Chapter 27: Cardiac Disorders
Differences between unstable angina vs stable angina:
- Unstable vs stable plaques - Responsive to nitro vs unresponsive to nitro - Pain at rest vs pain during exertion
Drug treatment for chronic stable angina (3)
- Vasodilators - Beta blockers - Calcium channel blockers
What pharmacological treatments might be administered to a patient with chronic stable angina?
- vasodilators - beta blockers - calcium channel blockers
Complications of shock
Acute respiratory distress syndrome Acute renal failure Gastrointestinal complications Disseminated intravascular coagulation Multiple organ dysfunction syndrome
Mitral valve prolapse
Advanced/critical state of regurgitation - valves completely "floppy," press back into left atrium during systole so less blood is pushed out of the left ventricle into the aorta
Preload
Amount of blood in ventricle at end of diastole
In circulatory shock, the adrenergic (or sympathetic) nervous system is activated. The nurse knows that stimulation of beta-2 adrenergic receptors will result in which responses? Select all that apply.
Vasodilation of the skeletal muscle vascular bed Dilation of the bronchioles
A client has developed left-sided heart failure. Which symptom might have precipitated this condition?
Myocardial infarction
Which acute coronary syndromes test positive for cardiac panel?
NSTEMI and STEMI
Which coronary artery disease result from unstable atherosclerotic plaque?
NSTEMI, STEMI, Unstable Angina
Difference between NSTEMI and STEMI
No ST elevation during NSTEMI
Are serum cardiac markers present during angina? Why?
No; angina is chest pain, not heart muscle death
Diastolic heart failure
Normal EF; abnormal diastolic pressure
A client who developed a deep vein thrombosis during a prolonged period of bed rest has deteriorated as the clot has dislodged, resulting in a pulmonary embolism. Which type of shock is this client at risk of experiencing?
Obstructive shock
S/S of hypovolemic shock
Pallor, clammy skin, thirst, tachycardia, lightheadedness, decreased urine output, and hypotension, symptoms of SNS activation
What are endothelins?
Peptides that constrict blood vessels and raise blood pressure, induce myocyte hypertrophy and fibrosis, and encourage water and salt reabsorption in the kidneys (bad for failing heart)
A client comes to the emergency room exhibiting signs and symptoms of right-sided heart failure. Upon X-ray it is determined that he has 250 mL of fluid in the pericardial cavity. Which disease should the nurse suspect this client is suffering?
Pericardial effusion
The nurse caring for a client 12 hours after a coronary bypass graft notes a sudden decrease in the amount of chest tube drainage, a rapidly narrowing pulse pressure, paradoxical pulse, and shortened amplitude of the QRS complex on the electrocardiogram monitor. Which action should the nurse take next?
Prepare for pericardiocentesis
Concentric hypertrophy
Pressure overload Left ventricular wall thickens in concentric fashion & chamber size remains the same
Serum cardiac markers
Proteins released into the blood from necrotic heart muscle after an MI - Troponin - Creatine Kinase CK-MB - Myoglobin
cardiac tamponade
Acute compression of the heart caused by fluid accumulation in the pericardial cavity
S/S of pericarditis
- Sharp, radiating pain - Worse with inhalation - Fever (if viral infection) - Positional - Pericardial friction rub
The nurse is teaching a client with a diagnosis of hypertrophic cardiomyopathy and aortic valve stenosis. Which statement by the client shows that the client understands this condition?
"I should report episodes of dizziness or fainting."
A nurse is performing client health education with a 68-year-old man who has recently been diagnosed with heart failure. Which statement demonstrates an accurate understanding of his new diagnosis?
"I'm trying to think of ways that I can cut down the amount of salt that I usually eat."
Treatment for primary cardiomyopathy
- Beta blockers - ACE inhibitors - Left ventricular assist device - Pacemaker - Ablation
Treatment for pericardial effusion (3)
- Diuretics - NSAIDS - Pericardiocentesis
Mitral valve regurgitation
A back flow of blood into the left atrium from the left ventricle caused by failure of the heart's mitral valve to close tightly.
Which valves are open during diastole and closed during systole?
AV valves (mitral on the left and tricuspid on the right)
Distributive or Vasodilatory Shock
1. Blood vessels dilate 2. Not enough blood to fill the circulatory system 3. Decreasing blood flow 4. Less blood returned to the heart 5. Less blood is circulated to the body
During an acute MI, there is ischemic damage to the heart muscle. The location and extent of the ischemic damage is the major predictor of complications, ranging from cardiac insufficiency to death, following an MI. What is the "window of opportunity" in restoring blood flow to the affected area so as to diminish the ischemic damage to the heart and maintain the viability of the cells?
20 - 40 minutes
In hypovolemic shock, renal perfusion and urinary output decline. The nurse will monitor urinary output and knows that output below which level indicates inadequate renal perfusion?
20 mL/hour
Hypovolemic shock
A condition in which low blood volume, due to massive internal or external bleeding or extensive loss of body water, results in inadequate perfusion.
Cardiomyopathy
A group of diseases that directly affect the structural or functional ability of the myocardium
How does the renin-angiotensin-aldosterone mechanism during compensation for heart failure actually cause further damage?
Angiotensin II tries to restore blood flow to kidneys by acting as a vasoconstrictor, stimulating release of norepinephrine to work as a vasoconstrictor (and inhibiting SNS from reabsorbing it) and aldosterone, which stimulates vasopressin (antidiuretic hormone). Increased salt and water retention is released into venous system in an effort to increase blood flow, but this adds to the backup in the venous system. Aldosterone is also an inflammatory hormone that might cause fibrosis of the heart, causing decreased contractility.
Over-the-counter drug used to treat STEMI
Aspirin
Coronary artery bypass grafting (CABG) is a treatment modality for which disorder of cardiac function?
Atherosclerosis and unstable angina
Consequences of right-sided heart failure
Body fills with blood causing peripheral edema, enlargement of liver, kidney, spleen, and abdominal cavity, and lungs do not oxygenate enough blood
Aortic valve regurgitation
Incompetent valve closure allows blood to flow back into left ventricle from aorta during diastole
Aortic valve stenosis
Calcification of aortic valve cusps restricts the forward flow of blood during systole from the left ventricle into the aorta. Because the aortic valve doesn't open all the way, it causes an increase in the workload of the left ventricle causing ventricular hypertrophy. Could lead to heart failure.
A client who has been admitted to the ICU with a diagnosis of pericardial effusion begins to experience severe tachycardia. Upon assessment, the nurse finds that his central venous pressure is increased, he has jugular vein distention, his systolic blood pressure has dropped, and there is a narrow pulse pressure. His heart sounds appear to be very muffled. Which diagnosis should the nurse suspect the physician will make?
Cardiac tamponade
Hypertrophic Cardiomyopathy
Cardiomyopathy; genetic defect causing a bulb to form in the left ventricle that blocks aortic valve
Arrythmogenic right ventricular dysplasia
Cardiomyopathy; replacement of myocytes with adipose or fibrous tissue
Acute aortic valve regurgitation
Caused by infection, trauma, or aortic dissection; heart tries to compensate through increased blood pressure -life-threatening emergency
Nitroglycerin does NOT relieve pain for (2):
Chronic Stable Angina and STEMI
Rheumatic fever
Complication of strep throat that may damage heart valves and weaken heart if chronic
How does the Frank-Starling Law cause more damage during heart failure?
Decreased EF leads to hypoxic body tissues, which triggers systems to return more blood to right side of heart, leading to an overfilling of an already damaged left ventricle which causes pulmonary congestion
Symptoms of systolic heart failure
Decreased stroke volume, decreased ejection fraction, enlarged heart, dyspnea, fatigue, JVD, edema
What are the characteristics of shock?
Depressed vital functions due to decreased circulating blood volume; key marker is low blood pressure
What phase does the heart receive blood into its own vessels?
Diastole
What is the primary physiologic result of obstructive shock?
Elevated right heart pressure
Treatment to correct and reverse shock
Fluid Resuscitation Restore blood flow Improve O2 delivery Hemodynamic stability
Treatment for hypovolemic shock
Fluids
Primary Restrictive Cardiomyopathy
Hardening of the ventricular walls
Systole
Heart chamber contract, pumps blood into arteries
Diastole
Heart chambers relax, fill with blood
What is the most important factor in myocardial oxygen demand?
Heart rate
Dilated Cardiomyopathy
Heart responds to extra fluid by thinning the walls, abnormally enlarging
The health care provider is discussing major risk factors for coronary artery disease (CAD) with a client. The most important information for the provider to include would be:
History of cigarette smoking and elevated blood pressure
What are natriuretic peptides?
Hormones that include atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), released in response to fluid overload in heart. These hormones are natural antagonists to the renin-angiotensin-aldosterone system and SNS. Useful biomarkers for heart failure (especially BNP)
Stroke volume
How much (mL) blood is moved out of the heart in 1 contraction
#1 cause of diastolic heart failure
Hypertension
Football fans at a college have been shocked to learn of the sudden death of a star player, an event that was attributed in the media to "an enlarged heart." Which disorder was the player's most likely cause of death?
Hypertrophic cardiomyopathy (HCM)
A client has just returned from his surgical procedure. During initial vital sign measurements, the nurse notes that the client's heart rate is 111 beats/minute and the BP is 100/78 (borderline low). In this early postoperative period, the nurse should be diligently monitoring the client for the development of:
Hypovolemic shock due to actue intravascular volume loss
Heart failure
Impairment of heart's ability to send oxygenated blood into circulation
The health care team is developing a plan of care for a client diagnosed with congestive heart failure (CHF). The primary treatment goal would be:
Improving quality of life by relieving symptoms.
Which statement regarding heart failure is true?
In compensated heart failure, an increase of end-diastolic volume causes increased force of left ventricular contraction.
An 86-year-old client is disappointed to learn that he or she has class II heart failure despite a lifelong commitment to exercise and healthy eating. Which age-related change predisposes older adults to the development of heart failure?
Increased vascular stiffness
Myocarditis
Inflammation of the heart muscle without evidence of myocardial infarction
Infective endocarditis
Inflammation of the inner layer of heart tissue caused by bacterial adhesion and growth on at-risk endocardial surface (usually streptococcus)
What happens in the heart during left-sided systolic heart failure?
LV does not pump enough blood to the body
What is the path of blood buildup during left-sided heart failure?
Left heart - lungs - right heart - body
Which side of the heart is more likely to have valve disorders? Why?
Left side due to amount of pressure
What happens in the heart during left-sided diastolic heart failure?
Left ventricle doesn't accept enough blood from the lungs
How does the heart adapt to mitral valve regurgitation?
Left ventricle hypertrophy
Systolic heart failure
Low EF (< 40%); normal blood pressure
Consequence of left-sided heart failure
Lungs fill with blood causing pulmonary edema and dyspnea, especially when the patient is lying down at night (paroxysmal nocturnal edema)
Afterload
Measure of force required to emit blood from ventricles
Contractility
Measurement of how well the heart contracts; high contractility is good
A client is admitted for observation due to abnormal heart sounds, pulmonary congestion, nocturnal paroxysmal dyspnea, and orthopnea. Upon auscultation a low-pitched, rumbling murmur, best heard at the apex of the heart, is also heard. Which condition does the client likely have?
Mitral valve stenosis
Chronic aortic valve regurgitation
More gradual onset; causes angina, particular awareness of heart during sleeping (nocturnal paroxysmal dyspnea), "blowing" heart sounds
How do the heart vessels compensate for increased work demands?
Myocardial cells and endothelial cells lining the vessels release vasodilators
How does nitroglycerin work?
Relaxes smooth muscle and blood vessels; decreases work load of the heart
How does the increased activity of the sympathetic nervous system during compensation for heart failure actually cause further damage?
Release of catecholamines can induce fatal cardiac arrhythmias, and increased blood pressure and heart rate through retention of water and sodium puts more demand on an already struggling heart
What's the path of blood buildup during right-sided heart failure?
Right heart - body - left heart - lungs
How does the SNS affect kidneys during heart failure?
SNS directs blood away from kidneys to the heart during hypoxic conditions
Which acute coronary syndrome results from a complete vessel occlusion?
STEMI
Which valves are open during systole and closed during diastole?
Semilunar valves (aortic on the left and pulmonary on the right)
S/S of MI
Severe or crushing chest pain, jaw pain, back pain, left arm pain, breathlessness, hypotension, feeling of impending doom; pain usually lasts 30+ min
Which condition does the nurse know can lead to right-sided heart failure?
Severe pneumonia
Anaphylactic shock
Severe vasodilatory shock caused by an allergic reaction.
Cardiogenic shock
Shock caused by inadequate function of the heart, or pump failure.
Obstructive Shock
Shock that occurs when there is a block to blood flow in the heart or great vessels, causing an insufficient blood supply to the body's tissues.
The plaques in a client's coronary arteries are plentiful, and most have small- to moderate-sized lipid cores with thick fibrous caps. This form of atherosclerosis is most closely associated with which diagnosis?
Stable angina
What causes chronic stable angina?
Stable plaques formed by atherosclerosis
How can the health care provider determine if the client has "aerobic fitness"?
Tests help to determine aerobic fitness by measuring heart rate while under the stress of exercise.
Ejection Fraction (EF)
The percentage of blood pumped out of the ventricles of the amount that entered. Normal = 60%
Frank-Starling Law of the Heart
The stroke volume of the heart increases in response to an increase in the volume of blood filling the heart (the end diastolic volume) when all other factors remain constant
A client has been diagnosed with aortic stenosis and asks the nurse what this means. The most appropriate response would be:
The valve opening is narrowed and produces increased resistance to blood flow out of the left ventricle and into the aorta.
Regurgitation
The valve will not close all the way
Stenosis
The valve will not open all the way
Nitroglycerin
Treatment for NSTEMI and Unstable Angina
A person with blood pressure of 68/38 fainted after donating a unit of blood. The blood bank technician stated that the person was experiencing low preload from loss of blood volume. The nurse knows that preload refers to what?
Venous return to the heart
Eccentric hypertrophy
Volume overload Myocytes get longer and heart walls get thinner
Is pericarditis responsive to NSAIDS? Why?
Yes; pain is related to inflammation
Population most likely to die of hypertrophic cardiomyopathy
Young athletes
Pericardial effusion
accumulation of fluid in the pericardial cavity
Most common cause of coronary artery disease
atherosclerosis
Mitral valve prolapse occurs frequently in the population at large. Its treatment is aimed at relieving the symptoms and preventing complications of the disorder. Which drug is used in the treatment of mitral valve prolapse to relieve symptoms and aid in preventing complications?
beta-adrenergic blocking drugs (beta-blockers)
A nurse is concerned that a resident of a long-term care facility may be developing left-sided heart failure. The nurse would communicate which set of manifestations as possible evidence of left-sided heart failure?
dyspnea, cough, fatigue
Treatment for anaphylactic shock
epinephrine
Constrictive pericarditis
fibrous scar tissue forms between visceral and parietal layers of serous pericardium -interferes with diastolic filling
Pericarditis
inflammation of the pericardium
Signs of cardiac tamponade (2)
paradoxical pulses (weak pulses on inhalation and strong pulse on exhalation) and jugular distention
Assessment of an older adult client reveals bilateral pitting edema of the client's feet and ankles; difficult to palpate pedal pulses; breath sounds clear on auscultation; oxygen saturation level of 93% (0.93); and vital signs normal. What is this client's most likely health problem?
right-sided heart failure
