Noncompaction Cardiomyopathy in Childhood Flashcards
What is Noncompaction Cardiomyopathy (NCCM)?
A genetic disease characterized by excessive and unusual trabeculations within the mature left ventricle.
What is the primary morphological appearance of NCCM?
A spongy morphological appearance of the myocardium with abnormal trabeculations.
Which part of the heart is primarily affected by NCCM?
The left ventricle (LV).
What are the two distinct layers of myocardium noted in NCCM?
- Compacted myocardium
- Non-compacted myocardium
What are some clinical associations of NCCM?
- Left ventricular dilation
- Hypertrophy
- Systolic dysfunction
- Diastolic dysfunction
- Atrial enlargement
- Congenital heart disease
What is the estimated occurrence of NCCM in live births?
Approximately 1 per 7000 live births.
True or False: NCCM can occur in both children and adults.
True.
What are the risks associated with NCCM?
- Left or right ventricular failure
- Ventricular arrhythmias
- Atrioventricular block
- Sudden death
What factors may contribute to the variability in clinical presentation of NCCM?
Age and presence of associated systemic diseases.
Which imaging technique is commonly used for diagnosing NCCM?
Echocardiography.
What are the genetic causes of left ventricular noncompaction?
- ACTC1
- CASQ2
- DTNA
- DYS
- GLA
- LDB3
- LMNA
- MIB1
- MYBPC3
- MYH7
- Nkx2-5
- TAZ
- TNNT2
What are the potential outcomes for patients with NCCM?
- Asymptomatic
- End-stage heart failure
- Lethal arrhythmias
- Sudden cardiac death
Fill in the blank: NCCM is also known as _______.
left ventricular noncompaction (LVNC)
What was the prevalence of NCCM reported among heart failure patients?
3–4%.
What is a significant feature of NCCM pathology?
Numerous excessively prominent trabeculations with deep intra-trabecular recesses.
What is the role of mitochondrial function in NCCM?
Disrupted mitochondrial function is thought to have a causal role.
What is the significance of the Notch or Wnt signaling pathways in NCCM?
They may be part of a ‘final common pathway’ for NCCM associated with congenital heart disease.
What treatments are focused on for NCCM?
- Improvement of cardiac efficiency
- Reduction of mechanical stress
- Arrhythmia therapy
- Implantation of an ICD
Which age group has the worst reported outcomes for NCCM?
Infants.
True or False: Most patients with NCCM are symptomatic.
False.
What does the American Heart Association classify NCCM as?
A distinct cardiomyopathy.
What are the clinical features of NCCM?
Highly variable, ranging from asymptomatic to severe heart failure or arrhythmias.
What is the role of thrombi in patients with NCCM?
Mural thrombi can develop, posing risks for stroke or coronary obstruction.
What can cause subendocardial ischemia in NCCM?
Prominent trabeculations and intra-trabecular recesses affecting perfusion.
What is the annualized event rate of cardiovascular deaths in adults with isolated NCCM?
4%
This statistic was reported in a study by Bhatia et al.
What percentage of first-degree relatives of index cases screened by echocardiography were identified with familial NCCM?
30%
This finding was noted in studies reviewed by Bhatia et al.
What was the mortality rate among children diagnosed with isolated left ventricular noncompaction?
12.8%
This statistic is based on a retrospective review by Brescia et al.
How many children diagnosed with isolated left ventricular noncompaction presented with or developed cardiac dysfunction?
62%
This statistic highlights the association between cardiac dysfunction and mortality.
What is the hazard ratio for mortality associated with the presence of cardiac dysfunction in NCCM patients?
11
This finding indicates a strong correlation between cardiac dysfunction and increased mortality risk.
What percentage of patients with NCCM had ECG abnormalities?
87%
Common ECG findings included ventricular hypertrophy and repolarization abnormalities.
True or False: Repolarization abnormalities in NCCM patients are associated with increased mortality.
True
The hazard ratio for repolarization abnormalities is 2.1.
What is the hazard ratio for mortality in NCCM patients with arrhythmias?
2.8
This statistic underscores the increased risk of mortality in patients with arrhythmias.
What are the two forms of NCCM primarily focused on in reports?
- Isolated NCCM
- NCCM with congenital heart disease
What characterizes the ‘benign’ form of NCCM?
Normal left ventricular size and wall thickness with preserved systolic and diastolic function
This subtype accounts for up to ~35% of NCCM patients.
What is the outcome of patients with the ‘benign’ form of NCCM in the absence of significant arrhythmias?
Good outcome
This form does not typically represent a cardiomyopathy.
What defines the NCCM subtype with arrhythmias?
Preserved systolic function with normal left ventricular size and wall thickness but evidence of underlying arrhythmias.
What is the outcome of the dilated cardiomyopathy form of NCCM?
Similar outcome compared to those with a similar degree of dilated cardiomyopathy
Neonates and infants have a worse outcome.
What characterizes the hypertrophic cardiomyopathy form of NCCM?
Left ventricular thickening, usually with asymmetric septal hypertrophy, diastolic dysfunction, and hypercontractile systolic function.
What is the risk associated with the mixed phenotype of hypertrophic and dilated cardiomyopathy form of NCCM?
Increased risk of mortality
Commonly associated with metabolic or mitochondrial disease in pediatric patients.
What is the hallmark of the restrictive cardiomyopathy form of NCCM?
Left atrial or biatrial dilation and diastolic dysfunction.
What imaging modalities are primarily used for diagnosing NCCM?
- Transthoracic echocardiography
- Cardiac magnetic resonance imaging (CMR)
What T/C ratio is typically considered diagnostic for NCCM using echocardiography?
> 2 at end diastole
Alternative diagnostic criteria exist but require expert assessment.
What is the significance of cardiac MRI in diagnosing NCCM?
Better definition of NCCM extent and additional morphological characterization of the myocardium.
What diagnostic criterion is proposed for CMR regarding trabeculations?
Trabeculations >20% of total mass being diagnostic.
What is the concern regarding the use of cardiac computed tomography for NCCM diagnosis?
High radiation doses
This is a significant concern for children requiring long-term surveillance.
What is the typical ECG finding in patients with NCCM?
Abnormal findings, including hypertrophy by voltage criteria.
What is the typical ECG finding in patients with Noncompaction Cardiomyopathy (NCCM)?
Abnormal findings include:
* Hypertrophy by voltage criteria
* T wave inversion
* ST segment abnormalities
* Left atrial enlargement
* Left axis deviation
* QTc prolongation
* Pre-excitation
* Extreme QRS voltages in neonates and young children
Up to 87% of patients exhibit these findings.
What are the common arrhythmias observed in Noncompaction Cardiomyopathy?
Supraventricular and ventricular arrhythmias, as well as bradyarrhythmias
Many arrhythmias can be life-threatening.
True or False: Implantable cardioverter defibrillators (ICDs) are ineffective in preventing sudden arrhythmic death in NCCM patients.
False
ICDs have been shown to be highly effective for prevention.
What percentage of adult patients with NCCM experience ventricular tachyarrhythmias?
38–47%
This includes those with cardiac arrest due to ventricular fibrillation.
In children with NCCM, what are the considerations prior to implanting an ICD?
Pharmacologic anti-arrhythmia therapies may be indicated due to high rates of lead fractures and inappropriate shocks
This is particularly relevant for small children.
What was the percentage of premature ventricular contractions (PVCs) documented in NCCM patients?
54% of patients
PVCs were documented in 250 ECGs from 55 patients.
Fill in the blank: The final common pathways of left ventricular noncompaction include disruptions in _______ and signaling pathway disturbances.
[sarcomere function]
This can be due to direct mutations or secondary disruptions.
What are the phenotypic classifications of NCCM according to the Pediatric Cardiomyopathy Registry?
Classifications include:
* Dilated NCCM
* Hypertrophic NCCM
* Restrictive NCCM
* Isolated NCCM
* Indeterminate NCCM
These classifications help assess patient outcomes.
Which NCCM phenotype had the best outcomes in terms of time to death or transplant?
Isolated NCCM
This was followed by the HCM-form of NCCM.
What was the five-year transplant rate for children with the DCM-form of NCCM?
27%
This was the same for the indeterminate phenotype group.
What is a significant finding regarding the progression of isolated NCCM cases?
12% progressed to an associated cardiomyopathy phenotype within 2 years
Two deaths were observed shortly after diagnosis among isolated NCCM cases.
