Module 1: Gas Exchange, Perfusion, Cognition Flashcards
What is Congestive Heart Failure? (HF)
When the heart can’t supply enough blood to meet the body’s demands. Blood backs into the lungs, causing fluid buildups (aka congestion).
- When blood flow is restricted
S/S of Heart Failure?
- SOB (on exertion or laying down)
- fluid buildup, edema
- dyspnea
- angina
- rapid or irregular HR, weakness
- chronic cough
- nausea
- rapid weight gain
What are the 2 types of Heart Failure?
Systolic and Diastolic
Contrast Systolic and Diastolic HF
Systolic HF: when the heart can’t pump hard enough (ventricles aren’t emptied)
- decreased CO
- EF = 40%
Diastolic HF: when the ventricles can’t fill enough (reduced preload/abnormal filling)
- low total volume of blood
- normal EF
What does EF stand for?
Ejection fraction.
Stroke volume/Total Volume.
- A measurement of the percentage of blood leaving the heart each time the ventricles contract.
- normal EF = 50-70%
What is the range of Ejection Fraction for systolic heart failure?
40% and below.
Causes of HF?
Left -sided and Right-sided HF.
Explain Left-sided HF and its causes
When blood gets backed up to the lungs
- Usually caused by systolic HF (lack of pumping), due to heart muscle damage (myocardium), but can also be diastolic.
- contributors: Longstanding HTN, Ischemic heart disease, dilated cardiomyopathy
Explain Right-sided HF and its causes
When blood gets backed up in the body
- congestion in systemic circulation –> fluid can move into interstitial spaces in organs = edema and pain
- usually caused by LS HF (increased pressure in pulmonary artery makes it hard for the right ventricle to fill)
- also caused by any ventricular or atrial septal defect which allows blood to move across ventricles –> increased volume on right side = hypertrophy, schema, diastolic dysfunction
Specific medications for Left-sided and Right-sided Heart failure?
ACE Inhibitors – relax veins and arteries to decrease BP
Diuretics – increase the amount of water and salt expelled from the body as urine (get rid of fluid)
What are some medications for Heart Failure?
- ) Cardiotonic Agents
- increase Ca levels in heart muscle, leading to increased contractility = increased CO
- Cardiac glycosides (ex: Digoxin) – allow more Ca into myocardial cells
- Phosphodiesterase inhibitors (block phosphodiesterase enzyme leading to increase in cAMP which increases Ca levels in cell = stronger contraction, vasodilation, increased O2 consumption)
- Beta blockers (block epinephrine = slower HR, less force = lower BP)
Causes of Left-sided HF - LONG STANDING HTN - (systolic)
Increased arterial pressure makes it harder to left ventricle to pump blood. the left ventricle compensates by bulking up, muscles grow to contract with greater force.
Negatives? : increased O2 demand, coronaries get squeezed down by extra muscle so less blood delivered to tissues.
weaker contractions = systolic failure
Causes of Left-sided HF - LONG STANDING HTN (diastolic)
Hypertrophy of ventricular wall can cause it to push into left side of ventricle space –> less room for filling = diastole failure
Causes of Left-sided HF - DILATED CARDIOMYOPATHY - (systolic)
Heart chamber dilates/grows in size in attempts to fill heart with increased preload –> increased contraction strength
- after a while the muscles thin out and weaken = systolic LS HF
Causes of Left-sided HF - DILATED CARDIOMYOPATHY - (diastolic)
Narrowing of aorta (aortic stenosis)
- stiffer and less compliant heart muscle –> ventricle can’t easily stretch out and fill = diastolic HF
Cardiomyopathy
A disease of the heart muscle that makes it harder to pump blood to the rest of your body
3 causes of Left-sided HF?
- ) Long standing HTN
- ) Dilated Cardiomyopathy
- ) Ischemic heart disease
- remember Left-sided HF is due to damage to heart muscle
With LS HF, less blood leaving the ventricle in diastole means decreased blood to kidneys –> activated RAAS system –> fluid retention –> increased preload and filling –> increased contraction strength.
But what happens over time with the fluid retention?
Over time, fluid leaks from the blood vessels, causing fluid buildup in the lungs, heat, and other areas of the body.
How is Gas Exchange impaired because of Heart failure?
Extra fluid that builds up in the pulmonary system (lungs), specifically the alveolus, result in a wider layer of fluid –> meaning longer diffusion time for co2 and o2.
- s/s: dyspnea, crackles, orthopnea (whilst laying down, more venous blood can’t flow into pulmonary circulation making it harder to breathe)
What are some causes of Right-sided HF?
- ) Left-sided HF
- increased BP in pulmonary artery due to fluid buildup makes it harder for RV filling - ) Ventricular or atrial septal defect
- blood shunted from left –> right side means blood moves from higher pressure left side to lower pressure right side = hypertrophy, schema, smaller volume. - ) Chronic lung disease
- makes it harder for heart to pump due to hypoxia = pulmonary arteriole constriction = RS hypertrophy and failure
What is an Arrhythmia?
an irregular heart beat due to electrical signal disturbances
- when the ventricles/atria do not work in sync anymore
How can Arrhythmia lead to Heart Failure?
Ineffective/impaired pumping of heart for a prolonged time period can lead to atrial fibrillation (atrial quivering) –> ventricular fibrillation
What is COPD?
Any kind of pulmonary disease where there’s an obstruction in the airways
s/s: Increased
S/S of COPD Exacerbation
- increased mucus production
- inflamed, airway narrowing
- further alveoli destruction
- dyspnea and cough w or w/o -sputum
- pursed-lip breathing
- chest congestion/discomfort
- sleep disturbances
- weakness, fatigue, fear
- decline in physical activity
