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Left ventricular noncompaction (LVNC) is associated with heart failure, arrhythmias, thromboembolic events, and sudden death.
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Arrhythmias are common and may have prognostic significance in LVNC; the risk of sudden death seems to be associated with left ventricular (LV) size, systolic function, and presence of arrhythmias.
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Arrhythmias are not restricted to noncompacted myocardium and include atrial fibrillation (AF) (adults), atrioventricular (AV) accessory pathways/Wolff-Parkinson-White (WPW)
Arrhythmias in Left Ventricular Noncompaction
Section snippets
Key points
Genetics
LVNC is associated with both sporadic and familial cases, with an estimated familial recurrence rate of 23% to 33%.16, 19, 20, 21, 22 Inheritance most commonly follows an autosomal dominant or X-linked pattern, although autosomal recessive and mitochondrial inheritance have also been observed.23, 24 As is seen with many inherited cardiac diseases, variable penetrance and phenotypic variability result in lack of clear genotype-phenotype correlation, even among family members carrying the same
Electrocardiographic findings
Electrocardiographic (ECG) abnormalities are a hallmark of many cardiomyopathies. Early findings in recent studies suggest that LVNC may be similar in this regard. An evaluation by Steffel and colleagues39 found that only 13% of adults with diagnosed LVNC had normal results of ECGs at presentation.39 The most common findings were intraventricular conduction delay such as left bundle branch block, voltage signs of hypertrophy, and repolarization abnormalities (Table 3). Over 70% of the
Ventricular arrhythmias
Early descriptions of LVNC point to 3 major clinical manifestations of the disease, including heart failure, embolic events, and arrhythmias.5, 8 Although a variety of arrhythmias have subsequently been identified in association with LVNC, ventricular tachyarrhythmias have been considered the hallmark. Recent larger series have found VT in as many as 47% of affected individuals (Table 4), with sudden cardiac death (SCD) accounting for a significant portion of the mortality.5, 8, 17, 40, 41
Supraventricular arrhythmias
Recent reports suggest that supraventricular arrhythmias are also implicated in the natural history of LVNC. In adults, this seems to be primarily manifested by AF. Studies by Weiford and colleagues18 and Ritter and colleagues8 describe a prevalence of AF in their cohorts of as high as 29% (see Table 4). Other evaluations, however, found a slightly lower prevalence of AF in LVNC, ranging from 5% to 26%.20, 21, 50 The mechanistic role of LVNC in the development of AF remains unclear; it may be
Sudden death
In current reports, rates of sudden death have varied significantly, ranging from 0% to 18%, possibly because of differences in selection of patient population (isolated vs nonisolated LVNC) and length of follow-up.5, 6, 8, 16, 17, 19, 20, 21, 52 In the largest pediatric study of isolated LVNC to date, the risk of sudden death was reported to be 6%.16 In the scheme of all-cause mortality, sudden death may account for up to 50% of deaths, suggesting the possible importance of primary or
Risk assessment
The ability to identify predictors of outcome is important in the effective and optimal management of all patients with cardiomyopathy. Unfortunately, determining risk factors for mortality or sudden death in LVNC has been complicated by several factors including: (1) phenotypic heterogeneity of disease, (2) varying diagnostic criteria, and (3) lack of randomized controlled studies. Thus, definitive risk factors remain lacking. Nonetheless, as mentioned above, increased mortality does seem to
Therapeutic approaches
Proposed therapeutic strategies for arrhythmias in LVNC are summarized in Table 5.
Summary
LVNC is a newly recognized form of cardiomyopathy that has been associated with heart failure, arrhythmias, thromboembolic events, and sudden death. Both ventricular and supraventricular arrhythmias are now well described as prominent clinical components of LVNC. Arrhythmias are not restricted to noncompacted myocardium and can include AF (adults), AV accessory pathways/WPW and SVT (children), and VT. Throughout the spectrum of age, these arrhythmias have been associated with prognosis and
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Cited by (26)
Anaesthetic management of a parturient with left ventricular noncompaction cardiomyopathy
2020, International Journal of Obstetric AnesthesiaCatheter ablation for patients with end-stage complex congenital heart disease or cardiomyopathy considered for transplantation: Trials and tribulations
2020, International Journal of CardiologyCitation Excerpt :Novel 3D mapping systems and other new technology, such as remote magnetic navigation, have improved CHD ablation success rates in recent years [10–14]. There are similarly sparse data with regards to the management of recurrent arrhythmias in patients with left ventricular non-compaction (LVNC) cardiomyopathy or arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) and end-stage heart failure, who require heart transplant action [15–17]. Thus, the limited knowledge regarding the natural course of both these cardiomyopathies (CMPs) with regards to development of heart failure precluded experts to provide specific recommendations concerning transplant candidacy, unlike other CMPs, such as hypertrophic cardiomyopathy [18].
Left Ventricular Noncompaction: A Distinct Genetic Cardiomyopathy?
2016, Journal of the American College of CardiologyCitation Excerpt :Risk stratification for arrhythmias and mural endocardial thrombosis is made on the basis of clinical, imaging, and biochemical data. Although there is concordance on high risk for heart transplantation in children with LVNC (107), and high arrhythmogenic and thromboembolic risk in patients with LVNC (108,109), major decisions (e.g., primary prevention of sudden death with implantable cardioverter-defibrillators) are made on the basis of individual risk estimates, according to current society guidelines (89,110). The prevention of mural endocardial thrombosis can eventually be a matter of earlier antiaggregation or anticoagulation therapy (7,111).
Usefulness of Fragmented QRS Complex to Predict Arrhythmic Events and Cardiovascular Mortality in Patients with Noncompaction Cardiomyopathy
2016, American Journal of CardiologyClinical Features of Noncompaction Cardiomyopathy Across All Age Strata
2024, Research SquareAtrial Fibrillation Ablation in Congenital Heart Disease: Therapeutic Challenges and Future Perspectives
2024, Journal of the American Heart Association
The authors have nothing to disclose.