# Left Ventricular Non-Compaction Cardiomyopathy-Still More Questions than Answers
## 6 Differential Diagnosis  
Improvement and accessibility of imaging techniques increased the number of detected patients with prominent trabeculation, which does not necessarily mean pathology. The most difficult problem in the differential diagnosis of LVNC is distinguishing pathological hypertrabeculation from physiological, resulting, for example, from individual or ethnic differences. A misdiagnose can be connected with the danger of stigmatizing healthy people. The diagnostic criteria are ambiguous and depend greatly on the method and criterion used. Alone, the most used NC/C ratio can be easily affected by hypertrophy of the compacted layer. First of all, the proper identification of left ventricular structures such as LV thrombus, false tendons, aberrant chords, cardiac fibromas, eosinophilic heart disease, endomyocardial fibrosis, and cardiac metastasis, which can imitate LVNC, should be performed. A multidisciplinary approach including a cardiologist, imaging specialist, geneticist, or rhythmologist is necessary to properly select the affected patients. Different diagnostic strategies have been proposed; however, none are generally accepted. [PERSON] and colleagues proposed the valuation of the left ventricular function in patients in whom the hypertrabeculation was found on echocardiography or CMR [64]. In patients with normal EF and no associated conditions, a family screening of first-degree relatives should be performed. No evidence of familial involvement makes diagnosing a normal variant of LVNC likely. In the case of familial involvement, the genetic origin of LVNC should be taken into consideration. In the case of impaired EF, the authors propose two possibilities: LVNC is caused by a genetic disorder and the LV dysfunction is secondary to LVNC. The second is when LVNC is caused by LV remodeling, for example, in DCM or HCM. Unfortunately, this theoretical approach is not quite sufficient to guide the diagnostic procedure in a real clinical situation. A much more practical approach was proposed by [PERSON] [6]. In patients in whom hypertrabeculation was found, a clinical examination, ECG, family history, and CMR or echocardiography should be performed. In the case of isolated LVNC without any other pathologies and negative family history, physiological hypertrabeculation would be considered. The probability of a disease is low. In the opposite case, family screening and testing including genetic testing, ambulatory ECG monitoring, and exercise testing should be performed. If the abnormalities consistent with cardiomyopathy were found without evidence of other cardiac diseases, LVNC cardiomyopathy should be diagnosed. The patients without clear signs of cardiomyopathy should be followed up as the exclusion of the disease is not possible. Our policy (Figure 7) depends on whether the LVNC was found accidentally or the patient presented with symptoms. In asymptomatic patients, family history is analyzed, a 12-lead ECG is performed and a supplementary echo or CMR is made, depending on which test was performed at the beginning. The value of CMR is not only to confirm hyper-trabeculation, but also to confirm or exclude the presence of late gadolinium enhancement (LGE) and thrombi, and to assess the function of the left ventricle. Myocardial fibrosis and reduced EF were both found to be related to a worse prognosis. Patients with no confirmed pathology have a shallow risk of cardiac events and genetic testing and close follow-up are not necessary. It is essential to look for cases with adaptive or transient hypertrabeculation. In symptomatic patients, a complete cardiological examination should be performed including 12-lead ECG, 24 h ECG monitoring, echocardiography, and CMR with special attention paid to LGE and thrombi. The family history of three generations should be carefully analyzed. All first-degree family members should undergo a complete cardiological examination including echocardiography and CMR.