Cardiovascular: Pathoma, BRS, First Aid Flashcards
Ischemic heart disease is caused by what?
Partial or complete interruption of arterial blood flow to the myocardium
What is the main cause for interruption of arterial blood flow to myocardium?
Atherosclerosis of coronary arteries
Incidence of IHD increases with what?
Age
How will ischemia present? (6)
- Silent
- Angina pectoris
- Coronary steal syndrome
- Myocardial infarction
- Sudden cardiac death
- Chronic ischemic heart disease
Frequency of IHD increases in patients who manifest what?
Metabolic syndrome
What does metabolic syndrome include?
- Central obesity
- Artherogenic lipid patterns
- Hypertension
- Insulin resistance
- Proinflammatory state
What predisposes someone to metabolic syndrome?
Obesity
Physical activity
Genetic factors
What is angina pectoris?
Episodic chest pain that is caused by inadequate oxygenation of myocardium
How much stenosis or obstruction of a vessel is needed to cause angina?
> 70-75%
Is there myocyte necrosis in angina?
Why?
No
Reversible
What is the most common type of angina?
Stable angina
What precipitates stable angina?
Why?
Exertion or stress
Can’t get enough blood (oxygen) to heart
What causes stable angina?
CAD of coronary arteries greater than 70%
How does stable angina present? 3
- Chest pain less than 20 minutes that radiates to left arm or jaw
- Diaphoresis
- Shortness of breath
Why is the 20 minute interval important?
After that you get irreversible injury and cell death
What does an EKG show in stable angina?
Why?
ST segment depression
Subendocardial ischemia
What relieves stable angina? (2)
- Rest
2. Vasodilators like nitroglycerin
Function of nitroglycerin?
Vasodilation of veins mainly that decreases preload and decreases stress on myocardia
Unstable angina is chest pain that occurs when?
At rest
What causes unstable angina?
Rupture of atherosclerotic plaque with thrombosis and incomplete occlusion of coronary artery
What type of damage is occurring in unstable angina?
Reversible injury to myocytes
What does an EKG show on unstable angina?
ST segment depression
What relieves unstable angina?
Nitroglycerin: Vasodilation to decrease preload which decreases stress
What are unstable angina patients at risk for?
Progressing to full occlusion: Myocardial infarction)
Prinzmetal angina is due to what?
Coronary artery vasospasm
What is the timing of pain in prinzmetal angina?
Episodic/intermittent chest pain at rest
What type of damage occurs in prinzmetal angina?
Reversible injury to myocytes
What does prinzmetal EKG show?
Why
ST segment elevation
Transmural ischemia
What relieves prinzmetal angina? 2
- Nitroglycerin: Decrease preload
2. Calcium channel blockers: Decrease spasm
What is the most important cause of morbidity from IHD?
Myocardial infarction
What is myocardial infarction?
Necrosis of cardiac myocytes (so after 20 minutes)
What mainly causes a myocardial infarction?
Rupture of a atherosclerotic plaque with thrombosis and complete occlusion of coronary artery
Other causes of myocardial infarction? (3)
- Coronary artery vasospasm (Complete prinzmetal)
- Emboli
- Vasculitis (kawasaki’s disease)
Symptoms of myocardial infarction?
- Severe chest pain greater than 20 minutes that radiates to left arm/jaw
- Diaphoresis
- Dyspnea: Heart can’t pump –> Fluid in lungs
Will nitroglycerin relieve myocardial infarction pain?
No
What ventricle is usually involved in an MI?
Left
What is most common artery involved in MI?
Which causes an infarction where?
LAD
Infarciton of anterior wall of LV and anterior part of IV septum
What is 2nd most common artery involved in MI?
Which causes an infarction where?
Right coronary
Infarction of right ventricle, posterior wall of LV and anterior portion of IV septum
What is 3rd most common artery involved in MI?
Which causes an infarction where?
Left circumflex
Infarction of lateral wall of LV
What are the 2 types of infarction based on heart layers involved?
Which is more common
- Transmural: Entire ventricular wall from endo to epi. More common
- Subendocardial infarction: Just 1/3 of the wall
ECG shows what during myocardial infarction?
- During the initial subendocardial infarction, ST depression
- During later transmural infarction, ST elevation
Why are there biomarkers for MI?
Irreversible damage to myocytes causes membrane breakdown thus releasing markers
What is the most SENSITIVE and most SPECIFIC cardiac marker?
Troponin I
When does troponin I peak?
24 hours
How long does troponin I remain high after MI?
7 to 10 days
CK-MB is most useful for what?
Detecting re-infarction
When does CK-MB rise?
4-6 hours after infarction
When does CK-MB peak?
24 hours
When does CK-MB return to normal? 72 hours
72 hours
What is the gold standard for diagnosing MI in first 6 hours?
ECG
When does LDH peak?
How long does it last?
3 days
4-7 days
When does myoglobin peak?
How long does it last?
First 6 hours
24 hours
Treatment of MI includes what? 6
Describe each
- ASA/Heparin: limit more thrombosis
- Supplemental O2: minimize ischemia
- Nitrates: Vasodilate –> Decrease preload
- Beta-blocker: Slow heart rate –> Decrease O2 need + decrease arrhythmia
- ACE inhibitor: Decrease dilatation
- Fibrinolysis/Angioplasty: Destroy blockage/open up vessel
How does an ACE inhiabitor decrease LV dilatation? 2
- Blocks ANG II production –> prohibit constriction of peripheral arterioles –> Decrease afterload
- Block ANG II –> No aldosterone secreted –> No blood volume increase
Two injuries due to fibrinolysis and angioplasty?
- Contraction band necrosis
2. Reperfusion
What is contraction band necrosis?
Calcium will enter cell after blood flow is restored and cause contraction –> visible contraction bands
What is reperfusion injury?
Returning O2 rapidly to cell causes ROS to form –> Further damage the cells
What is a lab test for reperfusion injury?
See cardiac enzymes continue to rise after reperfusion
Less than 4 hours from infarction, what risks does patient have?
- Cardiogenic shock: Heart fails –> Hypofusion
- CHF: Dead tissue –> Can’t pump–> Backs up into heart –> Decreased ejection fracture
- Arrhythmia
Between 4 and 24 hours after infarction, what changes do you see macroscopically?
What risk?
- Dark discoloration
- Coagulative necrosis: Karyolysis, pyknosis, karyorrhexis
Arrhythmia
Between 1 and 3 days what change do you see? 2
What is patient at risk for?
Yellow pallor
Neutrophils on scene
Fibrinous pericarditis
How does fibrinous pericarditis present in days 1-3?
Why does it occur?
Chest pain with friction rub
Transmural infarction –> Neutrophils enlame entire wall –> Debris into pericardium –> Pericarditis
How does MI present in days 4-7? 2
- Yellow pallor
2. Macrophages on scene
What is important about days 4-7 after MI?
Cardiac wall is weakest due to macrophages eating all the dead material.
What are the 3 things a patient is at risk for 4-7 days after MI?
- Rupture of ventricular free wall –> Blood leaks into pericardium –> Compresses heart –> Cardiac tamponade
- Rupture of IV septum –> Shunt from LV to RV
- Rupture of papillary muscle –> Mitral insufficiency
What causes rupture of papillary muscle?
Occlusion of right coronary artery
In weeks 1-3, what are the macroscopic changes? (2)
- Red border as granulation tissue enters from edge
2. Granulation tissue with fibroblasts, collagen, and BV’s
Months after, what changes does MI patient have?
- White scar of Type 1 collagen
2. Fibrosis
What risks does a patient with an MI have after months? (3)
- Weak scar: leads to balloon like dilatation –> Aneurysm
- Scar along heart wall –> Stasis –> Mural thrombus
- Dressler syndrome
What happens in Dressler’s syndrome?
Transmural infarct –> Pericardium leaks –> Form imune response against pericardium antigens –> Pericarditis 6-8 weeks after infarction
What is most common cause of death in first several hours after infarction?
Arrhythmia
What is sudden cardiac death due to?
Cardiac disease
How does sudden cardiac death appear? 2
- Asymptomatic before
2. Less than 1 hour after symptoms arise
What usually causes sudden cardiac death?
Fatal ventricular arrhythmia
Most common etiology of sudden cardiac death?
Acute ischemia
90% of SCD patients have what pre-existing condition?
Severe atherosclerosis
Less common etiologies of SCD? 3
- Mitral valve prolapse
- Cardiomyopathy
- Cocaine abuse
Chronic ischemic heart disease is defined how?
Poor myocardial function
What is Chronic IHD due to?
Chronic ischemic damage (with or without MI)
What do chronic IHD patients progress to?
CHF
What is coronary steal syndrome?
Vasodilator may aggravate ischemia by shunting blood from area of critical stenosis to an area of higher perfusion.
Congestive heart failure may be failure of what ventricle?
Right, Left or both
Causes of Left sided heart failure?
Explain each
- Ischemia: Decrease blood flow –> Damage myocardium –> Can’t pump well
- Hypertension: Get concentric LV hypertrophy to deal with stress –> Extra O2 demands –> Ischemic damage –> Can’t pump well
- Dilated cardiomyopathy: Stretch all four chambers –> Can’t contract well
- Myocardial infarction: Nonfunctional tissue –> Can’t pump well
- Restrictive cardiomyopathy: Can’t fill heart well –> Can’t pump enough out
- Aortic and mitral valvular disease
Two main Clinical manifestations of LCHF?
- Pulmonary congestion
2. Decreased forward perfusion
Pulmonary congestion from LCHF is due to what?
Heart can’t pump blood forward –> Backs up –>blood accumulates in lung –> Pulmonary congestion
Why does pulmonary congestion result in dyspnea?
Increase in hydrostatic pressure –> Pulmonary edema –> Dyspnea
What is PND?
Dyspnea upon laying flat for several hours
What is othopnea?
Dyspnea if late flat for a few minutes?
What are crackles?
Fluid in lungs upon auscultation
Ruptured pulmonary capillaries in LCHF results in what?
Blood in alveoli –> Macrophages arrive to clean up –> Iron fills maccrophages –> Forms hemosiderin laden cells called heart failure cells.
What are the 5 clinical manifestations of pulmonary congestion?
- Dyspnea
- PND
- Orthopnea
- Crackles
- Heart failure cells
Decreased forward perfusion results in activation of what?
RAS
RAS activation has what two effects?
Decreased blood flow to kidneys activates juxtaglomerular apparatus –> Release renin –> Release Ang II –>
- Constrict arterioles –> Increase total peripheral resistance
- Go to adrenal gland –> Release aldosterone –> Cause resorption of sodium –> Water follows –> Increase blood volume
OVERALL = Increase resistance –> Exacerbates problem
Main treatment for LCHF?
ACE inhibitor
Right sided failure has what causes? 6
- Left sided heart failure
- Left-sided lesions
- Pulmonary hypertension: Chronic lung disease/cor pulmonale –> Vessel constriction
- Cardiomyopathy/Diffuse myocarditis
- Tricuspid or pulmonary valvular disease
- Left to right shunts
Most common cause of RCHF?
Why?
LCHF
Backup into pulmonary circuit –> Backups into right heart
Isolated RCHF is usually due to what?
Cor pulmonale
Clinical manifestations of RCHF? 4
- Jugular vein backup –> JVD
- Hepato and spleno congestion –> Hepatosplenomegaly + cardiac cirrhosis + nutmeg liver
- Pitting edema: Due to increased hydrostatic pressure in low extremities.
- Renal hypoxia: Fluid retention
Congenital defects arise when?
During embryogenesis weeks 3-8
Congenital heart defects are seen in what percentage of live births?
1%
Most congenital defects are caused by what?
Undetermined = Sporadic
Congenital defects overall usually result in what?
Shunting between left and right circulations
What is most common congenital heart defect?
Ventricular septal defect
VSD is a defect associated with what syndrome?
Fetal Alcohol Syndrome
What happens with blood flow in VSD?
Blood enters right atrium and can enters normal low pressure RV over high pressure LV. However upon returning to LA, blood chooses low pressure RV instead of high pressure LV resulting in LEFT TO RIGHT SHUNT
How does size of defect affect symptoms in VSD?
Small VSD = asymptomatic
Large VSD = large amounts of blood entering RV –> increase of blood in pulmonary circuit –> Pulmonary hypertension
What does pulmonary hypertension from VSD result in over time?
P-HTN –> Right side to become high pressure –> Blood now shunts from high pressure right to low pressure left ventricle –> Deoxygenated blood in systemic circulation –> Cyanosis
The reversal of a shunt due to a change in pressure from pulmonary hypertension is known as what?
Eisenmenger syndrome
3 consequences of Eisenmenger’s syndrome?
- RV hypertrophy: Due to pumping against higher pressure
- Polycythemia: Deox blood –> Hypoxemia –> Release EPO –> Increase RBC’s
- Clubbing: Change in fingernails from cyanosis
Treatment of VSD? (2)
- Small VSD close on their own
2. Surgical closure
Atrial septal defect includes what five types?
- Patent foramen ovale
- Septum primum
- Septum secundum
- Sinus venosus
- Lutembacher syndrome
Patent foramen ovale is clinically significant how?
It’s not. 20-30% of people have it.
Septum primum/Ostium primum is associated with what consequence?
What genetic disease is associated with this?
Affects lower part of septum so it can affect AV valves.
Down’s syndrome
Most common type of ASD is what?
Ostium/Primum secundum
Ostium/Primum secundum is a defect in what?
Fossa ovalis
Sinus venosus affects what area?
Upper part of septum near SVC
Lutembacher syndrome has what two components?
- ASD
2. Mitral stenosis
Atrial septal defect results in what type of shunt?
Left to right shunt
ASD presents how on auscultation? 2
- Split S2
2. Loud S1
Why does split S2 occur in ASD?
Blood from high pressure LA crosses to low pressure RA –> Extra volume on right side –> Delayed closure of pulmonic valve –> Split S2
What is the S2 sound?
Pulmonary and aortic valves closing
What is an important complication of ASD?
Paradoxical emboli: DVT emboli enters RA normally but crosses over to LA and lodges in brian or extremities.
When are ASD symptoms seen?
What is the main one?
Late in life
Cyanosis due to Eisenmenger’s syndrome from P-HTN
What is Patent ductus arteriosus?
Failure of ductus arteriosus to close.
PDA is associated with what situations? 2
- Congenital Rubella
2. People living in high altitudes
What is the mechanism of PDA?
Blood enters RA –> RV –> Enters pulmonary artery –> Chooses to enter low pressure lungs over high pressure aorta –> LA –> Enters LV –> Enters aorta –> Chooses low pressure lungs over high pressure systemic circulation –> LEFT TO RIGHT SHUNT
What happens over time in PDA patients?
P-HTN develops –> Blood now chooses low pressure aorta over high pressure lungs –> Deox blood goes to LOWER extremities –> Cyanosis in lower extremities in late life.