Heart PT 2 Flashcards
Rhythmic disorders are most caused by?
ischemia
What is sick sinus syndrome and what does it cause
SA node is damaged d/t ischemia => causing bradycardia
What is a-fib? What can it cause and describe the heartbeat?
-
Sporadically depolarizing atrial myocytes d/t atrial dilation, causing variable transmission through the AV node, which can cause clots and an irregular irregular heartbeat
- Thus, give blood thinners
What is an AV block?
Fucked up AV node causes abnormal heart rhythm that causes the heart to beat too slowly (heart block)
What is the difference between first, second and third degree heart block?
- First degree heart block has a prolonged PR interval
- Second degree heart block has intermittent transmission
- Third degree heart block has complete heart failure.
What causes arrhythmias?
- Abnormalities in structure of gap junction/ spatial relationship,
- Ischmia/hypertrophy/ inflammation,
- Amyloid deposits or scarring/
- Genetics (AD)
What is the most common inherited arrhythmogenic disease?
- Long QT syndrome: arrythmias d/t with too much prolongation of cardiac repolarization d/t K+/Na+ channelopathy
Most common inherited arrhythmogenic disease have what pattern of genetic inheritance?
AD
What are 4 genes implicated in long QT syndrome?
- KCNQ1
- KCNH2
- SCN5A
- CAV3
Long QT syndrome is associated with ____ of K+ channels or _____ of Na+ channels
LOF of K+
GOF of Na+
arrhythmias associated with short repolarization intervals.
What is this and what can patients experience
Short QT syndrome
palpitations, syncome, sudden cardiac death
What syndrome has ECG abnormalities (ST-elevation; RBBB) without a structural defect in the heart?
What do they present with?
Brugada syndrome;
-syncope/SCD during rest, sleep or large meals
Pablo came into ER and was pronounced death after an unexpected cardiac cause within 24 hours of onset of symptoms. What can we diagnose this patient as? Are symptoms always required?
- Sudden cardiac death (SCD)
- No
Pablo was diagnosed with SCD (sudden cardiac death). SCD is due to?
fatal arrhythmia d/t damage of the myocardium d/t ischemia.
Pablo, who suffered from SCD, was able to be resuscitated. Based on statistics, what will his lab/ECG show?
- 80-90% of resuscitated patients have NO lab or ECG changes because they have no long-term damage.
What is the leading cause of SCD?
- CAD in 80-90% of patients: patients will usually have >75% stenosis of 1 or more of 3 main coronary arteries.
What is OFTEN first sign of IHD (ischemic heart disease)?
Sudden cardiac death :(
Hypertrophy of the heart is an adaptive response to chronically elevated pressures; with continued overload, the result can be
dysfunction, dilation, CHF or SCD.
What criteria are required to diagnose a patient with left-sided hypertensive heart diseases (systemic hypertensive heart disease)?
- 1. HTN
- LV hypertrophy that is concentric w no other probs => decrease lumen size
In systemic hypertensive heart disease, how will the heart adaptively response?
- Wall of LV thickens to more than 1.5 cm => weighs more than 500 grams.
In Systemic (left-sided) HHD as the LV wall continues to increase in thickness, what associated morphological changes occur?
- ↑ interstitial CT –> stiffness = impaired diastolic filling; LV does not fill with blood –> LEFT ATRIAL ENLARGEMENT => a-fib
In many pt’s, systemic HHD comes to attention due to what signs/sx’s?
- L atria enlarged => causes A-fib => leads to CHF, a risk factor for SCD.
Isolated pulmonary (right-sided) HTN heart disease (cor pulmonale) arises in the setting of what?
- Pulmonary HTN
What is the most common cause of pulmonary HTN?
- Left-sided heart disease.
How can we distinguish whether right-sided hypertensive disease (pulmonary hypertensive disease) is acute or chronic?
- Acute pulmonary HHD is caused by a large PE => pulmonary HTN => RV dilation w/t hypertrophy
- Chronic pulmonary HHD is caused primary pulmonary HTN or chronic dz that affects parynchma (COPD, CF, emphysema) => pulmonary HTN => RV wall thickens
Aubrey comes in and we suspect pulmonary HHD. What morphological changes will tell us whether or not it is acute or chronic?
- Acute: RV dilation without hypertrophy
- Chronic: RV wall thickens
What are 5 diseases affecting the lung parenchyma => cor pulmonale?
1. COPD
2. Diffuse pulmonary intersitial fibrosis
3. Pneuoconiosis
4. CF
5. Bronchostasis
________ can lead to cor pulmonale because of the physical pressure on the rib cage from being hunched over.
Kyphoscoliosis
Pathologic changes of valves include what 3 types?
-
Damage to collagen that weakens leaflets
- Mitral valve prolapse
- Nodular calcification that beings in interstitial cells
- Fibrotic thickening
Why are valves so vulnerable to damage?
- Because they are so thin and receive nourishment via diffusion, they have little BS.
When do we begin to clinically notice a valvular disease?
If chronic, what can these diseases cause
when they begin to cause clinical problems.
-
Stenosis
- Stenosis is stiffening/thickening of a valve, causing failure of a valve to open completely, which disrupts forward flow.
- Chronic stenosis can cause what? Pressure-overload hypertrophy => CHF
-
Insufficiency/regurgitation/incompetence
- Insufficiency: valve does NOT CLOSE completely, which reverses flow
- Chronic regurgitation may cause volume-overload hypertrophy => CHF
- Both
Other words for regurg
- incompetence
- insuffiiency
Chronic stenosis** may cause what type of overload hypertrophy vs. **chronic insufficiency?
- Chronic stenosis = cause pressure-overload hypertrophy
- Chronic insufficiency= cause volume- overload hypertrophy
Incompetence of a valve due to a abnormality in one of its support structure, NOT the valve itself is called?
- Functional regurgitation
Functional mitral valve regurg is clinically important in what 2 conditions?
- IHD
- Dilated cardiomyopathy
- What is the major etiology causing mitral stenosis?
- Rheumatic heart disease (post-inflammatory scarring)
- What is the major etiology causing mitral regurgitation?
- Problems in leaflets/commissures due to: post-inflammatory scarring and infective endocarditis
- Mitral valve prolapse
- Drugs
- What is the major etiology causing aortic stenosis?
- Abnormalities in leaflets/commissures due to rheumatic heart disease (RHD)
-
Senile calcification aortic stenosis
- Normal aortic valve that undergoes calcification. Thus, not bicuspid
- Calcification of a congenitally deformed valve (bicuspid or unicuspid)
- What is the major etiology causing aortic regurgitation?
- RHD that causes post-inflammatory scarring => damages leaflets and commissures
- Aortic insufficiency: dilation of ascending aorta, often due to HTN or aging.
Abnormalities of the tensor apparatus that cause aortic Regurgitation may be caused by what 4 things?
a. -Syphilitic aortitis *
b. Ankylosing spondylitis
c. Rheumatoid arthritis
d. Marfan Syndrome *
What is aortic insuffiency?
Dilation of ascending aorta, often d/t a HTN or aging => can cause aortic regurg
Aortic stenosis is a stiff aortic valve, causing obstruction of _________outflow and decrease ____. Thus, it is a ____ problem.
- LV outflow
- CO
- systemic => decrease blood going to body
3 cardiac signs of aortic stenosis.
- Exertional dizziness or syncope
- Exertional dyspnea
- Exertional angina
What is the most common valve abnormality?
- Calcific aortic stenosis; mounds of calcification prevent the cusps from completely opening.
When are you most likely to get calcific aortic stenosis and what is it usually due to?
- 60-80 yo
- “Wear and tear” due to. w/ chronic HTN, hyperlipidemia, and inflammation
Calcification, leading to aortic stenosis of previously normal valve differs in onset from calcification of a abnormal bicuspid aortic valve (BAV) how?
Senile calcific aortic stenosis occurs 60-80 YO, however if the patient has a bicuspid valve, onset occurs 1-2 decades earlier because it faces more stress.
How does valve injury of calcific aortic stenosis differ from atherosclerosis?
Abnormal valves contain osteoblast-like cells–> make bone matrix and deposit Ca2+=> ossifies
In contrast to rheumatic (and congenital) aortic stenosis, what are 2 major differences seen in nonrheumatic, calcific aortic stenosis?
- Commissural fusion is NOT usually seen
- Mitral valve = normal
What are the 3 main symptoms of calcific aortic stenosis? What do you see on XR?
- Angina
-
CHF
- Patients with calcific aortic stenosis + CHF will die in 2 years
- Syncope
- On XR, patients will have LV hypertrophy d/t increased pressure
If present, which site on the cusp is a major site of Ca2+ deposits in those with congenital bicuspid aortic valves (BAV)?
Midline raphe
Calcium deposits in the mitral valve tend to accumulate in the _______, resulting in _______\_
- Fibrous annulus
- Mitral annular calcification
As opposed to the cuspal involvement in aortic valve calcification, where do calcific deposits occur in the mitral valve?
Mitral annulus
What is the gross morphology of the calcific deposits in mitral annular calcification?
- Irregular, stony, hard ulcerated nodules.
How does mitral annular calcification affect valve function?
Valve function is usually NOT affected. However, it can cause:
- Stenosis by preventing opening
- Regurg by impaiing physio contraction
- Arrhythmia and sudden death if Ca2+ deposits fuck with the AV node
Ca2+ nodules in mitral annular calcification may provide a site for what complications?
Pt’s are at greater risk for what?
for thrombi or infective endocarditis
Mitral annular calcification is most common who?
- Females over 60 with mitral valve prolapse.
Mitral valve prolapse has a higher incidence in what gender?
F (7:1)
Mitral Valve Prolapse is often discovered incidentally by hearing what during ausculation?
Mid systolic click sometimes followed by mid-to-late systolic murmur
What occurs to the valve leaflets in Mitral Valve Prolapse?
“Floppy” leaflets balloon back into the LA during systole
Which heritable disorder of CT is associated with Mitral Valve Prolapse?
Marfan Syndrome
The leaflets in Mitral Valve Prolapse become thickened and rubbery due to what?
- Deposits of proteoglycans (myxomatous degeneration)
- Fucking up of elastic fibers
What is the characterstic anatomic change in mitral venous prolapse?
Interchordal ballooning (hooding) of mitral leaflets
- Majority of patients with Mitral Valve Prolapse are asymptomatic, but a small minority may develop which 4 serious, but RARE complications?
- 1. Infective endocarditis
- Mitral insufficiency
- Stroke or thromboembolism
- Arrythmias
2’ changes reflecting the stresses and tissue injury incident to the billowing leaflets in mitral valve prolapse include thickening of what 3 structures?
- Fibrous thickening of valve leaflets
- Linear fibrous thickening of LV endocardial surface
- Thickening of the mural endocardium of the LV or LA
How can the diagnosis/confirm of mitral valve prolapse be made?
- Auscultation
- Confirmed w/ Echocardiography
What is the most common cause for mitral valve surgery in the US?
MVP (mitral valve prolapse)
Rheumatic heart disease is virtually the only cause of what cardiac disorder?
mitral stenosis
What is rheumatic fever?
autoimmune reaction (type 2) that causes inflammation of joints, muscles and fibrous tissue. I can damage heart muscle => lead to rheumatic heart disease.
What is the pathogenesis of RF?
- CD4+ T cells that attack M-proteins on group A strep cross-react with cardiac self-antigens in a processes called molecular mimicry.
What bacteria causes rheumatic fever and when does it occur?
- Weeks after streptococcal pharyngitis “strep throat” due to group A strep.
Rheumatic heart disease is most common in who?
chilren