CARDIOMYOPATHY

✓ Medically ReviewedDISEASEID: MDBT0058🚨 TRIAGE: ROUTINEICD-10: I42

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Definition

CLINICAL DEFINITION

Cardiomyopathy is a primary disorder of heart muscle. Myocardium (muscular wall) shows abnormal size, thickness, stiffness or function. It impairs systole (pumping phase) or diastole (filling phase). It is not explained alone by blocked coronaries, valve disease or severe hypertension. It can cause heart failure (poor output with congestion), arrhythmia (abnormal rhythm) and sudden death.

IN PLAIN ENGLISH

Cardiomyopathy means the heart muscle is sick and weak. The heart may stretch too big, grow too thick or turn too stiff. A sick muscle pumps less blood with each beat. Fluid can back up into lungs, legs and belly. It can also cause fast beats, fainting or collapse.

COMMON MISCONCEPTION / WHAT IT DOES NOT MEAN

Cardiomyopathy is not blocked artery heart attack alone. It is not valve leakage or narrowing alone. It is not high pressure damage alone. It is not fluid around the heart from pericarditis (sac inflammation) alone. It is not normal athletic thickening that reverses with rest.

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Word Breakdown

cardi- / my-

=kardia (heart) and mys (muscle)

-pathy

=patheia (disease or disorder)

Literal Meaning: disease of heart muscle

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Abbreviations

DCM=Dilated cardiomyopathy - enlarged chamber with weak squeeze

HCM=Hypertrophic cardiomyopathy - thick walls with stiff filling

RCM=Restrictive cardiomyopathy - rigid walls with poor filling

ARVC=Arrhythmogenic right ventricular cardiomyopathy - scar with rhythm risk

TTC=Takotsubo cardiomyopathy - stress ballooning that often recovers

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Synonyms & Variants

Heart muscle disease›Myocardiopathy›Primary myocardial disease›

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Category-Specific Context

Cardiomyopathy is a Disease because it is a defined muscle disorder with causes and course. It has stages, complications and family risk. It needs cause workup, imaging and rhythm review. It needs long term follow-up, not one-off relief.

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Clinical Context & Usage

CLINICAL SETTINGS

Cardiology ClinicHeart Failure ClinicEmergency DepartmentInpatient Cardiology WardIntensive Care UnitGenetics and Family Screening Clinic

USAGE & DOCUMENTATION NOTES

Use cardiomyopathy when echo (heart ultrasound) shows muscle disease. Always state type such as dilated, hypertrophic or restrictive. Note severity, rhythm risk and family pattern. Do not use it for ischaemic (blocked artery) or valve disease alone. The label triggers imaging, rhythm checks and family screening.

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Primary Causes & Pathophysiology

PATHOPHYSIOLOGY

Sarcomere (tiny contractile unit) defects impair force and relaxation. Mutations cause energy waste, calcium mishandling and cell death. Dead cells are replaced by fibrosis (stiff scar) that blocks conduction. Chambers remodel (change size and shape) with dilation or thickening. Poor squeeze lowers output while poor relaxation raises filling pressures. Scar and stretch create circuits for ventricular arrhythmia and promote clot.

PRIMARY CAUSES

Sarcomeric gene variants MYH7 and MYBPC3 in hypertrophic disease

Mutant contractile proteins cause excess power and poor relaxation with hypertrophy and scar

Titin, lamin A/C and dystrophin variants in dilated disease

Weak cytoskeleton impairs force transfer so chambers dilate and squeeze falls

Viral myocarditis from coxsackievirus, parvovirus B19 and SARS-CoV-2

Direct viral injury plus immune attack kills muscle cells leaving scar and weakness

Chronic heavy alcohol use

Acetaldehyde harms mitochondria (energy factories) and calcium handling so output falls

Peripartum state in late pregnancy and early postpartum

Hormonal and vascular stress injures microvessels with acute dilation near delivery

AL and transthyretin amyloid infiltration

Misfolded fibrils stiffen walls and impair filling with block and clot risk

Iron overload in haemochromatosis and transfusion-dependent thalassaemia

Myocardial iron causes oxidative injury with restrictive or dilated failure

Cardiac sarcoidosis and Fabry disease

Granulomas (inflammatory lumps) or storage material thicken walls and trigger block and rhythm risk

Desmosomal variants PKP2 and DSP in arrhythmogenic disease

Faulty junctions cause cell loss and fatty scar that triggers ventricular tachycardia

Catecholamine surge in Takotsubo stress disease

Severe stress stuns microvessels with apical ballooning that often recovers

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Drug-Induced Causes

💊 Anthracyclines doxorubicin, daunorubicin and epirubicin ↗

Mechanism: Topoisomerase injury and oxidative stress kill muscle cells with dose related failure

→ Stop culprit with cardio-oncology input, start failure therapy, watch echo and troponin

💊 HER2 blockers trastuzumab, pertuzumab and T-DM1 ↗

Mechanism: Loss of HER2 survival signalling impairs contractility, often reversible, worse after anthracyclines

→ Hold therapy when function falls, treat failure, rechallenge only after recovery with echo

💊 Clozapine ↗

Mechanism: Hypersensitivity myocarditis with eosinophil (allergy cell) inflammation leading to dilated failure

→ Stop at once without rechallenge, give failure care with troponin and echo follow-up

💊 Immune checkpoint inhibitors nivolumab, pembrolizumab and ipilimumab ↗

Mechanism: T-cell attack on muscle causes fulminant inflammation with failure and arrhythmia

→ Stop therapy, give high dose steroids urgently, admit for monitoring and failure support

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Epidemiology

Prevalence:Cardiomyopathy is common in cardiology and heart failure clinics. Dilated disease is the most frequent adult systolic failure pattern. Hypertrophic disease is the most common inherited muscle disorder. Restrictive and arrhythmogenic types are uncommon but carry high rhythm risk. Takotsubo clusters after acute stress.

Age Group:Disease occurs at any age from infancy to old age. Hypertrophic disease often appears in teens and young adults with murmur or collapse. Dilated disease peaks in middle aged adults with breathlessness. Takotsubo mainly affects older adults after stress. Inherited forms need childhood and family screening.

Geographic Distribution:Cardiomyopathy occurs worldwide in all populations. Chagas disease (parasitic infection) causes dilated disease in Latin America. Founder gene variants cluster in some regions and families. Amyloid and iron overload vary with age and genetics. Detection rises where echo (heart ultrasound) and genetics are available.

Red Flags & Triage ★

TRIAGE LEVEL

🚨 ROUTINE

DO NOT MISS — LIFE-THREATENING PRESENTATIONS

Left ventricular outflow obstruction with faint risk
Cardiac amyloidosis with carpal tunnel and low voltage
Fabry disease with renal failure and skin lesions
Anomalous coronary in young exertional collapse
Advanced conduction disease needing urgent pacing

URGENT EVALUATION TRIGGERS

Faint or near faint on exertion
Sustained palpitations or documented ventricular tachycardia
Severe breathlessness, chest pain or lung fluid
Signs of stroke or systemic embolism
Family sudden death or high risk mutation with new symptoms

Contraindications & Precautions

CONTRAINDICATIONS

Competitive endurance and burst sports in hypertrophic and arrhythmogenic disease
Pregnancy without preconception counselling in severe dilated and peripartum disease
QT-prolonging and negatively inotropic drugs without cardiology review
Alcohol excess and stimulant drugs
Decongestants with sympathetic stimulation in outflow obstruction

SPECIAL PRECAUTIONS

Serial imaging and rhythm monitoring for progression
Pressure, salt and fluid control to reduce load
Anticoagulation review when atrial fibrillation or thrombus occurs
Anaesthesia and surgery planning with cardiology input
Genetic counselling and family cascade screening

Complications

DOWNSTREAM CLINICAL COMPLICATIONS

Heart failure with reduced or preserved pumping function
Ventricular arrhythmia and sudden cardiac death
Atrial fibrillation with stroke risk
Intracardiac thrombus with systemic embolism
Progressive conduction block needing pacing
End-stage disease needing device, transplant or palliative care

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Confused With (LASA & DDx) ★

LEXICAL (LASA) — SIMILAR NAMES

Cardiomegaly

Shares cardio prefix and big heart idea but is imaging finding of enlarged silhouette, not muscle disease

Myopathy

Shares myopathy suffix and muscle theme but is skeletal weakness disease, not heart pump failure

Pericarditis

Shares card root and chest pain but is outer sac inflammation with rub and ECG change, not muscle dysfunction

CLINICAL DIFFERENTIAL DIAGNOSES (DDx)

Coronary artery disease with ischaemic dysfunction

Key Distinguishing Feature: Angina with Q waves and regional defects in artery territories with blocked coronaries

Hypertensive heart disease

Key Distinguishing Feature: Long hypertension with concentric thickening that regresses with control and no family mutation

Severe aortic stenosis

Key Distinguishing Feature: Loud ejection murmur with fixed valve gradient and calcified valve on echo

Acute myocarditis

Key Distinguishing Feature: Recent viral prodrome with troponin spike and swelling on MRI with recovery

Constrictive pericarditis

Key Distinguishing Feature: Septal bounce with respiratory shift and thickened sac but preserved muscle

Athlete heart

Key Distinguishing Feature: Mild symmetric thickening with superb function and reversal with detraining

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Clinical Pearls

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State phenotype plus cause when possible. Dilated disease with wide bundle block may need resynchronisation, while obstructive hypertrophic disease needs different care.

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Take a three-generation family history and offer cascade screening. Sarcomeric and desmosomal disease is often autosomal dominant (one copy enough).

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Use cardiac MRI with late gadolinium (scar dye) to find fibrosis. Scar predicts rhythm risk even when pumping looks preserved.

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Review drugs, alcohol and pregnancy plans at each visit. Ongoing toxin exposure blocks recovery and changes device timing.

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Do not label all thick walls as hypertension. Asymmetric septal thickening with systolic anterior motion points to hypertrophic disease.

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Example Usage & SOAP

CLINICAL SENTENCE

""52-year-old man with dilated cardiomyopathy reports breathlessness climbing stairs over two weeks.""

IN A SOAP NOTE

S: 58-year-old woman with hypertrophic cardiomyopathy reports exertional tightness and lightheadedness, no faint at rest. O: BP 118/72, HR 88, RR 18, SpO2 97 percent on air, Temp 36.8C, systolic murmur louder standing, lungs clear. ECG shows left ventricular hypertrophy (wall thickening). Echo shows asymmetric septal thickening with preserved squeeze. A: Hypertrophic cardiomyopathy with exertional symptoms and possible outflow block. P: Urgent cardiology for Holter and cardiac MRI, avoid strenuous exercise and dehydration, review meds and family screening.

DIFFERENTIAL DIAGNOSIS CONTEXT

Septal thickening in a young athlete needs athlete heart versus hypertrophic disease split. Family history, ECG strain, scar on MRI and detraining response help separate them. Blocked coronaries must be excluded in older adults with dilated chambers before labelling primary dilated disease.

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Classifications & Scoring

GRADING SYSTEM

New York Heart Association Functional Classification

Grades symptoms from class I with no limits to class IV at rest to guide function and therapy

GRADING SYSTEM

MOGES Classification for Cardiomyopathy

Describes type, organ involvement, genetics, cause and stage for precise phenotyping

STAGING SCALE

American College of Cardiology and American Heart Association Heart Failure Stages

Stages from A at risk through B pre-failure to C symptomatic and D advanced to guide prevention to transplant

SCORING TOOL

Hypertrophic Cardiomyopathy Risk Sudden Cardiac Death Calculator

Estimates five-year sudden death risk from wall thickness, gradient and rhythm history to guide defibrillator choice

SCORING TOOL

CHA2DS2-VASc Score with Atrial Fibrillation

Estimates stroke risk from failure, hypertension, age, diabetes and vascular disease to guide anticoagulation

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Prognosis

SHORT-TERM OUTCOME

Short term risk follows presentation with decompensation (acute worsening), arrhythmia or clot. Stable mild disease often stays steady for months. New breathlessness, chest pain, faint or sustained palpitations signal danger. Early echo, rhythm checks and failure therapy improve stability. Takotsubo often recovers within weeks with support.

LONG-TERM PROGNOSIS

Long term course spans stable to progressive failure. Some gene carriers stay well for years with surveillance. Others develop refractory symptoms, shocks or stroke. Devices and transplant extend life in selected advanced cases. Lifelong follow-up with family screening is essential.

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References & Coding

ICD-10 DIAGNOSTIC CODE

I42

LITERATURE CITATIONS & GUIDELINES

[1]ESC Guidelines for cardiomyopathies

[2]AHA Scientific Statement on cardiomyopathy

[3]WHO ICD-10 I42

MEDICAL DISCLAIMER — This content is intended for educational purposes and qualified healthcare professionals only. Always refer to current clinical diagnostic criteria, institutional protocols, and official guidelines. Medobo is not responsible for clinical decisions made based on this content.