Lecture 10.1 - Pathophysiology of heart failure

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Questions and Answers

What is the primary characteristic of systolic heart failure?

Increased ejection fraction with reduced contractility

Increased afterload with preserved ejection fraction

Reduced stroke volume due to reduced contractility (correct)

Reduced ejection fraction with preserved contractility

What is a common underlying condition that leads to right-sided heart failure?

Dilated cardiomyopathy

Constrictive pericarditis

Pulmonary valve/tricuspid valve regurgitation (correct)

Mitral regurgitation

What is a key feature of high output heart failure?

Reduced ejection fraction

High cardiac output >8L/min (correct)

Increased afterload

Low cardiac output <5L/min

What is the primary difference between systolic and diastolic heart failure?

Systolic HF has reduced ejection fraction, while diastolic HF has preserved ejection fraction Signup and view all the answers

What is a common consequence of ventricular remodeling in heart failure?

Progressive ventricular dilatation or eccentric hypertrophy Signup and view all the answers

What is the normal range of ejection fraction?

55-70% Signup and view all the answers

What is a characteristic of diastolic heart failure?

Preserved ejection fraction with increased stiffness of ventricular walls Signup and view all the answers

What is the primary mechanism underlying right-sided heart failure?

Reduced contractility Signup and view all the answers

In a failing myocardium, which of the following statements is true regarding the Frank-Starling mechanism?

Beyond the physical limit, further increases in preload have a negative effect on stroke volume. Signup and view all the answers

Which of the following types of heart failure is characterized by a rapid onset of symptoms and/or signs of heart failure?

Acute heart failure Signup and view all the answers

What is the term for the complex clinical syndrome resulting from any structural and/or functional impairment of ventricular filling or ejection?

Heart failure Signup and view all the answers

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

Chronic cardiomyopathy Signup and view all the answers

What is the term for the process by which the ventricles are reshaped in response to injury or disease?

Ventricular remodelling Signup and view all the answers

Which type of heart failure is characterized by impaired ventricular relaxation and filling?

Diastolic heart failure Signup and view all the answers

What is the primary mechanism by which the renin-angiotensin-aldosterone system contributes to worsening heart failure?

Increased sodium retention leading to increased water retention and circulating volume Signup and view all the answers

Which of the following is a common cause of right-sided heart failure?

Respiratory disease Signup and view all the answers

What is the term for the combination of signs and symptoms of both left-sided and right-sided heart failure?

Congestive heart failure Signup and view all the answers

Which of the following is NOT a sign of left-sided heart failure?

Jugular venous distension Signup and view all the answers

What is the term for the increase in heart size and thickness in response to chronic overload?

Ventricular remodelling Signup and view all the answers

Which of the following is a cause of high-output heart failure?

AV fistula Signup and view all the answers

What is the term for the decreased ability of the heart to relax and fill with blood during diastole?

Diastolic heart failure Signup and view all the answers

Which of the following is a sign of right-sided heart failure?

Jugular venous distension Signup and view all the answers

What is the term for the inability of the heart to pump enough blood to meet the body's needs?

Systolic heart failure Signup and view all the answers

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

Dyspnoea Signup and view all the answers

Study Notes

Heart Failure

Characterised by progressive symptoms with episodes of acute deterioration
Classified into systolic (HFrEF) or diastolic (HFpEF) heart failure

Ejection Fraction

Stroke volume: 70ml
End-diastolic volume (EDV): 110ml
Ejection fraction: 64% (normal: 55-70%)

Systolic Heart Failure (HFrEF)

Heart cannot pump enough blood
Systolic dysfunction
Reduced stroke volume due to reduced contractility
Examples: MI, dilated cardiomyopathy
Reduced ejection fraction
Progressive ventricular dilatation or eccentric hypertrophy

Diastolic Heart Failure (HFpEF)

Reduced filling of the heart
Diastolic dysfunction
Preserved ejection fraction
Associated with concentric hypertrophy
Increased stiffness of ventricular walls
Increased afterload
Reduced preload: MI, constrictive pericarditis, cardiac tamponade

Ventricular Remodelling

Occurs in both systolic and diastolic heart failure

Right-Sided Heart Failure

Reduced contractility: MI
Increased afterload
Increased preload: pulmonary valve/tricuspid valve regurgitation
Often develops from left-sided heart failure

High Output vs Low Output Heart Failure

High output HF: high CO >8L/min, but heart unable to meet increased demand despite normal cardiac function
Frank-Starling mechanism: increased venous return increases stroke volume via increased contractile strength of the left ventricle
Failing myocardium: beyond a limit, further increases in preload have a negative effect on stroke volume

Acute vs Chronic Heart Failure

Acute heart failure: rapid onset of symptoms, requires urgent evaluation and treatment
Chronic heart failure: progressive cardiac dysfunction from structural and/or functional cardiac abnormalities

Pathophysiology of Heart Failure

Decreased CO causes decreased BP
Reduced BP stimulates sympathetic drive, leading to increased heart rate and peripheral resistance
Activation of the renin-angiotensin-aldosterone system, causing sodium retention, water retention, and vasoconstriction

Signs and Symptoms - Left-Sided Heart Failure

Pulmonary congestion and oedema
Decreased ventilation and hypoxia
Reduced CO and BP, compensated by increased TPR
Organ malperfusion can affect brain, heart, kidney, and intestine
Symptoms: dyspnoea, cough, orthopnoea, paroxysmal nocturnal dyspnoea
Signs: crackles/rales on auscultation, tachycardia, cardiomegaly, 3rd and 4th heart sounds

Signs and Symptoms - Right-Sided Heart Failure

Increased pressure in pulmonary veins, making it difficult for RV to pump through pulmonary circulation
Causes difficulty breathing, swelling, and chest discomfort
Symptoms: dyspnoea, chest discomfort, swelling
Signs: jugular venous distension, hepatic congestion, peripheral oedema, ascites

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Description

This quiz covers the characteristics and types of heart failure, including atrial fibrillation and ejection fraction. Learn about systolic and diastolic heart failure and how ejection fraction is calculated.