Left Sided Heart Failure

Slide 1 · Left-Sided Heart Failure

Mechanisms, cardiac and pulmonary morphology, clinical correlations

Dr Abu Suraih Sakhri

MBBS, MD (Pathology)

www.abusuraihsakhri.com

Slide 2 · Learning objectives

Etiology

Distinguish ischemic, pressure, valvular, and intrinsic myocardial substrates.

Mechanisms

Relate abnormal contraction or filling to pulmonary congestion and low output.

Morphology

Explain ventricular, atrial, interstitial pulmonary and alveolar alterations.

Clinical correlation

Connect symptoms, investigations and organ dysfunction to pathogenesis.

Slide 3 · Heart failure: A functional definition

The heart cannot provide enough perfusion to meet peripheral metabolic requirements.

Inadequate forward flow is commonly accompanied by venous congestion.

Clinical dysfunction may arise from impaired ejection, impaired filling, or both.

The anatomic appearance alone does not establish functional severity.

Slide 4 · Three connected consequences of left heart failure

Pulmonary backpressure

Passive congestion and edema

Intracardiac stasis

Atrial enlargement, fibrillation and thrombus

Low forward perfusion

Renal and cerebral dysfunction

Parallel consequences of impaired left ventricular function

Schematic

Slide 5 · Four major etiologic groups

Ischemic heart disease

Infarction or ischemic myocardial damage undermines pump performance.

Systemic hypertension

Sustained pressure load induces hypertrophy and later dysfunction.

Aortic / mitral valve disease

Stenosis or regurgitation changes loading and chamber structure.

Primary myocardial disease

Intrinsic cardiomyopathic or infiltrative processes can impair contraction or filling.

Slide 6 · Ischemic heart disease: Loss of effective myocardium

Myocardial infarction removes contractile myocardium and produces regional dysfunction.

Surviving myocardium carries greater mechanical work and undergoes compensatory hypertrophy.

Chronic ischemic injury may coexist with fibrosis and impaired ventricular relaxation.

Gross findings vary with infarct distribution and the surviving myocardial substrate.

Slide 7 · Systemic hypertension: Pressure loading of the LV

Elevated arterial load

Higher ventricular work

Parallel sarcomeres

Concentric hypertrophy

Interstitial fibrosis

Reduced compliance

Failure

Diastolic ± systolic impairment

Schematic

Slide 8 · Valvular disease imposes distinct loading patterns

Predominantly pressure overload

Aortic stenosis increases outflow resistance.

Parallel sarcomere addition expands myocyte cross-section.

Wall thickening initially compensates for the high systolic workload.

Predominantly volume overload

Aortic or mitral regurgitation increases chamber volume load.

Serial sarcomere addition favors ventricular enlargement.

Progressive dilation can coexist with greater total myocardial mass.

Slide 9 · Intrinsic myocardial disease can impair either phase

Primary myocardial pathology is a major Robbins etiologic category.

Contractile derangement can produce systolic pump failure.

Fibrosis and infiltrative disease can produce a stiff, poorly relaxing ventricle.

Restrictive cardiomyopathy may present without the usual dilated or hypertrophied LV pattern.

Slide 10 · Etiology and dominant mechanical consequence

Substrate

Initial mechanical disturbance

Possible phenotype

IHD / infarction

Loss of functioning myocardium

Reduced ejection; Remodeling

Systemic hypertension

Pressure overload

Hypertrophy; Stiffness

Aortic stenosis

LV outflow obstruction

Concentric wall thickening

Valve regurgitation

Volume overload

Chamber enlargement

Infiltrative myocardial disease

Reduced compliance

Impaired filling

Slide 11 · Systolic and diastolic left-sided failure

Systolic failure (HFrEF)

Reduced ejection fraction reflects deranged ventricular contraction.

Diastolic failure (HFpEF)

Stiffness and impaired relaxation limit filling despite a relatively preserved ejection fraction.

Shared downstream effect

Either mechanism can raise pulmonary filling pressure and cause congestion.

Clinical distinction

Ejection fraction describes a phenotype; The morphologic substrate still requires assessment.

Slide 12 · Reduced ejection fraction: The systolic pathway

Myocardial insult

Impaired contractility

Reduced ejection

Lower stroke volume

Reduced output

Tissue hypoperfusion

Compensation

Retention and overload

Schematic

Slide 13 · Preserved ejection fraction does not exclude failure

Stiff left ventricle

Relaxation is impaired

Filling pressure rises

Volume accommodation limited

Pressure backs up

Pulmonary congestion

Exercise intolerance

Output reserve is poor

Schematic

Slide 14 · Why exertion unmasks diastolic failure

At rest, a stiff ventricle may maintain relatively preserved cardiac function.

Increased peripheral metabolic demand requires an increase in cardiac output.

Poor relaxation limits the ability to expand ventricular filling.

Pressure may rise sharply and be transmitted backward to the lungs.

Slide 15 · Compliance and backward pressure transfer

More compliant ventricle

Accommodates diastolic inflow with smaller pressure change.

Effective relaxation helps maintain ventricular filling.

Pulmonary venous pressure remains less affected by a given filling demand.

Stiff ventricle

Limited expansion makes filling pressure rise quickly.

Pressure transmits to the left atrium and pulmonary veins.

Dyspnea and pulmonary edema can occur despite preserved EF.

Slide 16 · Substrates of diastolic failure

Hypertension

The commonest underlying cause.

Other associations

Diabetes, obesity and bilateral renal artery stenosis can contribute.

Myocardial disease

Fibrosis in IHD/cardiomyopathy, or cardiac amyloid infiltration, can impair relaxation.

Older age

Fibrotic myocardial stiffening may contribute even without a recognized underlying disease.

Slide 17 · A pericardial mimic of diastolic dysfunction

Constrictive pericarditis limits the ability of the heart to fill.

It can resemble intrinsic myocardial diastolic failure clinically.

The constraining structure differs: Pericardium versus myocardium.

Morphologic and echocardiographic evaluation is needed to distinguish mechanisms.

Slide 18 · Remodeling begins as compensation

Mechanical work

Persistent pressure or volume overload increases cardiomyocyte demand.

Cell hypertrophy

Protein synthesis and additional sarcomeres enlarge individual myocytes.

Cardiac enlargement

Greater myocyte mass increases heart size and weight.

Maladaptation

Fibrosis and inadequate capillary growth favor progression to failure.

Schematic

Slide 19 · Pressure and volume overload: Sarcomere geometry

Pressure hypertrophy

Sarcomeres added mainly in parallel.

Myocytes gain cross-sectional area.

Concentric wall thickening is characteristic.

Volume hypertrophy

Sarcomeres added mainly in series.

Chamber dilation is prominent.

Wall thickness can be high, normal or reduced.

Slide 20 · Wall thickness is not equivalent to myocardial mass

Pressure-loaded

Smaller cavity with thicker relative wall

Reference

Reference cavity and wall schematic

Dilated / hypertrophied

Larger chamber; Mass may rise despite modest wall thickness

Simplified ventricular cross-sections; Schematic, not a specimen

Slide 21 · Hypertrophy creates a supply–demand mismatch

Hypertrophied myocytes enlarge without proportional increases in capillary density.

A larger contractile mass increases myocardial oxygen and nutrient demand.

Greater heart rate or inotropic state can further raise oxygen consumption.

The remodeled myocardium is vulnerable to ischemic decompensation.

Slide 22 · Interstitial fibrosis links remodeling to filling failure

Mechanical overload

Fibroblast activation

Extracellular matrix

Interstitial deposition

Ventricular stiffness

Greater resistance to filling

Pulmonary congestion

Elevated left-sided pressure

Schematic

Slide 23 · Cellular remodeling extends beyond contractile size

Immediate-early genes

FOS, JUN, MYC and EGR1 in hypertrophic growth responses.

Fetal gene re-expression

Prolonged load is linked to fetal myosin forms, natriuretic peptides and collagen.

Myocyte nuclei

Enlarged or multiple nuclei may reflect increased DNA ploidy without cell division.

Stromal response

Nonmyocyte cells contribute fibrosis and remodeling.

Slide 24 · Adaptation can become a self-amplifying burden

Overload

Pressure, volume or injury

Hypertrophy

Temporary workload adaptation

Stress

Ischemic vulnerability and fibrosis

Failure

Pump or filling dysfunction

Schematic

Slide 25 · Regional injury versus diffuse mechanical burden

Myocardial infarction

Loss of muscle produces regional dysfunction.

Surviving myocardium hypertrophies under increased work.

Scars and viable regions can coexist.

Valvular overload

Pressure or volume burdens myocardium more globally.

Remodeling may affect the entire LV.

Resulting architecture depends on load and disease course.

Slide 26 · Gross pathology must be interpreted in context

The failing LV may contain an infarct, diseased valves, or intrinsic myopathy.

Severe hypertrophy, dilation, or both are common but not universal.

The usual LV response depends strongly on the initiating pathologic process.

Cardiac size and wall thickness do not alone define functional severity.

Slide 27 · The usual left ventricular phenotype

Hypertrophy

The left ventricle is usually hypertrophied in left-sided failure.

Dilation

Dilation is frequent and can be massive in advanced disease.

Geometry

The chamber may enlarge even when wall thickness seems unimpressive.

Interpretation

Consider load pattern, infarction and primary myocardial disorders.

Slide 28 · Two important exceptions to the usual LV pattern

Mitral stenosis

Left atrial inflow obstruction can cause pulmonary congestion.

The LV need not develop the common hypertrophied, dilated morphology.

Interpret the valve lesion before inferring LV structural change.

Unusual restrictive cardiomyopathies

Impaired filling may occur without marked LV dilation.

Stiff myocardial tissue can produce pulmonary backpressure.

Preserved size is not proof of preserved diastolic function.

Slide 29 · Microscopic findings in failing myocardium

Myocyte hypertrophy is a frequent but nonspecific microscopic alteration.

Interstitial fibrosis varies in extent between causes and disease courses.

Myocyte nuclei may appear enlarged in hypertrophic remodeling.

Microscopy must be integrated with gross and clinical etiology.

Slide 30 · Myocyte enlargement and interstitial fibrosis

Reference myocardium

Hypertrophy

Myocyte enlargement, larger nuclei and interstitial fibrosis (red lines)

Original editable schematic; Not a photomicrograph

Slide 31 · Ventricular dilation can worsen mitral competence

LV dilation

Chamber geometry changes

Papillary displacement

Tethering forces increase

Mitral regurgitation

Valve incompetence develops

Further volume load

Dilation can progress

Schematic

Slide 32 · Why the left atrium enlarges

Diastolic dysfunction elevates pressures transmitted to the left atrium.

LV dilation with mitral incompetence adds atrial pressure and volume load.

Secondary atrial dilation increases the susceptibility to atrial fibrillation.

The atrial structural response has clinical thromboembolic implications.

Slide 33 · Atrial fibrillation compounds cardiac dysfunction

LA enlargement

Electrical instability

Atrial fibrillation

Uncoordinated atrial contraction

Reduced atrial contribution

Lower ventricular filling

Reduced stroke volume

Further functional compromise

Schematic

Slide 34 · Stasis favors left atrial appendage thrombus

Atrial fibrillation predisposes to uncoordinated atrial contraction and blood stasis.

Stasis is especially important in the left atrial appendage.

The atrial appendage is a common site for thrombus formation.

An intracardiac thrombus represents an additional complication beyond pulmonary edema.

Slide 35 · Cardiac consequences form a connected chain

LV dysfunction

Pressure or volume stress changes the left atrium.

Left atrial dilation

Predisposes to atrial fibrillation.

Blood stasis

Disorganized contraction promotes appendage stasis.

Thrombus

Atrial appendage thrombus may form.

Schematic

Slide 36 · Backward failure culminates in pulmonary edema

LV filling/emptying defect

Left-sided pressure elevation

Left atrial pressure

Pulmonary venous backpressure

Microvascular filtration

Interstitial fluid expands

Edema

Airspaces can fill

Schematic

Slide 37 · Pulmonary congestion reflects venous backpressure

Blood backs up in the pulmonary circulation when the left heart fails.

Elevated hydrostatic forces promote movement of fluid from vessels into lung tissue.

Pulmonary congestion may occur with systolic or diastolic failure.

Fluid accumulation ultimately compromises gas exchange and causes breathlessness.

Slide 38 · Earliest pulmonary edema: Interstitial fluid

The first changes include perivascular and interstitial edema.

Interlobular septa are particularly involved in this early stage.

Alveolar airspaces may not yet be filled with fluid.

This step precedes more extensive edema of alveolar structures.

Slide 39 · Progression to edematous alveolar septa

Fluid extends through the pulmonary interstitium.

Alveolar septa become progressively widened by edema.

Widened septa alter the interface between pulmonary capillaries and air.

Further progression permits edema fluid to enter alveolar spaces.

Slide 40 · Alveolar edema is the severe pulmonary stage

Edema fluid accumulates within alveolar airspaces.

Fluid-filled alveoli contribute to impaired ventilation and dyspnea.

Extravasated red blood cells and plasma proteins may also enter airspaces.

Alveolar macrophages subsequently clear red cells and proteins.

Slide 41 · Morphologic sequence of pulmonary edema

Interstitial

Perivascular / interlobular

Septal

Widened alveolar septa

Alveolar

Airspaces accumulate fluid

Schematic: Fluid distribution, not actual histology

Slide 42 · Gross lung morphology in left-sided failure

Weight

Pulmonary congestion and edema yield heavy lungs.

Moisture

Edema produces characteristically wet lung tissue.

Distribution

Fluid accumulates in perivascular, interstitial and ultimately alveolar compartments.

Interpretation

Gross pulmonary findings indicate congestion; Cardiac disease establishes its cause.

Slide 43 · Red cells and iron lead to heart failure cells

Congested lung

Erythrocyte extravasation

Alveolar macrophage

Phagocytosis of red cells

Hemoglobin breakdown

Iron is stored as hemosiderin

Siderophage

Heart failure cell

Schematic

Slide 44 · Heart failure cells signify previous bleeding

Alveolar macrophages ingest red cells that have escaped into edematous alveoli.

Iron derived from digested erythrocytes accumulates as hemosiderin.

Hemosiderin-laden macrophages are termed “heart failure cells.”

They are evidence of prior episodes of pulmonary edema rather than a specific myocardial etiology.

Slide 45 · Why pleural effusions occur

Elevated pleural capillary pressure

Hydrostatic drive rises

Higher lymphatic pressure

Clearance becomes less effective

Fluid transudation

Serous fluid accumulates

Pleural effusion

Expansion of pleural fluid space

Schematic

Slide 46 · Compare fluid compartments affected by congestion

Compartment

Structural change

Clinical / morphologic relevance

Pulmonary interstitium

Perivascular and interlobular edema

Early congestion

Alveolar septa

Progressive septal widening

More extensive tissue edema

Alveolar airspaces

Intraluminal fluid; RBCs; Macrophages

Advanced edema; Heart failure cells

Pleural cavity

Serous transudative effusion

Fluid outside the lung parenchyma

Slide 47 · Exertional cough and dyspnea may be the first symptoms

Early pulmonary congestion commonly causes cough and breathlessness on exertion.

Exercise increases demand on a ventricle with limited cardiac reserve.

The pulmonary fluid burden may worsen as ventricular dysfunction advances.

Absence of resting dyspnea does not exclude early left-sided failure.

Slide 48 · Orthopnea: A positional consequence of congestion

Supine position

Pulmonary symptoms worsen

Congested lungs

Breathlessness when lying flat

Sitting or standing

Symptoms improve

Schematic

Slide 49 · Paroxysmal nocturnal dyspnea

Timing

A severe episode of breathlessness typically occurs during the night.

Experience

Patients may awaken with an intense sensation of suffocation.

Underlying problem

Worsening pulmonary edema produces the respiratory symptoms.

Context

Often signifies progression beyond uncomplicated exertional dyspnea.

Slide 50 · Clinical progression of pulmonary symptoms

Early disease

Cough and exertional breathlessness.

Worsening congestion

Orthopnea and paroxysmal nocturnal dyspnea.

Further decompensation

Breathlessness can occur at rest.

Examination

Fine basal rales may accompany alveolar fluid.

Schematic

Slide 51 · Basal rales arise from edematous alveoli

Fine rales are characteristically heard at the lung bases.

In the Robbins account, edematous alveoli snap open during inspiration.

This links an auscultatory finding directly to alveolar fluid accumulation.

Rales are a manifestation of pulmonary congestion, not proof of one specific cause.

Slide 52 · S3 and S4 reflect different loading states

Third heart sound (S3)

Associated with ventricular volume overload.

Can accompany enlargement and impaired systolic function.

Interpret along with chamber size and LV performance.

Fourth heart sound (S4)

Associated with increased myocardial stiffness.

Suggests impaired ventricular compliance.

Fits a diastolic dysfunction phenotype.

Slide 53 · Cardiac examination and imaging clues

Cardiomegaly

An enlarged cardiac silhouette may be apparent on imaging.

Tachycardia

A common compensatory manifestation of LV failure.

Ventricular sounds

S3 may reflect volume overload; S4 suggests increased stiffness.

Valve effects

Progressive ventricular enlargement can cause secondary mitral regurgitation.

Slide 54 · Link clinical findings to pathology

Finding

Pathologic mechanism

Interpretation

Exertional dyspnea

Pulmonary congestion

Early reduced reserve

Orthopnea / PND

Progressive pulmonary edema

More symptomatic congestion

Basal fine rales

Opening of edematous alveoli

Alveolar fluid

S3

Ventricular volume overload

Loading abnormality

S4

Myocardial stiffness

Impaired compliance

Slide 55 · Reduced renal perfusion recruits compensatory pathways

Falling output

Renal hypoperfusion

Renin–angiotensin–aldosterone

Compensatory activation

Sodium and water retention

Blood and interstitial volume expand

Congestion worsens

Pulmonary edema is aggravated

Schematic

Slide 56 · Renin–angiotensin activation can become maladaptive

The kidney responds to diminished perfusion as if the circulation were underfilled.

Salt and water retention expands intravascular and interstitial fluid volumes.

Additional volume increases the burden on the failing left heart.

Pulmonary congestion can therefore worsen despite an initially compensatory response.

Slide 57 · Prerenal azotemia reflects severe hypoperfusion

Progressively reduced renal blood flow can impair nitrogenous waste excretion.

The resulting azotemia is described as prerenal in the Robbins account.

This consequence indicates inadequate forward perfusion as well as congestion.

It is distinct from the direct pulmonary manifestations of backward failure.

Slide 58 · Severe cerebral hypoperfusion is a late consequence

Advanced failure

Systemic perfusion deteriorates severely.

Cerebral hypoxia

Cognitive and behavioral changes emerge.

Encephalopathy

Irritability, inattention and restlessness may occur.

Extremes

Stupor, coma and ischemic injury can follow.

Schematic

Slide 59 · Forward failure and backward failure affect different organs

Dominant mechanism

Target compartment

Representative consequence

Backward congestion

Pulmonary microcirculation

Interstitial / alveolar edema

Backward congestion

Pleural capillaries and lymphatics

Serous pleural effusions

Cardiac stasis

Left atrium / appendage

Atrial thrombus

Forward hypoperfusion

Kidney

RAAS activation; Prerenal azotemia

Forward hypoperfusion

Brain

Hypoxic encephalopathy

Slide 60 · Echocardiography interrogates multiple mechanisms

Ejection fraction

Measures systolic performance and helps identify reduced-EF failure.

Wall motion

Displays regional dysfunction potentially associated with infarction or ischemia.

Valve function

Assesses stenosis or regurgitation and their loading consequences.

Thrombus / structure

Can identify chamber changes and possible mural thrombus.

Slide 61 · BNP provides complementary evidence of heart failure

Ventricular cardiomyocytes release B-type natriuretic peptide in response to wall stress.

BNP can support quantitative assessment of clinical heart failure.

A low BNP value has high negative predictive value for heart failure in the Robbins account.

BNP should be interpreted alongside history, examination and cardiac imaging.

Slide 62 · Integrating a suspected left-sided failure presentation

Clinical syndrome

Dyspnea, signs of congestion

Cardiac characterization

Echocardiographic EF, valves, motion

Laboratory support

BNP reflects ventricular wall stress

Etiologic assessment

IHD, pressure, valves, myocardium

Schematic

Slide 63 · Left-sided and right-sided failure: Predominant effects

Left-sided failure

Pulmonary congestion and edema predominate.

Left atrial stasis and systemic underperfusion may coexist.

Common causes: IHD, HTN, valve and myocardial disease.

Right-sided failure

Systemic and portal venous congestion predominate.

Dependent edema and visceral congestion are typical.

Often occurs secondary to longstanding left-sided failure.

Slide 64 · Chronic left-sided failure may evolve into biventricular failure

Left-sided failure

Pulmonary venous pressure increases

Pulmonary load

RV strain increases

Right ventricular dysfunction

Systemic venous congestion

Biventricular failure

Both clinical patterns coexist

Schematic

Slide 65 · Case study: Breathlessness after myocardial infarction

A patient with established ischemic heart disease develops exertional dyspnea, later orthopnea, cardiomegaly and an S3. Imaging suggests an enlarged left ventricle.

Discussion prompts

Which functional phenotype is plausible?

Explain why the lungs become edematous.

What additional atrial complication may arise?

Slide 66 · Case interpretation: Ischemic LV dysfunction

Mechanism

Infarcted myocardium can impair contraction and promote LV enlargement.

Congestion

Raised left-sided pressures cause pulmonary edema and orthopnea.

Complication

Atrial dilation can predispose to fibrillation and thrombus.

Slide 67 · Case study: Preserved EF with pulmonary symptoms

An older patient with longstanding systemic hypertension experiences marked dyspnea during activity and cannot lie flat comfortably. Echocardiography shows preserved ejection fraction, and the LV is thick-walled.

Discussion prompts

Explain how a preserved EF can coexist with failure.

Identify the likely loading substrate.

Why might an S4 be present?

Slide 68 · Case interpretation: Impaired ventricular relaxation

Mechanism

Pressure overload and interstitial fibrosis may produce LV stiffness.

Hemodynamics

Filling pressure can rise and transmit to pulmonary veins.

Examination

S4 is associated with increased myocardial stiffness.

Slide 69 · Case study: Hemosiderin-containing alveolar macrophages

A lung tissue specimen from a patient with chronic cardiac decompensation contains pigment-bearing macrophages in alveolar spaces. The lungs are described as heavy and wet.

Discussion prompts

What does the macrophage pigment represent?

Reconstruct the sequence that generated it.

Does this finding identify a specific cardiac etiology?

Slide 70 · Case interpretation: Heart failure cells

Pigment

Hemosiderin is stored iron from phagocytosed extravasated red cells.

Sequence

Congestion → alveolar bleeding → macrophage uptake → hemosiderin.

Meaning

Previous pulmonary edema is supported; The exact cardiac cause is not established.

Slide 71 · Integrated pathology synthesis

Causes

IHD, hypertension, aortic or mitral disease, and myocardial disorders are dominant substrates.

Heart

LV hypertrophy or dilation, nonspecific fibrosis, atrial enlargement and possible thrombus.

Lungs

Interstitial then alveolar edema, heart failure cells and serous pleural effusions.

Systemic effects

Low output promotes RAAS retention, azotemia and, when severe, cerebral dysfunction.

Slide 72 · Primary reference

Robbins, Cotran & Kumar

Pathologic Basis of Disease · 11th edition (2026)

Left-Sided Heart Failure and adjacent Heart Failure material

All explanatory drawings are original editable schematics; no reproduced clinical or histologic specimens.