Myocardial Function and Heart Disease Quiz

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Questions and Answers

What is the primary function of the myocardium?

To pump blood throughout the body (correct)

To regulate heart rate

To generate electrical impulses

To provide structural support for the heart

Which of the following is NOT a modifiable risk factor for coronary artery disease (CAD)?

High cholesterol levels

Smoking

High blood pressure

Family history of heart disease (correct)

Which process involves the growth of new capillaries within a tissue?

Collateral circulation

Angiogenesis (correct)

Atherosclerosis

Arteriogenesis

A blockage in which coronary artery would most likely affect both the left and right sides of the heart?

Right coronary artery (B) Signup and view all the answers

Which of the following is a characteristic of atherosclerosis progression?

Breakdown of plaque and release of inflammatory mediators (A) Signup and view all the answers

What happens to the heart muscle cells after 20 minutes of ischemia?

They begin to die (necrosis). (B) Signup and view all the answers

Which of the following is NOT a cardiac-specific serum biomarker?

Lactate dehydrogenase (LDH) (A) Signup and view all the answers

What causes the pain associated with a myocardial infarction?

Lack of oxygen to the heart muscle. (A) Signup and view all the answers

Which of the following is NOT a complication of a myocardial infarction?

Pulmonary embolism (A) Signup and view all the answers

What is the primary difference between unstable angina and a non-ST-segment elevation myocardial infarction (NSTEMI)?

Unstable angina does not cause permanent damage to the heart muscle, while NSTEMI does. (C) Signup and view all the answers

Which type of ECG change is indicative of a STEMI?

ST-segment elevation (C) Signup and view all the answers

What is the significance of reperfusion injury?

It can worsen the damage caused by the initial infarction. (B) Signup and view all the answers

Which of these is a possible cause of all the serum biomarkers mentioned in content?

Tissue damage (B) Signup and view all the answers

What is the primary cause of heart failure (HF)?

The heart is unable to pump enough blood to meet the body's metabolic needs. (A) Signup and view all the answers

Which of the following is NOT a common cause of heart failure?

Hypothyroidism (B) Signup and view all the answers

What is the difference between systolic heart failure (HFrEF) and diastolic heart failure (HFpEF)?

HFrEF involves a problem with the heart's ability to contract, while HFpEF involves a problem with the heart's ability to relax and fill with blood. (B) Signup and view all the answers

What is the role of natriuretic peptides (NPs) in the body, specifically in the context of heart failure?

NPs are released to counteract the negative effects of RAAS and SNS activation, improving heart function. (B) Signup and view all the answers

What is the mechanism behind the Frank-Starling law of the heart?

The heart muscle is stretched more with increased preload, resulting in stronger contractions and increased cardiac output. (D) Signup and view all the answers

Which type of cardiomyopathy is characterized by an enlarged heart chamber and weakened contractility?

Dilated cardiomyopathy (A) Signup and view all the answers

What is the most likely cause of hypertrophic cardiomyopathy?

High blood pressure (B) Signup and view all the answers

Which of the following is a common symptom of left-sided heart failure?

Dyspnea (shortness of breath) (D) Signup and view all the answers

What is the primary difference between premature ventricular contractions (PVCs) and ventricular tachycardia?

PVCs are usually harmless, while ventricular tachycardia can be life-threatening. (B) Signup and view all the answers

What is the primary goal of treatment for heart failure?

To reduce the symptoms and improve the patient's quality of life. (C) Signup and view all the answers

Which of the following is a compensatory mechanism that the body uses to try to maintain cardiac output in heart failure?

Activation of the renin-angiotensin-aldosterone system (RAAS) (A) Signup and view all the answers

Which of the following is a common complication of deep vein thrombosis (DVT)?

Pulmonary embolism (PE) (A) Signup and view all the answers

Which type of dysrhythmia is considered cardiac arrest?

Ventricular fibrillation (B) Signup and view all the answers

Which of the following is NOT a common clinical manifestation of right-sided heart failure?

Dyspnea (shortness of breath) (C) Signup and view all the answers

What is the role of catecholamines in the compensatory mechanisms of heart failure?

Catecholamines increase heart rate and contractility, helping to maintain blood flow. (A) Signup and view all the answers

What is the main effect of β1-Adrenergic Receptor Blockers like Metoprolol?

Decreasing blood pressure (A) Signup and view all the answers

Which statement correctly describes a potential adverse effect of ACE inhibitors?

Cough (C) Signup and view all the answers

What is the role of neprilysin inhibitors like Sacubitril/Valsartan?

Reduce blood pressure (C) Signup and view all the answers

Which of the following drugs acts as a cardiac glycoside?

Digoxin (B) Signup and view all the answers

What is a key monitoring consideration for patients taking potassium-sparing diuretics with ACE inhibitors?

Monitor for hyperkalemia (B) Signup and view all the answers

Which medication classification does Clopidogrel belong to?

Antiplatelets (C) Signup and view all the answers

What is the main function of thrombolytic agents like tissue plasminogen activator (tPA)?

Dissolve existing clots (A) Signup and view all the answers

What therapeutic effect do cyclooxygenase (COX) inhibitors such as Acetylsalicylic Acid primarily provide?

Reduce inflammation (D) Signup and view all the answers

Which of the following medications is used as an antidote for heparin therapy?

Protamine sulfate (D) Signup and view all the answers

What is a desired effect of using Digoxin in patients?

Enhanced cardiac contractility (C) Signup and view all the answers

What is one of the primary goals in the pharmacological treatment of acute myocardial infarction (MI)?

Reduce post-MI mortality (B) Signup and view all the answers

Which mechanism is primarily targeted in the treatment of heart failure (HF)?

Reduction of preload (A) Signup and view all the answers

How does morphine affect preload and afterload in a clinical context?

It reduces preload and afterload (B) Signup and view all the answers

What is a contraindication for administering nitroglycerin?

Hypotension (A) Signup and view all the answers

What is a desired effect of calcium channel blockers like diltiazem?

Peripheral vasodilation (B) Signup and view all the answers

What nursing implication is crucial for the administration of nitroglycerin paste?

Use gloves to prevent self-administration (B) Signup and view all the answers

What is the pharmacological role of opioids like morphine during an acute MI?

To provide analgesia and reduce anxiety (A) Signup and view all the answers

What is a primary goal of pharmacotherapy in managing heart failure regarding systemic vascular resistance (SVR)?

Reduce SVR (D) Signup and view all the answers

Which of the following drugs is classified as a vasodilator?

Nitroglycerin (B) Signup and view all the answers

What is a common adverse effect associated with the use of opioids like morphine?

Respiratory depression (B) Signup and view all the answers

What is the desired effect of administering a thrombolytic drug such as alteplase?

To dissolve existing blood clots and improve blood flow (C) Signup and view all the answers

Which of the following is a contraindication to the administration of thrombolytics?

History of stroke within the past 3 months (A) Signup and view all the answers

Which of the following is a common adverse effect associated with the use of heparin?

Bleeding (B) Signup and view all the answers

What is the antidote for heparin overdose?

Protamine sulfate (C) Signup and view all the answers

Which of the following statements is TRUE regarding warfarin?

Warfarin works by blocking the synthesis of vitamin K-dependent clotting factors. (C) Signup and view all the answers

Which of the following medications can interact with warfarin, potentially increasing the risk of bleeding?

Ibuprofen (Advil) (C) Signup and view all the answers

Which of the following is a low-molecular-weight heparin (LMWH)?

Enoxaparin (B) Signup and view all the answers

Which of the following diuretics is classified as a potassium-sparing diuretic?

Spironolactone (C) Signup and view all the answers

Which of the following is a common adverse effect of furosemide, a loop diuretic?

Hypokalemia (D) Signup and view all the answers

What is the mechanism of action of thiazide diuretics like hydrochlorothiazide?

Blocking the reabsorption of sodium chloride in the distal convoluted tubule (C) Signup and view all the answers

Study Notes

Cardiac Anatomy & Physiology

The heart wall has three layers: epicardium, myocardium, and endocardium.
The myocardium is the thickest layer and responsible for contraction.
Cardiomyocytes provide the contractile force.
Coronary arteries and veins are located between the myocardial layers.
The right coronary artery (RCA) supplies the backside of the left ventricle and the right side of the heart.
The left coronary artery (LCA) supplies the left side of the heart.
Coronary arteries supply blood to different areas of the heart.
Occlusion of either the RCA or LCA can cause left ventricular damage.

Coronary Circulation

The RCA feeds the backside of the LV and right side of the heart.
The LCA feeds the left side of the heart.
Coronary arteries supply blood to different areas of the heart.
Occlusion of either the right or left coronary artery can cause LV damage.
RCA occlusion damages the SA node, which affects the electric pulse to the LCA.

Collateral Circulation

Collateral vessels form through arteriogenesis and angiogenesis.
Collateral circulation helps supply blood to areas with decreased blood supply due to CAD.
Collateral circulation develops alongside atherosclerosis.
Symptoms of CAD do not appear until the disease is advanced.

Normal Electrocardiogram (ECG) & Cardiac Electrical Activity

The ECG measures electrical activity of the heart.
Depolarization and repolarization are represented in the ECG.
Atrial depolarization is represented by a P wave.
Ventricular depolarization is represented by a QRS complex.
Ventricular repolarization is represented by a T wave.

Progression of Atherosclerosis

Endothelial injury initiates atherosclerosis.
Inflammation of the endothelium is a key aspect.
Cytokines are released.
Cellular proliferation occurs.
Macrophages migrate.
LDL oxidation occurs, forming foam cells with oxidative stress.
Fatty streaks, fibrous plaques and complicated plaques develop.
Result is partial or total occlusion of coronary arteries.

Atherosclerosis & Coronary Artery Disease (CAD)

Atherosclerosis is the most common cause of CAD.
CAD narrows or occludes coronary arteries.
Dyslipidemia (abnormal lipoproteins) is strongly linked to CAD.
Imbalance between coronary blood supply and myocardial demand can cause myocardial ischemia.
Myocardial ischemia can cause irreversible infarction.

Modifiable Risk Factors for CAD

Maintaining normal blood pressure is crucial.
Smoking cessation is recommended.
Limiting alcohol consumption, maintaining a healthy weight, and adhering to a nutritious diet are also beneficial.
Regular exercise is an important factor in preventing CAD.

Nontraditional Risk Factors for CAD

Markers of inflammation,ischemia, and thrombosis (like CRP).
Adipokines (like adiponectin and leptin).
Chronic kidney disease.
Air pollution and ionizing radiation.
Certain medications.
Coronary artery calcification and carotid wall thickness.
Microbiome
Chronic kidney disease
C-reactive protein

Pathophysiology Continuum of CAD

CAD: transient ischemia, persistent ischemia, myocardial infarction (MI)
Stable angina: predictable, intermittent chest pain, not at rest.
Acute coronary syndrome (ACS): unpredictable, often at rest. Includes unstable angina, non-ST-segment elevation myocardial infarction (NSTEMI), and ST-segment elevation myocardial infarction (STEMI).
Unstable angina: pain with increasing frequency, occurs during rest or minimal exertion.
Myocardial infarction (MI): irreversible, sustained myocardial ischemia.

Stable Plaque Versus Unstable Plaque

Stable plaques have a stable, fibrous cap, while unstable plaques have a large lipid core and a thin, vulnerable fibrous cap.
Unstable plaques are more likely to rupture and cause thrombosis.

Pathophysiology of Acute Coronary Syndromes (ACSs)

Plaque progression, disruption, and subsequent clot formation are common in ACS.
Unstable angina (UA): transient episodes of thrombotic vessel occlusion.
Myocardial infarction (MI): irreversible cardiac cellular death. (NSTEMI and STEMI)

Oxygen Supply & Demand

Oxygen supply depends on blood flow to the myocardium, affected by CAD and atherosclerosis.
Oxygen demand depends on sympathetic activity, physical activity, etc.

Cycle of Myocardial Ischemic Events

Sudden events & heart failure can result from imbalances between coronary supply and myocardial demand.
Dysrhythmias are caused by abnormal electrical impulses. Greater than 20 minutes of myocardial ischemia is likely a myocardial infarction (MI).

Pathogenesis of Unstable Plaque

Shear forces, inflammation, apoptosis and macrophage-derived enzymes may increase inflammation.
Increased inflammation can lead to the rupture of the fibrous cap, which initiates thrombosis

Evaluation and Treatment of Unstable Angina

Evaluation: Serum biomarkers (troponin, CPK-MB) and ECG are important diagnostic tools.
Treatment: Immediate hospitalization, administration of nitrates, antithrombotics, and anticoagulants.
PCI is crucial if conditions do not improve.

Myocardial Infarction (MI)

Irreversible damage to the heart muscle due to prolonged ischemia.
Subendocardial MI results from transient or incomplete coronary occlusion.
Transmural MI results from prolonged and/or complete occlusion.

What Causes Cellular Injury in MI?

Inadequate O2 and nutrients deplete energy reserves in minutes.
Anaerobic metabolism produces lactic acid, leading to cellular acidosis.

Cellular Death in MI

After about 20 minutes, irreversible hypoxic injury causes cellular death and tissue necrosis.
Enzymes like troponin are released into the bloodstream, enabling diagnosis of MI.

Structural and Functional Changes in Acute MI

Myocardial stunning: temporary loss of contractile function.
Hibernating myocytes: adapt to prolonged ischemia through metabolic adaptation for survival.
Myocardial remodeling occurs in the myocardium after MI.
Infarcted myocardium is surrounded by a zone of hypoxic injury.

Diagnostic Tools for MI

ECG: Changes can indicate location, extent (partial/subendocardial, vs entire wall thickness/transmural).
Serum Biomarkers (Cardiac troponin, CPK-MB, LDH) indicate MI or cardiac damage.

Cardiac Specific Serum Biomarkers

Cardiac biomarkers are released when myocardial cells die.
Troponin and CPK-MB are commonly checked as serum biomarkers of myocardial cells damage.

Non-Cardiac Specific Serum Biomarkers

Lactate dehydrogenase (LDH): an enzyme found in many body tissues, including the heart.
Myoglobin: present in cardiac and skeletal muscles; quickly released when myocardial damage occurs.

Additional Labs in MI

Leukocytosis: an elevation in white blood cell count.
Elevated CRP: indicates inflammation
Hyperglycemia: evident during early phase after AMI.

Symptoms/Assessment of MI

Sudden severe chest pain that can radiate, often described as heavy or crushing.
Pain can be located in the neck, jaw, shoulder, or left arm.

Atypical Symptoms of MI

Atypical symptoms differ from the typical chest pain in some cases, such as in women or people with diabetes.
Severe chest pain is not always present.
Hypotension can accompany severe myocardial damage.

Treatments for MI

Bed rest: Reduce cardiac workload
Morphine: pain relief, vasodilator, reduce cardiac workload
Stools softeners: reduce exerting activities/increasing cardiac workload
Non-pharmacological (PCI or CABG)

Coronary Artery Disease (CAD)

CAD is a process that occurs over a long time, often involves buildup of plaque in the walls of coronary arteries.
Plaques are composed of lipids, cholesterol, inflammatory cells, and connective tissue.
Plaques can rupture creating thrombi.
Thrombi can block blood flow.

Relationship between CAD, ACS, and Heart Failure (HF)

CAD can lead to the development of ACS and/or HF
Risk factors, like diabetes, HTN, smoking, and obesity, play a role in all three conditions.
Understanding how they are related is crucial for risk assessment, prevention, and treatment of all three diseases.

Pharmacotherapy for CAD, ACS, HF

Drugs like aspirin, beta blockers, and ACE inhibitors are commonly used to treat or prevent CAD/ACS/HF.
Nitroglycerin is used for chest pain (angina) treatment.
Anticoagulants/antithrombotics are used to prevent blood clot formation.
Pharmacotherapy for CAD, ACS, and HF is designed to reduce cardiac workload, and/or improve oxygen supply, and reduce afterload and preload.

Pharmacotherapy: Coagulation Modifiers

Antiplatelets (aspirin, clopidogrel) reduce platelet aggregation.
Anticoagulants (heparin, warfarin) prevent clot formation.
Thrombolytics (tPA) dissolve existing clots.
Administration and monitoring for adverse effects are crucial when using these medication types.

Pharmacotherapy Classifications and Uses

Many medications and classes of medications are used to treat these conditions
Opioids: pain relief
Calcium channel blockers for vessel dilation
ẞ₁-adrenergic receptor blockers slow heart rate
ACE inhibitors reduce afterload
Mineralocorticoid receptor antagonists improve sodium and water excretion
Loop diuretics: treat edema
Thiazide diuretics: treat hypertension
Cardiac glycosides: treat heart failure
Antidysrhythmics: maintain a normal heart rhythm

Antidotes for specific classes of anticoagulants

protamine sulfate for heparin
Vitamin K for warfarin

Nursing Implications for specific classes of drugs

Monitor vital signs and look for signs of adverse effects

Pathophysiology of Heart Failure

Heart failure involves a condition when the heart cannot pump enough blood to meet the body's needs.
There are two main types of heart failure (systolic and diastolic).
Systolic HF involves a problem with the contraction of the heart.
Diastolic HF involves a problem with the relaxation phase of the heart.
Pathophysiology of heart failure describes the disease processes leading to the various problems.
Compensatory mechanisms are activated to address the reduced output, but they ultimately lead to more damage.

Assessment & Monitoring for HF

Physical examination for signs of fluid overload (edema, JVD)
Auscultation for murmurs or abnormal sounds
ECG
Chest X-ray (CXR)
Echocardiography (important for EF and ejection fraction)
Serum troponin (and CPK-MB) to monitor for myocardial injury
Serum BNP for assessment of fluid volume status
Complete blood count (CBC) to rule out anemia or infection

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Description

Test your knowledge on the myocardium's functions, risk factors for coronary artery disease, and the nuances of myocardial infarction. This quiz covers essential concepts related to heart health, including atherosclerosis and ECG changes. Perfect for those studying cardiology or health sciences.