Assessment of left ventricular diastolic function using color kinesis: differentiation between normal and pseudonormalized patterns

Left ventricular diastolic and systolic functions by cardiac magnetic resonance in beta-thalassemia major: correlation with clinical findings and cardiac complications

This cross-sectional study explored the association of left ventricular (LV) fractional area change (FAC) with demographic characteristics, clinical data, cardiovascular magnetic resonance (CMR) findings, and cardiac complications (heart failure and arrythmias) in patients with beta-thalassemia major (β-TM). We included 292 β-TM patients (151 females, 36.72 ± 11.76 years) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia project and 20 healthy controls (8 females, 36.97 ± 3.54 years). CMR was used to assess FAC and derive LV systolic and diastolic indexes, to quantify myocardial iron overload (MIO) by the T2* technique and LV volumes and ejection fraction, and to detect late gadolinium enhancement (LGE). Healthy subjects and β-TM patients showed comparable LV systolic and diastolic indexes. In β-TM, the LV systolic index was significantly correlated with global heart T2* values, and patients with significant MIO (T2*<20ms) were more likely to have a reduced LV systolic index compared to those without MIO (odds ratio-OR = 3.13; p = 0.013). In multivariate analysis, global heart T2* values and positive LGE emerged as independent determinants of the LV systolic index. The number of segments with LGE inversely correlated with the LV systolic index (p = 0.003). Patients with a reduced LV systolic index were more likely to have cardiac diseases than those with a normal LV systolic index (OR = 5.34; p < 0.0001). No significant correlates were found for the LV diastolic index. In well-treated β-TM patients, MIO and LGE were the strongest determinants of the LV systolic index, and a reduced LV systolic index was associated with an increased risk of cardiac complications.

Echocardiography without electrocardiogram using nonlinear dimensionality reduction methods

PURPOSE

The aim of this study is to evaluate the efficiency of a new automatic image processing technique, based on nonlinear dimensionality reduction (NLDR) to separate a cardiac cycle and also detect end-diastole (ED) (cardiac cycle start) and end-systole (ES) frames on an echocardiography system without using ECG.

METHODS

Isometric feature mapping (Isomap) and locally linear embeddings (LLE) are the most popular NLDR algorithms. First, Isomap algorithm is applied on recorded echocardiography images. By this approach, the nonlinear embedded information in sequential images is represented in a two-dimensional manifold and each image is characterized by a symbol on the constructed manifold. Cyclicity analysis of the resultant manifold, which is derived from the cyclic nature of the heart motion, is used to perform cardiac cycle length estimation. Then, LLE algorithm is applied on extracted left ventricle (LV) echocardiography images of one cardiac cycle. Finally, the relationship between consecutive symbols of the resultant manifold by the LLE algorithm, which is based on LV volume changes, is used to estimate ED (cycle start) and ES frames. The proposed algorithms are quantitatively compared to those obtained by a highly experienced echocardiographer from ECG as a reference in 20 healthy volunteers and 12 subjects with pathology.

RESULTS

Mean difference in cardiac cycle length, ED, and ES frame estimation between our method and ECG detection by the experienced echocardiographer is approximately 7, 17, and 17 ms (0.4, 1, and 1 frame), respectively.

CONCLUSION

The proposed image-based method, based on NLDR, can be used as a useful tool for estimation of cardiac cycle length, ED and ES frames in echocardiography systems, with good agreement to ECG assessment by an experienced echocardiographer in routine clinical evaluation.

Evaluation of left ventricular diastolic function by fractional area change using cine cardiovascular magnetic resonance: a feasibility study

BACKGROUND

Evaluation of left ventricular (LV) diastolic function is essential for the management of heart failure. We verified whether LV diastolic function could be evaluated by measuring the fractional area change (FAC) using cine cardiovascular magnetic resonance (CMR).

METHODS

We collected clinical data from 59 patients who underwent echocardiography and cine CMR. Normal, impaired relaxation, pseudonormal, and restrictive LV filling were observed in 15, 28, 11, and 5 patients, respectively. We calculated FAC during the first 30% of diastole (diastolic-index%) in the short-axis view, by tracing the contours on only three MR cine images.

RESULTS

The diastolic index was significantly lower (p < 0.0001) in patients with impaired relaxation (32.4 ± 7.5), pseudonormal filling (25.4 ± 5.6), and restrictive filling (9.5 ± 1.5) compared to those with normal diastolic function (67.7 ± 10.8), and the index decreased significantly with worsening of diastolic dysfunction. The diastolic index correlated positively with early diastolic mitral annular velocity measured by tissue Doppler imaging (r = 0.75, p < 0.0001), respectively.

CONCLUSIONS

Measurement of FAC can be useful for the evaluation of LV diastolic function using cine CMR.