Cardiomyopathies. Shape, tissue and clinical decisions
Compare cardiomyopathy patterns, identify inherited and acquired causes, interpret imaging, and choose current treatments through complete clinical cases.
An ejection fraction, or EF, of 65% does not guarantee a healthy heart. A small, stiff ventricle may eject a normal fraction of an inadequate filling volume. Start with chamber shape, filling and tissue, then ask what disease produced that pattern.
Describe the heart before naming its cause
The familiar comparison is useful if it stays flexible. Dilated cardiomyopathy features LV dilation and systolic dysfunction. Hypertrophic cardiomyopathy features unexplained ventricular thickening. Restrictive physiology limits filling and raises atrial pressure. These are descriptions, not mutually exclusive lifelong boxes. A patient can progress from a thick-walled phenotype to systolic failure. [1]
Fraction ejected is not volume delivered
Dilated example
End-diastolic volume 200 mL
Stroke volume 60 mL
EF 30%
A large chamber ejects a small fraction.
Small-cavity example
End-diastolic volume 60 mL
Stroke volume 39 mL
EF 65%
The fraction is preserved, but the volume is smaller.
Calculate ejection fraction from the stated volumes. EF equals stroke volume divided by end-diastolic volume. Cardiac output also depends on heart rate, and regurgitation can reduce effective forward output.
Look beyond the three classic shapes. The 2023 ESC framework also recognizes arrhythmogenic right ventricular cardiomyopathy and nondilated LV cardiomyopathy, where scar or systolic dysfunction can exist before LV enlargement. Restrictive physiology can occur in infiltrative disease with increased wall thickness, although the strict restrictive morphological category has normal wall thickness. Preserve the difference between physiology and phenotype. [24][36]
Assess blood pressure, valve disease, coronary disease and congenital lesions that could explain the appearance. Global hypokinesis does not rule out ischemic disease, and regional dysfunction does not prove it. ECG and rhythm monitoring describe electrical disease; echo describes anatomy and loading; CMR adds tissue characterization. Family history, medicines, alcohol exposure, pregnancy timing and extracardiac findings direct further testing. [1]
The useful question is not just which shape. It is which cause, which complication and which treatment the patient needs.
Try it here · Checkpoint 1 of 3
Make your prediction before reading the choices. A first attempt is just a starting point.
Case 36
Show answer and explanations for case 36
A. Pulmonary embolism causing isolated RV failure (Why this does not fit)
Postpartum embolism is an important alternative, but isolated RV strain would not explain the demonstrated global LV systolic dysfunction after assessment for other causes.
B. Hypertensive pulmonary edema with preserved EF (Why this does not fit)
Her blood pressure is not elevated and LV EF is markedly reduced, so this alternative does not match the hemodynamic and imaging findings.
C. Previously established dilated cardiomyopathy worsening postpartum (Why this does not fit)
Known antecedent DCM would be an alternative cause, but the evaluation identifies no prior explanatory disease. Otherwise unexplained new systolic HF near delivery fits PPCM.
D. Peripartum cardiomyopathy (Best answer)
Otherwise unexplained HF with reduced EF near pregnancy or postpartum fits PPCM. Medication and device choices require pregnancy/lactation context.
Takeaway: Postpartum dyspnea with objective LV dysfunction deserves cardiac evaluation, not attribution to normal recovery.
Adult HCM generally involves maximal end-diastolic wall thickness of at least 15 mm that loading conditions cannot explain. Thickness of 13 to 14 mm can be diagnostic with an established pathogenic or likely pathogenic variant or an affected family member, after assessing other causes. Pediatric assessment uses body-size-adjusted criteria. A septal-to-posterior-wall ratio alone is not diagnostic, and HCM can be apical or relatively concentric rather than asymmetric septal. [31]
MYH7 and MYBPC3 are common sarcomeric genes. Myocyte hypertrophy, disarray and fibrosis can impair relaxation and create an arrhythmic substrate. Autosomal dominant inheritance is common, but penetrance and expression vary. A normal examination in one parent or a negative genetic panel does not exclude HCM. Do not assign a universal de novo percentage or predict a patient's prognosis from the gene name alone. [1][2]
Obstruction depends on anatomy and loading
With susceptible septal and mitral apparatus anatomy, systolic flow forces bring the anterior mitral leaflet toward the septum. This is systolic anterior motion, or SAM. The resulting LV outflow tract obstruction is dynamic, and accompanying MR can add to symptoms. A small cavity, stronger contraction or reduced vascular resistance can worsen the gradient. A Venturi suction analogy alone does not capture the full mitral and ventricular geometry. [26]
Predict the obstruction from the cavity
Less filling
Standing, Valsalva strain or dehydration
↓
Smaller LV cavity
↓
More leaflet-septal interaction and often a larger gradient
More filling or resistance
Leg raising, squatting or increased afterload
↓
More cavity volume maintained during contraction
↓
Usually less dynamic obstruction
Handgrip primarily increases afterload. The figure describes dynamic obstruction, not every cause of heart failure.
A resting or provoked LVOT gradient of at least 30 mmHg identifies obstruction. A gradient of at least 50 mmHg is the usual threshold relevant to advanced obstruction treatment in a symptomatic patient. If resting testing does not show a sufficient gradient, provocation and exercise echo can expose it. A high EF does not exclude severe symptoms. [2]
Obstructive HCM often produces a left parasternal systolic ejection murmur, sometimes with an S4 or bisferiens arterial pulse. AS more typically gives a neck-transmitted ejection sound with delayed carotid upstroke. MVP can also intensify with reduced LV volume, but its click occurs earlier and the late systolic murmur lengthens. No single maneuver proves HCM. [23]
Treat symptoms and sudden-death risk separately
A nonvasodilating beta blocker is first-line treatment for symptomatic obstruction. Verapamil or diltiazem can substitute when appropriate, but verapamil is unsuitable with hypotension, severe resting symptoms or very high resting gradients. Persistent symptoms warrant specialist discussion of a cardiac myosin inhibitor, disopyramide or septal reduction. Myectomy removes obstructing tissue; alcohol septal ablation creates a targeted septal infarction and later scar, with heart block among its risks. Selection depends on anatomy and clinical circumstances. [2]
Mavacamten reduces myosin participation in force generation and favors the energy-sparing super-relaxed state. It does not shift myosin out of that state. The US indication is adults with symptomatic NYHA class II or III obstructive HCM. Initiation is not recommended if EF is below 55%; echo monitoring and interruption if EF falls below 50% are required.
Pregnancy risk and interacting medicines also require label-specific assessment. Aficamten is another FDA-approved option for symptomatic obstructive HCM in adults. Both can cause systolic dysfunction; use each drug's own interaction and monitoring instructions. Myosin inhibitors are not a general treatment for all thick-walled hearts. [5][6]
Avoid reflex positive inotropy or substantial preload reduction in obstructive physiology. Digoxin, nitrates and aggressive diuresis can worsen the gradient. Small diuretic doses may still be appropriate for documented congestion. Monitored hypotension may require volume assessment and a vasoconstrictor without inotropic activity, such as phenylephrine. [2]
Prior cardiac arrest or sustained VT strongly supports an ICD. Primary prevention considers the whole risk profile, including suspected cardiac syncope, family history, major hypertrophy, apical aneurysm, LV dysfunction, rhythm findings and CMR scar. Symptom improvement does not replace risk assessment. Clinical AF in HCM warrants anticoagulation independent of the usual stroke-score threshold. Rate control can use a beta blocker, verapamil or diltiazem when tolerated and appropriate to the hemodynamics; poorly tolerated AF may warrant rhythm control with cardioversion or specialist-selected medication.
Avoid reflex digoxin use when obstruction is present. Mild to moderate recreational exercise is encouraged; competitive activity requires expert assessment and shared decisions rather than universal exclusion. [2]
A dilated heart needs a cause search and complete therapy
DCM requires LV dilation with impaired systolic performance not fully explained by another loading or coronary condition. Four-chamber enlargement and thin walls can occur but are not required. A displaced apex, S3, functional MR/TR and congestion fit a remodeled ventricle. S3 occurs during early rapid filling; an S4 reflects atrial contraction into a stiff ventricle and requires organized atrial activity. Neither is a stand-alone phenotype test. Slow flow, scar and dilation create risks of thrombus and arrhythmia, but anticoagulation is not automatic for every patient in sinus rhythm. [1][3]
Inherited structure
TTN truncating variants are a common genetic cause. LMNA disease can announce itself with conduction block or ventricular arrhythmia before marked EF decline. Dystrophin deficiency damages cardiomyocyte structural support and causes progressive fibrosis. Family screening matters even when exposure to alcohol or pregnancy appears to explain the presentation. [1][16]
Acquired injury
Alcohol toxicity, inflammatory myocarditis, cancer treatment and persistent tachyarrhythmia can impair contraction. A viral prodrome does not identify Coxsackie B or prove a viral etiology. CMR helps assess inflammation; biopsy is selective, especially when identifying a treatable subtype would change management. [18]
Alcohol abstinence and nutritional correction can allow improvement, but recovery is not guaranteed. Thiamine deficiency can produce high-output failure through vasodilation and impaired metabolism, which differs from typical alcohol-related low-output DCM. Give thiamine promptly when deficiency is suspected; emergency glucose for hypoglycemia should not be delayed. Treat reversible contributors alongside HF therapy. [27][28]
Doxorubicin can cause cumulative myocardial injury involving oxidative and DNA damage. Trastuzumab blocks HER2 signaling and can reduce EF; cardiac-specific HER2 deletion in mice supports a protective role for this pathway, although that experiment does not determine human treatment decisions. [38][39] The old division into always irreversible anthracycline injury and always reversible trastuzumab dysfunction is too rigid. Surveillance, cardioprotective treatment and interruption or continuation decisions belong to a cardio-oncology plan. Dexrazoxane can provide cardioprotection in selected anthracycline settings. [10]
Chronic Chagas disease can cause right bundle branch block with left anterior fascicular block, ventricular dysfunction, apical aneurysm and thrombus. None of these alone proves infection. Antiparasitic treatment decisions depend on disease stage; established structural damage does not reliably reverse with parasite treatment. [14]
Scar-related sustained monomorphic VT usually reflects reentry through surviving myocardial bundles interspersed with fibrosis. Slow conduction and areas of block permit a circulating impulse. Dense scar itself does not conduct the circuit; the surviving tissue around and within scar does. This substrate can persist despite improved symptoms or EF. [32]
The HFrEF foundation has four classes
ARNI, or ACE inhibitor/ARB when ARNI is unsuitable.
An evidence-based beta blocker.
A mineralocorticoid receptor antagonist when renal function and potassium permit.
An SGLT2 inhibitor, including in patients without diabetes.
Loop diuretics relieve congestion but do not replace these disease-modifying classes. Initiation and dose adjustment depend on clinical stability, blood pressure, kidney function and potassium. Selected symptomatic patients with EF at most 35% despite appropriate therapy and meaningful expected survival beyond a year benefit from primary-prevention ICD assessment. CRT is particularly effective with EF at most 35%, LBBB and QRS at least 150 ms in the appropriate symptomatic patient. Genetic risk can justify specialist ICD consideration at higher EF. [1] Refer advanced, refractory HF for advanced-therapy assessment. [3]
Improved EF often means remission. Continue indicated therapy rather than declaring the cardiomyopathy cured. TRED-HF documented frequent relapse after supervised withdrawal in recovered DCM. [17]
Find what is making filling difficult
Restrictive physiology raises filling pressure despite normal or small ventricular cavities. The atria often enlarge as pressure accumulates upstream. EF may initially be preserved and later decline; longitudinal contraction can already be impaired while EF looks normal. Kussmaul sign, a rise in jugular venous pressure with inspiration, signals impaired right-sided filling but is not unique to myocardial restriction. [1][19]
Amyloid suspicion is not amyloid typing
Cardiac amyloidosis is usually AL or ATTR, not predominantly AL and AA. ATTR can involve wild-type or variant transthyretin. Thick walls with unexpectedly low ECG voltage, conduction disease, carpal tunnel syndrome, neuropathy or unexplained HF can raise suspicion. Normal voltage does not exclude it. Apical sparing on strain is supportive, not a stand-alone diagnosis; a granular echo appearance is nonspecific. [4]
Suspect amyloid → obtain an assay for serum free light chains plus serum and urine immunofixation. Ordinary protein electrophoresis alone is inadequate.
Monoclonal testing abnormal → specialist evaluation and tissue confirmation with reliable amyloid typing. A positive bone scan cannot by itself establish ATTR in this branch. Kidney dysfunction can alter the ratio of kappa to lambda free light chains, so interpretation needs context.
Monoclonal screen negative → appropriate bone-tracer scintigraphy, including SPECT confirmation of myocardial uptake, can establish ATTR with compatible imaging and grade 2 or 3 uptake. TTR genetic testing then distinguishes hereditary from wild-type disease.
Congo red with characteristic birefringence supports tissue amyloid, but protein typing determines therapy. AL requires prompt hematology-directed treatment. Tafamidis and acoramidis stabilize TTR; vutrisiran reduces hepatic TTR synthesis and has a US ATTR-CM indication. It also lowers circulating vitamin A, requiring recommended supplementation. These are not interchangeable with plasma-cell therapy for AL. [4][7][8]
Other causes leave different evidence
Sarcoidosis can produce inflammatory injury, patchy scar, AV block and VT. It is not restricted to a restrictive phenotype. CMR and FDG-PET answer complementary questions about scar and active inflammation; no single scar pattern is diagnostic. [9]
Iron overload can cause restrictive or dilated physiology. Transferrin saturation and ferritin assess systemic iron; cardiac MRI evaluates myocardial iron. Diabetes, liver disease and skin pigmentation can accompany systemic overload but are not required. When tissue is examined, Perls Prussian blue staining demonstrates iron deposits; a liver stain alone does not establish cardiac iron burden. [37] Phlebotomy is usual treatment for suitable hereditary hemochromatosis. When phlebotomy is unsuitable, chelation may be considered after specialist risk-benefit assessment; life-threatening cardiac iron overload is a particular setting. EASL grades this as a weak recommendation supported by limited evidence. [13]
Eosinophilic disease can injure endomyocardium, promote mural thrombus and ultimately produce apical fibrosis or obliteration. Necrotic, thrombotic and fibrotic phases may overlap. Treat the eosinophilic cause and the cardiac complications. [20]
Radiation and systemic sclerosis can cause myocardial fibrosis. Systemic sclerosis can also cause pulmonary hypertension, renal crisis or pericardial disease; do not call every cardiac problem primary myocardial fibrosis. [10][21]
Fabry disease is a hypertrophic phenocopy caused by deficient alpha-galactosidase A activity and glycosphingolipid accumulation. Burning extremity pain, angiokeratomas, renal disease and LV thickening suggest it. Women can have substantial disease. Enzyme replacement or a suitable variant-specific chaperone addresses the cause. Fabry is an X-linked GLA disorder with globotriaosylceramide accumulation. Pompe disease is an autosomal recessive GAA deficiency with lysosomal glycogen accumulation; cardiomyopathy is characteristic of infantile disease, while later presentations more often emphasize skeletal and respiratory weakness.
Danon disease is an X-linked LAMP2-associated vacuolar myopathy, often with marked hypertrophy and pre-excitation in young males; females can have hypertrophic or dilated disease. Friedreich ataxia is a distinct FXN-related frataxin deficiency that impairs mitochondrial function and can combine progressive ataxia with cardiomyopathy. [33][34][35][15][1]
Try it here · Checkpoint 2 of 3
Make your prediction before reading the choices. A first attempt is just a starting point.
Case 23
Show answer and explanations for case 23
A. Use the absence of affected relatives as the deciding test (Why this does not fit)
Hereditary ATTR can have late onset and variable expression, so an apparently negative family history does not establish wild-type disease.
B. Congo red staining without protein or genetic analysis (Why this does not fit)
Staining detects amyloid but cannot distinguish wild-type from variant TTR.
C. TTR genetic testing with counseling (Best answer)
A pathogenic TTR variant establishes hereditary ATTR and informs family assessment.
D. Use the intensity of PYP uptake to identify a hereditary variant (Why this does not fit)
Uptake supports cardiac ATTR in the appropriate diagnostic pathway but does not determine the TTR genotype.
Takeaway: Age and a positive PYP scan cannot independently establish wild-type ATTR.
Restriction is a myocardial filling problem. Constriction is a pericardial constraint with exaggerated ventricular interdependence. Both may cause edema, ascites and Kussmaul sign. In constriction, respiratory septal shift, preserved medial mitral annular e′ and expiratory hepatic vein diastolic flow reversal are useful together. Restrictive myocardial disease more often reduces annular relaxation velocities. Pericardial thickening supports constriction but its absence does not exclude it. BNP is not a binary separator, particularly with renal disease or mixed pathology. [19][29][30]
Athlete adaptation versus inherited disease
An enlarged athletic cavity with preserved relaxation may support adaptation, while disproportionate thickness, pathological ECG changes, symptoms, scar or family history raise concern. No single wall measurement, absence of scar or detraining result definitively settles all cases. Integrate history, ECG, echo, CMR and genetics when informative. A relative with a pathogenic variant is more useful for cascade testing than an unclassified variant. [1][2]
Arrhythmogenic cardiomyopathy
Desmosomal disease can produce fibrotic or fibrofatty replacement and ventricular arrhythmias, particularly with strenuous endurance exercise. ARVC may show RV regional dysfunction, dilation and right-precordial T-wave inversion; an epsilon wave is neither required nor sufficient. DSP disease may be predominantly left ventricular, so do not force all desmosomal disease into an RV-only category. [1]
Takotsubo and pregnancy-associated dysfunction
Takotsubo syndrome is transient regional dysfunction that often extends beyond one coronary territory. Apical ballooning is familiar, but midventricular and basal variants occur. A stress trigger is supportive, not required. Suspected acute coronary syndrome still needs urgent evaluation; coexisting coronary disease does not exclude Takotsubo. Recovery is common, but shock, arrhythmia and thrombus can occur. [12][25]
Peripartum cardiomyopathy is otherwise unexplained systolic HF near the end of pregnancy or after delivery, usually with EF below 45%. The traditional last-month-to-five-month window should not dismiss compatible disease outside it. Pregnancy and lactation change medication choices. During pregnancy, selected beta blockers, hydralazine with nitrates and cautious diuresis may be used as the clinical situation requires.
Postpartum treatment needs a separate review of lactation compatibility. A wearable defibrillator may bridge selected patients while recovery is assessed. During pregnancy, avoid the routine adult HFrEF package that includes renin-angiotensin inhibitors and SGLT2 inhibitors. Subsequent-pregnancy counseling depends strongly on LV recovery, but even normalized EF does not remove recurrence risk. [11]
Hypertension can cause concentric hypertrophy and HFpEF. Obesity, pulmonary vascular disease and sleep-related breathing disorders can add distinct loading stresses. Awake hypercapnia in a patient with obesity should prompt assessment for obesity hypoventilation, not attribution of all RV failure to uncomplicated sleep apnea. [3][22]
Choose the next action and include the family
Shock, sustained arrhythmia or high-grade block requires stabilization and urgent specialty care before completing phenotype classification.
Thick walls prompt assessment of loading, HCM, amyloid and storage disease. Determine whether obstruction is present before using preload-reducing treatment.
Dilation with reduced EF calls for coronary and cause assessment, complete tolerated HF therapy and arrhythmia evaluation.
Congestion with preserved EF calls for filling and tissue assessment rather than reassurance from EF.
Family disease or unexplained sudden death calls for a three-generation history, genetic counseling and clinical screening of first-degree relatives.
Offer cascade testing when the family has an established pathogenic or likely pathogenic variant. A variant of uncertain significance is not a diagnosis. When the genetic cause is unresolved, clinical surveillance remains useful. For asymptomatic at-risk HCM relatives, ECG and echo are generally repeated every 1 to 2 years in children from genotype-positive families or families with early-onset disease; other children and adolescents are generally screened every 2 to 3 years, beginning no later than puberty.
Adult intervals are generally 3 to 5 years. Symptoms or an aggressive family course shorten intervals. A relative who tests negative for the established familial pathogenic variant generally does not need ongoing HCM screening unless variant reclassification or clinical findings change the assessment. [1][2]
Match the treatment to the mechanism, reassess the electrical risk and plan follow-up even when the patient feels better.
Try it here · Checkpoint 3 of 3
Make your prediction before reading the choices. A first attempt is just a starting point.
Case 40
Show answer and explanations for case 40
A. Diagnose her son with inherited cardiomyopathy from the uncertain genetic variant alone (Why this does not fit)
Uncertain classification is not proof that the variant causes disease.
B. End further clinical evaluation of the family because no pathogenic variant was identified (Why this does not fit)
Clinical family screening can remain indicated when genetic testing is inconclusive.
C. Use the uncertain genetic variant as a definitive predictive test for each family member (Why this does not fit)
Predictive cascade testing is based on established pathogenic or likely pathogenic variants, with appropriate counseling.
D. Offer genetic counseling and phenotype-based family screening during variant reassessment (Best answer)
This maintains useful surveillance without falsely assigning disease from an uncertain genetic result.
Takeaway: An uncertain genetic result does not replace clinical screening or establish a diagnosis.
A. Repeat a resting EF measurement alone (Why this does not fit)
A high EF does not measure a provoked LVOT gradient.
B. Physiologic provocation and exercise echocardiography (Best answer)
Dynamic obstruction may emerge with loading changes or exercise despite a low resting gradient.
C. A serum BNP level as the sole diagnostic test (Why this does not fit)
BNP may reflect hemodynamic stress but cannot localize or quantify dynamic obstruction.
D. Proceed directly to resting cardiac catheterization without provocation (Why this does not fit)
Resting invasive pressures may still miss exertional obstruction. Physiologic stress echo directly addresses the unresolved symptom-gradient relationship.
Takeaway: A low resting gradient does not exclude symptomatic provoked obstruction.
Its beta-1 inotropy can intensify dynamic obstruction in this setting, despite its role in other low-output states.
B. Dopamine at a dose with prominent beta-1 effects (Why this does not fit)
Increased contractility and heart rate can worsen the obstructive gradient; a pressor without direct inotropy is preferred here.
C. Epinephrine (Why this does not fit)
Its beta-adrenergic effects can worsen dynamic obstruction. This stem asks for pressure support after fluid replacement, without increasing inotropy.
D. Phenylephrine (Best answer)
Predominant alpha-mediated vasoconstriction supports vascular resistance without direct beta-1 inotropic stimulation, fitting persistent hypotension with obstruction after appropriate fluids.
Takeaway: In obstructive HCM hypotension, loading and inotropy matter as much as the pressure number.
A. Reduce the dose but continue treatment without interruption (Why this does not fit)
The mavacamten algorithm requires interruption when LVEF is below 50%; dose reduction while continuing is not the initial response.
B. Interrupt mavacamten and reassess using the label algorithm (Best answer)
The label requires interruption when EF is below 50%, with clinical and echocardiographic reassessment.
C. Continue unchanged until the next routine monitoring visit (Why this does not fit)
LVEF 46% with new fatigue requires action now. Waiting for routine follow-up risks further systolic dysfunction.
D. Permanently discontinue after this first decline without reassessing EF (Why this does not fit)
Immediate interruption is required, but the label allows selected restarting after reassessment and recovery. A first decline does not by itself establish permanent discontinuation.
Takeaway: Serial EF monitoring is an active treatment requirement for mavacamten.
A. It surgically excises the hypertrophied basal septum (Why this does not fit)
Excision describes myectomy. Alcohol ablation achieves tissue reduction through a local infarction and subsequent remodeling.
B. It primarily lowers the gradient by permanently slowing the sinus node (Why this does not fit)
Alcohol is delivered to a septal coronary branch, not the sinus node. Conduction block is a complication rather than its intended therapeutic mechanism.
C. It creates a targeted septal infarction followed by remodeling (Best answer)
The treated septal segment scars and thins, reducing obstruction. Injury to conduction tissue can cause heart block.
D. It enlarges the cavity through permanent reduction of systemic vascular resistance (Why this does not fit)
Systemic vasodilation can worsen dynamic obstruction. Septal ablation changes local obstructing anatomy.
A. Recommend anticoagulation for clinical AF in HCM regardless of stroke-score threshold (Best answer)
HCM-associated AF has sufficient embolic risk that the conventional score alone should not determine withholding therapy.
B. Use aspirin alone for stroke prevention because she is younger than 65 (Why this does not fit)
Age alone does not negate the HCM-specific embolic risk, and aspirin does not substitute for indicated anticoagulation.
C. Defer anticoagulation until she develops an additional conventional stroke risk factor (Why this does not fit)
Clinical AF in HCM has a guideline anticoagulation indication independent of the conventional score; waiting for another risk factor is not appropriate.
D. Base anticoagulation solely on whether resting LVOT obstruction is present (Why this does not fit)
Stroke prevention in clinical HCM-associated AF is not conditional on a particular obstructive gradient.
Takeaway: HCM with clinical AF changes the anticoagulation decision.
A. Restrict activity to light household tasks because of the HCM diagnosis (Why this does not fit)
Routine exclusion from moderate recreational activity is not recommended after individualized evaluation; the proposed activity fits the recommended recreational range.
B. Encourage mild to moderate recreation with a personalized exercise plan (Best answer)
Current guidance supports recreational exercise; higher-intensity or competitive activity needs additional shared assessment.
C. Approve competitive racing on the basis of her preserved ejection fraction alone (Why this does not fit)
Competitive participation needs broader expert risk assessment and shared decisions; EF alone is insufficient.
D. Implant a defibrillator solely to allow her to participate in sports (Why this does not fit)
An ICD should follow clinical risk indications, not serve as a shortcut to sports clearance.
Takeaway: Exercise advice in HCM is individualized, not a universal prohibition.
A. Defer arrhythmia assessment until EF falls below 35% (Why this does not fit)
LMNA-related arrhythmic risk may be important before severe EF decline.
B. Plan a conventional pacemaker without assessing defibrillator need (Why this does not fit)
Pacing may address bradycardia but does not provide defibrillation for malignant ventricular arrhythmias; her genotype and rhythm history warrant broader assessment.
C. Treat presyncope as vasovagal without rhythm assessment because EF is above 40% (Why this does not fit)
Conduction disease, NSVT and familial sudden death require assessment for an arrhythmic cause despite moderately preserved EF.
D. Refer for genotype-informed arrhythmic risk and device assessment (Best answer)
Variant, family history, ventricular arrhythmia and conduction phenotype should be integrated rather than applying EF alone.
Takeaway: In genetic cardiomyopathy, conduction disease and scar can matter before a conventional EF threshold.
A. Support sustained abstinence, assess nutrition and start tolerated HF guideline therapy (Best answer)
Alcohol toxicity and nutritional contributors should be addressed while treating systolic HF. Recovery is possible but not guaranteed.
B. Treat congestion with a loop diuretic and reassess before offering disease-modifying HF therapy (Why this does not fit)
Diuretics relieve fluid retention but do not replace appropriate foundational therapy while the cause is addressed.
C. Provide thiamine replacement as the entire treatment plan for his cardiac disease (Why this does not fit)
Nutritional deficiency should be treated when suspected, but this low-EF dilated phenotype also requires HF therapy and sustained alcohol abstinence.
D. Refer directly for cardiac transplantation without treating reversible contributors (Why this does not fit)
Advanced-therapy referral may be needed in refractory HF, but the stem has not established failure of abstinence, nutritional support and appropriate HF therapy.
Takeaway: Treat the exposure and the ventricular dysfunction together.
A. Coordinate cardioprotective treatment, monitoring and cancer-therapy decisions with cardio-oncology (Best answer)
The clinical severity and oncologic benefit guide continuation or interruption; a rigid reversible-versus-irreversible label is insufficient.
B. Permanently stop trastuzumab in every asymptomatic patient with EF 40% to 49% (Why this does not fit)
The 2022 ESC approach permits continuation in selected asymptomatic moderate dysfunction with cardioprotection and frequent monitoring, after multidisciplinary assessment.
C. Continue the oncology regimen without cardiac treatment or closer monitoring (Why this does not fit)
An asymptomatic EF decline still warrants cardioprotection and monitoring; absence of congestion does not make it inconsequential.
D. Use a loop diuretic alone to treat the measured EF decline (Why this does not fit)
She has no congestion, and a diuretic alone does not address the systolic dysfunction or the need to coordinate ongoing cancer treatment.
Takeaway: Cancer treatment decisions should integrate EF, symptoms, risk and cancer benefit.
A. A dihydropyridine calcium channel blocker (Why this does not fit)
This may treat hypertension but does not complete the four foundational HFrEF classes.
B. An SGLT2 inhibitor (Best answer)
SGLT2 inhibitors benefit eligible HFrEF patients regardless of diabetes status.
C. Ivabradine regardless of resting heart rate (Why this does not fit)
Ivabradine is an adjunct for selected patients in sinus rhythm with sufficiently high resting heart rate despite beta blockade; it does not replace the missing foundational SGLT2 class.
D. Routine oral anticoagulation solely for reduced EF (Why this does not fit)
Reduced EF in sinus rhythm without another indication does not automatically require anticoagulation.
Takeaway: SGLT2 therapy is a heart-failure treatment even without diabetes.
A. Implant a conventional RV pacemaker to correct the wide QRS (Why this does not fit)
A wide LBBB QRS in symptomatic HFrEF is a setting for resynchronization assessment; conventional RV pacing does not provide equivalent biventricular coordination.
B. Implant a defibrillator alone without evaluating resynchronization (Why this does not fit)
A defibrillator may be appropriate, but it does not address the mechanical dyssynchrony for which she meets strong CRT assessment criteria.
C. Assess CRT, choosing defibrillator capability according to her risk (Best answer)
The combination of low EF, persistent symptoms and broad LBBB fits a strong CRT indication.
D. Defer assessment for resynchronization until QRS duration exceeds 200 ms (Why this does not fit)
A 150-ms LBBB threshold already identifies a strong-benefit group in the appropriate symptomatic, treated patient; waiting for 200 ms is unnecessary.
A. Serum free light chains plus serum and urine immunofixation (Best answer)
The complete screen is necessary; ordinary electrophoresis alone can miss a monoclonal process.
B. Serum protein electrophoresis alone (Why this does not fit)
This lacks sufficient sensitivity to exclude AL.
C. Serum free light chains and serum immunofixation without urine immunofixation (Why this does not fit)
This omits part of the complete monoclonal screen. Serum and urine immunofixation plus free light chains are used together before the nonbiopsy pathway.
D. Serum and urine protein electrophoresis without immunofixation (Why this does not fit)
Ordinary electrophoresis is insufficiently sensitive to replace immunofixation and free light protein testing for this purpose.
Takeaway: Use all three components of the monoclonal screen before relying on bone scintigraphy for ATTR.
A. Beta-glucocerebrosidase deficiency (Why this does not fit)
Gaucher disease classically emphasizes reticuloendothelial and skeletal involvement rather than this specific renal, neuropathic and cardiac combination.
B. Acid alpha-glucosidase deficiency (Why this does not fit)
Infantile Pompe can cause hypertrophy but the adult neuropathic, cutaneous and renal pattern favors Fabry.
C. Frataxin deficiency (Why this does not fit)
Friedreich ataxia can involve the heart but usually features a prominent neurologic ataxic syndrome rather than angiokeratomas and acroparesthesias.
D. Alpha-galactosidase A deficiency (Best answer)
GLA-related Fabry disease produces glycosphingolipid accumulation with these characteristic organ manifestations.
Takeaway: A hypertrophic phenotype with renal and neuropathic findings should trigger a phenocopy search.
Normal cavity size and EF with characteristic respiratory physiology do not fit a dilated systolic pattern.
B. Restrictive myocardial disease from cardiac amyloidosis (Why this does not fit)
Amyloid can cause similar congestion, but preserved medial e-prime and the respiratory septal and hepatic-flow findings favor constriction in combination.
C. Constrictive pericarditis (Best answer)
The combination of septal shift, preserved medial annular velocity and hepatic venous findings supports pericardial constraint.
D. Severe tricuspid regurgitation (Why this does not fit)
TR can cause systemic congestion and hepatic systolic flow reversal. The specified expiratory diastolic reversal with respiratory septal shift instead supports pericardial constraint.
Takeaway: Use an integrated respiratory echo pattern to distinguish constriction from myocardial restriction.
A. Increased pulmonary vascular resistance alone producing isolated RV pressure loading (Why this does not fit)
The assessment has excluded significant pulmonary hypertension and identified direct myocardial abnormalities.
B. Ischemic scar from obstructive epicardial coronary disease (Why this does not fit)
This is an alternative source of myocardial fibrosis, but explanatory coronary disease has been excluded in the stem.
C. ATTR infiltration unrelated to systemic sclerosis (Why this does not fit)
ATTR is a separate differential diagnosis requiring specific evidence and typing. Systemic sclerosis does not establish it; the described evaluation supports primary sclerosis-related involvement.
D. Sclerosis-related inflammation, microvascular injury and myocardial fibrosis (Best answer)
These are recognized components of primary systemic sclerosis heart involvement after secondary causes are assessed.
Takeaway: Separate primary myocardial sclerosis-related disease from pulmonary, renal and coronary contributors.
Myocarditis remains an initial differential, but the circumferential dysfunction, CMR assessment and recovery together favor Takotsubo in this case. Absence of enhancement alone would not exclude myocarditis.
B. Acute infarction confined to a single LAD territory (Why this does not fit)
The dysfunction extends beyond a single territory and the coronary and CMR findings do not support an infarction explaining this pattern.
C. Takotsubo syndrome (Best answer)
A physical trigger and transient regional pattern beyond one vascular territory support stress-associated myocardial dysfunction.
D. Tachycardia-induced cardiomyopathy (Why this does not fit)
That requires a sufficient sustained arrhythmia burden, which is absent here. The acute regional pattern and postoperative setting favor Takotsubo.
Takeaway: Takotsubo can follow physical stress and still requires acute cardiac care.
