Cardiac Flashcards
Acute Myocardial Infarction
A heart attack:
occurs when sudden narrowing or complete inclusion of coronary arteries causes myocardial tissue necrosis.
Responsibilities of the cardio vascular system
This system delivers oxygenated blood and nutrients to every cell in the body, also delivers chemical messengers(hormones) within the body and transports the waste products of metabolism from the cells to sites of recycling or disposal.
The coronary sinus
A large vein on the posterior side of the heart that collects blood from the great cardiac vein and several coronary veins and then drains the blood in to the right atrium.
Cardiac cells four important properties that help a heart funtion efficiently
automaticity, excitability, conductivity, contractility.
The six parts of the cardiac conduction system.
The SA node, the AV node, the bundle of His, and the purkinje fibers.
Stimulation of the sympathetic nerves.
Strengthends the force of contraction and increases the heart rate.
Stimulation of the parasympathetic nerve fibers
Slows the rate of discharge of the SA node, slows the conduction through the AV node, weakends the strength of atrial contraction, and can cause a small reduction in the force of ventricular contraction.
How can the primary survey/primary assessment change in a cardiac patient.
If the patient is unresponsive and suspected of being in cardiac arrest then the order will change from ABCDE to CABDE.
What are Acute coronary syndromes
Acute coronary syndromes are a series of cardiac conditions that are caused by an abrupt reduction the blood flow through a coronary artery. The three major ACSs are unstable angina, non-ST segment elevation myocardial infarction(NSTEMI), and ST segment elevation myocardial infarction(STEMI).
Syncope cause
brief loss of conciousness cause by a temporary, sudden decrease in blood flow to the brain.
Pulmonary edema is accompanied by what type of cough
Productive cough containing pink, frothy sputum.
What is Paroxysmal nocturnal dyspnea`and what cardiac conditions can cause it.
PND is a sudden onset of difficulty breathing in which the patient suddenly awakens from sleep. PND is often associated with left ventricular failure. It is often accompanied by coughing, wheezing, and sweating.
Why is it important to know the time that cardiac symptoms started.
Reperfusion therapy(therapies and medications to open blocked coronary arteris) may or may not be used depending on how long the tissue has been infarcted. Time will also help diagnose the type of cardiac problem present.
Commonly perscribed Antiarrhythmics
digoxin(Lanoxin), procainamide(Procan, Pronestyl), amiodorone(Cordarone), verapamil(Calan, Isoptin, Verelan)
Commonly perscribed anticoagulants
enoxaparin(Lovenox), clopidogrel(Plavix), warfarin(Coumadin)
Angiotension-converting enzyme inhibitors commonly perscribed
captopril(Capoten), enalapril(Vasotec), lisinopril(Prinivil, Zestril)
Beta-blockers commonly perscribed
atenolol(Tenormin), metoprolol(Lopressor), propranolol(Inderal)
Lipid lowering agents commonly perscribed
gemfibrozil(Lopid) atorvastatin(Lipitor), fluvastatin(Lescol), lovastatin(Mevacor), pravastatin(Pravachol), rosuvastatin calcium(Crestor), simvastatin(Zocor)
diuretics commonly perscribed
furosemide(Lasix)
vasodilators commonly perscribed
nitroglycerin(Nitrostat) or isosorbide(Isordil)
What is cool diaphoretic skin caused by
Cool diaphoretic skin is a sympathetic response. The body shunts blood to the vital organs via peripheral vasoconstriction to maintain perfusion of the vital organs. this leads to less blood in the skin causing less heat and sweating.
Venous pressure is increased in what cardiac situations
Venous pressure increases with a significant increase in blood volume, when the right ventricle fails, or increased pressure in the pericardial sac hinders venous return to the heart.
Venous pressure is decreased in what cardiac situations.
Venous pressure decreases when blood volume is decreased significantly or if ejection of blood occurs from the left ventricle
What lung sounds may be present in patients with left ventricle failure
Wheezes or crackles
Strong pulsations in the epigastric area may be a sign of what cardiac condition
abdominal aortic aneurysm
Bilateral pitting edema may be a sign of what cardiac condition
Right ventricular failure
Pitting edema to one side of the body may be a sign of what cardiovascular condition
A blockage of a major vein.
Reduced cardiac output will do what to the pulse
The patients pulse will become weak and thready.
What are the three types of electrical therapy
Defibrillation, synchronized cardioversion, or transcutaneous pacing.
How do u measure a pulse deficit and what does it indicate
Place a stethoscope over the hearts apex which is located between the fifth and sixth ribs on the left side of the chest. Listen to the stethoscope while palpating the peripheral pulse. The difference between the pulses indicates an abnormal heart rhythm.
A difference of more that 10mmhg between inspirationiand expiration blood pressure is called.
pulsus paradoxus
Pulsus Alternans is
A beat to beat difference in the strength of a pulse caused by severe ventricular failure. Decreased number of myocardial cells contracting.
Elevated blood pressure may cause
AMI, Stroke, aortic dissection
How to determine pulse pressure and normal pulse pressure
Pulse pressure is the difference between diastolic and systolic blood pressures. Normal pulse pressure is 30 to 40 mm hg
What is a murmur
an abnormal whooshing sound that is associated with turbulent blood flow through heart valves. This turbulent blood flow can occur from increased blood flow accross normal valve, an irregular or constricted valve, blood flow into an enlarged heart chamber, or backwards blood flow.
A resting(polarized) cardiac cell normally has a net internal charge of…?
-90 mV relative to the outside of the cell.
Steps and order of ions entering and leaving a cell during depolarization and re-polarization of a cardiac cell.
The cell receives an electrical stimulus, sodium ions rush in making the cell charge more positive, calcium ions also enter more slowly(these help maintain the depolarized state), the cell is depolarized and if all the cells are acting together then mechanical contraction occurs, sodium and calcium channels close halting depolarization and beginning re-polarization, potassium channels open allowing rapid escape of potassium ions, net negative charge is restored in the cell, proper ion distribution of cells is restored as sodium and calcium are pumped out and potassium is pumped back in.
Cardiac action potential phase 0
Starts when the cardiac muscle receives an impulse, depolarization, qrs, sodium(+) in, calcium(+) in
cardiac action potential phase 1
repolarization, sodium channels close, chloride(-) in, potassium(+) out,
Cardiac action potential phase 2
plateau phase, repolarization sodium(+) and calcium(+) in, while potassium(+) out. contraction ends when the outward flow of potassium exceeds the inward flow of sodium and calcium. ST
Cardiac action potential phase 3
Final repolarization phase. calcium channels close and calcium is transported out of the cell. Potasium(+) out. by the end of phase 3 the cell is back to normal potential. T
Cardiac action potential phase 4
resting phase. Potential of -90mV
Refractory period
The period in which the cell is depolarized or in the process of repolarizing.
The two phases of the refractory period.
Absolute refractory period. (cells unable to respond to any electrical stimulus)
Relative refractory period(middle of phase 3 to the beginning of phase 4) the cell has been partially repolarized and may depolarize in response to an electrical stimulus.
Which cell in the heart can act as the cardiac pacemaker
any cell can potentially act as the cardiac pace maker. The usual pacemaker in a healthy person is SA node.
Intrinsic rate of the SA node
60 - 100
Intrinsic rate of the AV node
40 - 60
Location of the SA node
Junction of the superior vena cava and the right atrium.
Location of the AV node.
floor of the right atrium behind the tricuspid valve.
The amount of blood that fills the ventricles via gravity vs atrial contraction.
70 to 80% comes from gravity.
20 to 30% comes from atrial contraction.
Intrinsic rate of the purkinje network
20 - 40
What are accessory conduction pathways.
extra heart muscle tissue that connects the atria and the ventricles that creates an alternative electrical pathway that can bypass the AV node.
also called accessory pathway or bypass tract.
Delta wave
slurring of the upstroke on the first part of the qrs complex that occurs in wolf parkinson white syndrome.
Bundle of Kent
accessory conduction pathway located between the left atrium and ventricle or right atrium and ventricle. creates a delta wave on the ECG
Ways the Vegas nerve can be stimulated causing a decreased heartrate
increasing pressure on the carotid sinus, straining or forced exhalation against a closed glottis, distention of a hollow organ such as the bladder or stomach.
The chemical messenger released at the SA node by the vegas nerve that signals the SA node and AV node to slow.
Acetylcholine(ACh)
Where are Baroreceptors located
internal carotid arteries and the aortic arch.
What is it that Chemo receptors measure in the blood
They measure the concentration of hydrogen ions(pH), oxygen, and carbon dioxide.
Lead I direction
right arm to left arm
Lead II direction
right arm to left leg
Lead III direction
left arm to left leg
aVR direction
right arm to combination of left arm and leg
aVL direction
left arm to combination of right arm and leg
aVF direction
up and down
Contiguous leads definition
leads that view similar areas of the myocardium.
On a right sided ECG, how will the leads be placed and labeled.
v1 and v2 remain in the same position. v3 through v6 will be mirrored across the midline. All leads will be labeled with an R after the lead name. (VxR)
What can a right sided ECG be used for
to detect a right ventricular AMI.
What lead is most important in looking for a right ventricluar AMI
V4R. Most likely the only one recorded
What is a posterior ECG used for
to determine the posterior electrical activity of the heart.
How are the leads placed and labeled in a posterior ECG
place three of the precordial leads on the left posterior thorax. V7 is between V6 and V8 in the fifth ICS. V8 is midscapular in the fifth ICS. V9 is just to the left of the spine in the fifth ICS