Module 4 Flashcards
What is cardiac output?
The volume of blood ejected by the heart each minute
What is pre-load?
resting force of the myocardial muscle and is determined by the volume in the ventricle prior to contraction
What is Frank-Sterling law of the heart?
The greater the heart is filled during diastole, the greater the quanity of blood is pumped into the aorta
What is afterload?
is the force that the ventricles must overcome in order to contract and eject its blood
What does a high afterload cause?
The heart has to work harder and under greater strain
What drugs help decrease afterload?
Vasodilators decrease afterload, thus improving stroke volume and cardiac output
What coronary arteries originate off the aorta?
left and right coronary arteries
What coronary arteries branch off the left CA?
circumflex and left anterior descending branch
What coronary arteries branch off the right CA?
posterior descending artery
The circumflex artery supplies what part of the heart?
left posterior side
The left anterior descending artery supplies what part of the heart?
left anterior side
The posterior descending artery supplies what part of the heart?
Right ventricle
The right coronary arteries supply what part of the heart?
right anterior and posterior
What is the underlying rate of the SA node?
60-100 BPM
What is the underlying rate of the AV node?
45-50 BPM
What is the underlying rate of the bundle of HIS
40-45 BPM
What is the underlying rate of the purkinje fibers?
30-40 BPM
What is the pathway of an impulse through the heart
SA node –> AV node –> bundle of his –> Left and right bundle branches
What heart rhythms arise from issues with the SA node?
Sinus tachycardia and bradycardia
1st degree AV block
What heart rhythms arise from issues with the atria?
Atrial tachycardia, flutter and fibrillation
What heart rhythms arise from issues with the ventricles?
V-Fib, V-tach, PVC’s (more the ventricular myocardial cells)
What heart rhythms arise from issues with the AV node?
Premature junctional beats, 1st, 2nd, 3rd degree AV blocks
What nerve controls the heart under the PNS?
Vagus nerve
How does the PNS decrease heart rate?
By reducing SA node firing and slowing AV nodal conduction
How does the SNS increase heart rate and stroke volume?
Stimulating alpha receptors and beta 1 receptors
Where are the alpha receptors and what is the role of them?
Alpha receptors are located on the arteries and when stimulated by epi/nor-epinephrine, they will either vasocontrict (in SNS) to send blood back to the core–>Heart, brain and lungs OR they will cause vasodilation (in PNS) in the peripheral vessles
Where are the beta 1 receptors and what is their role?
Located in the heart and increase SA node firing, increase AV nodal conduction and increase contractilty
What do the SNS do to beta 2 receptors?
Cause the lungs to broncodialte
Where are the beta 2 receptors located?
In the lungs
Where are the baroreceptors located?
Aortic arch and carotid arteries
What do the baroreceptors do?
They detect changes in BP and respond accordingly with either a parasympathetic or sympathetic reflex action
What is PNS response is triggered by baroreceptors?
If BP is excessively high, the baroreceptor reflex will increase parasympathetic stimulation (e.g., decrease HR)
What is SNS response is triggered by baroreceptor ?
if BP is low, the baroreceptor reflex will increase sympathetic stimulation (e.g., increase HR)
What do the chemoreceptors do?
Respond to changes in oxygen, carbon dioxide, and hydrogen ion concentration in the blood
Where are the chemoreceptors located?
Aortic arch and carotid arteries
What is the first compensatory mechanisms when cardiac output decrese
Peripheral vasoconstrcition and an increase in heart rate
What are some red flags in a patient assessment with the ED handshake?
Cool and clamy skin and a fast pulse
What are two disease process that can bring on heart failure?
Hypertension and coronary artery disease
How does heart failure impact cardiac output?
when the heart is damaged, it is unable to contract proberly, blood begins to pool within either or both ventricles, eventually backing up in they system.
What is the forward effect of heart failure?
is decreased cardiac output
What is the backwards effect of heart failure?
Pulmonary and peripheral edema
What is the most common type of heart failure?
Systolic heart failure
What is happening during systolic heart failure?
The cardiac muscle is often stretched and unable to contract effectively. consequently, the ventricles re unable to eject the cardiac output required to meet tissue needs, which leads to decreased end-organ perfusion
What does systolic heart failure represent?
A problem with the pump
What chronic disease causes diastolic heart failure?
Cardiac muscle cells are thickened and the heart “bulks up” in response to chronic conditions such as hypertension and left ventricular hypertrophy
What is happening during diastolic heart failure?
The heart is unable to relax and fill appropriately as the ventricles become stiff and non-compliant. The cardiac muscle attempts to compensate for the decreased cardiac output by increasing contractility. This results in an increase in pressure in the atria and pulmonary vasculature
What does diastolic heart failure represent?
Diastolic heart failure represents a problem with filling
What is family centred care in ED?
Collaboration among patients, family, and health care professionals, and recognises families as constant in patient’s lives.
What do patient’s families need in the ED?
Consisten, open and comprehensive communication with health care providers
To be able to see the patient frequently and to be allowed to physically and emotionally close to the patient
To feel that healthcare providers care about their patients
To know exactly what has been done to the patient
What are some common medications given to patients with heart failure?
Lasix’s, nitroglycerine, digoxin, morphine
How do lasixs help with heart failure?
Loop diuretic that increases the excretion of water and sodium within the body
Reduces afterload by decreasing overall fluid volume
How does nitroglycerine help with heart failure?
Works as a vasodialtor
Nitrates help decreases pre load and afterload, therefore decreasing overall workload on the heart
How does morphine help with heart failure?
Morphine is a opoiod agonist that helps with the pain associated with heart failure, shortness of breath and helps slightly with vasodilation.
Vasodialtion decrease preload congestion and afterload, leading to a decrease in myocardial workload
How does digoxin help with heart failure?
increase myocardial systolic contractions
What is the formula for CO?
CO= Heart rate X stroke volume
