Exam 3 Flashcards
Angiotensin II is a potent what?
vasoconstrictor
What causes arrhythmias?
Electrolyte imbalance, hypoxia, structural damage, acidosis, cardiac drugs
Blood Pressure
the pressure of blood pushing against the walls of your arteries
Systolic BP
- the top number
- measures the pressure in your arteries when your heart beats
Diastolic BP
- the bottom number
- measures the pressure in your arteries when your heart rests between beats
Pulse Pressure
- the difference between the upper and lower numbers of your blood pressure.
- helps to predict heart attack or stroke
- tends to increase with age
- normal: 40-60
- wide pressure associated with heart attack
- narrow pressure associated with heart failure
Cardiac Output
- how many liters of blood your heart can pump in a minute
- multiply stroke volume and heart rate
- determines the heart’s strength and health
- need more cardiac output when exercising since body’s cells need more oxygen
- measured when difficulty exercising arises or heart failure present
- normal: 4 to 8 L/min
Perpheral Vascular Resistance
- force that resists the flow of blood through the vessels, mostly determined by the arterioles, which contract to increase resistance; important in determining overall blood pressure
- heart rate, stroke volume, and peripheral vascular resistance are factors that determine BP
- when there is low pressure on the baroreceptors, the medulla is stimulated to increase the sympathetic nervous system to constrict the blood vessels and increase peripheral vascular resistance
What do we need to have a blood pressure in our body?
the amount of blood the heart pumps and how hard it is for the blood to move through the arteries
EKG
- detects the patterns of electrical impulse generation and conduction through the heart and translates that information into a recorded pattern, which is displayed as a waveform on a cardiac monitor
- a measure of electrical activity; it provides no information about the mechanical activity of the heart
Edema
- swelling caused by excess fluid trapped in your body’s tissues
- usually seen on hands, arms, feet, ankles and legs
- occurs when tiny blood vessels in your body (capillaries) leak fluid
- risk factors: CHD, lung diseases, venous insufficiency, long periods of sitting and standing
- treatment of the underlying cause (if possible), reducing the amount of salt (sodium) in your diet, and, in many cases, use of a medication called a diuretic to eliminate excess fluid, using compression stockings and elevating the legs may also be recommended
Endothelial Layer of the Heart
- the innermost layer of the heart and lines the chambers and extends over projecting structures such as the valves, chordae tendineae, and papillary muscles
- endothelial cells release substances that control vascular relaxation and contraction as well as enzymes that control blood clotting, immune function and platelet (a colorless substance in the blood) adhesion
Heart Electrical Conductivity
property of heart cells to rapidly conduct an action potential of electrical impulse
1. starts when your sinoatrial (SA) node creates an excitation signal
2. tells atria (top heart chambers) to contract
3. The atrioventricular (AV) node, delaying the signal until your atria are empty of blood.
4. The bundle of His (center bundle of nerve fibers), carrying the signal to the Purkinje fibers.
5. The Purkinje fibers to your ventricles (bottom heart chambers), causing them to contract.
Hypertension
- Intermittent or sustained elevation of diastolic or systolic blood pressure
- HTN: Systolic blood pressure of 139 mm Hg or higher or a diastolic blood pressure greater than 89 mm Hg
- Pre-HTN: systolic pressure from 120–139 and diastolic from 80-89
Determined by
* amount of blood pumped from ventricles w/ each heartbeat
* Total PVR – resistance of muscular arteries to blood being pumped
* Baroreceptors
* RAAS
Hyperlipidemia
Causes
* When the levels of lipids in the blood increase, hyperlipidemia occurs
* This can result from excessive dietary intake of fats or from genetic alterations in fat metabolism, leading to a variety of elevated fats in the blood
* Hypercholesterolemia, hypertriglyceridemia, alterations in LDL and HDL concentrations
Best Ways to Combat
* reduce intake of saturated fats in dairy and red meat
* Niacin, Fenofibrate, Omega-3
Troponin Labs
chemical in heart muscle that prevents the reaction between actin and myosin, leading to muscle relaxation; it is inactivated by calcium during muscle stimulation to allow actin and myosin to react, causing muscle contraction
Normal Values:
* Troponin I: 0 - 0.04 ng/mL.
* Troponin T: 0 - 0.01 ng/mL.
High Levels Correlate with
* Heart surgery.
* Infections or inflammation in your heart.
* Cardioversion (this is the use of an electric shock to make an irregular heart rhythm return to normal).
Creatine Kinase Labs
An enzyme that’s found in your skeletal muscle, heart muscle and brain.
When any of these tissues are damaged, they leak creatine kinase into your bloodstream.
Elevated CK levels may indicate muscle injury or disease.
Normal
* 22 to 198 U/L
Three Types
* These are CK-MB, CK-MM, and CK-BB. CK-MB is the substance that rises if your heart muscle is damaged. CK-MM rises with other muscle damage. CK-BB is found mostly in the brain.
Myoglobin Labs
measures the amount of myoglobin, a protein found in your skeletal and heart muscles, in your blood or urine.
* Myoglobin is a protein that’s found in your striated muscles, which includes skeletal muscles (the muscles attached to your bones and tendons) and heart muscles. Its main function is to supply oxygen to the cells in your muscles (myocytes).
* High levels generally indicate muscle damage; though, the test cannot determine the cause or location of the muscle damage.
Normal
* For men: Less than 91 ng/mL (nanograms per milliliter).
* For women: Less than 63 ng/mL.
Triglycerides
lipids that give the body energy from the food we eat
Pure cholesterol cannot mix with or dissolve in the blood. Instead, the liver packages cholesterol with triglycerides and proteins called lipoproteins. The lipoproteins move this fatty mixture to areas throughout the body.
* High triglycerides combined with high cholesterol raise your risk of heart attack, strokes and pancreatitis
Levels: 150 or less
Phospholipids
a class of lipids whose molecule has a hydrophilic “head” containing a phosphate group and two hydrophobic “tails” derived from fatty acids, joined by an alcohol residue
antiphospholipid syndrome
* autoimmune disorder that causes blood clots by the body’s immune system attacking proteins bound to phospholipids
* These antibodies make it much more likely that you will have blood clots in your arteries or veins
Cholesterol
found in large quantities in the membrane, and it works to keep the phospholipids in place and the cell membrane stable
* necessary component of human cells that is produced and processed in the liver and then stored in the bile until stimulus causes the gallbladder to contract and send the bile into the duodenum via the common bile duct; a fat that is essential for the formation of steroid hormones and cell membranes; it is produced in cells and taken in by dietary sources
* Normal: less than 200 mg/dL
Chylomicrons
carrier for micelles or lipids in the bloodstream, consisting of proteins, lipids, cholesterol, and so forth
* chylomicrons pass through the wall of the small intestine, are picked up by the surrounding intestinal lymphatic system, travel through the system to the heart, and then are sent out into circulation
VLDL
produced in the liver and released into the bloodstream to supply body tissues with a type of fat (triglycerides)
* High levels of VLDL cholesterol have been associated with the development of plaque deposits on artery walls, which narrow the passage and restrict blood flow.
* An elevated VLDL cholesterol level is more than 30 milligrams per deciliter
IDL
are formed from the degradation of very low-density lipoproteins as well as high-density lipoproteins
* enable fats and cholesterol to move within the water-based solution of the bloodstream
* refers to a density between that of low-density and very-low-density lipoproteins.
LDL
tightly packed fats that are thought to contribute to the development of coronary artery disease when remnants left over from the LDL are processed in the arterial lining
* enter circulation as tightly packed cholesterol, triglycerides, and lipids, all of which are carried by proteins that enter circulation to be broken down for energy or stored for future use as energy
* Lab: 100 or less
HDL
loosely packed chylomicron-containing fats, able to absorb fats and fat remnants in the periphery; thought to have a protective effect, decreasing the development of coronary artery disease
* enter circulation as loosely packed lipids that are used for energy and to pick up remnants of fats and cholesterol that are left in the periphery by LDL breakdown
* Lab: 40 or more
Orthostatic Hypotension
A form of low blood pressure that happens when standing up from sitting or lying down
Causes include dehydration, long-term bed rest, pregnancy, certain medical conditions and some medications.
* commonly seen in the elderly because of age-related impairment in baroreflex compensatory reflexes (maintains blood pressure at constant rate) to upright position
* Hypovolemia: Loss of fluid within the blood vessels is the most common cause of symptoms linked to orthostatic hypotension. This could be due to dehydration brought about by diarrhea, vomiting, and the use of medication, such as diuretics or water pills.
Myocardial Infarction
blockages in coronary arteries within the heart
heart does not get enough O2 from the blockage
Plaque Rupture
Plaques inside the coronary arteries sometimes break open or “rupture.” This is what causes most heart attacks. When a plaque breaks open, it causes a blood clot to form inside the artery. As the clot grows, it can completely block off the flow of blood through the artery.
RAAS
the system of hormones, proteins, enzymes and reactions that regulate your blood pressure and blood volume on a long-term basis
1. When your blood pressure falls, your kidneys release the enzyme renin into your bloodstream.
2. Renin splits angiotensinogen, a protein your liver makes and releases, into pieces. One piece is the hormone angiotensin I.
3. Angiotensin I, which is inactive (doesn’t cause any effects), flows through your bloodstream and is split into pieces by angiotensin-converting enzyme (ACE) in your lungs and kidneys. One of those pieces is angiotensin II, an active hormone.
4. Angiotensin II causes the muscular walls of small arteries (arterioles) to constrict (narrow), which increases blood pressure. 5. Angiotensin II also triggers your adrenal glands to release aldosterone and your pituitary gland to release antidiuretic hormone (ADH, or vasopressin).
6. Together, aldosterone and ADH cause your kidneys to retain sodium. Aldosterone also causes your kidneys to release (excrete) potassium through your urine.
7. The increase in sodium in your bloodstream causes water retention. This increases blood volume and blood pressure, thus completing the renin-angiotensin-aldosterone system.
7 P’s of Arterial Occulusion
condition involving partial or complete blockage of blood flow through an artery, stops flow of oxygen, causing ischemia
1. pistol pain
2. pallor
3. polar (coldness)
4. pulselessness
5. pain
6. paresthesia (pins and needles sensation)
7. paralysis
What regulates the smooth muscles in the heart?
the sinoatrial node of the heart
the pacemaker
Thrombin
an enzyme in blood plasma which causes the clotting of blood by converting fibrinogen to fibrin
One-Way Valves
supports the return of blood flow to the heart through venous circulation
Virchow’s Triad
three contributing factors in the formation of thrombosis: venous stasis, vascular injury, and hypercoagulability
Risk Factors for Venous Stasis
- immobility
- spinal cord injury
- CHF
- venous obstruction
Acute Coronary Syndrome
Patho: Blood supply to the myocardium is interrupted from occlusion of one or more of the coronary arteries.
Causes:
* Atherosclerosis
* Thrombosis
* Platelet aggregation
* Coronary artery stenosis or spasm
Types:
* Unstable angina
* Variant or Prinzmetal’s angina
* Non–ST-elevation myocardial infarction (non-STEMI or non–Qwave MI)
* ST-elevation myocardial infarction (STEMI or Qwave MI)
S/S
* Chest pain, radiating shoulder pain, NV, DOE, SOB
Complications: Damage caused by an MI:
* Reduced contractility with abnormal wall motion
* Altered LV compliance
* Reduced SV
* Reduced EF
* Elevated LV end-diastolic pressure
Treatment
* Treat chest pain
* Stabilize heart
* Reduce cardiac workload
Aneurysms
Patho: a bulge or ballooning in a blood vessel in the brain
may occur in any part of the aorta or major arteries
Causes:
* Usually caused by atherosclerosis (thickening of the arterial walls)
* infection
* trauma
* congenital abnormalities
S/S
* Back pain
* Cough
* Weak, scratchy voice (hoarseness)
* Shortness of breath
* Tenderness or pain in the chest
Atherosclerosis
leading cause of coronary heart disease
Risk Factors:
* age
* male
* women after menopause
* family history
* lifestyle: smoking, obesity, diet
* type 1 and 2
Clinical Manifestations
* Atherosclerosis is the buildup of fats, cholesterol and other substances in and on the artery walls. This buildup is called plaque. The plaque can cause arteries to narrow, blocking blood flow. The plaque can also burst, leading to a blood clot.
Complications:
* ischemic heart disease, stroke, peripheral vascular disease
Hypercholesterolemia
a lipid disorder in which your low-density lipoprotein (LDL), or bad cholesterol, is too high
* This makes fat collect in your arteries (atherosclerosis), which puts you at a higher risk of heart attack and stroke
* 190 mg/dL or higher without other risk factors.
Higher than 160 mg/dL with another major risk factor.
Above 130 mg/dL with two risk factors.
Risk For:
* stroke
* coronary artery disease
* peripheral artery disease
Vasculitis
inflammation of the blood vessels
* The inflammation can cause the walls of the blood vessels to thicken, which reduces the width of the passageway through the vessel. If blood flow is restricted, it can result in organ and tissue damage.
Arterial Disease of Extremities
peripheral artery disease
* narrowing or blockage of the vessels that carry blood from the heart to the legs
* primarily caused by the buildup of fatty plaque in the arteries, which is called atherosclerosis.
Arterial Anerysms
An aortic aneurysm is a balloon-like bulge in the aorta, the large artery that carries blood from the heart through the chest and torso.
Aortic aneurysms can dissect or rupture: The force of blood pumping can split the layers of the artery wall, allowing blood to leak in between them.
Cardiomyopathy
a disease of the heart muscle that makes it harder for the heart to pump blood to the rest of the body
Causes:
* Infectious disease
* Diabetes
* Renal failure
* Pregnancy complications
* Alcohol / drug toxicity
* Ischemia, HTN
* Systemic inflammatory disorders
* Nutritional disorders
* Genetic predisposition
* Idiopathic
Types: dilated, hypertrophic, restrictive
* dilated: causes the heart chambers (ventricles) to thin and stretch, growing larger
* hypertrophic: the heart muscle becomes abnormally thick.
* restrictive: the muscles of your heart’s lower chambers (ventricles) stiffen and can’t fill with blood
Coronary Artery Disease
Fatty, fibrous plaques progressively narrow the coronary artery lumens reducing volume of blood flow through them.
* Causes the loss of oxygen and nutrients to myocardial tissue because of poor coronary blood flow.
Causes
* Modifiable vs Nonmodifiable
* Atheroma: Fatty tumors in intima of heart vessels
* Atherosclerosis: Narrowing of the heart vessels
* Angina Pectoris: “suffocating of chest”
* Prinzmetal’s angina: spasms of vessels + narrowing
* MI: Cells in myocardium become necrotic & die
Types
* Stable: No damage to heart; reflexes restore blood flow
* Unstable: Episodes of ischemia occur at rest
* MI: completely occluded coronary vessel unable to deliver blood to heart, that area becomes ischemic and then necrotic -> excruciating pain, NV, and severe sympathetic stress reaction
S/S
* unstable or stable angina
Complications
* heart attack
