RESUMO
Objective To explore the role of cine sequence of cardiac magnetic resonance (CMR) imaging in evaluating left ventricular (LV) diastolic function in patients with heart failure with preserved ejection fraction (HFpEF). Methods LV two-chamber, three-chamber, four-chamber long-axis and series of short-axis cine images were obtained from 30 patients with HFpEF (HFpEF group) and 15 cases with normal cardiac function (control group) using CMR examination. LV volume-time curve (VTC) and global strain curves were drawn. Peak filling rate and peak filling volume, global longitudinal, global radial, global circumferential peak strain and peak diastolic strain rate were compared between the two groups. Results Compared with the control group, LV remodeling index (LVRI) in the HFpEF group was significantly increased (0.86±0.15 vs 0.73±0.08, P<0.05), first peak filling rate/second peak filling rate (PFR1/PFR2) was significantly decreased or even inverted (0.74 ±0.14 vs 1.43±0.34, P=0.001), and first filling volume (FV1) and FV1/total filling volume (FV1/FV) were significantly decreased (26.24±9.74 vs 31.30±5.17, P<0.05; 0.59±0.05 vs 0.69±0.03, P<0.05). Global longitudinal peak strain (GLS) ([-14.96±1.79]% vs[-20.96±0.84]%,P<0.01), global longitudinal diastolic peak strain rate (0.65±0.16 vs 1.29±0.27, P<0.05), global radial diastolic peak strain rate (-2.23±0.71 vs -3.80±1.13, P<0.05) and global circumferential diastolic peak strain rate (GDCSR) (1.02±0.14 vs 1.77±0.63, P<0.05) in the HFpEF group were significantly decreased versus control group. Conclusion LVRI, PFR1/PFR2, FV1 and GDCSR obtained by CMR can accurately evaluate the changes of LV diastolic function in HFpEF, which may play important roles in the diagnosis and treatment of HFpEF.
RESUMO
The volume-time curve change in patients with normal left ventricular (LV) diastolic function and diastolic dysfunction was evaluated by real-time three-dimensional echocardiography (RT3DE). LV diastolic dysfunction was defined by E'＜A' in pulse-wave tissue Doppler for inter-ventricular septal (IVS) of mitral annulus. In 24 patients with LV diastolic dysfunction, including 12 patients with delayed relaxation (delayed relaxation group) and 12 patients with pseudo-normal function (pseudo-normal group) and 24 normal volunteers (control group), data of full-volume image were acquired by real-time three-dimensional echocardiography and subjected to volume-time curve analysis. EDV (end-diastolic volume), ESV (end-systolic volume), LVEF (left ventricular ejection fraction), PER (peak ejection rate), PFR (peak filling rate) from RT3DE were examined in the three groups. Compared to the control group, PFR (diastolic filling index of RT3DE) was significantly reduced in the delayed relaxation group and pseudo-normal group (P＜0.05). There were no significant differences in EDV, ESV, LVEF, PER (P＞0.05). It is concluded that PFR, as a diastolic filling index of RT3DE, can reflect the early diastolic function and serve as a new non-invasive, quick and accurate tool for clinical assessment of LV diastolic function.
RESUMO
An efficient BASIC program was established on Apple-Ⅱ microcomputer with the CHESTAC-3EF pulmonary function testing system to calculate the time-constant histogram from the spirogram.By a set of analogue studies, we confirmed that the recovered time-constant histogrgram was within one compartment of the assumed one and that the root of mean square values of the residuals between the experimental and model volume-time curves was 0.02. In four adult healthy subjects, the mean value of time-constant histograms (TCx ) had the variation coefficient (6.6%). The results show that our method is reliable and reproducible, and it can be used for clinical investigation.