7-Year Follow-Up of a Patient with FLNC Gene Mutation-Related Cardiomyopathy: A Case Report (QF_TH_072)

A 52-year-old male patient with a history of presenting with dyspnea and chest pain in 2017 was initially investigated with echocardiography, which revealed new left ventricular dysfunction. The patient had no known preexisting comorbidities and no family history of cardiomyopathies. Further investigation included cardiac magnetic resonance imaging (CMR), which showed diffuse enlargement of the left ventricular dimensions, along with multiple non-ischemic late gadolinium enhancement (LGE) foci, no myocardial edema, initially interpreted as a previous myocarditis (Figure 1). At that time, the patient was treated with standard medications for heart failure with reduced ejection fraction (HFrEF).

In 2024, the patient was referred to our service due to persistent HFrEF and palpitations. We decided to repeat the CMR. The examination revealed biventricular systolic dysfunction, diffuse hypokinesia, absence of myocardial edema, T1 mapping (1120ms) and extracellular volumes (42%) slight increase, and extensive areas of non-ischemic late gadolinium enhancement ( >35%), with ring-like signal (Figure 2). Holter Monitoring show a Total Events: 102,754, Heart Rate Range: 57-74-141 bpm

• Ventricular Ectopy: 10,130 events (10%)




• 9,323 isolated; 44 in bigeminy; 402 in pairs; 1 non-sustained ventricular tachycardia (NSVT) with 3 beats




• Supraventricular Ectopy: 503 events (< 1%)




• 408 isolated; 43 paired; 3 non-sustained atrial tachycardia (NSAT) (largest with 3 beats)

Genetic testing (Tabela 1) indicated a pathogenic heterozygous variant in the filamin C (FLNC) gene, usually non-dilated left ventricular cardiomyopathy (NDLVC). Optimized clinical treatment was provided, and the option of an implantable cardioverter-defibrillator to prevent sudden cardiac death was discussed.

Diagnostic Techniques and Their Most Important Findings:

The NDLVC phenotype is defined as the presence of non-ischemic left ventricular (LV) scarring or fatty replacement, regardless of the presence of global or regional wall motion abnormalities. This includes individuals previously described as having dilated cardiomyopathy (but without LV dilation), arrhythmogenic left ventricular cardiomyopathy (ALVC), left-dominant arrhythmogenic right ventricular cardiomyopathy (ARVC), or arrhythmogenic dilated cardiomyopathy (DCM). In this case, we present a patient who developed symptomatic LV systolic dysfunction due to extensive myocardial compromise.

Learning Points from this Case: The growing knowledge of non-ischemic cardiomyopathies, particularly with the availability of genetic testing, allows for the elucidation of cases previously classified as myocarditis