Unit 2 - Cardiovascular System Part 3 Flashcards
heart failure
occurs when the heart is unable to pump enough blood to meet the body’s metabolic demands. Indicative of a weakened and dilated heart
the end result of many different cardiovascular diseases, including:
Coronary artery disease (CAD) – “progressive atherosclerosis” Post myocardial infarction Intrinsic muscle disease Increased pressure/volume load Hypertension Valvular disease
common cause: decrease in myocardial capacity
Post myocardial infarction
Heart muscle is damaged, which in turn has a negative impact on pumping function. Necrotic muscle tissue is replaced by scar tissue and no longer contributes to ejection of blood.
b. Intrinsic muscle disease - myocarditis, cardiomyopathy
Coxsackie virus, bacteria, genetic, alcohol or drug induced, Idiopathic
common cause: increased pressure/volume load
a. Hypertensive cardiovascular disease Increased resistance to blood flow. Causes: Diffuse or localized vessel narrowing Fluid retention Requires an increased Driving Pressure – “the heart has to work harder to pump blood into the systemic and/or pulmonary circulation”.
b. Valvular disease
Examples:
Acquired (Rheumatic fever)
Congenital
stenosis
restricted or narrowed opening
results in increased mycardial workload as the heart works to pump blood through the narrowed aorta
valve becomes stiff and non compliant
insufficiency
valve does not close properly and allows blood to flow in a retrograde (backwards) direction
rheumatic heart disease
typically occurs in childhood, caused by group A beta hemolytic streptococcus bacteria
damage to heat valves, scarred/stiff
mitral valve prolapse
congenital disorder characterized by a tendency for the mitral valve leaflets to buckle up into the LA as the ventricle contracts
s/s of mitral valve prolapse
Murmur Palpitations Tachycardia Shortness of Breath Note: MVP is fairly common and does not typically result in serious complications.
initial ventricular hytrophy - starling curve
with increased filling (EDV) of the heart, the muscle fibers are stretched which allows for a more optimal arrangement and increases contractility and stroke volume
dilated cardiomyopathy and risk factors
impaired contraction/relaxation of myocardial muscle fibers secondary to significant dilation of the ventricle
risks: black men 40-60yrs, alcohol abuse, rheumatic fever, mx dystrophy, sarcoidosis
myocarditis
inflammation of the heart muscle
- from viral or bacterial infection, radiation, drugs, sarcoidosis, lupus
myocardial ischemia
chronic O2 deprivation can result in depressed pump function
can increase risk of CHF
progressive ventricular dilation law of LaPlace
T= P x R
T=wall tension
P= descending pressure
R=radius
left sided vs right sided components
“Forward” = Decreased Perfusion
blood is unable to pump hard enough to go through the capillaries isn’t working
“Backward” = Passive Congestion
heart isn’t pumping hard enough so it can come back up
left sided HF etiology
AMI
Systemic HTN
Mitral/Aortic Valve Disease
Coarctation of the Aorta
HF “fun facts”
Most common Hosp. Discharge Dx. Incidence is increasing due to better management of MI’s (decreased mortality) and HTN > 30 billion in costs annually >5 million patients 500,000 new diagnoses/yr 12-15 million office visits/yr
systems affected by left sided heart failure
Lungs - Passive congestion - Pulmonary edema - Orthopnea - Paroxysmal Nocturnal - Dyspnea Kidneys - Decreased renal perfusion - Sodium and Water Retention
Anasarca (generalized massive edema)
Pedal edema (Pitting)
Facial edema
Left sided vasoconstriction
due to reduced renal perfusion with subsequent increase in renin release and formation angiotensin II, a potent vasoconstrictor. Renin also leads to increased aldosterone release from the adrenal glands which promotes reabsorption of sodium and water in the renal tubules
left sided hyper/hypotension
hypertension is usually seen earlier on, with hypotension occurring as the CHF worsens and pump function deteriorates.
additional left sided HF s/s
Pulsus Alterans (alternating strong and weak pulse beats)
Fever & Pallor
Cardiac Cachexia
3rd heart sound
right sided HF etiology
85% of those patients diagnosed with right sided failure have COPD AMI - Right Ventricle Pulmonary HTN Tricuspid/Pulmonic Valve Disease Pulmonary Artery Stenosis
right sided systems affected
Lungs
- Increased pulmonary vascular resistance
- No Pulmonary Edema
- No Passive Congestion
Spleen & Liver
- Passive Congestion
- Splenomegaly
- Hepatomegaly
- Ascites
Kidneys
- Decreased perfusion
- Sodium/Water retention
- Generalized Edema
Anasarca
Pedal Edema/Pitting
Facial Edema
orthostatic hypotension
Drop in SBP > 20 mmHg and/or drop in DBP > 10mmHg, with reflexive increase in HR (10-20%) as individual transitions from supine or sitting to a standing position.
