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J W-H Fung

Publications and source records attributed to J W-H Fung.

2 recordsLinked to original sources

Tissue Doppler velocity is superior to displacement and strain mapping in predicting left ventricular reverse remodelling response after cardiac resynchronisation therapy.

OBJECTIVE: To compare the values of three different forms of tissue Doppler imaging (TDI) processing in predicting left ventricular (LV) reverse remodelling-namely, tissue velocity, displacement and strain mapping. DESIGN: Standard echocardiography with TDI was performed before and 3 months after cardiac resynchronisation therapy (CRT). SETTING: University teaching hospital. PATIENTS: 55 patients with heart failure who received CRT and were followed up for at least 3 months were recruited. INTERVENTIONS: During off-line analysis, the time to peak systolic velocity in the ejection phase, time to peak positive displacement and time to peak negative strain were measured in the six basal, six mid-segmental model. Parameters of systolic asynchrony derived by velocity, displacement and strain mapping were correlated with percentage reduction in LV end systolic volume (LVESV) and absolute gain in ejection fraction (EF). RESULTS: Among the three TDI processing technologies, all parameters of tissue velocity correlated with LV reverse remodelling (r = -0.49 to r = -0.76, all p < 0.001), but the predictive value was strongest in models with 12 LV segments. For displacement mapping, only the two parameters that included 12 LV segments correlated modestly with reduction in LVESV (r = -0.36, p < 0.05) and gain in EF. However, none of the strain mapping parameters predicted a favourable echocardiographic response. The receiver operating characteristic (ROC) curve areas were higher for parameters of tissue velocity based on 12 LV segments (ROC areas 0.88 and 0.94) than the corresponding areas derived from displacement mapping (ROC areas 0.72 and 0.71). CONCLUSION: Tissue velocity parameters of systolic asynchrony are superior to those of displacement and strain mapping in predicting LV reverse remodelling response after CRT.

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Variable left ventricular activation pattern in patients with heart failure and left bundle branch block.

OBJECTIVE: To determine the left ventricular (LV) activation pattern in patients with chronic heart failure and left bundle branch block (LBBB) on ECG. DESIGN: Prospective study. SETTING: Tertiary cardiology referral centre in Hong Kong. PATIENTS: Seven patients with LV ejection fraction < 35% and typical LBBB on ECG with QRS duration > or = 130 ms were recruited. Five of them had non-ischaemic dilated cardiomyopathy. METHODS: Non-contact mapping was used to investigate the LV global activation sequences. Tissue Doppler imaging was performed with the LV mapping and correlated with the activation sequences. RESULTS: Three patients had preserved left bundle activation despite LBBB on ECG. Conduction block was detected in four patients during LV activation and the other three had homogeneous depolarisation propagation within the left ventricle. The latest segment of activation was located in either the lateral or the posterior region. Tissue Doppler imaging correlated well with non-contact mapping to locate the conduction block and the latest segment of activation. CONCLUSIONS: LV endocardial activation sequences in patients with chronic heart failure and LBBB are variable. This may have implications for patient selection for treatment with cardiac resynchronisation.

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