Cardiovascular Emergencies Flashcards
What is ischemia?
decreased blood (and oxygen) supply to a body organ or part, usually due to functional constriction or actual obstruction of a blood vessel
What is infarction?
necrosis or death of tissues due to local ischemia
What is necrosis?
localized tissue death that occurs in grounds of cells or part of a structure or an organ in
response to disease or injury
What is gangrene?
death of body tissue due to lack of blood flow or bacterial infection
What is perfusion?
the process or act of pouring over or through, especially the passage of a fluid through a
specific organ or area of the body
What is a thrombus?
stationary mass of clotted blood or other formed elements that remains attached to its place of origin along the wall of a blood vessel
What is an embolus?
a mass of clotted blood or other formed elements (such as bubbles of air, calcium fragments or fat) that circulates in the blood stream until it becomes lodged in a vessel, obstructing circulation
What is preload?
volume of blood returning to the right atrium of the heart
What is afterload?
pressure/force the left ventricle must obtain to open the aortic semilunar valve and pump
blood into systemic circulation
What do arteries do?
-carry oxygenated blood from the heart to all tissues in the body
-also responsible for regulating blood pressure and capillary flow
What do veins do?
provide a return pathway to the heart and play an important role in providing the preload required to maintain cardiac contraction
What is dislipidemia?
-A condition of imbalance of the lipid components of the blood
-Cholesterol and triglycerides combine with water-soluble transport proteins in order to travel through the bloodstream - this transport molecule is called a lipoprotein
-Characterized by increased triglycerides, increased total blood cholesterol, increased LDL cholesterol and decreased HDL cholesterol
What is a low density lipoprotein (LDL)?
the primary transport molecule for cholesterol liver to target tissues, aka - “bad cholesterol”
What is high density lipoprotein (HDL)?
-the primary transport molecule for cholesterol from tissues back to the liver, aka - “good cholesterol”
What is cholesterol?
a lipid molecule with many functions including membrane and hormone synthesis
What are some risk factors for LDL cholesterol?
-Smoking
-Excessive alcohol consumption
-Sedentary lifestyle
-Poor dietary intake
-Type 2 diabetes
-Genetic predisposition
-Many of these risk factors will also decrease HDL levels, worsening the imbalance
What is arteriosclerosis?
an abnormal hardening and thickening of the arteries
What is atherosclerosis?
a form of arteriosclerosis characterized by the formation of fibrofatty lesions in the Intima lining of large and medium-sized arteries
What causes atherosclerosis?
-Atherosclerosis is, at its core, an inflammatory condition
-Several triggers exist that create lesions and plaque build-up in the intimal layer of the artery
-Atherosclerotic plaque consists of smooth muscle cells (SMCs), macrophages/leukocytes, collagen and elastin fibres, platelets, and a large lipid
core
How does the buildup of atherosclerotic plaque occur?
- A trigger causes initial endothelial injury
- Migration and adhesion of inflammatory cells to the injury site
- The foam cells begin to accumulate, which increases the progression of the lesion. Foam cells die and deposit their contents (necrotic debris and lipids) into the vascular wall (contained by the SMC and ECM)
- Atherosclerotic plaque is contained in the bulging vascular wall (reduction of blood
flow) and is prone to rupture (hemorrhage) or thrombotic vessel occlusion
What are the clinical manifestations of atherosclerosis?
-Typically do not become evident for over 20 years of plaque build up
-Depend on the vessels involved and the extent of vessel obstruction
-Atherosclerotic plaque exerts its effect through narrowing of the vessel producing ischemia, sudden vessel obstruction (thrombosis, embolism), aneurysm formation (weakened vessel wall) with possible rupture
-Larger vessels tend to produce aneurysms as a high-risk complication and smaller vessels tend to be more prone to vessel occlusion
What is peripheral artery disease/peripheral vascular disease?
-A disorder of the circulation in the extremities
-Can produce ischemia, pain, impaired function and, occasionally, infarction and tissue necrosis
-Caused by atherosclerosis/arteriosclerosis in peripheral arteries
What are the clinical manifestations of peripheral vascular disease?
-Symptoms don’t start until there is a 50% narrowing of the vessel
-Pain with walking (commonly in the calf), vague complaints of muscle aches and/or numbness
-Atrophy of leg muscles and thinning of the skin and subcutaneous tissue
-Weak or absent peripheral pulses (popliteal/ pedal) with signs poor perfusion (pale/mottled while elevated or deep red while dependent, delayed cap refill, cool to touch)
-Can progress to necrosis, ulceration, gangrene and amputation
What is Raynaud disease/phenomenon?
-A functional disorder caused by intense vasospasm of the arteries and arterioles in the
fingers and (occasionally) toes
-Exposure to cold or strong emotions causes vasoconstriction in the fingers (blood shunting) producing temporary, and self-limiting, ischemia
-Cause can be unknown or a direct byproduct of a previous vessel injury (frost bite, prolonged use of heavy/vibrating machinery, etc.)
What are the clinical manifestations of Raynaud disease?
-Distal pallor/cyanosis, cold sensation/altered sensory perception
-Following the spasm - intense redness, throbbing, paresthesia
What is an aneurysm?
-An abnormal localized dilation of a blood vessel that can occur in both arteries and veins
-Aneurysms can be classified according to their cause, location and anatomical features
What is a true aneurysm?
bounded by a complete vessel wall and the blood remains within the vascular compartment
What is a false aneurysm?
a localized dissection or tear in the inner wall of the artery with formation of an extravascular hematoma (causing vessel enlargement)
What is a berry aneurysm?
a true aneurysm that consists of a small, spherical dilation of the vessel at a bifurcation (usually found in the circle of Willis)
What is a fusiform aneurysm?
a true aneurysm that involves the entire circumference of the vessel with gradual
and progressive vessel dilation - these vary in diameter and length
What is a saccular aneurysm?
a true aneurysm that extends over part of the circumference of the vessel (appears “sac-like”)
What is a dissecting aneurysm?
a false aneurysm resulting from a tear in the intimal layer of the vessel that allows blood to enter the vessel wall, dissecting its layers to create a blood-filledcavity
What causes an aneurysm?
-Atherosclerosis (and its risk factors) is a common cause as is degeneration of the tunica media
-Weakness that leads to aneurysm formation may be due to congenital defects, trauma, infections or atherosclerosis
-As the tension/pressure in the vessel increases, so does the size of the aneurysm -eventually may rupture
-Even an unruptured aneurysm may cause damage by exerting pressure on adjacent structures and interrupting blood flow
What are the clinical manifestations of an anuerysm?
-Often asymptomatic until vessel rupture
-Other symptoms (pre-rupture) are dependent upon the vessel location
-May produce pain, discomfort - severe/significant if ruptured
-Pulsatile masses may be present in some
What is a ruptured aneurysm?
-A ruptured aneurysm is a significant life threat and must be treated immediately in an operating room
-Location of aneurysm will dictate the specific symptoms, but pain is typically unbearable and rapid blood loss will quickly progress to hypovolemic shock, an altered LOC, and death
-Observe for signs of shock (increased HR/RR, declining BP, pallor, etc.) and prepare for resuscitation
What is a dissecting aortic aneurysm?
-An aortic dissection is an acute life threatening condition that involves hemorrhage into
the vessel wall with longitudinal tearing that forms a blood- filled channel
-Can occur anywhere along the length of the aorta but it is most common in the ascending aorta and descending (thoracic) aorta (just distal to the subclavian artery)
What are the clinical manifestations of a dissecting aortic aneurysm?
-Abrupt and excruciating pain described as tearing or ripping
-Ascending Aorta - anterior chest
-Descending - mid upper back (between scapula)
-Hypovolemic shock
-Difference in bilateral blood pressures
What are varicose veins?
-Dilated veins of the lower extremities (usually superficial)
-Often lead to secondary problems of venous insufficiency
-Prone to rupture with minimal direct trauma - easily managed with direct pressure and often does not require any further medical intervention
What is deep vein thrombosis (DVT)?
-The presence of thrombus, and the accompanying inflammatory response, in the wall of a deep vein - most commonly in the lower extremities
-Pulmonary embolism (PE) is a significant complication of DVT
What is Virchow’s Triad?
-Stasis of blood (prolonged flights, bed rest, SCI)
-Increased blood coagulability (clotting deficiencies, oral contraceptive use, hormone therapy, cigarettes)
-Vessel wall injury (trauma, post-surgery, IVs, infection)
What are the clinical manifestations of DVT?
-Often asymptomatic (usually because the vein isn’t completely occluded)
-S&S can be related to the inflammatory process - pain, swelling, deep muscle tenderness, fever, general malaise
-Other findings are dependent on location of the thrombus
-Most commonly occurs below the knee (calf pain/tenderness, swelling, redness, warm to touch)