Left Ventricular Noncompaction Cardiomyopathy: Lessons from the Past to Explain a Diagnostic Conundrum

Estimation of Prevalence of the Left Ventricular Noncompaction Among Adults

The prevalence of left ventricular noncompacted myocardium (LVNC) is not clearly defined yet. The goal of this study was to prospectively assess the prevalence of LVNC in a population of patients assessed for cardiovascular disease and to analyze the coincidence between observers using the echocardiographic criteria for diagnosis of LVNC. We included patients prospectively during a 1-year period. To analyze the concordance between different observers, we performed a blind analysis of 50 patients between 7 operators to calculate Kappa index for each criteria. The analysis of concordance for final diagnosis of LVNC was free-marginal kappa: 0.94. A total of 10,857 patients underwent echocardiography; 2,931 (27%) were normal. LVNC was found in 26 patients (prevalence = 0.24%), 16 patients were women, mean age of 52.6 years. Patients were divided into 2 groups; group A: ejection fraction (EF) <50% (n = 20) and group B: normal systolic function (n = 6). Among abnormal studies, 294 (2.7%) were dilated cardiomyopathies (DCs) Patients with LVNC and EF <50% comprised 6.8% of DC (20 of 294) and 24% (20 of 75) of patients with idiopathic DC (p <0.0001). Group A patients were older and with less presence of women (both p <0.05). In conclusion, the prevalence of LVNC in a population assessed for cardiovascular diseases is low. In contrast, it is very high in the subgroup of patients with idiopathic DC. The group of patients with LVNC and normal LVEF is younger and with a higher presence of women than those with LVNC and depressed LVEF. Coincidence between operators is very good for the identification of echocardiographic criteria.

Prominent left ventricular trabeculations in competitive athletes: A proposal for risk stratification and management

BACKGROUND

Recently, an unexpectedly large prevalence of Left Ventricular Non Compaction (LVNC) has been reported in athletes, raising the question of the appropriateness of current diagnostic criteria. We sought to describe prevalence and clinical characteristics of athletes with suspected LVNC in a large cohort of Olympic athletes.

METHODS

Over 29months, 2501 consecutive athletes underwent a cardiac evaluation including physical examination, ECG, exercise test and echocardiography. Additional investigations (Cardiac Magnetic Resonance and/or genetic testing) were selectively performed in athletes with abnormal ECGs, ventricular arrhythmias, borderline LV dysfunction or positive family history.

RESULTS

Of the 2501 athletes, 36 (1.4%) showed prominent trabeculations suggestive for LVNC. Of these, 3 (0.1%) were considered to be affected by LVNC, based on presence of LV dysfunction (ejection fraction<50%) and/or positive family history and genetic testing; these athletes were cautiously restricted from competitions and entered a clinical follow-up program. The remaining 33 athletes, in the absence of LV impairment or familial cardiac diseases, were considered normal (n=24) or unlikely affected (n=9), regardless of the extent of the trabeculations.

CONCLUSIONS

In a large athlete population, a marked LV trabecular pattern was seen in 1.4%. Only a small subset of these athletes (0.1%) showed familial, clinical and morphologic changes supporting the diagnosis of LVNC. In the vast majority of the athletes, the increased trabeculations were not associated with LV dysfunction and/or positive family history, likely representing a morphologic LV variant, deprived of clinical significance.

Decreased Deformation in Asymptomatic Children with Isolated Left Ventricular Non-compaction and Normal Ejection Fraction

Echocardiography is the mainstay of screening and disease surveillance in isolated left ventricular non-compaction (iLVNC). The aim of our study is to determine the early regional and global myocardial functional changes and whether the myocardial changes that cannot be detected by conventional echocardiography could be detected by tissue Doppler imaging (TDI) or two-dimensional speckle-tracking echocardiography (STE) in iLVNC cases without symptoms. Longitudinal and circumferential strain (S) and strain rates (SR) as determined by STE in 20 children aged 12.1 ± 3.3 years was compared with those in 20 controls. All children underwent echocardiographic assessment using two-dimensional, tissue Doppler and speckle-tracking echocardiography. iLVNC patients who had normal systolic function by ejection and shortening fractions were included in this study. According to the TDI in all three segments [the non-compacted (NC), neighboring NC (NNC) and compacted (C) segments], isovolumic contraction time, isovolumic relaxation time and myocardial performance index values were significantly higher, while ejection time were significantly lower in the iLVNC group. According to STE in two segments (NC and NNC-segments) longitudinal S and SR values and also circumferential S and SR values were significantly lower in the iLVNC group compared with the control group; whereas, in the global measurements both longitudinal and circumferential S and SR values in all three segments were significantly lower in the iLVNC group compared with the control group. We believe that TDI and STE that evaluates myocardial deformation can be used for the detection of early myocardial dysfunction in the iLVNC patients who are subclinical and whose left ventricular functions were detected as normal by conventional methods with normal ejection and shortening fractions.

Left Ventricular Noncompaction Diagnosis and Management Relevant to Pre-participation Screening of Athletes

Left ventricular noncompaction (LVNC) has been extensively studied over the last years, and an increasing number of cases have been reported worldwide, with a large proportion comprising young and asymptomatic subjects, including athletes. The current epidemic of LVNC is likely the consequence of several causes, that is, the increased awareness of the disease and the refined cardiovascular imaging techniques. The current diagnostic methods, based uniquely on definition of morphologic findings, do not always resolve the overlap of a physiological myocardial architecture comprising a prominent trabecular pattern from a mild phenotypic expression of the real disease. Appropriate criteria for identification and management of LVNC in athletes have, therefore, become a novel challenge for cardiologists and sport physicians, who are required to solve the question of diagnosis and appropriate management in the setting of pre-participation cardiovascular screening. Indeed, although it is important to timely identify a true myocardial disease, to reduce the burden of adverse cardiac event in a young athlete, in contrast, a misdiagnosis of LVNC may lead to unwarranted restriction of the athlete lifestyle, with detrimental psychological, social, and economic consequences. This review report has been planned, therefore, to help physicians in diagnosing and managing athletes presenting with a morphologic pattern suggestive of LVNC with specific focus on criteria for advising sport participation.