title: Four-dimensional blood flow-specific markers of LV dysfunction in dilated cardiomyopathy.
abstract: OBJECTIVE
  Patients with mild heart failure (HF) who are clinically compensated may have normal left ventricular (LV) stroke volume (SV). Despite this, altered intra-ventricular flow patterns have been recognized in these subjects. We hypothesized that, compared with normal LVs, flow in myopathic LVs would demonstrate a smaller proportion of inflow volume passing directly to ejection and diminished the end-diastolic preservation of the inflow kinetic energy (KE).
  
  
  RESULTS
  In 10 patients with dilated cardiomyopathy (DCM) (49 ± 14 years, six females) and 10 healthy subjects (44 ± 17 years, four females), four-dimensional MRI velocity and morphological data were acquired. A previously validated method was used to separate the LV end-diastolic volume (EDV) into four flow components based on the blood's locations at the beginning and end of the cardiac cycle. KE was calculated over the cardiac cycle for each component. The EDV was larger (P = 0.021) and the ejection fraction smaller (P < 0.001) in DCM compared with healthy subjects; the SV was equivalent (DCM: 77 ± 19, healthy: 79 ± 16 mL). The proportion of the total LV inflow that passed directly to ejection was smaller in DCM (P = 0.000), but the end-diastolic KE/mL of the direct flow was not different in the two groups (NS).
  
  
  CONCLUSIONS
  Despite equivalent LVSVs, HF patients with mild LV remodelling demonstrate altered diastolic flow routes through the LV and impaired preservation of inflow KE at pre-systole compared with healthy subjects. These unique flow-specific changes in the flow route and energetics are detectable despite clinical compensation, and may prove useful as subclinical markers of LV dysfunction.
authors.affiliation: Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. jonatan.eriksson@liu.se
authors.forename: Jonatan
authors.initials: J
authors.lastname: Eriksson
authors.forename: Ann F
authors.initials: AF
authors.lastname: Bolger
authors.forename: Tino
authors.initials: T
authors.lastname: Ebbers
authors.forename: Carl-Johan
authors.initials: CJ
authors.lastname: Carlhäll
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology