Pulsed tissue Doppler and strain imaging discloses early signs of infiltrative cardiac disease: A study on patients with familial amyloidotic polyneuropathy

BACKGROUND: Familial amyloidotic polyneuropathy (FAP) is a hereditary systemic amyloidosis with cardiac involvement. As early identification of the cardiac involvement is of major clinical interest we performed this study to test the hypothesis that tissue Doppler imaging (TDI) and strain imaging (SI) might disclose cardiac involvement in patients with early stages of FAP. METHODS: Twenty-two patients with FAP and 36 healthy controls were studied. Standard M-mode and Doppler echocardiography were performed. TDI and SI were used to assess the regional longitudinal left ventricular (LV) lateral and septal and right ventricular (RV) wall functions. All time intervals were corrected for heart rate by dividing with R-R interval and presented as percentage. RESULTS: We found that patients in comparison with controls had increased LV and RV wall thickness and by using TDI a prolonged isovolumic relaxation time (IVRt) at the septal segment (15.0+/-7.0 vs 10.7+/-4.1%, p<0.05) and prolonged isovolumic contraction time (IVCt) at LV lateral (12.8+/-4.3 vs 10.1+/-3.3%, p<0.05), septal (12.5+/-3.5 vs 8.9+/-1.9%, p<0.001) and RV free wall segments (12.0+/-3.6 vs 8.3+/-2.1%, p<0.001). Strain was reduced at LV lateral basal segment (-4.6+/-14.0 vs -20.2+9.1, p<0.001), RV free wall mid segment (-16.2+/-12.8 vs -29.4+/-15.2) as well as both septal segments (-4.1+/-11.7 vs -16.2+/-9.0%, p<0.001, -8.8+/-11.5 vs -19.4+/-8.4%, p<0.001 for septal basal and mid-segment). Even in the absence of septal hypertrophy the septal strain was reduced and the regional IVCt was prolonged. CONCLUSIONS: This is the first clinical study using TDI and strain in patients with FAP showing functional abnormalities before any morphological echocardiographic abnormalities were present. Both the left and right heart functions are involved and the disease should therefore be regarded as biventricular.