Week 11 Flashcards
Perfusion: HF & Shock
The relaxation of the ventricles during the cardiac cycle
Diastole
The mechanism describing how the ventricle can adjust its pumping force to accommodate various levels of preload and afterload
Frank Starling Law
Describes how the cardiac muscle force of contraction is affected
Inotropic Function= contraction
The volume of blood in the heart at the end of diastole, also known as ventricular end diastolic volume
Preload> precardiac cycle
The amount of blood the heart pumps out of the ventricle each minute
Cardiac Output
Describes how the heart rate is affected?
Chronotropic= HR
The volume of blood pumped out of the ventricle with each contraction
Stroke Volume
The amount of resistance the ventricle must overcome in order to pump blood out of the heart
Afterload= resistance
The contraction of the ventricles during the cardiac cycle
Systole
Weak distended left ventricle cannot pump blood forward:
- Systolic/ diastolic dysfunction?
Systolic dysfunction
Stiff non-elastic left ventricle with less filling of blood:
- Systolic/ diastolic dysfunction?
Diastolic dysfunction
Can occur in traumatic injuries blocking venous return to heart:
- High/low output failure?
Low output failure
-don’t have enough output
Can be caused by systemic conditions with high metabolic demand:
- high/ low output failure?
High-output failure
- High demand= high output
Symptoms include jugular venous distention and ascites:
-L/R ventricle failure?
Right ventricular failure
Symptoms include paroxysmal nocturnal dyspnea and crackles:
L/R ventricle failure?
Left ventricular failure
The most common cause of heart failure is _____
Ischemic heart failure
- damages muscles and causes them to not work
In Cor Pulmonale, _______ stimulates vasoconstriction of the pulmonary arterial circulation, creating high pressures or pulmonary hypertension
Chronic Hypoxia
- tries to conserve O2 w/ vasoconstriction
The term, ______ is commonly used to describe a disease that targets the heart muscle itself. It can described as restrictive or __________.
- Cardiomyopathy
- Hypertrophy(muscle is too big)
Cardiogenic shock can be caused by _______, which occurs when there is an increased amount of fluid in the pericardial sac that surround the heart
Cardiac Tamponade
The underlying cause of ____ is widespread vasodilation that reduces venous return to the heart and unopposed action of the parasympathetic nervous system
Neurogenic
- spinal cord injury
- parasympathetic nervous system and heart don’t balance each other
In the _________ stage of shock, wide spread cellular hypoxia and lactic acid build up occurs
- irreversible
- when lactic acid build up occurs and irreversible damage occurs
Cardiac Contractility
The myocardium’s ability to stretch and contract in response to the filling of the heart wih blood.
- Afterload can negatively affect contractility by increasing the heart’s workload
- Also influenced by the ANS, acid-base, and electrolytes
Starling capillary forces
the two opposing pressure forces present at every capillary bed-hydrostatic pressure and oncontic/osmotic pressure…. normally they balance eachother out
Hydrostatic fluid
forcing fluid out of the vessel and into the intracellular and interstitial spaces
Oncotic pressure
force attempts to pull fluid from the intracellular spaces back to the vessel
What is hemodynamic monitoring
measuring pressure within the chambers and vessels of the right and left sides of the heart
How to measure the right heart pressure
using central venous pressure
Pressure measurement within the IVC at that locations is referred to as
Central Venous Pressure
When the L ventricle is not working and pressure is high what happens?
Backflow of the blood occurs
How to measure the left heart pressure
catheter inserted into femoral or radial artery, advanced into aorta, then further advanced into left ventricle
What percentage is concerning of LVEF and indicated heart failure
any percentage lower than 40%
In heart failure can you differentiate between right and left-sided failure? T or F
TRUE
Regulatory and compensatory mechanisms include
- RAAS
- ANS (barorecptors)
- Posterior pituitary(ADH released)
-Natriuretic peptide (BNP & ANP)
The inability of the heart and lungs to satisfy the metabolic and oxygen requirements of the peripheral tissues
SHOCK
Angiotensin II is a potent _____
vasodilator
Aldosterone does what
- raises bp
- raises blood volume
When ADH hormones go wrong they can act like a _____
vasoconstrictor
ANP is secreted by
The hearts atria
BNP is secreted by
The hearts ventricles
T or F:
High Blood volume stimulates releases of ANP and BNP, which stimulates the process of natriuresis
TRUE, increased excretion of sodium and water by nephron
Is lower or elevated BNP an indicator in heart failure
Elevated
Nitric oxide is a _________
vasodilator, produced by vascular endothelial cells
TNF means
tumor numeric factor, elevated levels present with heart failure
Endothelium stimulates ______
vasoconstriction
What other organ is involved with maintaining blood pressure?
The kidney
When the heart is filled with more blood, the heart is able to eject more blood describes
Preload
A pt has a fluid overload due to CHF. what compensations will the body attempt to address the fluid volume overload
Increased natriuretic peptide
Which type of hemodynamic pressure helps evaluate right ventricular failure?
Central Venous Pressure
Which type of hemodynamic pressure helps evaluate left ventricular failure?
Pulmonary Capillary Wedge Pressure
LVEF lower than ___% is indicative of heart failure
40%
A patient with left ventricular failure is completing a cardiac assessment. Which of the following results would be concerning to a clinician?
A. Left ventricular ejection fraction (LVEF) of 35%
B. Resting cardiac output of 5.2 liters per minute
C. Low to normal central venous pressure
D. Blood pressure of 130/82
A, LVEF of 35%
A patient is given an angiotensin receptor blocker. As the nurse with the discharge instructions, which of the following would you tell the patient is the effect of the medication?
A. The medication increases heart rate
B. The medication decreases pulmonary congestion
C. The medication decreases the constriction and resistance of your blood vessels
D. The medication increases urine output
C. medication decreases the constriction and resistance of your blood vessels
- goes along with the RAAS
A patient is displaying increased pulmonary capillary wedge pressure due to coronary issues. What else may the nurse expect to see?
A. Increased jugular vein distension
B. Paroxysmal nocturnal dyspnea (PND)
C. Decreased left ventricular size
D. Hepatomegaly
B. Paroxysmal nocturnal dyspnea (PND)
- greater pressure in the lungs
What is Cardiac Tamponade
- Increased amount of fluid in the pericardial sac that surrounds the heart
- the heart becomes restricted
A patient’s blood pressure is failing due to hemorrhage. Which of the following are appropriate compensations by the body? Select all that apply:
a. Decreased heart rate
b. Increased antidiuretic hormone (ADH)
c. Increased aldosterone
d. Decreased peripheral vasoconstriction
e. Increased fluid retention
b, c, e
The lungs, kidneys, gut, pancreas and liver begin to suffer decreased perfusion while all available blood is conserved for the heart and brain in which stage of shock?
a. Initial
b. Progressive
c. Irreversible
b. heart and brain are still conserved with bloodflow
A patient in Hawaii presented to the ED with extremely low BP, bradycardia, mild confusion and inability to feel their legs. The recent history included ocean swimming in high surf, and difficulty exiting the water after being pushed ashore (per witness). Which type of shock is this patient most likely experiencing?
Anaphylactic
Cardiogenic
Neurogenic
Hypovolemic
Septic
Neurogenic!
- spinal cord injury
