Exam 3 Concept Review: Chapter 12 Flashcards
Electrocardiogram (ECG):
What does P, QRS, and T wave represent?
P wave
Depolarization of atria (atrial contraction)
QRS wave
Depolarization of ventricles (ventricles contraction)
T wave
Repolarization of ventricles (recharging to start it over again – RESTING)
Ventricles are relaxing
CONDUCTION OF THE HEART:
What is the normal conduction of the heart?
Conduction pathway
Sinoatrial (SA) node
Natural Pacemaker
Sinus rhythm
Atrioventricular (AV) node
Located in floor of the right atrium
AV bundle (bundle of His) Right and left branches (branches off into two separate sides)
Purkinje fibers Terminal fibers (completes beat)
CARDIAC FUNCTION:
What is the preload (“preheart”)?
Amount of blood delivered to heart by venous return
The amount of blood the veins are bringing back to the heart
CARDIAC FUNCTION:
What is the afterload?
Force required to eject blood from ventricles
Determined by peripheral resistance in arteries (throw anything else that causes peripheral resistance like damaged blood vessels it will require higher blood pressure)
CARDIAC FUNCTION:
What is the cardiac output?
Blood ejected by a ventricle in 1 minute
CO = SV x HR (heart rate)
What are the factors that increase heart rate?
Increased thyroid hormones or epinephrine
Hyperthyroidism everything is red up
Elevated body temperature, infection
Example: Fever
Increased environmental temperature
Especially in high humidity
Exertion or exercise
Smoking
Nicotine is a vasoconstricts (vessels become smaller)
Patient might come in with chest pain and nurse will not order a nicotine patch because they don’t the vessels that could be potentially block already, become smaller which further cuts off blood flow
Stress response
Pregnancy
Pain
CONTROL OF HEART:
What plays a role in controlling the heart?
Cardiac control center in medulla oblongata
Controls rate and force of contraction
Located in the medulla
Baroreceptors
Detect changes in blood pressure
Based on the changes they are detecting, they can respond and stimulate sympathetic (fight or flight) or parasympathetic (rest or digest) nervous system to alter the rate and force
Located in the aorta and internal carotid arteries
Sympathetic stimulation (cardiac accelerator nerve) Increases heart rate (tachycardia) Stress response (increase in blood pressure, heart rate – prepares the body to fight)
Parasympathetic stimulation (cranial nerve [CN] X; vagus nerve)
Decreases heart rate (bradycardia)
Focusing on kidneys, GI systems, Reproductive systems
ANGINA PECTORIS:
What is the cause of Angina?
Occurs in patient who has partial blockage (they are still blood flow but not enough) - In other words, partial obstruction that reduces blood flow
There is chest pain that is caused by lack of oxygenation but this does not indicate Myocardial Infraction (“MI”) because MI is complete obstruction
ANGINA PECTORIS:
What patterns do chest pain occur?
Classic or exertional angina (MOST IMPORTANT)
Unstable angina (MOST IMPORTANT) Prolonged pain at rest—may precede myocardial infarction
Variant angina (RARE)
Vasospasm occurs at rest.
As the vessels are spasming, it reducing vessels which causes chest pain
WE WANT PATIENT TO SIT DOWN BECAUSE THE NITRO IS GOING TO VASODILATE WHICH DROPS PATIENT BLOOD PRESSURE SO THE NURSE DOESN’T WANT THEM TO PASS OUT
IF THE MEASURES ARE NOT WORKING OR THE PATIENT HAS NO HISTORY OF ANGINA, IT IS CONSIDERED UNSTABLE
What are the warning signs of a HEART ATTACK (Myocardial Infraction)?
Feeling of pressure, heaviness, or burning in chest—especially with increased activity
Sudden shortness of breath (MOST IMPORTANT), weakness, fatigue
Nausea, indigestion (MOST IMPORTANT)
Anxiety and fear
Pain may occur and, if present, is usually
Substernal
Crushing
Radiating - to arm or jaw (MOST IMPORTANT)
ARTERIOSCLEROSIS AND ATHEROSCLEROSIS:
What is the difference between Arteriosclerosis and Atherosclerosis?
Arteriosclerosis (hardening of arteries; vessels are stiffer and narrow) -OCCURS OVERTIME WHILE A PERSON GETS OLDER
General term for all types of arterial changes
Degenerative changes in small arteries and arterioles
Loss of elasticity
Lumen gradually narrows and may become obstructed
Cause of increased BP
Atherosclerosis (plaque buildup in arteries)
Presence of atheromas (plaque) in large arteries
Plaques consisting of lipids, calcium, and possible clots (result from the body attempting to heat)
Related to diet, exercise, and stress
HEART SOUNDS:
What are the lubb and dubb of the heart? and What causes murmurs?
“Lubb-dub” (happens when listening to heart sounds)
“Lubb”—closure of AV valves
“Dub”—closure of semilunar valves
Murmurs
Caused by incompetent valves
Causes an unusually turbulence
The valves are one way gates meaning blood can’t go back when valve closes, only moves forward so when a patient has a problem with the valve and it is not closing completely or working properly, blood can backflow through the valve – the turbulence of the blood flowing back through again can cause a noise called a murmur
AV VALVES = are those that connect the atrium to the ventricles and include the mitral valve as well as the tricuspid valve.
SEMILUNAR VALVES = “semilunar valves” refers to the aortic valve and the pulmonic valve.
BLOOD PRESSURE:
What are the changes of blood pressure?
Changes in blood pressure
Sympathetic branch of ANS
Increased output → vasoconstriction and increased BP
Decreased output (rest and digest) → vasodilation and decreased BP
BLOOD PRESSURE:
What are hormones that impact hormones?
Hormones Antidiuretic hormone (↑ BP); aldosterone (↑ blood volume, ↑ BP); renin-angiotensin-aldosterone (vasoconstriction; ↑ BP)
Antidiuretic, aldosterone, renin-angiotensin-aldosterone are put into play to increase the blood pressure (these might kick in when there is not enough fluid – basically organs are don’t getting perfused) so they will vasoconstrict to hold onto fluid and sodium.)
CARDIOVASCULAR DRUGS:
Describe Nitroglycerin
Use:
Angina attacks and prophylaxis
Action:
Reduces cardiac workload, peripheral and coronary vasodilator
Adverse effects:
Dizziness, Headaches due dilated vessels
MYOCARDIAL INFRACTION:
When does myocardial infraction occur?
Occurs when coronary artery is totally obstructed
There is no blood getting through, no oxygen to heart tissue so no oxygen causes the tissue to die (infraction)
MYOCARDIAL INFRACTION:
What causes an myocardial infraction?
Atherosclerosis (plaque buildup) is most common cause
Vasospasm is cause in a small percentage.
MYOCARDIAL INFRACTION IS NOT GOING TO GO COMPLETELY AWAY WITH REST,NITRO (sometimes it helps not all the time)
MYOCARDIAL INFRACTION:
What determines the amount of damage done to the heart?
Size and location of the infarct determine the damage.
MYOCARDIAL INFRACTION:
What obstructs the artery?
Thrombus from atheroma may obstruct artery
MYOCARDIAL INFRACTION: TREATMENT
What does “MONA” stand for?
MONA = Morphine Oxygen Nitroglycerin Aspirin
MORPHINE HELPS WITH PAIN (RELAXES THE PATIENT)
OXYGEN IS GOING TO HELP REDUCE CARDIAC DEMAND
NITROGLYCERIN VASODILATE WHICH REDUCES CARDIAC DEMAND
ASPIRIN GIVES ANTICOAGULANTATION
MYOCARDIAL INFRACTION: COMPLICATIONS
What are the complications associated with Myocardial Infraction?
Sudden death
Cardiogenic shock
Congestive heart failure
MYOCARDIAL INFRACTION:
What are the diagnostic tests for Myocardial?
Changes in ECG
Serum enzyme and isoenzyme levels
CKMB = Creatine kinase-MB (CK-MB) is a form of an enzyme found primarily in heart muscle cells.
This test measures CK-MB in the blood. CK-MB is one of three forms (isoenzymes) of the enzyme creatine kinase (CK).
Serum levels of myosin and cardiac troponin are elevated.
Troponin is an enzyme that is released when the cardiac muscle is damaged
This level can change over a period of time so if a patient comes into the room complaining of chest pain but doesn’t know if it is cardiac related, the nurse would serial EKG (serial enzymes)
(TOP IS MOST IMPORTANT)
They are going to check EKG or cardiac enzymes every six hours for total of three times
Leukocytosis, elevated CRP and ESR common Inflammatory markers (tissue injury initiates inflammatory response)
Arterial blood gas measurements may be altered in severe cases.
Pulmonary artery pressure measurements helpful
MYOCARDIAL INFRACTION:
Describe the pathophysiology for Myocardial Infraction.
- There is a complete obstruction of the coronary artery
- Obstruction of the coronary artery results in no blood flow to the heart
- No blood flow leads to ischemia (Cardiac ischemia is the name for decreased blood flow and oxygen to the heart muscle)
- Ischemia further leads to infraction moves to necrosis (tissues dies due to no oxygen)
CARDIAC DYSRHYTHMIAS;
What are cardiac dysrhythmias? and What are it caused by?
Deviations from normal cardiac rate or rhythm
Caused by electrolyte abnormalities, fever, hypoxia, stress, infection, drug toxicity
Electrocardiography—for monitoring the conduction system
Detects abnormalities
Reduction of the efficiency of the heart’s pumping cycle
Many types of abnormal conduction patterns exist
THE REDUCTION OF THE EFFICIENCY OF THE HEART WILL AFFECT A PERSON’S ORGANS IN BODY BECAUSE IT IS NOT PUTTING OUT BLOOD AND OXYGEN, THE WAY IT IS SUPPOSED TO
