, causing acute mitral regurgitation (at left heart)
what is chronic ischemic heart disease? what’s another name for it? what patietn population is it generally seen?
progressive heart failure due to ischemic myocardial damage, including previous MI and CAD
- ischemic cardiomyopathy
- elderly patients
what changes in the heart occur as a result of chronic ischemic myocardial damage
- LV enlarged— hypertrophic early, and dilated late
define sudden cardiac death
- unexpected death from cardiac cause – EARLY AFTER OR WITHOUT ONSET OF Sx; often manifestaiton of ischemic hert disease
what is usual cause of sudden cardiac death
- lethal arrythmia
what condition is usually present when sudden cardiac death occurs
- coronary atherosclerosis with stenosis
name some nonatherosclerotic causes of sudden cardiac death
- aortic valve stenosis
- mitral valve prolapse
- myocarditis
- DCM/HCM
- pulmonary HTN
- myocarditis
