Chapter 17 Flashcards
sa node
pace maker of the heart; causes initial contraction in the heart
av node
creates pulse if sa node fails
purkinje fibers
deliver the impulse to the working cells of the heart. If both higher pacemaker sites fail, the Purkinje network can also initiate an impulse to maintain some ventricular contraction.
atria
top two chambers of heart
ventricles
bottom two chambers of heart
flow of blood through heart
vena cavae, R atrium, T valve, R ventricle, P valve, P artery, P Vein, L atrium, M/B valve, L ventricle, A Valve, Aorta
Flow of blood through body (starting from heart)
Arteries, arterioles, body capillaries, venules, veins,
coronary artery
first two arteries to originate off the aorta and are the same arteries that are associated with many cardiac emergencies
thrombus
formed clot
electrocardiogram EKG/ECG
graphic representation of the heart’s electrical activity as detected from the chest wall surface.
two distinct components of electrical activity in heart
depolarization, repolarization
depolarization
first, in which electrical charges of the heart muscle change from negative to positive and cause heart muscle contraction
repolarization
second component, in which the electrical charges of the heart muscle return to a resting negative charge and cause relaxation of the heart muscle.
waves, or deflections, of a normal ECG have three portions
P wave, qrs complex, T wave
P wave
first waveform of the ECG and represents the depolarization (contraction) of the atria
QRS Complex
second waveform and represents the depolarization (contraction) of the ventricles and the main contraction of the heart.
T wave
third waveform and represents the repolarization (relaxation) of the ventricles.
Coronary Artery Disease
the narrowing and hardening of the coronary arteries, is the most common type of heart disease and is responsible for more than 385,000 deaths each year.
Arteriosclerosis
condition that causes the smallest of arterial structures to become stiff and less elastic. This is often referred to as “hardening of the arteries.”
atherosclerosis
systemic arterial disease in which plaque builds up inside the arteries. It is the underlying pathogenic process in most patients that have coronary artery disease that causes myocardial infarctions as well as the arterial changes that result in stroke.
Acute Coronary Syndrome
results from a variety of conditions that can affect the heart in which the coronary arteries are narrowed or occluded by fat deposits (plaque), clots, or spasm. Two conditions that are part of any acute coronary syndrome are unstable angina (prolonged chest pain) and myocardial infarction (heart attack)
angina pectoris
chest pain
unstable angina
prolonged chest pain
Acute myocardial infarction AMI
when portion of the heart muscle dies because of the lack of an adequate supply of oxygenated blood
AMI s/s
Chest discomfort radiating to jaw, arms, shoulders, or back
Anxiety
Dyspnea
Sense of impending doom
Diaphoresis
Nausea and vomiting
Light-headedness or dizziness
Weakness
aortic aneurysm
when a weakened section of the aortic wall, usually resulting from atherosclerosis, begins to dilate or balloon outward from the pressure exerted by the blood flowing through the vessel
occur most often in the abdominal region. Pain can be felt, especially in the back, when the aneurysm gets large enough, perhaps shortly before rupture occurs. Usually, the aorta cannot be felt with a physical examination, but at this final stage it can be felt as a pulsating mass in the abdomen,
aortic dissection
when there is a tear in the inner lining of the aorta and blood enters the opening and causes separation of the layers of the aortic wall
The pain is usually most severe when the dissection first occurs, and a patient often describes it as “sharp” pain, or sometimes as a “tearing” or “ripping” pain, often felt in the back, flank, or arm.
Syncope may be the only sign in some patients. Depending on the location of the dissection along the aorta, it may cause symptoms similar to a stroke or myocardial infarction and, in fact, may lead to a myocardial infarction or other damage to the heart
reperfusion
restoration of blood to an area of tissue that was ischemic from low blood flow or occlusion of a vessel
reperfusion injury
oxygen in the blood flowing to the reperfused tissue increases the production of oxygen free radicals. The free radicals directly damage cell membranes and other cellular components and result in cell death.
heart failure
heart can no longer adequately eject blood out of the ventricle,
pure R heart failure
low to normal systolic bp
clear breath sounds
jvd/peripheral edema
pure L heart failure
normal to high systolic bp
rales
no jvd/peripheral edema
congestive heart failure
condition in which there is a buildup of fluid (congestion) in the body resulting from the pump failure of the heart. It represents the condition in which the left, the right, or both ventricles are failing to meet the body’s needs.
s/s heart failure
marked/severe dyspnea
tachycardia
difficult breathing supine
sudden waking with dyspnea
fatigue with exertion
anxiety
tachypnea
diaphoresis
cool clammy pale skin
chest discomfort
cyanosis
agitation due to hypoxia
edema in ankles feet hands
crackles and possible wheezing
s/s of pulmonary edema
jvd
distendeded soft/spongy abdomen
