Petra S Niemann

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OBJECTIVES We tested a newly developed 4-dimensional (4D) right ventricular (RV) analysis method for computing RV volumes for both 3-dimensional (3D) ultrasound (US) and magnetic resonance (MR) images. BACKGROUND Asymmetry and the anatomical complexity of the RV make accurate determination of RV shape and volume difficult. METHODS Thirty patients, 14(More)
BACKGROUND Torsion is an essential component of left ventricular (LV) function. Systolic rotation, as a component of torsion, winds the heart muscle up like a spring, setting up recoil for early diastole. We used a new 2-dimensional speckle tracking strain method to study differences in twisting in subendocardial and subepicardial layers of the LV in(More)
BACKGROUND Clinically useful indices of fetal cardiac function have not been fully delineated for tissue Doppler imaging (TDI). METHODS AND RESULTS In the present study, 56 pregnancies between the 17(th) and 38(th) weeks of gestation included 38 normal fetuses, 6 cases of hydrops fetalis (HF), and 12 of intrauterine growth retardation (IUGR). Peak(More)
Patch-clamp experiments were done on sodium channels of neuroblastoma cells (N1E-115) in the presence of tetraethylammonium ions to block potassium channels. In Ringer solution whole-cell records revealed a diphasic I Na inactivation with the fast (τ0) component being clearly larger than the slow (τ1 ≈ 3 τ0) component. In single-channel studies on(More)
Functional characterization of membrane channels by patch clamp techniques has revealed great diversity of transmitter or Voltage gated channels in native membranes. Concomitantly recombinant DNA techniques revealed a plethora of genes encoding channel subunits. Thus functional diversity within a particular class of channels may be generated by families of(More)
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