Cardiac Failure Flashcards
The right side of the heart receives
———-blood from the body and pumps it to the lungs.
deoxygenated
The left side of the heart receives——-
blood from the lungs and pumps it to the body.
oxygenated
Both sides of the heart work.
simultaneously
HEART RATE (HR)
Healthy adult:
Children and infants:
60 to 80 beats per minute
faster pulses
Children and infants have faster pulses because of
their smaller size and higher metabolic rate.
A person in excellent physical condition has a——
resting pulse because?
slow /
the heart is a more efficient
pump and pumps more blood per beat.
Cardiac output (CO) is
the amount of blood pumped by
a ventricle in 1 minute.
Stroke volume (SV) is
is the amount of blood pumped by
a ventricle in one beat; average is 60 to 80 mL.
Stroke volume (SV) Determined by
1) preload
2) afterload and
3) myocardial contractility
Cardiac output =
stroke volume x pulse (heart rate)
average resting
cardiac output is approximately— liters
5
Starling’s law of the heart:
the more cardiac muscle
fibers are stretched, the more forcefully they
contract.
During exercise, stroke volume increases as ?
venous
return increases and
stretches the myocardium of
the ventricles (Starling’s law).
During exercise, the increase in stroke volume and
the increase in pulse result in
increase in
cardiac output: two to four times the resting level.
Cardiac reserve is
the difference between
resting cardiac output and the maximum
cardiac output
Cardiac reserve may be - liters or more.
15
ejection fraction (EF) is
the percent of
total blood that a ventricle pumps per beat;
average is 60% to 70%.
The force of contraction of cardiac muscle depends on
its preloading and its afterloading.
Preload the degree to which the myocardium is
stretched before it contracts
Preload
– Volume of blood in ventricles at—-
– Depends on?
- end diastole
1) venous return
2) compliance
Afterload the
resistance against which blood is
expelled.
Afterload
– Force needed to eject blood into circulation
– Arterial B/P, pulmonary artery pressure
– Valvular disease increases afterload
T
Heart Failure (HF)
Definition
When the heart is unable to pump blood at a rate sufficient to meet the metabolic demands of the tissues or can do so only at an elevated filling pressure.
Heart Failure (HF)
Often called
congestive heart failure (CHF).
forward failure
CO = SV x HR-becomes insufficient to meet
metabolic needs of body
backward failure
Accumulation of blood in the venous system
CHF Common end point of many
cardiac conditions.
Congestive Heart Failure Has—- prognosis.
poor
Classifications of HF
1) Systolic versus diastolic
2) Left-sided versus right –sided
3) High output:
Systolic versus diastolic
– Systolic:
– Diastolic:
– Mixed
- loss of contractility decreased CO
- decreased filling or preload
Left-sided versus right –sided
– Left- lungs
– Right-peripheral
High output:
hyper-metabolic state e.g thyrotoxicosis.
CHFcan develop over different time periods:
Chronic CHF
Acute CHF
Chronic CHF
Chronic work overload (valve disease, HTN or post
MI)
Acute CHF
Acute hemodynamic stress (fluid overload, acute
valvular dysfunction or acute MI)
CHF- Etiology
- Impaired cardiac function
- Increased cardiac workload
- Acute non-cardiac conditions
Impaired cardiac function
- Coronary heart disease
- Cardiomyopathies
- Rheumatic fever
- Endocarditis
- Arrythmias
Increased cardiac workload
- Hypertension
- Valvular disorders
- Anemias
- Congenital heart defects
Acute non-cardiac conditions
- Volume overload
* Hyperthyroid, Fever, infection
Heart Failure-Risk Factors
Primary risk factors
Contributing risk factors
Primary risk factors:
– Coronary artery disease
– Advancing age
Contributing risk factors:
– Hypertension – Diabetes – Tobacco use – Obesity – High serum cholesterol – African descent – Valvular heart disease – Hypervolemia
Systolic dysfunction (—)
pump failure
Systolic dysfunction (pump failure) , result of progressive
myocardial contractile dysfunction.
systolic dysfunction
Hallmark
decreased left ventricular ejection
fraction (EF)
decreased left ventricular ejection
fraction (EF)
– Left side
congested pulmonary vasculature and
edema.
decreased left ventricular ejection
fraction (EF)
– Right side
systemic venous hypertension and
edema.
Causes of systolic dysfunction
• Ischemic injury • Volume overload • Pressure overload • Dilated cardiomyopathy • Drugs arrhythmia
