The coronary arteries supply the blood to the heart and atherosclerosis and arteriosclerosis cause obstructions in the coronary arteries and block the blood flow to the heart and cause
acute coronary syndrome or myocardial ischemia
If myocardial ischemia is prolonged it can lead to
myocardial infarction
Most common type of heart disease
coronary artery disease
The three layers of the heart (inside to out)
endocardium, myocardium, epicardium
Cardiac muscle stores very little calcium and relies on an
influx of extracellular calcium ions for contraction
Very thin, three layered membrane that lines the interior of the heart and covers the valves
endocardium
Moves blood from the pulmonary artery into the lungs and allows oxygenation and gas exchange at the capillary bed to the pulmonary vein that empties into the left atria where the artery carries deoxygenated blood and a vein carries oxygenated blood
pulmonary system
Begins at the aorta, where blood from the left ventricle s moved into the tissue for oxygenation and the cells absorb O2 and deoxygenated blood is carried back to the heart via the veins and drain into IVC
systemic circulation
Functions as a low pressure system that allows the blood to move through the lungs slowly that improves adequate gas exchange
pulmonary circulatory system
High pressure system where its pulsations reflect the contraction of the left ventricle that must work against gravity to move blood into the body's tissues
systemic circulation
Pushes blood through the pulmonary circulation
right ventricle
Pushes the blood through the aorta to all the body's peripheral tissues
left ventricle
Time where the ventricles contract and the left ventricle ejects 70% of the blood into the aorta
systole
When the left ventricle ejects 70% of blood into the aorta is called
stroke volume or left ventricular ejection fraction
Also during systole the right ventricle
ejects blood into the pulmonary artery
Time when the ventricles relaxed and the ventricles accept blood from atrial contraction
diastole
During diastole, in the left ventricle the blood that is accepted by ventricles from the atria is known as
LV end diastolic volume
Where is the SA node located
right atrium
Where is the AV node located
centrally in the heart between the atria and the ventricles and the bundle of His
Impulse of heart begins where
in the SA node within the right atrium
Also known as the hearts pacemaker
SA node
Provides a one-way conduction of the impulse down into the ventricles and the bundle of His
AV node
The bundle of His activates the Purkinje fibers and the fibers
excite the left and right ventricles
Nerve impulse that occurs in cardiac tissues
action potential
In the five-phase action potential the action potential rises in voltage in the stage
depolarization or phase 0
Action potential reaches its max point and then slightly decreases in voltage
phase 1
Long plateau phase
phase 2
Rapid depolarization
phase 3
Returns to baseline
phase 4
Disorders of cardiac rhythm
dysrhythmias or arrhythmias
Two types of cardiac dysrhythmias
supraventricular or ventricular
Dysrhythmias in the SA node, atria, and AV node
supraventricular
Dysrhythmias in the conduction system (bundle of His, Purkinje fibers, and ventricular muscle
ventricular
Dysrhythmias that are potentially fatal
ventricular
Excitable area outside the normal conduction pathway
ectopic pacemaker
Occurs when ectopic pacemaker initiates a contraction
premature ventricular contraction (PVC)
When several PVCs in a row can lead to
ventricular tachycardia
Happens when the ventricle is beating independently without waiting for a completion of each action potential
ventricular tachycardia
Ventricular tachycardia can lead to
ventricular fibrillation
Occurs when heart is beating so rapidly that the ventricle is actually quivering and not ejecting blood
ventricular fibrillation
Recording of electrical activity of the heart that can eb measured
electrocardiogram
P wave
SA node and atrial depolarization
ORS waves
ventricular depolarization
T wave
ventricular repolarization
Disorder caused by the deprivation of blood to the myocardium of the heart
ischemic heart disease
Can be temporary and blood flow can be reestablished
myocardial ischemia
Acute coronary syndrome is also called
chronic stable angina
Acute coronary syndrome can present in two types
unstable angina and MI
squeezing pain in the chest that occurs when there is lack of blood flow to the myocardium
angina pectoris
Angina can be
stable or unstable
Chronic chest pain that the patient has experienced in the past and feels similar to past episodes
stable angina
Cardiac chest pain that is occurring for the first time in a patient
unstable angina
Is an emergency situation that requires immediate medical attention
unstable angina
Angina is more common in
women at 62
Signs of myocardial ischemia that differ from the classic chest pain such of dyspnea, sweating, feeling faint, dizziness, extreme fatigue or heartburn
anginal equivalents
When a patient clenches a fist over the sternum when experiencing angina pain is known as
positive Levine's sign
Is common in people with MI or angina pectoris
positive Levine's sign
Coronary vasospasm can lead to
Prinzmetal's or variant angina
If a patient with angina takes 3 NTG tablets in a 10 minute period without the relief of chest pain always assume
MI
NTG and other nitrate preparations can cause
severe hypotension
Should not be administered with sildenafil due to the severe risk of hypotension
NTG
Considered the preferred biomarker for diagnosing MI
cTnI
Cardiac specific contractile protein that is not normally found in serum and is released only when myocardial cell death has occurred
cTnI
Indicates that the infarction is completely through the heart wall
Stemi
Indicates that the MI is subendocardial and not completely through the heart wall
NSTEMI
Echocardiogram cannot diagnose an
MI or dx an acute MI
Main tx of an acute MI
-reestablish blood flow to affected areas-chewing non-coated ASA-O2 if sat is less than 95%-sublingual NTG
Who should not take NTG
males taking drugs to EDPt with aortic stenosis and hypertrophic cardiomyopathy
The murmur of pericarditis
pericardial friction rub
Pericardial friction rub sound
rough, scratchy sound
Inflammation of the membrane that surrounds the heart
pericarditis
When does pericarditis occur?
2-3 days after MI
What does pericarditis feel like
sharp, stabbing pain that is aggravated with deep inspiration and positional changes
Pericarditis is a component of
Dressler's syndrome
Hypersensitivity reaction to tissue necrosis of MI that includes pericarditis, pleuritis, pneumonitis and tx with anti-inflammatory agents
Dressler's syndrome
Weakening of the ventricles and is a common complication of MI
heart failure
Heart's blood pumping action becomes impaired, blood accumulates in chambers, and pressure builds up backwards in cardiovascular system
heart failure
Left sided heart failure
pulmonary edema
S/S of left sided heart failure
dyspnea, cough, crackles, peripheral edema
right sided heart failure
causes swelling in extremities
S/S of right sided heart failure
Enlarged organs, edema, weight gain, distended neck veins, ascites
Chronic coronary artery disease
stable angina
Characterized by recurring chest pain caused by transient myocardial ischemia
chronic coronary artery disease
Chest pain with stable angina occurs during
exertion or other conditions that increase the hearts work demands
Inflammation of the pericardium and epicardium
Pericarditis
When pericardium undergoes inflammation, additional fluid accumulates in pericardial space
pericardial effusion
If pericardial effusion exceeds 200mL or greater the heart becomes compressed and the heart chambers are restricted and they are unable to stretch and fill with blood
cardiac tamponade
Cardiac tamponade presents
-sudden sharp pain that worsens with deep breathing, swallowing, and coughing -pain radiates to the neck, jaw, ABD, or back-pericardial friction rub
S/s of cardiac tamponade are called
Beck triad
Beck triad of cardiac tamponade
Distant heart sounds, distended neck veins, hypotension
prinzmental (variant) angina is caused by
vasospasm of coronary arteries
Myocarditis is caused by
viral infection
Major reason for cardiac transplant rejection
myocarditis
Manifestation of ineffective endocarditis is a
heart murmur, petechiae, splinter hemorrhages, Janeway lesions, Osler's nodes, Roth spots
Janeway lesions
nontender hemorrhagic lesions - fingers, toes, nose, earlobes - associated with endocarditis
Osler's nodes
painful nodules on finger and toe pads....seen in endocarditis caused by strep viridans
Roth spots
Round white spots on retina surrounded by hemorrhage
Leading cause for IE
aureus bacteremia