Cardiomyopathy nursing: types, assessment, and management

Introduction

Cardiomyopathy refers to disease of the heart muscle that impairs the heart’s ability to pump blood effectively. Unlike structural heart disease caused by valve problems or coronary artery blockages, cardiomyopathy originates within the myocardium itself — affecting its size, shape, thickness, or function. The four primary types each have distinct pathophysiology, clinical presentations, and management strategies that nursing students must be able to distinguish.

Understanding cardiomyopathy is essential for NCLEX success and clinical practice. These conditions are common causes of heart failure, sudden cardiac death, atrial fibrillation, and cardiac transplantation. Each type carries specific nursing priorities — and in hypertrophic cardiomyopathy, the wrong intervention can be lethal.

Cardiomyopathy quick reference

Dilated cardiomyopathy (DCM)

Pathophysiology

In dilated cardiomyopathy, one or both ventricles become enlarged and weakened. The left ventricle — most commonly affected — dilates under the stress of progressive systolic dysfunction, reducing ejection fraction (EF) and cardiac output. As the chamber expands, wall tension increases per the law of Laplace, further impairing contractility. The mitral valve annulus stretches with ventricular dilation, causing functional mitral regurgitation that further reduces forward flow.

The result is a heart that pumps less blood per beat, compensates initially through neurohormonal activation (sympathetic nervous system, RAAS), but ultimately decompensates into the clinical syndrome of heart failure with reduced ejection fraction (HFrEF). EF is typically less than 40% at diagnosis.

Causes

Ischemic heart disease is the most common cause of DCM in the United States — coronary artery disease leading to myocardial infarction and scar tissue replacing functional myocytes. For nursing students, this connection is important: a patient with a history of MI presenting with worsening dyspnea and peripheral edema should prompt consideration of ischemic DCM. See the MI/ACS nursing reference for the ischemic pathway.

Other causes include:

• Idiopathic (no identifiable cause; accounts for ~50% of non-ischemic DCM)
• Alcohol — chronic excess leads to direct myocardial toxicity; among the most reversible causes if alcohol is stopped
• Viral myocarditis — myocarditis (especially Coxsackievirus B, Chagas disease) can progress to DCM as the post-inflammatory phase causes fibrosis and remodeling
• Peripartum cardiomyopathy — a distinct form of DCM occurring in the last month of pregnancy or within five months postpartum; more common in older, multiparous women and in those of African descent
• Genetic/familial — mutations in sarcomeric proteins (titin, lamin A/C); family history increases risk 20–35%
• Toxic — anthracycline chemotherapy (dose-dependent), cocaine, methamphetamines
• Endocrine — thyroid disease, acromegaly, phaeochromocytoma

Clinical presentation

• Dyspnea — on exertion initially, progressing to rest; orthopnea and paroxysmal nocturnal dyspnea with worsening HF
• Fatigue — reduced cardiac output limits oxygen delivery to skeletal muscle
• S3 gallop — pathognomonic for volume overload and poor ventricular compliance; heard best at the cardiac apex with the bell
• Displaced PMI (point of maximal impulse) — the enlarged LV shifts the apex beat laterally beyond the mid-clavicular line; a key NCLEX physical exam finding
• Peripheral edema — bilateral, dependent; from elevated venous pressure and neurohormonal fluid retention
• JVD — elevated jugular venous distension reflecting right-sided pressure elevation
• Crackles — pulmonary edema as pulmonary venous hypertension causes fluid transudation into alveoli
• Functional mitral regurgitation — holosystolic murmur from annular dilation; may be audible

Management

Standard guideline-directed medical therapy (GDMT) for HFrEF applies:

• ACE inhibitors or ARBs — reduce afterload and prevent adverse cardiac remodeling; first-line unless contraindicated
• Beta-blockers — reduce sympathetic drive, lower heart rate, prevent arrhythmias, reverse remodeling; carvedilol, metoprolol succinate, and bisoprolol are evidence-based choices
• Loop diuretics — furosemide or bumetanide for volume overload; symptom relief but no mortality benefit
• Mineralocorticoid receptor antagonists — spironolactone or eplerenone for EF ≤35%; reduce mortality and hospitalizations
• ARNI (sacubitril/valsartan) — superior to ACE inhibitor alone in stable HFrEF; replaces ACE inhibitor when tolerated
• SGLT2 inhibitors — dapagliflozin, empagliflozin; reduce HF hospitalizations and mortality regardless of diabetes status
• ICD — for EF ≤35% despite 3 months of GDMT; primary prevention of sudden cardiac death
• CRT (cardiac resynchronization therapy) — for EF ≤35% with LBBB and QRS ≥150 ms; improves symptoms, EF, and survival
• Heart transplantation — for refractory end-stage disease; considered when EF remains severely reduced despite optimal therapy

See the heart failure nursing reference for detailed HFrEF management, diuretic dosing, and monitoring protocols.

Hypertrophic cardiomyopathy (HCM / HOCM)

Pathophysiology

Hypertrophic cardiomyopathy is the most common inherited cardiac disease, affecting approximately 1 in 500 people. It is caused by mutations in genes encoding sarcomeric proteins — most commonly myosin heavy chain (MYH7) and myosin-binding protein C (MYBPC3). These mutations cause disordered, disorganized cardiomyocyte architecture (myocardial disarray), abnormal calcium handling, and pathological hypertrophy — particularly of the interventricular septum.

The asymmetric septal hypertrophy narrows the left ventricular outflow tract (LVOT). During systole, the high-velocity blood flow through the narrowed LVOT creates a Venturi effect that draws the anterior mitral valve leaflet toward the septum — this is systolic anterior motion (SAM) of the mitral valve. SAM worsens LVOT obstruction and causes mitral regurgitation. The degree of obstruction fluctuates dynamically based on loading conditions: reduced preload (less blood in the ventricle) worsens obstruction; increased preload (more filling) reduces it.

The ventricle is thick and non-compliant, producing diastolic dysfunction even when systolic function is preserved. The hyperdynamic LV actually ejects blood with abnormally high force — EF is often supranormal (>70%).

When obstruction is present at rest or with provocation, the condition is termed hypertrophic obstructive cardiomyopathy (HOCM). Approximately 70% of HCM patients have some degree of LVOT obstruction.

HCM as the leading cause of sudden cardiac death in young athletes

HCM is the most common cause of sudden cardiac death (SCD) in athletes under 35 in the United States. The mechanism is ventricular fibrillation, triggered by the combination of myocardial disarray (arrhythmogenic substrate), dynamic LVOT obstruction reducing coronary perfusion during exertion, and exercise-induced catecholamine surges. Athletes can die during or immediately after exercise — often with no prior symptoms.

Clinical presentation

• Dyspnea on exertion — the most common symptom; from diastolic dysfunction, elevated filling pressures, and outflow obstruction
• Syncope — particularly exertional syncope; results from inadequate cardiac output with LVOT obstruction or arrhythmia; an important red flag for SCD risk
• Chest pain (angina) — in the absence of obstructive CAD; caused by increased myocardial oxygen demand from hypertrophy combined with impaired coronary microvascular perfusion
• Palpitations — from supraventricular or ventricular arrhythmias; atrial fibrillation complicates HCM in 20–25% of cases and is particularly dangerous because loss of atrial kick dramatically worsens filling of the non-compliant LV
• Harsh systolic murmur — best heard at the left sternal border; crescendo-decrescendo (ejection type); this murmur is dynamic and responds predictably to maneuvers that change preload or afterload

The HOCM murmur and Valsalva — the most tested NCLEX fact

The HOCM murmur is the only murmur in cardiology that increases with maneuvers that decrease preload (less blood in the LV = more obstruction):

• Valsalva maneuver (forced exhalation against a closed glottis) → decreases venous return → reduces LV filling → worsens LVOT obstruction → murmur gets louder
• Standing from squatting → decreases venous return → same mechanism
• Squatting from standing → increases venous return → more LV filling → less obstruction → murmur gets softer
• Passive leg raise → increases preload → murmur decreases

This is opposite to aortic stenosis and most other systolic murmurs, which become softer with Valsalva.

What to avoid in HOCM

Several common cardiac interventions are contraindicated in HOCM because they reduce preload or afterload, worsen LVOT obstruction, and can precipitate hemodynamic collapse:

• Vasodilators — nitrates, ACE inhibitors, ARBs — reduce afterload, pulling the mitral valve toward the septum
• Diuretics — reduce preload; less LV filling worsens obstruction
• Digoxin — increases contractility, making the dynamic obstruction worse
• Strenuous exercise — catecholamine surge increases contractility and reduces peripheral resistance; competitive sports are restricted

Management

• Beta-blockers — first-line; reduce heart rate (increases filling time), decrease contractility (reduces obstruction), and are antiarrhythmic; metoprolol and propranolol are most used
• Non-dihydropyridine calcium channel blockers — verapamil or diltiazem when beta-blockers are not tolerated; also reduce contractility and improve diastolic filling
• Disopyramide — negative inotrope sometimes added in refractory obstruction
• ICD implantation — for primary prevention of SCD; indicated for patients with significant risk factors (prior SCD/cardiac arrest, family history of HCM-related SCD, massive LV hypertrophy ≥30 mm, unexplained syncope, NSVT on Holter)
• Activity restriction — lifelong restriction from competitive sports; the AHA/ACC recommends avoiding most competitive athletics regardless of whether an ICD is present
• Septal myectomy — surgical removal of a portion of the hypertrophied septum; gold standard for symptom-refractory LVOT obstruction; performed at specialized HCM centers
• Alcohol septal ablation — catheter-based technique; alcohol injected into a septal perforator artery creates a controlled infarct, thinning the septum; less invasive than surgery but higher rate of complete heart block

Restrictive cardiomyopathy

Pathophysiology

Restrictive cardiomyopathy is the least common of the primary cardiomyopathies. The ventricles are small to normal in size with normal or near-normal wall thickness but become abnormally stiff — unable to relax and fill adequately during diastole. The fundamental problem is diastolic dysfunction: the stiff myocardium resists filling, causing elevated filling pressures with preserved (or only mildly reduced) systolic function.

The consequence is a heart that cannot accommodate adequate ventricular volume at normal filling pressures. To maintain stroke volume, filling pressures rise — producing elevated venous pressures on both sides: elevated right-sided pressure causes JVD, hepatomegaly, ascites, and peripheral edema; elevated left-sided pressure causes pulmonary venous hypertension and dyspnea.

Restrictive cardiomyopathy is preload-dependent: the stiff ventricle requires adequate filling pressure to generate sufficient stroke volume. Volume depletion — from over-diuresis or bleeding — can cause profound reduction in cardiac output.

Causes

Unlike DCM or HCM, restrictive cardiomyopathy is almost always secondary to an infiltrative or fibrotic process that replaces or stiffens normal myocardial architecture:

• Cardiac amyloidosis — the most clinically important cause; abnormal protein (amyloid) deposits infiltrate the myocardium. Classic findings: “sparkling” or granular appearance on echocardiography, low-voltage ECG despite thickened walls (amyloid dampens electrical signals), elevated BNP disproportionate to LV size. Two main subtypes: AL amyloidosis (light chain, from plasma cell dyscrasia) and ATTR amyloidosis (transthyretin, hereditary or wild-type/“senile”)
• Sarcoidosis — non-caseating granulomas infiltrate the myocardium; high risk of complete heart block and ventricular tachycardia; can mimic pericarditis or myocarditis
• Hemochromatosis — iron deposition in cardiomyocytes; presents with HF, arrhythmias, and conduction defects; potentially reversible with phlebotomy or chelation if detected early
• Radiation fibrosis — mediastinal radiation (e.g., for lymphoma or breast cancer) causes progressive myocardial and pericardial fibrosis over years
• Endomyocardial fibrosis — tropical disorder affecting the endocardial layer
• Glycogen storage diseases (Fabry disease, Pompe disease) — lysosomal enzyme deficiencies causing intracellular substrate accumulation

Clinical presentation

Patients present with signs and symptoms of biventricular heart failure with preserved ejection fraction (HFpEF):

• Progressive dyspnea, orthopnea, and reduced exercise tolerance
• Markedly elevated JVP — one of the most prominent findings; the elevated venous pressure from impaired RV filling manifests as prominent jugular venous distension
• Kussmaul’s sign — paradoxical rise in JVP with inspiration (normal JVP falls with inspiration); results from the right ventricle’s inability to accommodate the increased venous return that occurs during inhalation; classically associated with restrictive cardiomyopathy and constrictive pericarditis
• Peripheral edema, ascites, and hepatomegaly from chronic venous hypertension
• Fatigue from low cardiac output
• Arrhythmias — particularly complete heart block in sarcoidosis and hemochromatosis

Management

There is no specific treatment for most restrictive cardiomyopathies. The goals are managing volume overload, treating the underlying cause where possible, and preventing complications:

• Treat the underlying cause: Phlebotomy or chelation for hemochromatosis; immunosuppression for sarcoidosis; tafamidis (transthyretin stabilizer) for ATTR amyloidosis; chemotherapy for AL amyloidosis
• Diuretics — used cautiously; these patients are highly preload-dependent, and over-diuresis causes significant reduction in cardiac output and hemodynamic compromise
• Rate control — atrial fibrillation is common; controlling ventricular rate preserves filling time, which is already impaired by diastolic dysfunction
• Anticoagulation — for atrial fibrillation given high thromboembolic risk
• Avoid vasodilators — the stiff ventricle cannot compensate for reduced afterload with increased filling
• Heart transplantation — may be considered in younger patients with end-stage disease, though amyloidosis recurrence in the transplanted heart is a concern with AL type

The distinction between restrictive cardiomyopathy and constrictive pericarditis is clinically important because constrictive pericarditis is surgically curable. Both share Kussmaul’s sign and similar hemodynamics; cardiac MRI, CT, and hemodynamic catheterization are used to differentiate them. See pericarditis nursing for the pericardial differential.

Takotsubo (stress/apical ballooning) cardiomyopathy

Pathophysiology

Takotsubo cardiomyopathy — also called stress cardiomyopathy or apical ballooning syndrome — is a transient, reversible form of ventricular dysfunction triggered by a sudden catecholamine surge. The condition is named for the Japanese octopus trap (takotsubo), whose shape resembles the characteristic appearance of the ballooned LV apex on ventriculography.

The trigger is emotional or physical stress: sudden grief, fright, medical procedures, natural disasters, or severe physiological illness (sepsis, stroke, intracranial hemorrhage). The catecholamine surge is believed to cause direct myocardial toxicity and microvascular spasm, producing transient dysfunction predominantly in the apical segments of the LV — while the basal segments, which have higher sympathetic receptor density, may contract normally or even hypercontract.

On echocardiography or left ventriculography, the apex appears dyskinetic and ballooned while the base contracts normally — the inverse of what is seen in typical MI patterns (which follow coronary territory). Coronary angiography shows normal or near-normal coronary arteries, which distinguishes Takotsubo from STEMI — though the two are often clinically indistinguishable on initial presentation.

Clinical profile

• Demographics: Predominantly post-menopausal women (90% female, median age 67–70); the drop in estrogen may reduce catecholamine protection in the microvasculature
• Trigger: An identifiable emotional or physical stressor in the vast majority of cases — death of a loved one, major accident, argument, medical procedure, acute medical illness
• Presentation: Sudden-onset chest pain and dyspnea; often indistinguishable from STEMI at initial presentation — ST-segment elevation on ECG, troponin elevation, wall motion abnormalities on echo
• Troponin: Mildly elevated — the degree of troponin elevation is disproportionately low relative to the extent of wall motion abnormality (unlike true MI, where larger territory infarction produces higher troponin peaks)
• Coronary angiogram: Normal or near-normal coronary arteries; the diagnostic hallmark; apical ballooning pattern on left ventriculography confirms the diagnosis

Clinical course and management

Takotsubo is generally a reversible condition. LV function typically recovers within two to eight weeks with supportive care. However, the acute phase carries real risk — cardiogenic shock, LV outflow tract obstruction (in some variants), LV thrombus formation, and arrhythmias can all occur.

• Supportive care — the foundation; most patients recover without specific intervention
• Beta-blockers — reduce catecholamine stimulation, protect against arrhythmias; most experts recommend during the acute phase and for at least several months after recovery
• ACE inhibitors — promote LV recovery and prevent remodeling
• Anticoagulation — LV thrombus forms in the akinetic apical segment; full anticoagulation until LV function recovers
• Avoid catecholamines — epinephrine and dobutamine can worsen Takotsubo and precipitate LVOT obstruction in the apical variant; use norepinephrine if vasopressor support is needed
• Recurrence rate — approximately 5% per year; patients should be counseled on triggers and stress reduction

Because Takotsubo mimics STEMI, nursing students must understand why patients go for emergent catheterization — and why the “normal arteries” result leads to the diagnosis rather than ruling out a cardiac cause. The condition is real, the myocardial dysfunction is real, and the nursing priorities (monitoring, anticoagulation, follow-up echo) are the same as for ACS in the acute phase. See the MI/ACS nursing reference for parallel management priorities.

HOCM vs DCM comparison

Nursing priorities by type

Complications across cardiomyopathy types

All cardiomyopathy types share common downstream complications, though the mechanisms and timing differ:

Atrial fibrillation — a major complication of all cardiomyopathy types. In DCM, left atrial enlargement from elevated filling pressures predisposes to AFib. In HOCM, the non-compliant LV is particularly dependent on atrial kick for filling — AFib causes rapid hemodynamic deterioration. In restrictive cardiomyopathy, elevated filling pressures chronically dilate both atria. AFib in any cardiomyopathy patient warrants rate control, rhythm management, and anticoagulation evaluation. Review the atrial fibrillation nursing reference for management protocols.

Heart failure — the shared clinical endpoint across all types. DCM produces HFrEF; HOCM and restrictive cardiomyopathy produce HFpEF physiology; Takotsubo can cause transient HF or cardiogenic shock. Nurses caring for any cardiomyopathy patient must be competent in heart failure nursing assessment and intervention.

Sudden cardiac death — highest risk in HOCM (young athletes) and severe DCM (EF ≤35%). Risk stratification and ICD consideration are fundamental to the long-term management of both.

Thromboembolic events — sluggish blood flow in a dilated, poorly contracting LV (DCM) or akinetic apical segment (Takotsubo) creates thrombus. Embolization causes stroke, systemic embolism, and organ infarction.

Infective endocarditis — structural cardiac disease and indwelling devices (ICDs, LVADs) increase the risk of endocarditis. See the infective endocarditis nursing reference for prevention and recognition.

Medication interactions and pharmacology — cardiomyopathy patients are on complex multi-drug regimens. The cardiovascular medications nursing reference covers ACE inhibitors, beta-blockers, loop diuretics, mineralocorticoid antagonists, and antiarrhythmics in depth.

NCLEX tips

• HOCM murmur increases with Valsalva and standing — reduced preload worsens LVOT obstruction, making the murmur louder. This is the opposite of every other systolic murmur (which decreases with Valsalva) and is pathognomonic for HOCM. If NCLEX asks which maneuver increases a murmur, the answer is Valsalva only for HOCM.

• Never give vasodilators, diuretics, or digoxin in HOCM — reducing preload or increasing contractility worsens LVOT obstruction and can cause hemodynamic collapse. Digoxin is a positive inotrope that makes the dynamic obstruction worse. These drugs are not “use with caution” — they are contraindicated.

• Displaced PMI in DCM — the apex beat is shifted laterally beyond the mid-clavicular line due to LV dilation. This is a physical exam finding NCLEX tests as a distinguishing feature of DCM.

• S3 gallop signals volume overload — an S3 heard at the apex in a patient with DCM indicates ventricular dilation and HF. Report to the provider immediately. (An S4 suggests a stiff ventricle and diastolic dysfunction, more typical of HOCM or restrictive cardiomyopathy.)

• Peripartum cardiomyopathy is defined as DCM presenting in the last month of pregnancy or within five months postpartum with no identifiable cause and no prior cardiac disease. NCLEX can test this with a question about a postpartum woman presenting with dyspnea — the answer is peripartum cardiomyopathy.

• Cardiac amyloidosis classic triad: sparkling myocardium on echo + low voltage ECG + elevated BNP disproportionate to LV size. The combination of thickened walls (suggesting hypertrophy) with low-voltage ECG (when hypertrophy should cause high voltage) is a signature finding of amyloid deposition.

• Takotsubo is triggered by catecholamine surge — always ask about a recent emotional or physical stressor (death of a loved one, accident, severe illness, medical procedure). The patient is most commonly a post-menopausal woman. Coronary arteries are normal on angiogram.

• Avoid catecholamines (epinephrine, dobutamine) in Takotsubo — they worsen the catecholamine-mediated dysfunction. If vasopressor support is required, norepinephrine is preferred.

• HOCM and sudden cardiac death in athletes — HCM is the leading cause of SCD in competitive athletes under age 35 in the United States. Pre-participation sports screening (ECG, echo at specialized centers) aims to identify at-risk athletes before competition.

• ICD in DCM — indicated for primary prevention of SCD when EF remains ≤35% after at least three months of optimized GDMT. NCLEX may ask when ICD is appropriate — the EF ≤35% threshold is the key number.

• Kussmaul’s sign — JVP rises with inspiration instead of falling; found in restrictive cardiomyopathy and constrictive pericarditis. The right ventricle cannot accommodate increased venous return during inhalation due to its non-compliant or constrained surroundings.

• HCM is autosomal dominant — first-degree relatives of an HCM patient should be screened with echocardiography and genetic testing. NCLEX tests this as a teaching point for patient education after HCM diagnosis.

Internal links

• Heart failure nursing: assessment, interventions, and NCLEX review — DCM produces HFrEF and HOCM/restrictive produce HFpEF physiology; essential companion reference
• Atrial fibrillation nursing: assessment, interventions, and NCLEX review — AFib complicates all cardiomyopathy types; particularly dangerous in HOCM due to LV preload dependence
• Myocarditis nursing: assessment, interventions, and NCLEX review — viral myocarditis is a cause of DCM and shares early clinical features
• Pericarditis nursing: assessment, interventions, and NCLEX review — differential diagnosis for chest pain; constrictive pericarditis mimics restrictive cardiomyopathy
• Infective endocarditis nursing: assessment, interventions, and NCLEX review — cardiac structural disease cluster; shared SBE prophylaxis considerations
• MI/ACS nursing: assessment, interventions, and NCLEX review — ischemic cardiomyopathy is the most common cause of DCM; Takotsubo mimics STEMI at presentation
• Cardiovascular medications nursing reference — detailed pharmacotherapy reference for ACE inhibitors, beta-blockers, diuretics, antiarrhythmics
• Aortic dissection nursing: assessment, interventions, and NCLEX review — chest pain differential; hypertension management overlaps with cardiomyopathy management