Cardiac Amyloidosis Shows Decreased Diastolic Function as Assessed by Echocardiographic Parameterized Diastolic Filling

Abstract

Cardiac amyloidosis is a rare but serious condition with poor survival. One of the early findings by echocardiography is impaired diastolic function, even before the development of cardiac symptoms. Early diagnosis is important, permitting initiation of treatment aimed at improving survival. The parameterized diastolic filling (PDF) formalism entails describing the left ventricular filling pattern during early diastole using the mathematical equation for the motion of a damped harmonic oscillator. We hypothesized that echocardiographic PDF analysis could detect differences in diastolic function between patients with amyloidosis and controls. Pulsed-wave Doppler echocardiography of transmitral flow was measured in 13 patients with amyloid heart disease and 13 age- and gender matched controls. E- waves (2 to 3 per subject) were analyzed using in-house developed software. Nine PDF-derived parameters were obtained in addition to conventional echocardiographic parameters of diastolic function. Compared to controls, cardiac amyloidosis patients had a larger left atrial area (23.7 ± 7.5 cm² vs. 18.5 ± 4.8 cm², p = 0.04), greater interventricular septum wall thickness (14.4 ± 2.6 mm vs. 9.3 ± 1.3 mm, p < 0.001), lower e' (0.06 ± 0.02 m/s vs. 0.09 ± 0.02 m/s, p < 0.001) and higher E/e' (18.0 ± 12.9 vs. 7.7 ± 1.3, p = 0.001). The PDF parameter peak resistive force was greater in cardiac amyloidosis patients compared to controls (17.9 ± 5.7 mN vs. 13.1 ± 3.1 mN, p = 0.03), and other PDF parameters did not differ. PDF analysis revealed that patients with cardiac amyloidosis had a greater peak resistive force compared to controls, consistent with a greater degree of diastolic dysfunction. PDF analysis may be useful in characterizing diastolic function in amyloid heart disease.

Keywords: Cardiac amyloidosis; Diastology; Echocardiography; Parameterized diastolic filling.