patho chapter 18: alterations in cardiac function

what is coronary heart disease also called?

ischemia heart disease

what can be implied by the phrase "ischemic heart disease"

disease is associated with lack of blod flow to the heart

what is the main cause of coronary heart disease?

artherosclerosis of coronary arteries

what is artherosclerosis?

formation of plaques in arteries

regarding artherosclerosis, what are plaques?

sticky substance made up of cholesterol, fat, blood cells, calcium, and other substances in the blood

when plaques build up in the arteries, what can happen?

plaque can narrow or block arteries, reducing blood flow to organs and tissues

what is coronary heart disease?

layers of fatty material (plaques) build up inside the coronary arteries, narrowing them.

besides artherosclerosis, what are two uncommon causes of coronary heart diseases?

abnormalities of blood oxygen content

poor perfusion pressure

what does artherosclerosis cause narrowing of?

the arterial lumen

true or false-artherosclerosis can lead to the formation of a thrombus

true

true or false-artherosclerosis can lead to a coronary vasospasm

true

true or false-artherosclerosis does not have an affect on endothelial cell function

false

what is the most common symptom of coronary heart disease?

angina pectoris (chest pain)

besides chest pain, what other complications are associated with coronary heart disease?

myocardial infarction

dysthythmias

heart failure

sudden cardiac death

what is a myocardial infarction?

when blood stops flowing properly to part of the heart and the heart muscle is injured due to not receiving enough oxygen

what are dysrhythmias?

abnormal heart rhythms

what is heart failure?

the inability of the heart to pump sufficient blood to meet the needs of the tissues for oxygen and nutrients

what is sudden cardiac death?

an unexpected death from cardiac causes producing an abrupt loss of cardiac output and cerebral blood flow

what are some major risk factors of coronary heart disease?

age

family history

abnormal lipid levels

cigarette smoking

hypertension

diabetes

obesity

what two critical factors in meeting cellular demands for oxygen include?

rate of coronary perfusion

myocardial workload

what is coronary perfusion?

blood supply to the left and right side coronary arteries

what are the 3 patterns of angina pectoris?wh

stable angina

vasospastic angina

acute coronary syndrome (unstable angina or MI)

regarding the 3 patterns of angina pectoris, what is the most common?

stable angina

what is stable angina characterized by?

stenotic artherosclerotic coronary vessels

how would the onset of anginal (chest) pain be described?

generally predictable and elicited by similar stimuli each time

how is stable angina relieved?

by rest and nitroglycerin

regarding the 3 patterns of angina pectoris, what is vasospastic angina also known as?

prinzmental or variant angina

true or false-vasospastic angina is associated with common chest pain and is not very severe

false, vasospastic angina is associated with rare chest pain and can be severe

how would vasospastic angina attacks be described as?

unpredictable

what are symptoms associated with vasospastic angina unrelated to?

physical or emotional exertion

what is acute coronary syndrome also known as?

unstable angina or MI

what condition might acute coronary syndrome progress to?

acute ischemia

true or false-patients presenting with acute coronary syndrome may have be asymptomatic

true

what is an occlusion?

blockage of an artery by fatty deposits

regarding unstable angina, how would the occlusion be described?

partial occlusion (not a complete blockage of the artery)

regarding a MI (myocardial infarction), how would the occlusion be described?

occlusion is complete (complete blockage of the artery)

what two features are used for diagnosis of acute coronary syndrome?

ECG and biomarkers

regarding acute coronary syndrome, what events can acute occlusion (blockage) in coronary arteries trigger?

a range of cellular events

in acute coronary syndrome, what three factors influence the extent of tissue damage caused by an acute occlusion (blockage)?

-the availability and adequacy of blood flow

-the relative workload of the myocardium

-the length of time the myocardium is deprived of oxygen

how does the availability and adequacy of blood flow affect the outcome of an acute coronary occlusion?

adequate circulation of blood flow can limit tissue damage by supplying oxygenated blood to the affected area, reducing the extent of ischemia and infarction

how does the relative workload of the myocardium influence the severity of an acute occlusion?

higher myocardial workload increases oxygen demand, worsening the impact of ischemia when blood flow is compromised during an acute occlusion.

how does the length of time that tissue is deprived of oxygen influence the severity of acute coronary syndrome?

the longer the myocardium is deprived of oxygen, the more severe the damage and the larger the infarct size, leading to a higher risk of irreversible tissue necrosis

what is an infarct?

area of tissue death (necrosis) due to inadequate blood supply, typically caused by an obstruction such as a blood clot or plaque

what determines the size of infarcted tissue in acute coronary syndrome?

duration of ischemia,

adequacy of circulation

oxygen demand of the affected myocardium

what are the 3 indicators that aid in diagnosis acute coronary syndrome?

signs and symptoms

electrocardiographic changes

elevations of specific marker proteins in the blood

what clinical manifestations are associated with acute coronary syndrome?

crushing

excruciating chest pain that may radiate to the arm, shoulder, jaw, or back

nausea/vomiting

diaphoresis (sweating)

shortness of breath

true or false-acute coronary syndrome is associated with diaphoresis and shortness of breath

true

how long does an acute coronary syndrome flare up last?

more than 15 minutes

true or false-acute coronary syndrome is relieved by rest or nitroglycerin

false; it is not relieved by rest or nitroglycerin

what is an asymptomatic/silent MI?

heart attack where the individual does not experience the typical symptoms like chest pain, but the event can still be detected through diagnostic tools such as an ECG or blood tests

what atypical symptoms of myocardial infarction are more common in women, the elderly, and patients with diabetic neuropathies?

fatigue

nausea

back pain

abdominal discomfort

why are women, the elderly, and people with diabetic neuropathies more likely to experience atypical symptoms during an MI?

these populations often have altered pain perception or other conditions that mask typical symptoms like chest pain, making diagnosis more challenging

what ECG change is commonly associated with myocardial ischemia or injury?

ST-segment elevation

large Q waves

inverted T waves

what happens to cardiac output after a myocardial infarction (MI) in acute coronary syndrome?

cardiac output decreases due to damaged heart muscle and impaired pumping ability

what compensatory response occurs in the body after an MI to counteract reduced cardiac output?

the body activates the sympathetic nervous system, which triggers compensatory mechanisms to maintain cardiac output

how does sympathetic nervous system activation affect myocardial workload following an MI?

it increases myocardial workload by raising the heart rate, contractility, and blood pressure, which can put additional stress on the damaged heart

what three key physiological changes occur due to sympathetic activation after an MI?

increase in heart rate, contractility, and blood pressure

why is it difficult to determine the overall prognosis for an acute myocardial infarction?

depends on how quickly treatment is sought, the extent and location of the infarct, cardiovascular history, the patient's age, and other disease processes

how does the timing of seeking treatment affect the prognosis of an acute myocardial infarction?

the quicker treatment is sought, the better the prognosis, as early intervention can limit the extent of heart damage

what is preload in the heart?

how much the heart muscle is stretched by blood filling it before it pumps, usually measured during diastole

what is afterload in the heart?

the pressure the heart has to push against to get blood out

(the resistance the left ventricle must overcome to pump blood into the systemic circulation)

what is the primary goal of treatment for acute coronary syndrome?

to decrease myocardial oxygen demand and increase myocardial oxygen supply

(decrease preload and afterload)

true and false-rest, heart rate control, and pain relief are important for decreasing oxygen demand on the heart in patients who have acute coronary syndrome

true

how can the myocardial oxygen supply be increased during treatment for acute coronary syndrome? ?

supplemental oxygen

antiplatelet therapy (avoids clotting)

thrombolysis

angioplasty

coronary bypass grafting (CABG)

why is rest important in managing acute coronary syndrome?

rest reduces the workload on the heart, thereby lowering oxygen demand

how does controlling heart rate help in treating acute coronary syndrome?

slowing the heart rate reduces the heart's oxygen demand and improves the efficiency of blood flow

why is pain relief a key component in the treatment of acute coronary syndrome?

pain increases sympathetic nervous system activity, raising heart rate and blood pressure, which in turn increases oxygen demand; relieving pain helps reduce this demand

why is continuous ECG monitoring important in the treatment of acute coronary syndrome?

helps in the early detection of dysrhythmias or conduction disorders, which are common complications of myocardial infarction

what is sudden cardiac arrest in coronary syndromes?

unexpected death from cardiac causes

what is the primary cause of sudden cardiac arrest?

lethal dysrhythmias (abnormal heart rhythyms)

how are patients who present sudden cardiac arrest taken care of?

immediate CPR

use of external defibrillators to restore a normal heart rhythym

what is chronic ischemic cardiomyopathy?

heart failure develops gradually due to progressive ischemic damage to the heart muscle

does chronic ischemic cardiomyopathy cause heart damage slowly or rapidly?

slowly

what are common clinical manifestations in patients with chronic ischemic cardiomyopathy?

history of angina or myocardial infarction (MI)

typically elderly

what is the prognosis for patients with chronic ischemic cardiomyopathy?

poor prognosis

(due to the progressive nature of ischemic myocardial damage leading to heart failure)

what 3 factors can damage endocardial and valvular structures, causing altered hemodynamics and increasing myocardial workload?

inflammation and scarring

calcification

congenital malformations

wow does inflammation affect the endocardial and valvular structures of the heart?

inflammation can lead to scarring, which damages the valves and affects their ability to open and close properly.

what is the impact of calcification on heart valves?

calcification makes the valves stiff and less flexible, which impairs their function

what are congenital malformations of the heart valves

structural abnormalities present at birth that can affect how the valves develop and function

what is stenosis?

failure of the valve to open completely

what does stenosis result in?

extra pressure work for the heart

what is regurgitation (insufficiency)?

inability of a valve to close completely results in extra volume work for the heart (back flow)

what are murmurs?

abnormal heart sounds

what are murmurs associated with?

abnormal turbulence of blood flow

true or false-murmurs are common with vascular disorders

true

what is mitral stenosis?

condition where the mitral (bicuspid)valve is narrowed, impairing blood flow from the left atrium to the left ventricle

how does mitral stenosis affect the left atrium?

causes increased pressure in the left atrium, leading to atrial chamber enlargement and hypertrophy

why does mitral stenosis cause increased pressure in the left atrium?

since blood has such a hard time going into the ventricles due to a narrowing in the valve, the pressure builds up in the atrium

what are the potential complications of untreated mitral stenosis?

chronic pulmonary hypertension

right ventricular hypertrophy

right-sided heart failure

what is the most common symptom of mitral stenosis?

exertional dyspnea

(difficulty breathing during exertion)

what physical changes occur in the left atrium due to mitral stenosis?

the left atrium enlarges and hypertrophies

(due to increased pressure from the obstructed blood flow)

what is mitral regurgitation?

backflow of blood from the left ventricle to the left atrium

(less blood is being pumped to the circulation since it's going back to the atrium instead of out the aorta into the blood stream)

what happens to the left atrium and left ventricle in mitral regurgitation?

they both dilate and hypertrophy as they accommodate the increased volume of blood

true or false-mitral regurgitation is associated with left-sided heart failure

true

what are some common clinical manifestations of mitral regurgitation?

chronic weakness and fatigue

what is a mitral valve prolapse?

displacement (ballooning) of the mitral valve leaflets into the left atrium

are women or men more affected by mitral valve prolapse?

women

are mitral valve prolapses usually symptomatic or asymptomatic?

asymptomatic

how are mitral valve prolapses detected?

by midstystolic click or systolic murmur

what are the clincial manifestations of a mitral valve prolapse?

palpations

rhythm abnormalities

dizziness

fatigue

dyspnea

chest pain

depression

anxiety