What is the recommended diagnostic and therapeutic approach for a patient with left ventricular non‑compaction (LVNC)?

Management of Left Ventricular Non-Compaction (LVNC)

Patients with LVNC should be managed according to their functional phenotype—treating heart failure with standard guideline-directed medical therapy, using ICD criteria identical to dilated cardiomyopathy based on LV systolic dysfunction severity, and implementing anticoagulation for atrial fibrillation or documented LV thrombus—rather than basing treatment decisions on the morphological diagnosis of non-compaction alone. 1

Diagnostic Approach

Imaging Criteria

• Echocardiography remains the initial diagnostic test, looking for a two-layered myocardial structure with a non-compacted to compacted layer ratio >2:1 2
• Cardiac MRI provides confirmatory diagnosis when the non-compacted to compacted ratio is >2.3:1, though validation of these morphological criteria has been questioned 2
• The presence of prominent trabeculations alone does not establish disease—functional assessment, tissue characterization, and clinical context are essential to distinguish pathologic cardiomyopathy from benign anatomical variants 3

ECG Findings

• Common abnormalities include T-wave inversion, ST-segment depression, or ventricular conduction delay (particularly LBBB) 2
• These findings support the diagnosis but are non-specific 2

Genetic and Family Evaluation

• Screen all first-degree relatives with echocardiography and ECG, as 18-50% of cases are familial with predominantly autosomal dominant inheritance 2, 1
• Genetic testing identifies clinically significant variants in 35-40% of patients, most commonly in sarcomere-encoding genes (MYH7, MYBPC3), calcium-handling proteins, LMNA, LDB3, and Taffazin 2, 1

Heart Failure Management

For Reduced Ejection Fraction (LVEF <50%)

• Implement full guideline-directed medical therapy: ACE inhibitors/ARBs, beta-blockers, aldosterone antagonists, and SGLT2 inhibitors 1
• Evaluate for concomitant causes of systolic dysfunction, particularly coronary artery disease, before attributing dysfunction solely to non-compaction 1
• The non-compaction morphology should not alter standard heart failure treatment—treat the functional phenotype, not the anatomical appearance 1

For Preserved Ejection Fraction

• Initiate beta-blockers or non-dihydropyridine calcium channel blockers as first-line therapy for exertional dyspnea or angina in symptomatic patients 1

Sudden Cardiac Death Risk Stratification and ICD Therapy

Critical Principle

The presence of non-compaction morphology alone does NOT justify ICD implantation 2, 1

ICD Indications (Primary Prevention)

• LVEF ≤35% with NYHA class II-III symptoms despite optimal medical therapy for ≥3 months 1
• Use identical criteria as for dilated cardiomyopathy—the non-compaction diagnosis does not change these thresholds 2, 1

ICD Indications (Secondary Prevention)

• Sustained ventricular arrhythmias documented on monitoring warrant ICD consideration using standard criteria 2, 1
• The severity of LV systolic dysfunction and presence of sustained ventricular arrhythmias guide ICD decisions, not the trabeculation pattern 2

Risk Factors for Adverse Outcomes

• Clinical outcome is governed by the magnitude of LV dysfunction, prevalence of atrial and ventricular arrhythmias, and thromboembolic events 2
• Increased age, LV end-diastolic diameter, symptomatic heart failure, persistent atrial fibrillation, and bundle branch block predict increased mortality 2

Anticoagulation Strategy

Mandatory Indications

• All patients with atrial fibrillation or atrial flutter require oral anticoagulation regardless of CHA₂DS₂-VASc score 1
• Documented LV thrombus requires anticoagulation 1
• History of systemic thromboembolism warrants long-term anticoagulation 1

Rationale

• LVNC carries risk of systemic thromboembolism as part of its clinical presentation, making anticoagulation critical in these specific scenarios 2

Arrhythmia Management

Atrial Fibrillation

• Rate control is critical given fixed stroke volume and dependence on diastolic filling 1
• Beta-blockers are first-line for rate control unless contraindicated by hypotension or severe bradycardia 1
• Amiodarone or sotalol for rhythm control if symptoms persist despite rate control 1

Ventricular Arrhythmias

• Frequent or complex ventricular tachyarrhythmias on ambulatory ECG monitoring and exercise testing indicate higher risk and should guide ICD consideration using standard DCM criteria 2

Advanced Heart Failure Management

Transplant Evaluation

• Evaluate for heart transplantation in patients with NYHA class III-IV symptoms despite optimal medical therapy 1
• Perform cardiopulmonary exercise testing to quantify functional limitation and aid in transplant selection 1

Pediatric Considerations

• Children with LVNC have particularly poor outcomes: 1-year transplant-free survival 48%, 2-year 34%, 5-year 22% 1
• Early transplant evaluation is critical in pediatric cases given these dismal outcomes 1

Exercise and Sports Participation

Competitive Sports Restrictions

• Athletes with symptomatic LVNC, LVEF <40%, extensive late gadolinium enhancement (>20%) on CMR, frequent/complex ventricular arrhythmias, or history of unexplained syncope should NOT engage in competitive sports 2
• These patients should limit exercise to leisure-time activities and undergo regular clinical surveillance 2

Selective Participation

• Asymptomatic athletes with LVNC and preserved LV function may selectively engage in competitive sports after comprehensive risk assessment and clear explanation of associated risks 2

Critical Pitfalls to Avoid

Do NOT:

• Withhold standard heart failure therapy based solely on the non-compaction diagnosis—always treat the functional phenotype 1
• Implant ICDs for primary prevention based on non-compaction morphology alone without meeting standard criteria for reduced LVEF or documented arrhythmias 2, 1
• Assume all prominent trabeculations represent pathologic cardiomyopathy—many represent benign anatomical variants 3

DO:

• Base all therapeutic decisions on functional parameters (LVEF, symptoms, arrhythmias) rather than morphological appearance 1
• Screen family members systematically given high familial prevalence 2, 1
• Maintain high suspicion for thromboembolic complications and anticoagulate appropriately 1