Cardiovascular Flashcards
List the path a cardiac electrical impulse travels through the heart.
Sinoatrial node (SA) in upper right atrium over the atrial myocardium via Bachmann’s bundle and internodal pathways, causing atrial contraction.
Then to atrioventricular (AV) node through the bundle of His and down the left and right bundle branches, ending in the Purkinje fibers, which transmit the impulse to the ventricles resulting in ventricular contraction.
SA—>AV—>bundle of His—> Purkinje fibers
(S..A..B..P)
Which components of the autonomic nervous system affect the heart?
Right and left vagus nerve fibers of the parasympathetic nervous system and fibers of the sympathetic nervous system.
Plays a role in the rate of impulse formation, speed of conduction and strength of cardiac contraction
Sinus bradycardia has normal sinus rhythm but SA fires slower than 60bpm.
What are causes?
Athlete Valsalva maneuver Hypothermia Parasympathomimetic drugs Hypothyroidism Increased intracranial pressure Obstructive jaundice Inferior wall myocardial infarction
Treatment for bradycardia
Atropine (anticholinergic)
Pacemaker
Sinus tachycardia- normal sinus rhythm but at a rate greater than 100 bpm.
What are causes?
Vagal inhibition or sympathetic stimulation Exercise, Fever, Pain, anxiety, Hypotension, Hypovolemia Anemia, Hypoglycemia Myocardial ischemia, Heart failure Hyperthyroidism Side effect of drugs
What is PAC?
Premature Atrial Contraction
Contraction in atria with ectopic focus (other than SA node). Similar to PVC but in atrium. Usually not significant.
Usually caused by caffeine tobacco alcohol, hypoxia or electrolyte imbalance,
or hyperthyroidism, COPD, CAD
What is paroxysmal supra ventricular tachycardia (PSVT)?
What are causes and treatments?
Dysrhythmia that is usually triggered by a PAC.
associated with over exertion, emotional stress, caffeine and tobacco.
Can also be associated with rheumatic heart disease, digitalis toxicity, CAD and cor pulmonale.
Treatment includes vagal stimulation and drug therapy possibly IV adenosine.
What is atrial flutter?
What are some causes?
Atrial tachidysrhythmia identified by recurring regular sawtooth shaped flutter waves.
Associated with CAD, hypertension,
mitral valve disorders, pulmonary embolus, chronic lung disease, cardiomyopathy, hyperthyroidism,
use of drugs such as digoxin, quinidine, and epinephrine.
What are some consequences of atrial flutter?
And what would be treatment?
Heart rate over 100 bpm and the loss of the atrial “kick” can cause decreased Cardiac output and cause serious consequences such as chest pain and heart failure.
Increase risk of stroke because of the risk of thrombus formation in atria from stasis of blood.
Goal of treatment of atrial flutter is to slow ventricular response by increasing AV block.
What is atrial fibrillation?
Who is at risk for a fib?
Total disorganization of atrial electrical activity due to multiple ectopic foci resulting in loss of effective atrial contraction.
A fib is associated with CAD, rheumatic heart disease, cardio myopathy, heart failure, pericarditis.
Can be caused by thyrotoxicosis, alcohol intoxication, caffeine, electrolyte disturbances, stress and cardiac surgery.
What are some complications from Atrial fibrillation and
what is the goal of treatment?
Complications: can result in decreased cardiac output.
thrombi may form and the atria as a result of blood stasis consequently causing a stroke or pulmonary embolism.
Goals of treatment include a decrease in ventricular response and prevention of cerebral embolic events.
What is heart block?
Heart block is an abnormal heart rhythm where the heart beats too slowly (bradycardia). In this condition, the electrical signals that tell the heart to contract are partially or totally blocked between the upper chambers (atria) and the lower chambers (ventricles). For this reason, it is also called atrioventricular block (AV block).
What is first degree heart block?
AV block
First-degree heart block - The electrical impulses are slowed as they pass through the conduction system, but they all successfully reach the ventricles. First-degree heart block rarely causes symptoms or problems. Well-trained athletes may have first-degree heart block. Some medications can also cause this condition. No treatment is generally needed for first-degree heart block.
What is Second degree AV block type 1
Also called Mobitz 1 or Wenckebach heart block
Second-degree heart block (Type I) - The electrical impulses are delayed further and further with each subsequent heartbeat until a beat fails to reach to the ventricles entirely. This type of block most often is physiologic and is seen in a highly relaxed state and during sleep. It rarely causes symptoms. It sometimes causes dizziness and/or other symptoms.
What is second Degree AV block type 2?
Mobitz 2 heart block
Second-degree heart block (Type II) - With this condition, some of the electrical impulses are unable to reach the ventricles. This condition is less common than Type I, and is more serious.
Usually, pacemaker treats type II second degree heart block, as it frequently progresses to third degree heart block.
What is third degree AV block or complete heart block?
none of the electrical impulses from the atria reach the ventricles. When the ventricles do not receive electrical impulses from the atria, they may generate some impulses on their own, called junctional or ventricular escape beats. Ventricular escape beats, the heart naturally occurring backups, are usually very slow. Patients frequently feel fatigue, lightheadedness, and decreased stamina in complete heart block. Patients are usually treated by implanting a permanent pacemaker.
Premature ventricular contraction PVC?
And treatment?
Contraction originating in an ectopic focus in ventricle.
Usually benign. Associated with stimulants, caffeine, alcohol, and nicotine, epinephrine, digoxin.
Treatment if needed: Beta blockers, procainamide, amiodarone, lidocaine
What is Ventricular tachycardia (VT)?
VT is a run of three or more PVCs. It occurs when an ectopic focus or foci fire repetitively in the ventricle takes control as the pacemaker.
This is a life-threatening dysrhythmia because of decreased cardiac output and the possibility of deterioration to Ventricle fibrillation.
What can cause ventricle tachycardia VT?
VT is associated with MI, CAD,
significant electrolyte imbalances, cardiomyopathy,
mitral valve prolapse, digitalis toxicity and
central nervous system disorders.
VT Can be:
stable: patient has a pulse
OR
unstable: patient is pulseless.
Ventricular fibrillation VF
What is it and what can cause it?
Severe derangement of heart rhythm. Mechanically the ventricle is simply quivering and no effective contraction consequently no cardiac output occurs.
Occurs in acute MI, myocardial ischemia, chronic diseases such as CAD and cardiomyopathy.
What is the treatment for V fib?
V fib results in unresponsive, pulseless, apneic state. If not rapidly treated the patient will die.
Treatment consists of immediate CPR and ACLS measures with the use of defibrillation and definitive drug therapy
Asystole
Total absence of ventricular electric goal activity. No ventricular contraction occurs.
Asystole is a lethal dysrhythmia that requires immediate treatment consisting of CPR, ACLS such as intubation, IV therapy with epinephrine and atropine.
Pulseless electrical activity (PEA)
Electrical activity can be observed on ECG, but there is no mechanical activity of the ventricles and the patient has no pulse.
Prognosis is poor unless underlying cause can be identified and quickly corrected. Treatment begins with CPR followed by intubation and IV therapy with epinephrine.
Arteriosclerosis
Hardening of the arteries, abnormal deposits of lipids, cholesterol, plaque buildup leading to narrowing or blockage and arteries.
Atherosclerosis
Fatty deposits called plaque on inner lining of vessel walls
Calcific sclerosis:
arteriolar sclerosis:
Calcific sclerosis:
Calcium deposits on middle layer of the wall of the arteries
arteriolar sclerosis: Thickening of the arterioles caused by hypertension
Difference between arteries and arterioles
Arteries transport blood away from the heart and branch into smaller vessels, forming Arterioles.
Arterioles distribute blood to capillary beds.
Arteriosclerosis vs. atherosclerosis
Arteriosclerosis is the stiffening or hardening of the artery walls.
Atherosclerosis is the narrowing of the artery because of plaque build-up.
Atherosclerosis is a specific type of arteriosclerosis.
Coronary heart disease (CHD) also known as coronary artery disease (CAD) Also known as arteriosclerotic heart disease
Narrowing of the small blood vessels that supply blood and oxygen to the heart. Occurs when plaque buildup on the walls of the arteries and they get narrow.
Blood flow to the heart can stop or slow.
What are symptoms of CAD and who is at risk?
Symptoms include stable angina, shortness of breath, heart attack.
Leading cause of death in the United States.
Men in their 40s have a higher risk than women. But as women get older their risk is almost equal.
genetic causes, diabetes, hypertension, abnormal cholesterol specifically LDL, smokers, CKD.
Paroxysmal
Paroxysmal attacks or paroxysms are a sudden recurrence or intensification of symptoms, such as a spasm or seizure. These short, frequent symptoms can be observed in various clinical conditions.
Three types of angina
Stable angina is the most common type. It happens when the heart is working harder than usual.
Unstable angina is the most dangerous. It does not follow a pattern and can happen without physical exertion.
Variant (Prinzmetal’s) angina is rare. It happens when you are resting.
What are 3 types of antianginals?
Antianginals relieve chest pain by reducing myocardial oxygen demand, increasing the supply of oxygen to the heart, or both.
Beta adrenergic blockers: slow heart rate, increase force of contractions. examples: atenolol, metoprolol, propranolol
Calcium channel blocker: Dilate coronary and peripheral arteries and prevent coronary vasospasm. Examples: Amlodipine, diltiazem, verapamil
Nitrates: produce vasodilation, decrease preload and afterload and reduce myocardial oxygen consumption. Examples: Nitroglycerin and isosorbide
Difference between
NSTEMI and STEMI
NSTEMI: non ST segment elevation MI.
A non-STEMI is usually caused by a severely narrowed artery but the artery is usually not completely blocked
STEMI: ST-elevation myocardial infarction is caused by a sudden complete (100 percent) blockage of a heart artery (coronary artery).
A STEMI heart attack is a serious form of heart attack.
3 examples of acute coronary syndrome. (Ischemia is prolonged and not immediately reversible)
Unstable angina
NSTEMI
STEMI
Unstable angina
Chest pain that is new in onset, occurs at rest or has a worsening pattern.
Unpredictable and is an emergency.
What are hallmark signs of MI?
Severe, immobilizing chest pain not relieved by rest, position change, or nitrate administration.
Pain is described as heaviness, pressure, tightness, burning, constriction or crushing.
What are complications of MI?
Dysrhythmias are most common cause of death in prehospital period.
Heart failure
Cardiogenic shock (inadequate oxygen and nutrients because of left ventricular failure. High mortality.
Pericarditis
CABG
Coronary artery bypass graft surgery.
What nursing measures should be taken for stable angina?
6
1- oxygen 2- vitals 3- 12 lead ekg 4- prompt pain relief 5- auscultation of heart 6- comfortable positioning of patient
What is the contraindication of nitrates and erectile dysfunction drugs?
Cause severe hypotension and even death.
what is Myocardial infarction and some factors that contribute to MI?
Disruption in blood supply to myocardium. Factors contributing include: Arteriosclerosis, emboli, thrombus, shock, hemorrhage.
Hypoxia from ischemia can lead to vasodilation of blood vessels.
MI can cause acidosis with electrolyte imbalance.
Most commonly reported signs and symptoms associated with myocardial infarction:
Substernal chest pain of duration greater than 15 minutes described as heavy, viselike.
radiating down the left arm pain that begins spontaneously and is not relieved by nitro or rest.
Radiates to jaw and neck.
accompanied by shortness of breath, pallor, diaphoresis, dizziness, nausea and vomiting. Increased heart rate, decreased blood pressure, increased temperature, increased respiratory rate.
CK, (Creatine phosphokinase)
CK is a type of protein. The muscle cells in your body need CK to function.
Levels of CK can rise after a heart attack, skeletal muscle injury, strenuous exercise, or drinking too much alcohol, and from taking certain medicines or supplements.
If this test shows that your CK levels are high, you may have muscle or heart damage.
Myoglobin
Myoglobin is found in your heart and skeletal muscles. There it captures oxygen that muscle cells use for energy. When you have a heart attack or severe muscle damage, myoglobin is released into your blood.
Myoglobin increases in your blood 2 to 3 hours after the first symptoms of muscle damage. It usually peaks about 8 to 12 hours later.
Troponin
Even a slight increase in the troponin level will often mean there has been some damage to the heart. Very high levels of troponin are a sign that a heart attack has occurred. Most patients who have had a heart attack have increased troponin levels within 6 hours.
Brain natriuretic peptide (BNP)
blood test that measures levels of a protein called BPN that is made by your heart and blood vessels. BNP levels are higher than normal when you have heart failure.
CRP
C-reactive protein
A high level of CRP in the blood is a marker of inflammation. … High CRP levels can also indicate that there’s inflammation in the arteries of the heart, which can mean a higher risk of heart attack. However, the CRP test is an extremely nonspecific test, and CRP levels can be elevated in any inflammatory condition.
How to calculate drop rate
The formula for calculating the IV flow rate (drip rate) is… total volume (in mL) divided by time (in min), multiplied by the drop factor (in gtts/mL), which equals the IV flow rate in gtts/min.
High pulmonary pressure in patent ductus arteriosus leads to what problems?
CHF or pneumonia
What rhythms can defibrillation be used for?
V-fib
Pulseless VT
Hypertension control is better for African Americans with which meds?
Beta blockers AND diuretics
When do the coronary arteries receive blood?
Coronary arteries may receive SMALL amount of blood during systole.
MOST of the blood flow is supplied during diastole.
(Breathing patterns are irrelevant to blood flow.)
Where is the landmark for apical pulse?
Left fifth intercostal space in the midclavicular line.
The apex of the heart
What are the 2 atrioventricular valves?
What are the two semilunar valves?
atrioventricular valves:
Mitral (aka bicuspid or left atrioventricular)
tricuspid
semilunar valves:
Pulmonic
Aortic
What do the aortic and pulmonic valves do?
Aortic:
Prevents backflow from aorta into left ventricle.
Pulmonic:
Prevents backflow from the pulmonary artery into the right ventricle.
What do the tricuspid valve and the mitral valve do?
tricuspid:
Prevents backflow from the right ventricle into the right atrium.
Mitral:
Prevents backflow from left ventricle into the left atrium.
Symptoms of ruptured abdominal aneurysm
Severe low back pain,
decreased blood pressure,
decreased rbc,
increased wbc
What allergies would be a problem with radiopaque dye in cardiac catheterization?
Shellfish
iodine
