Cardiac Muscle Dysfunction Flashcards
Heart failure definition
results from any structural or functional impairment of VENTRICULAR filling or ejection of blood
3 cardinal manifestations of cardiac dysfunction include
- dyspnea
- fatigue
- fluid retention
Which term is preferred? Heart failure or congestive heart failure?
Heart failure
What is dyspnea?
Labored breathing, shortness of breath
What is congestive heart failure?
As blood slows out of coming out of the heart it backs up in tissues on it’s return. “Congesting” the aforementioned tissues and resulting in swelling
What are 3 clinical manifestations of heart failure?
Marked decrease in exercise tolerance
Decline in functional status
Decrease in quality of life
What can lead to heart failure?
- Excess work loads (HTN, Aortic Stenosis, Pulmonary HTN)
- Intrinsic Cardiac Diseases
- Myocardial damage, chemotherapy, radiation, drugs
Family history, chronic alcohol abuse, steroids
What is cardiomyopathy?
Heart mucsle is abnormal; loses ability to pump effectively. Heart becomes larger to compensate for weakened condition. —> results in enlarged heart
Abnormal stroke volume can result from
Impaired contractillity , increased afterload, and impaired ventricular filling
What is a normal cardiac output amount? In one minute
4-8 L a min
What is the normal amount of ejection fraction of the left ventricle? (LVEF)
55-75%
What is preload?
Tension on muscle fibers at EDV
If that heart cannot contract fully, how does this affect preload?
There will be an increase of volume in the ventricles, raising EDV
What is afterload
resistance encountered by left ventricle as it attempts to eject blood (systole)
Increase in arterial vasomotor tone leads to what?
Afterload
Increased afterload causes what 4 characteristics?
increases myocardial oxygen consumption
decreased stroke volume
in normal heart increased afterload has little affect on SV
In heart failure, small increases in afterload can have large impact on stroke volume
3 main types of cardiomyopathy are?
Dilated
Restrictive
Hypertrophic
What is dilated cardiomyopathy?
Heart is dilated and enlarged and cannot pump blood efficiently
What is restrictive myopathy?
The heart walls are rigid and prevent proper stretching of tissues. Loose flexibility
What is hypertrophic myopathy?
Heart muscle is abnormally thick and makes it harder to pump blood. Mostly common in left ventricle.
Myopathy dysfunctions that affect systolic pressure affect these 4 things:
- Loss of contractility
- Dilated ventricle
- Increase in LVEDV
- Lead to decreased ejection fraction
Diastolic dysfunction from myopathy affect? Resulting from?
Impaired filling due to hypertrophy or decreased filling
Results from HTN or aortic stenosis/
Name 3 causes of right sided heart failure?
Increased pulmonary resistance
Increased afterload
Low preload or poor pump
Name 4 causes of left sided heart failure
Impaired contractility
Increased afterload
Low preload
Loss of myocardial tissue
What is a common symptom of right heart failure?
Venous congestion!!!
Weight gain, peripheral edema, hepatomegaly, jugular venous distention are all symptoms of what side heart failure?
right sided
What is pitting edema?
Observable swelling of body tissues due to fluid accumulation that may be demonstrated by applying pressure to the swollen area (such as by depressing the skin with a finger).
Dyspnea, orthopnea, nocturnal dyspnea, S3 heart sound and excessive weight gain, decreased tolerance to exercise are signs of what sided heart failure?
Left Heart Failure
Pulmonary edema is when pulmonary venous pressure is above ___ mmhg?
This leads to a ______ in pulmonary compliance and _____ work of breathing.
> 20mmhg
decreased, increased
Pulmonary edema often has this type of heart sound, and is common in what side of heart failure?
Crackles, and left heart failure
What is the purpose of a compensatory mechanism?
Maintain cardiac output and arterial pressure that can perfuse the brain and heart adequately.
The ______ of compensatory adaptations can lead to maladaptive processes leading to end stage HF.
Magnitude
Compensatory Mechanisms include:
______ Increase in MAP
______ fluid retention
______ LVEDP
______ stroke volume/ ejection fraction
________ contractility
increase
Moderate
Increase
Decreased
Decreased
What does decompensated HF refer to?
Deterioration
Reduction in exercise tolerance and increasing breathlessness on exertion
Compensated heart failure has _____ symptoms. Fluid retention and pulmonary edema are often _____.
stable, absent
What is B-type natriuretic peptide BNP?
Endogenous nuerohormone, maintains normal fluid state and promotes normal cardiac function
What secretes BNP?
What prompts it’s secretion?
Left ventricle in response to volume expansion and pressure overload “myocardial stretch”
What is BNP’s purpose?
Counter regulation of renin-angiotension-aldosterone system
VASODILATION, diuresis, while inhibits renin/angiotension system
How many classes of heart failure are there for the New York Heart Association Classification?
4
What is class I in the NY Heart association classification?
No limitation of physical activity
What is class II in the NY Heart association classification?
Slight limitation of activity.
Example: dyspnea and fatigue with ordinary physical activity
What is class III in the NY Heart association classification?
OK at rest
Symptoms of HF with less than ordinary activities.
What is class V in the NY Heart association classification?
Symptoms present at rest
How does one correct salt and water retention in regards to their preload?
Low sodium diet and diuretics
How does one improve contractility of cardiac muscle and it’s performance?
Pacemaker, decrease of workload, B-Blockers
How does one reduce peripheral resistance as seen in afterload?
Lower BP
What 3 drugs are in the HF triple drug cocktail? and why?
ACE inhibitors - decrease afterload
Diuretics - decrease volume
Beta-Blockers - limit sympathetic stimulation to heart and hold HR down.
