Cardiac - Class 3 - Alterations in Cardiovascular Function Flashcards
What does the prognosis of a MI depend on?
■ Extent of tissue death
■ Surrounding tissue
■ Location
● MI can occur in various regions of the heart wall: anterior, inferior, posterior, lateral, subendocardial, transmural
Causes of Angina?
1.) Obstruction
● Vessel spasm
● Atherosclerosis (stable plaques)
● Atherosclerosis (unstable plaques)
■ Other
● Hypotension
● Anemia
● Hypoxemia
● Increased demand for oxygen (Causes of increased demand for oxygen: tachycardia, exercise, hypertension (hypertrophy), valvular disease)
What happens if hypovolemic shock can’t resuscitate quickly?
systemic inflammation and multiple organ dysfunction
What is relative hypovolemia with neurogenic shock?
It is a loss of vascular tone
blood volume is same but Systemic Vascular Resistance decreases…by a lot (amount of space
containing blood has increased)
- Inadequate distribution of blood volume between the central and peripheral compartments – systemic vascular resistance is too low to get blood back to the heart
What does a decrease in preload result in?
decrease preload = decrease in stretch = decrease in contractility = decrease in cardiac output
What is cardiogenic shock?
It is defined as decreased cardiac output and evidence of tissue hypoxia in the presence of adequate intravascular volume.
Causes/process of two of the main reasons for myocardial Ischemia?
- decreased coronary blood flow due to atherosclerotic plaque – plaque can also cause ulceration or rupture – underlying tissue is exposed – thrombus formation – can block blood supply to heart muscle – if not reversed ischemia becomes infarct
- coronary spasm, hypotension dysrhythmias and decreased oxygen carrying capacity of blood
what are the 4 progression steps to acute coronary syndrome? what happens at each of the stages?
1.) Stable angina
-Angina pain develops when there is increased demand in the setting of a stable atherosclerotic plaque. The vessel is unable to dilate enough to allow adequate blood flow to meet the myocardia demand.
2.) Unstable angina
-The plague ruptures and a thrombus forms around the ruptured plaque, causing partial occlusion of the vessel. Angina pain occurs at rest or progresses rapidly over a short period of time
3.) nSTEMI
-The plague ruptures and thrombus formation causes partial occlusion to the vessel that results in injury and infarct to the subendocardial myocardium
4.) STEMI
-A complete occlusion of the blood vessel lumen, resulting in transmural injury and infarct to the myocardium, which is reflected by ECG changes and rise in tropinins
What is CAD usually caused by?
Atheroclerosis
What is stable angina caused by?
Caused by:
■ Gradual luminal narrowing and hardening of arterial walls,
with associated inflammation, endothelial cell dysfunction, and decrease in endogenous vasodilators.
● More prevalent in those with diabetes, obesity, dyslipidemia
Causes of neurogenic shock?
1.) Can be caused by any factor that stimulates parasympathetic or inhibit sympathetic stimulation
2.) Trauma to the spinal cord (above T6)
3.) Interruption of O2 to the medulla
4.) Depressive medications,
5.) anesthetic agents,
6.) severe emotional stress and pain other causes
Sings and symptoms for angina and MI regarding Substernal Chest Discomfort?
Substernal chest discomfort:
-Sensation of heaviness or pressure
-May radiate to neck, lower jaw, left arm and shoulder
-Pallor, diaphoresis, dyspnea
-Women – atypical chest pain
Complications of MI?
○ Dysrhythmias (arrhythmias)
○ *Heart failure
○ *Cardiogenic shock
○ Sudden cardiac death
○ Aneurysm of heart wall
○ Rupture of ventricular wall
○ Rupture of papillary muscles
○ Rupture of interventricular septum
What is stable angina pectoris activated by? What relives it? What might the pain be mistaken for?
Activated by physical exertion or stress
Relieved by rest
-Pain may be mistaken for indigestion
Signs and symptoms of right sided heart failure? (Cor Pulmonale)
1.) Fatigue
2.) Ascites
3.) Enlarged liver and spleen
4.) Dependant edema
5.)Weight gain
6.)May be secondary to chronic pulmonary problems
7.) Increased peripheral venous pressure
8* Weight gain
9* Anorexia and complaints of GI distress
What does Decreasing contractility, increasing preload, and increasing afterload develop in left sided heart failure?
Decreasing contractility, increasing preload, and increasing afterload develops, causing progressive worsening of symptoms – pulmonary edema – fluid backing up into the lungs
What is Mitral stenosis? What is it most commonly seen in the from of?
It impaires the flow of blood from the left atrium to the left ventricle
It is most commonly seen in the form of rheumatic heart disease
Manifestations of left sided heart failure?
Main ones:
Pale cool,
decreased capillary refill, weak pulses
Decreased urine output
OTHERS:
Dyspnea,
orthopnea,
cough of frothy sputum, fatigue,
decreased urine output, edema,
confusion,
restlessness,
tachycardia,
cyanosis,
crackles
Paroxysmal Nocturnal Dyspnea
Tachypnea
-S3 gallop, underlying CAD or hypertension
What is Preload?
stretching of the cardiac muscle at end diastole, right before contraction
What is a Transmural infarction?
■ If infarction extends through the myocardium all the way from endocardium to epicardium
■ Severe cardiac dysfunction
■ STEMI: acute ST-elevation myocardial infarction
What are the clinical manifestations of cariogenic shock caused by?
What do they include/what are they?
Clinical manifestations caused by a widespread impairment of cellular metabolism
1.) Impaired through process
2.) Dyspnea and tachypnea
3.) Systemic venous and pulmonary edema
4.)Dusky skin color
5.) Hypotension
6.)oliguria (scant urine),
7.) ileus (lack of movement in bowel)
What does high after load mean?
high afterload means a decrease in cardiac output
Blockage of coronary arteries is a common cause of?
Blockage of these arteries is a common cause of angina, heart disease, heart attacks and heart failure.
Risk factors for septic shock
Genetics – our reaction, chronic diseases, immune deficiency state, timeliness of intervention
What is a Subendocardial infarction?
■ Occurs when thrombosis disintegrates before complete distal tissue necrosis occurs
■ Infarction only in the myocardium directly beneath the endocardium
What causes heart failure?
Mostly because of LV dysfunction
○ RV failure (pulmonary disease)
○ High-output failure (inadequate perfusion despite normal/high cardiac output)
Patho for right sided heart failure with left ventricular failure?
(Class notes) increased left ventricular filling pressure is reflected back in to the pulmonary circulation
As the pressure in the pulmonary circulation rises there is increased resistance to the right ventricle emptying
(Will notes) Pressure in pulmonary circulation rises → resistance to RV emptying increases
■ RV will dilate and fail
■ Pressure will increase in systemic venous circulation, leading to
● Peripheral edema
● Hepatosplenomegaly
● If LV failure is absent, diffuse hypoxic pulmonary
diseases (such as COPD, cystic fibrosis, and ARDS) can be attributed to it
What is Ischemia?
A local state in which the cells are temporary deprived of blood supply
-Cells remain alive but cannot function properly
What is unstable angina?
It is the result of reversible myocardial ischemia and is harbinger of impending infarction
new onset angina, occurs at rest, or angina with increasing severity or frequency
Risk factors for aortic stenosis?
hypertension, smoking dyslipidemia
What is septic shock?
Shock that is caused mostly by bacteria, fungal, and viruses
-infectious organisms cause systemic inflammation, initiating a cascade of physiological responses
What is a STEMI?
Continued coronary occlusion leads to transmural infarction extending from endocardium to pericardium
○ ST elevation
Why is it important to recognize unstable angina?
Because it signals that the athersclortic plague has become complicated, and infarction may soon follow
Non-modifable risk factors for CAD?
Age
Gender – assigned male at birth are at greater risk – after menopause – women increased risk
Family history – environment, genetics
Risk factors to heart failure?
Main ones: ischemic heart disease and hypertension
Age, obesity, diabetes, renal failure, valvular heart disease, cardiomyopathies, myocarditis, congenital heart disease, excessive alcohol use
Onset of anaphylactic shock?
Sudden onset – death imminent without intervention
What kind of substernal chest discomfort may accompany stable angina pectoris?
Substernal chest discomfort:
-Sensation of heaviness or pressure
May radiate to neck, lower jaw, left arm and shoulder
-Pallor, diaphoresis, dyspnea
Women – atypical chest pain – (microvascular angina – vasoconstriction of small coronary arteries)
Mortality rate of cariogenic shock?
70%
In early septic shock what does tachycardia do?
Early – tachycardia – CO remains normal
It causes cardiac output to remain normal or become elevated, although myocardial contractility is reduce
What do extra heart sounds (murmurs or gallops) represent?
Impaired left ventricular function
What ultimately happens in shock?
Ultimately Anaerobic metabolism, acidosis, sodium-potassium pump fails, cell membrane permeability, cellular edema, cell death
Whatcan prinzmetal angina result from?
Decreased vagal activity, hyperactivity of the SNS, or decreased nitric oxide activity
Risk factors for stable angina pectoris?
Uncontrolled Diabetes, dyslipidemia, obesity
Hypertension
Increased LDLs (low density lipoproteins)
Decreased HDLs (High Density Lipoproteins )
Sedentary lifestyle
High BMI
Genetics
What is happening during aortic regurgitation?
During systole, blood is ejected from the left ventricle into the aorta. During diastole, some of the ejected blood flows back into the left ventricle through the leaking valves
Modifiable risk factors for CAD?
1.) Dyslipidemia – Low density lipoproteins (LDL) need to stay low and high density lipoproteins (HDL) need to stay high – LDL – cholesterol in arteries, HDL reverses LDL
Control
2.) hypertension – stress, medication compliance
3.) Cigarette smoking – generating free radicals – contribute to atherogenesis -formation of fatty plaques
- Stimulates epinephrine & norepinephrine which are going to increase our HR & peripheral vasoconstriction = HTN
4.) Diabetes mellitus – insulin won’t work property, increase inflammation & thrombosis, damage to endothelium, thickening of vessel walls
5.) Obesity & Sedentary lifestyle – causes metabolic syndrome – will look at again later
6.) Atherogenic diet – high in protein, cholesterol, & saturated fats and then low fruit and vegetables
How long can cardiac cells withstand ischemic conditions before hypo injury causes cellular death and tissue necrosis?
20 min
