Cardiac Pathologies: Cardiac Muscle Dysfunction and Failure Flashcards
What can be the cause of CMD?
CMD = Cardiac Muscle Dysfunction
Usually develops with some hidden dysfunction in the heart
- which can also have hidden problems
CMD is the most common cause of what?
Congestive heart failure
- most common manifestation from CMD
In a nutshell, how does CMD sx develop?
when the heart can’t pump = can’t meet the demand
- CMD pt’s will have no sx at the start but develop as the heart can’t meet the demand
What is the prevalence of CHF and the risk factor?
5.7 million and accounting
- 1 in 5 over 40 can get it
- 85 and older annual rate of getting heart failure is 65%
How dangerous is CMD?
Causes the left ventricle to lose detriorate
- most fatal and severe
- most common diagnosis of patients over 65
How does hypertension cause CMD?
↑ arterial pressure = left ventricle hypertropy
- overstretched fibers and pump is less effective
Using ACE-inhibitors, CCB, diuretics, BB
How does CAD cause CMD?
second most cause (!!)
= bad left or/and right ventricle because of injury
How does cardiac arrhythmias cause CMD?
fast or slow HR = impair left and/or right ventricle function
How does renal insuffiency cause CMD?
acute or chronic problems = fluid buildup
Using dieuretics or dialysis to decrease reabsorption of fluid from kidney
How does cardiomyopathy cause CMD?
cardiac muscle fiber’s ability to contract and relax is broken frfr
- primary cause = pathological procress
- secondary cause = systemic disease
What is the leading cause of heart failure and transplants?
cardiomyopathy with 3 main types
What is dilated cardiomyopathy and it’s dysfunction?
BIG VENTRICLES
- systolic dysfunction
What is hypertrophic cardiomyopathy and it’s dysfunction?
WEIRD LEFT VENTRICLE WALL IS THICC
- diastolic dysfunction
What is restrictive cardiomyopathy and it’s dysfunction?
WEIRD LEFT VENTRICLE WALL IS STIFF
- diastolic dysfunction
What are the causes of cardiomyopathy?
Primary:
- inherited
- onset is younger
Secondary:
- medical issue
What are the sx of dilated cardiomyopathy?
- same sx as MI with ↓ ejection fraction
- S3 sounds and mitral valve regurgitation
- crackles and dull when listening
- image = big heart UwU
What are the sx of hypertrophic cardiomyopathy?
- sx can vary
- avg age of sx is 20
- dyspnea and angina
- arrhythmias and syncope
- S4 heart sound
breathing hard = need more O2 because of THICC wall
What are the sx of restrictive cardiomyopathy?
↓ CO
fatigue and ↓ exercise ability
systemic edema
Arrhythmias
How does heart valve weirdness and acquired heart disease cause cardiac muscle dysfunction?
weirdness = abnormal
blocked or incapable valves = needing heart to contract more
associated w/ myocardial dilation and hypertrophy
What are some common surgeries to assist with valve weirdness?
valve replacement
valvuloplasty
valvulotomy
commissurotomy
How does pulmonary hypertension cause CMD?
defined by mean pulmonary artery pressure
abnormal = greater than 25
- COPD = greater than 20
How does pulmonary embolism cause CMD?
Dysfunction because of elevated pulmonary artery pressure = increase right ventricle WORK
- possibly life-threatening
medical management:
- rapidly acting fibronolytic agent
- sedative to decrease anxiety and pain
- O2
- Embolectomy
How does age-related changes cause CMD?
↓ CO by changing contract and relax of heart muscle
higher chance of:
- heart disease
- hypertension
- other pathological processes
- congential heart disease - embryonic
How does contractility affect heart failure?
length and tension of cardiac muscle is curvelinear
- tension proportional to length
What is optimized during ventricular stretching regarding the myocardium stretch?
During filling, there needs to be overlap of the actin and myosin = increased cross bridging and more force
What are the normal limits of an intact heart?
- bigger ventricle volume during diastole (greater stretched)
- pressure made depends on the load it has to contract against
- contract is dependent on other factors (preload, afterload, chemicals or hormones)
What is indicated by the frank-starling mechanism?
greater venous return = greater SV
- ability of the heart to change how much it contracts = SV response to changes in venous return
- allows the heart to adjust quickly adjust preload so output is constant
Why is the frank-starling law length dependent?
An natural property of the myocardium which states that because of letting a bigger stretch = bigger contraction is possibe
i.e. controlling the eccentric load in a squat = greater force on the concentric contractability
How does cardiac contractility affect heart failure?
when impaired - contraction is as problem (systolic problem)
- there is a reduction of muscle mass
- increase likelihood of cardiomyopathies
How does afterload affect heart failure?
Reminder: afterload is the pressure the heart needs to have to eject the blood through aortic valve and push blood to the body
when there is an increase in afterload there is a contraction issue (systolic dysfunction)
- systemic/pulmonary HTN
- aortic or pulmonic valve stenosis = ventricular hypertrophy