Noncompaction Cardiomyopathy in Childhood Flashcards

1
Q

What is Noncompaction Cardiomyopathy (NCCM)?

A

A genetic disease characterized by excessive and unusual trabeculations within the mature left ventricle.

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2
Q

What is the primary morphological appearance of NCCM?

A

A spongy morphological appearance of the myocardium with abnormal trabeculations.

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3
Q

Which part of the heart is primarily affected by NCCM?

A

The left ventricle (LV).

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4
Q

What are the two distinct layers of myocardium noted in NCCM?

A
  • Compacted myocardium
  • Non-compacted myocardium
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5
Q

What are some clinical associations of NCCM?

A
  • Left ventricular dilation
  • Hypertrophy
  • Systolic dysfunction
  • Diastolic dysfunction
  • Atrial enlargement
  • Congenital heart disease
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6
Q

What is the estimated occurrence of NCCM in live births?

A

Approximately 1 per 7000 live births.

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7
Q

True or False: NCCM can occur in both children and adults.

A

True.

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8
Q

What are the risks associated with NCCM?

A
  • Left or right ventricular failure
  • Ventricular arrhythmias
  • Atrioventricular block
  • Sudden death
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9
Q

What factors may contribute to the variability in clinical presentation of NCCM?

A

Age and presence of associated systemic diseases.

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10
Q

Which imaging technique is commonly used for diagnosing NCCM?

A

Echocardiography.

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11
Q

What are the genetic causes of left ventricular noncompaction?

A
  • ACTC1
  • CASQ2
  • DTNA
  • DYS
  • GLA
  • LDB3
  • LMNA
  • MIB1
  • MYBPC3
  • MYH7
  • Nkx2-5
  • TAZ
  • TNNT2
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12
Q

What are the potential outcomes for patients with NCCM?

A
  • Asymptomatic
  • End-stage heart failure
  • Lethal arrhythmias
  • Sudden cardiac death
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13
Q

Fill in the blank: NCCM is also known as _______.

A

left ventricular noncompaction (LVNC)

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14
Q

What was the prevalence of NCCM reported among heart failure patients?

A

3–4%.

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15
Q

What is a significant feature of NCCM pathology?

A

Numerous excessively prominent trabeculations with deep intra-trabecular recesses.

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16
Q

What is the role of mitochondrial function in NCCM?

A

Disrupted mitochondrial function is thought to have a causal role.

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17
Q

What is the significance of the Notch or Wnt signaling pathways in NCCM?

A

They may be part of a ‘final common pathway’ for NCCM associated with congenital heart disease.

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18
Q

What treatments are focused on for NCCM?

A
  • Improvement of cardiac efficiency
  • Reduction of mechanical stress
  • Arrhythmia therapy
  • Implantation of an ICD
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19
Q

Which age group has the worst reported outcomes for NCCM?

A

Infants.

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20
Q

True or False: Most patients with NCCM are symptomatic.

A

False.

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21
Q

What does the American Heart Association classify NCCM as?

A

A distinct cardiomyopathy.

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22
Q

What are the clinical features of NCCM?

A

Highly variable, ranging from asymptomatic to severe heart failure or arrhythmias.

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23
Q

What is the role of thrombi in patients with NCCM?

A

Mural thrombi can develop, posing risks for stroke or coronary obstruction.

24
Q

What can cause subendocardial ischemia in NCCM?

A

Prominent trabeculations and intra-trabecular recesses affecting perfusion.

25
Q

What is the annualized event rate of cardiovascular deaths in adults with isolated NCCM?

A

4%

This statistic was reported in a study by Bhatia et al.

26
Q

What percentage of first-degree relatives of index cases screened by echocardiography were identified with familial NCCM?

A

30%

This finding was noted in studies reviewed by Bhatia et al.

27
Q

What was the mortality rate among children diagnosed with isolated left ventricular noncompaction?

A

12.8%

This statistic is based on a retrospective review by Brescia et al.

28
Q

How many children diagnosed with isolated left ventricular noncompaction presented with or developed cardiac dysfunction?

A

62%

This statistic highlights the association between cardiac dysfunction and mortality.

29
Q

What is the hazard ratio for mortality associated with the presence of cardiac dysfunction in NCCM patients?

A

11

This finding indicates a strong correlation between cardiac dysfunction and increased mortality risk.

30
Q

What percentage of patients with NCCM had ECG abnormalities?

A

87%

Common ECG findings included ventricular hypertrophy and repolarization abnormalities.

31
Q

True or False: Repolarization abnormalities in NCCM patients are associated with increased mortality.

A

True

The hazard ratio for repolarization abnormalities is 2.1.

32
Q

What is the hazard ratio for mortality in NCCM patients with arrhythmias?

A

2.8

This statistic underscores the increased risk of mortality in patients with arrhythmias.

33
Q

What are the two forms of NCCM primarily focused on in reports?

A
  • Isolated NCCM
  • NCCM with congenital heart disease
34
Q

What characterizes the ‘benign’ form of NCCM?

A

Normal left ventricular size and wall thickness with preserved systolic and diastolic function

This subtype accounts for up to ~35% of NCCM patients.

35
Q

What is the outcome of patients with the ‘benign’ form of NCCM in the absence of significant arrhythmias?

A

Good outcome

This form does not typically represent a cardiomyopathy.

36
Q

What defines the NCCM subtype with arrhythmias?

A

Preserved systolic function with normal left ventricular size and wall thickness but evidence of underlying arrhythmias.

37
Q

What is the outcome of the dilated cardiomyopathy form of NCCM?

A

Similar outcome compared to those with a similar degree of dilated cardiomyopathy

Neonates and infants have a worse outcome.

38
Q

What characterizes the hypertrophic cardiomyopathy form of NCCM?

A

Left ventricular thickening, usually with asymmetric septal hypertrophy, diastolic dysfunction, and hypercontractile systolic function.

39
Q

What is the risk associated with the mixed phenotype of hypertrophic and dilated cardiomyopathy form of NCCM?

A

Increased risk of mortality

Commonly associated with metabolic or mitochondrial disease in pediatric patients.

40
Q

What is the hallmark of the restrictive cardiomyopathy form of NCCM?

A

Left atrial or biatrial dilation and diastolic dysfunction.

41
Q

What imaging modalities are primarily used for diagnosing NCCM?

A
  • Transthoracic echocardiography
  • Cardiac magnetic resonance imaging (CMR)
42
Q

What T/C ratio is typically considered diagnostic for NCCM using echocardiography?

A

> 2 at end diastole

Alternative diagnostic criteria exist but require expert assessment.

43
Q

What is the significance of cardiac MRI in diagnosing NCCM?

A

Better definition of NCCM extent and additional morphological characterization of the myocardium.

44
Q

What diagnostic criterion is proposed for CMR regarding trabeculations?

A

Trabeculations >20% of total mass being diagnostic.

45
Q

What is the concern regarding the use of cardiac computed tomography for NCCM diagnosis?

A

High radiation doses

This is a significant concern for children requiring long-term surveillance.

46
Q

What is the typical ECG finding in patients with NCCM?

A

Abnormal findings, including hypertrophy by voltage criteria.

47
Q

What is the typical ECG finding in patients with Noncompaction Cardiomyopathy (NCCM)?

A

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.

48
Q

What are the common arrhythmias observed in Noncompaction Cardiomyopathy?

A

Supraventricular and ventricular arrhythmias, as well as bradyarrhythmias

Many arrhythmias can be life-threatening.

49
Q

True or False: Implantable cardioverter defibrillators (ICDs) are ineffective in preventing sudden arrhythmic death in NCCM patients.

A

False

ICDs have been shown to be highly effective for prevention.

50
Q

What percentage of adult patients with NCCM experience ventricular tachyarrhythmias?

A

38–47%

This includes those with cardiac arrest due to ventricular fibrillation.

51
Q

In children with NCCM, what are the considerations prior to implanting an ICD?

A

Pharmacologic anti-arrhythmia therapies may be indicated due to high rates of lead fractures and inappropriate shocks

This is particularly relevant for small children.

52
Q

What was the percentage of premature ventricular contractions (PVCs) documented in NCCM patients?

A

54% of patients

PVCs were documented in 250 ECGs from 55 patients.

53
Q

Fill in the blank: The final common pathways of left ventricular noncompaction include disruptions in _______ and signaling pathway disturbances.

A

[sarcomere function]

This can be due to direct mutations or secondary disruptions.

54
Q

What are the phenotypic classifications of NCCM according to the Pediatric Cardiomyopathy Registry?

A

Classifications include:
* Dilated NCCM
* Hypertrophic NCCM
* Restrictive NCCM
* Isolated NCCM
* Indeterminate NCCM

These classifications help assess patient outcomes.

55
Q

Which NCCM phenotype had the best outcomes in terms of time to death or transplant?

A

Isolated NCCM

This was followed by the HCM-form of NCCM.

56
Q

What was the five-year transplant rate for children with the DCM-form of NCCM?

A

27%

This was the same for the indeterminate phenotype group.

57
Q

What is a significant finding regarding the progression of isolated NCCM cases?

A

12% progressed to an associated cardiomyopathy phenotype within 2 years

Two deaths were observed shortly after diagnosis among isolated NCCM cases.