Abstract 3289: Vortex Formation Index in Heart Failure: Novel Non-invasive Assessment Of Fluid Dynamics using Transthoracic Echocardiography
Background: In clinical heart failure (HF), inefficient propagation of blood through the left ventricle (LV) may result from suboptimal vortex formation (VF) ability of the LV during early diastole. We aim to
validate echocardiographic-derived VF index (VFI) in normal subjects and
examine its utility in both systolic and diastolic HF.
Method: Echocardiography was performed in 100 normals and 155 pts admitted with HF (110, systolic and 45, isolated diastolic failure). In additon to biplane LV ejection fraction (EF) and conventional parameters, the Tei index and tissue Doppler (TD) indices were measured. VFI was obtained using: 4 X (1-β) / πX α3 X LVEF where β is the fraction of total transmitral diastolic stroke volume contributed by atrial contraction (assessed by time velocity integral of the mitral E and A waves) and α is the biplane end diastolic volume (EDV)1/3 divided by mitral annular diameter during early diastole.
Results: Mean VFI was 2.75 ± 0.7 in control subjects; reduced in heart failure, diastolic, 2.21 ± 0.8; systolic, 1.24 ± 0.5 (P<0.001, Fig 1⇓). It correlated positively with TD early diastolic myocardial velocities (E, septal, r =0.58; lateral, r =0.58), inversely with LV filling pressure (E/E’ septal, r =−0.42; lateral, r =−0.41) and the Tei index (r =−0.57, curvilinear relation, Fig 2⇓); all Ps <0.001. In comparison with age, sex and LVEF-matched controls, only VFI, but not all other echo indices, remained significantly different (attenuated) in diastolic HF patients (2.01 ± 0.7 vs 2.74 ± 0.8, P=0.005).
Conclusion: VFI, a novel, dimensionless index, incorporating LV geometry, systolic and diastolic contributions to fluid dynamics, may be useful in heart failure.