Chapter 17_1 flashcards

Question 1

Heart Failure (HF): General Definition

Answer 1

A syndrome characterized by elevated cardiac filling pressure and/or inadequate peripheral oxygen delivery, at rest or during stress, caused by cardiac dysfunction where the ventricular muscle is unable to pump sufficient blood to meet the circulatory and oxygen needs of the tissues.

Question 2

Left Ventricular Ejection Fraction (LVEF): Definition & Normal Range

Answer 2

The percentage of blood propelled out of the left ventricle with each contraction. Normal: 50%-70%.

Question 3

Heart Failure Classifications by LVEF

Answer 3

Heart Failure with Reduced Ejection Fraction (HFrEF): LVEF <= 40%. Heart Failure with Preserved Ejection Fraction (HFpEF): LVEF >= 50%. Heart Failure with Mildly Reduced Ejection Fraction (HFmrEF): LVEF 41%-49%.

Question 4

Heart Failure vs. Cardiac Arrest

Answer 4

Heart Failure: Heart continues to pump but inadequately. Cardiac Arrest: Cessation of all heart activity.

Question 5

Epidemiology of Heart Failure in U.S.

Answer 5

Affects ~6.2 million Americans, most common cause of hospitalization for those >65 years. Lifetime risk ~20% for those >40 years. Higher prevalence and earlier onset in African Americans.

Question 6

Major Risk Factors for Heart Failure (General List)

Answer 6

Hypertension (greatest risk factor), Myocardial Infarction (MI), Coronary Artery Disease (CAD), Metabolic Syndrome, Diabetes Mellitus, Age, Ethnicity, Family History, Obesity, Sleep Apnea, Lifestyle (smoking, sedentary).

Question 7

Cardiac Output (CO): Definition & Formula

Answer 7

Amount of blood pumped by the LV per minute. CO = Heart Rate (HR) x Stroke Volume (SV). Approximately 5 L/min at rest.

Question 8

Preload: Definition & Effect on Stroke Volume

Answer 8

Volume of blood in the heart at the end of diastole (End-Diastolic Volume - EDV); essentially the volume entering the right atrium. Increased preload (to a point) increases Stroke Volume (SV) in a healthy heart.

Question 9

Afterload: Definition & Effect on Cardiac Output

Answer 9

Resistance the ventricle must overcome to pump blood out. Increased afterload (e.g., high aortic pressure/systemic HTN for LV) reduces cardiac output as it increases the heart’s workload.

Question 10

Cardiac Contractility (Inotropy): Definition & Influencing Factors

Answer 10

Myocardium’s ability to stretch and contract. Influenced by preload (Frank-Starling Law), afterload (high afterload reduces contractility), autonomic nervous system (SNS increases), Ca++ availability.

Question 11

Frank-Starling Law (Box 17-3)

Answer 11

Describes how the ventricle adjusts pumping force to accommodate preload/afterload. Increased preload stretches myocardial fibers, increasing contractility and SV in a healthy heart (up to 2.5x resting length). In a failing heart, excessive preload overtaxes weakened fibers, decreasing contractility and SV. [Text]

Question 12

Inotropic vs. Chronotropic vs. Dromotropic Effects on Heart

Answer 12

Inotropic: Force of contraction (e.g., positive inotrope Digitalis increases force). Chronotropic: Heart rate (e.g., negative chronotrope Digitalis decreases HR). Dromotropic: Conduction velocity of impulse through AV node (e.g., positive dromotrope SNS increases velocity).

Question 13

Starling Capillary Forces & Edema Formation

Answer 13

Two opposing forces at capillary beds: Hydrostatic pressure (pushes fluid out of capillary) and Oncotic/Osmotic pressure (pulls fluid into capillary, mainly by albumin). Imbalance (e.g., high hydrostatic or low oncotic) leads to fluid in interstitial/intracellular spaces (edema).

Question 14

Cardiovascular Regulatory Mechanisms: RAAS - General Role in HF

Answer 14

Renin-Angiotensin-Aldosterone System. Triggered by low renal perfusion (due to failing heart). Leads to vasoconstriction (Angiotensin II) and Na+/water retention (Aldosterone), increasing blood volume and BP, which further strains the weak heart.

Question 15

Cardiovascular Regulatory Mechanisms: Natriuretic Peptides (ANP & BNP)

Answer 15

ANP (Atrial Natriuretic Peptide): From atria when stretched by high volume. BNP (Brain/B-type Natriuretic Peptide): From ventricles when overstretched by high volume. Both promote natriuresis (Na+ and water excretion) to reduce blood volume. BNP is a key lab marker for HF.

Question 16

Pathological Changes Leading to Heart Failure (General List)

Answer 16

1. Increased fluid volume or volume overload. 2. Impaired ventricular filling. 3. Degeneration of ventricular muscle. 4. Decreased ventricular contractile function.

Question 17

Heart Failure Classifications: Systolic vs. Diastolic Dysfunction

Answer 17

Systolic Dysfunction (HFrEF): Weakened ventricle has difficulty EJECTING blood. Diastolic Dysfunction (HFpEF): Stiff ventricle has difficulty RELAXING and FILLING adequately.

Question 18

Heart Failure Classifications: Right-sided vs. Left-sided

Answer 18

Failure of one side of the heart eventually affects the other. Most common way to classify. Each side has distinct forward and backward failure effects.

Question 19

Forward Effects of Heart Failure (General)

Answer 19

Due to decreased cardiac output leading to decreased pressure and perfusion of vital organs (brain, kidneys, etc.).

Question 20

Backward Effects of Heart Failure (General)

Answer 20

Due to backup of hydrostatic pressure because the failing ventricle cannot eject blood effectively, leading to congestion in the circulation behind that ventricle.

Question 21

Framingham Criteria for Diagnosis of Congestive Heart Failure (General)

Answer 21

A set of major and minor clinical criteria used to establish a diagnosis of HF (requires at least 1 major and 2 minor criteria).

Question 22

Treatment of Heart Failure: General Goals & Approaches

Answer 22

Lifestyle modifications (diet, exercise, smoking cessation). Pharmacological agents (diuretics, ACE inhibitors, ARBs, beta-blockers, inotropes). Devices (pacemakers, LVADs) and cardiac transplantation for severe cases.

Question 23

Key Term: Ascites

Answer 23

Abnormal accumulation of fluid in the peritoneal cavity, often due to increased hydrostatic pressure from venous congestion in right-sided heart failure.

Question 24

Key Term: Cardiac Contractility

Answer 24

The myocardium’s ability to stretch and contract in response to the filling of the heart with blood; the force of contraction.

Question 25

Key Term: Cardiomyopathy

Answer 25

Disease that targets the heart muscle itself, causing hypertrophy, dilation, or rigidity of the myocardium.

Question 26

Key Term: Central Venous Pressure (CVP)

Answer 26

Pressure in the vena cava or right atrium; reflects right ventricular preload. Elevated with right-sided heart failure. Normal: 1-5 mm Hg.

Question 27

Key Term: Chronotropic Function

Answer 27

Refers to influences on heart rate. Positive chronotropes increase HR; negative chronotropes decrease HR.

Question 28

Key Term: Dromotropic Function

Answer 28

Refers to influences on the conduction speed of the electrical impulse through the AV node. Positive dromotropes increase conduction velocity.

Question 29

Key Term: Hydrostatic Pressure (Capillary)

Answer 29

The pushing force exerted by water in the bloodstream through capillary pores into the ISF and ICF.

Question 30

Key Term: Inotropic Function

Answer 30

Refers to the force of contraction of the cardiac muscle. Positive inotropes increase contractility; negative inotropes decrease it.

Question 31

Key Term: Jugular Venous Distention (JVD)

Answer 31

Visible bulging of the jugular veins in the neck; a classic sign of increased central venous pressure due to backward effects of right ventricular failure.

Question 32

Key Term: Orthopnea

Answer 32

Difficulty breathing when lying flat; a common symptom of left ventricular failure due to pulmonary fluid accumulation.

Question 33

Key Term: Paroxysmal Nocturnal Dyspnea (PND)

Answer 33

Sudden shortness of breath that occurs in the middle of the night, disrupting sleep; caused by fluid accumulation in the lungs when supine in LVF.

Question 34

Key Term: Pulmonary Capillary Wedge Pressure (PCWP)

Answer 34

Pressure measured in the pulmonary capillary bed (reflects left atrial pressure); elevated with left-sided heart failure. Normal: 12-15 mm Hg.

Question 35

Key Term: Pulmonary Edema

Answer 35

Accumulation of fluid in the pulmonary interstitial spaces and alveoli, hindering oxygen diffusion; often caused by backward effects of LVF.

Question 36

Key Term: Neprilysin

Answer 36

An enzyme that breaks down natriuretic peptides (ANP and BNP). Neprilysin inhibitors are used in HF to allow ANP/BNP to exert their diuretic effects longer.