Background: This study evaluated whether subclinical myocardial dysfunction occurs in first-degree relatives of patients with idiopathic dilated cardiomyopathy (IDCM), using strain echocardiographic imaging, before apparent left ventricular (LV) failure is observed.
Patients and methods: The study comprised 77 subjects aged 16-63 years who had first-degree relatives with a previous or new diagnosis of IDCM. LV myocardial deformation parameters of the first-degree relatives with normal LVEF (≥55%) values, as assessed using 2D echocardiography, were evaluated. The findings of the first-degree relatives were compared with an age- and sex-matched control group (n = 86).
Results: No difference in terms of age, gender, and body surface area was detected between first-degree relatives and controls. First-degree relatives of IDCM patients had significantly lower LVEF (62.04 ± 5.8% vs. 65.65 ± 6.3%, p < 0.001) and FS values (39.4 ± 6.6 vs. 41.45 ± 5.5, p = 0.03) compared with the controls. Assessment of LV deformation parameters revealed that LV global longitudinal strain (-17.34 ± 2.19% vs. -19.21 ± 2.16%, p < 0.001) and strain rate (0.94 ± 0.14 s-1 vs. 1.03 ± 0.14 s-1, p < 0.001), radial strain (34.47 ± 9.14% vs 42.79 ± 11.91%, p < 0.001) and strain rate (1.6 ± 0.38 s-1 vs. 1.75 ± 0.29 s-1, p = 0.006), circumferential strain (-6.07 ± 2.83% vs. -18.29 ± 3.39%, p < 0.001) and strain rate (1.09 ± 0.24 s-1 vs. 1.2 ± 0.25 s-1, p = 0.004), and torsion (10.07 ± 5.18o/cm vs. 12.42 ± 5.78o/cm, p = 0.009) were significantly reduced in first-degree relatives compared with controls.
Conclusion: LV deformation parameters are impaired in first-degree relatives of patients with IDCM. Screening of this population using standard 2D echocardiography and strain imaging may provide early detection of those with subclinical myocardial dysfunction.
Keywords: Cardiomyopathy, familial idiopathic; Cardiomyopathy, idiopathic dilated; Dilated cardiomyopathy; Echocardiography.