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OBJECTIVE: To examine the predictive value of systolic dyssynchrony measured by tissue Doppler velocity versus tissue Doppler strain imaging on long-term outcome after cardiac resynchronisation therapy (CRT). DESIGN: Cohort study. SETTING: Two university hospitals. PATIENTS: Two hundred and thirty-nine patients (65 (SD 12) years, 76% males) who underwent CRT. INTERVENTIONS: Baseline echocardiography with tissue Doppler imaging (TDI) and clinical follow-up for 37 (20) months. MAIN OUTCOME MEASURES: The time to peak systolic velocity during ejection phase (Ts) and the time to peak systolic strain (T(epsilon)) were assessed for dyssynchrony, that is the maximal delay in Ts and the maximal delay in T(epsilon) among the four left ventricular basal segments. Occurrence of cardiovascular endpoints between patients with and without dyssynchrony was compared by Kaplan-Meier curves, followed by Cox regression analysis for potential predictor(s). RESULTS: There were 78 (33%) deaths, with cardiovascular causes in 64 (27%) patients, while 136 (57%) patients were hospitalised for cardiovascular events, including decompensated heart failure in 87 (36%) patients. Patients with the maximal delay in Ts of > or =65 ms showed a lower event rate for cardiovascular mortality (19% vs 38%, logrank chi2 = 7.803, p = 0.005) and other prognostic endpoints. In Cox regression analysis, the maximal delay in Ts (hazard ratio (HR) 0.463, 95% CI 0.270 to 0.792, p = 0.005) and ischaemic aetiology (HR 2.716, 95% CI 1.505 to 4.901, p = 0.001) were independent predictors of cardiovascular mortality. In contrast, the maximal delay in T(epsilon) of > or =80 ms failed to predict any cardiovascular event. CONCLUSIONS: Echocardiographic evidence of prepacing systolic dyssynchrony measured by TDI velocity, but not TDI strain, predicted lower long-term cardiovascular events after CRT.

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BACKGROUND: Childhood obstructive sleep apnoea (OSA) is suggested to be associated with cardiac structural abnormalities and dysfunction but existing evidence is limited and the treatment effect on echocardiographic outcome remains controversial. OBJECTIVE: To examine the presence of subclinical cardiac abnormalities in childhood OSA and the effects of treatment on cardiac changes. METHODS: Polysomnography (PSG) and echocardiographic examinations were performed in 101 children aged between 6 and 13 years who were invited from a community based questionnaire survey. They were classified into a reference group (apnoea-hypopnoea index (AHI) <1, n = 35), mild OSA group (AHI 1-5, n = 39) and moderate to severe group (AHI >5, n = 27) based on the PSG results. Treatments, including adenotonsillectomy or nasal steroids, were offered to the mild and moderate to severe OSA groups. RESULTS: The moderate to severe OSA group had greater right ventricular (RV) systolic volume index (RVSVI), lower RV ejection fraction (RVEF) and higher RV myocardial performance index (RVMPI) than the reference group. They also had more significant left ventricular (LV) diastolic dysfunction and remodelling with larger interventricular septal thickness index (IVSI) and relative wall thickness than those with lower AHI values. The moderate to severe OSA group had an increased risk of abnormal LV geometry compared with the reference group (odds ratio 4.21 (95% CI 1.35 to 13.12)). Log transformed AHI was associated with RVSVI (p = 0.0002), RVEF (p = 0.0001) and RVMPI (p<0.0001), independent of the effect of obesity. Improvement in RVMPI, IVSI and E/e' were observed in those with a significant reduction in AHI (>50%) comparing 6 month with baseline data. CONCLUSIONS: OSA is an independent risk factor for subclinical RV and LV dysfunction, and improvement in AHI is associated with reversibility of these abnormalities.

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OBJECTIVE: To examine the impact of heart failure (HF) aetiology on long-term outcome after cardiac resynchronisation therapy (CRT). DESIGN: Prospective cohort study. SETTING: University hospital. PATIENTS: 119 patients (44% with ischaemic and 56% non-ischaemic aetiology) who underwent CRT. INTERVENTIONS: Clinical follow-up for 39 (24) months. MAIN OUTCOME MEASURES: Cardiovascular mortality, HF and cardiovascular hospitalisation were compared by Kaplan-Meier curves between the two groups, followed by Cox regression analysis for prognostic predictor(s). RESULTS: 41 (34%) patients died, in whom cardiovascular causes were identified in 32 (27%) patients. The ischaemic group had a higher cardiovascular mortality (log-rank chi(2) = 4.293, p = 0.038) and cardiovascular hospitalisation (log-rank chi(2) = 5.123, p = 0.024) when compared with the non-ischaemic group, though no difference was found in HF hospitalisation (log-rank chi(2) = 0.019, p = 0.892). At three months, left ventricular reverse remodelling occurred in 52% of the ischaemic group and 55% of the non-ischaemic group (chi(2) = 0.128, p = 0.720). By Cox regression analysis, ischaemic aetiology and absence of reverse remodelling at three months were independent predictors of cardiovascular mortality (HR = 2.698, p = 0.032; HR = 3.541, p = 0.030) and cardiovascular hospitalisation (HR = 1.905, p = 0.015; HR = 2.361, p = 0.004). Furthermore, these two factors had an incremental value in predicting cardiovascular mortality when compared with either alone (left ventricular reverse remodelling, log-rank chi(2) = 10.275 vs 6.311, p = 0.05; Ischaemic aetiology, log-rank chi(2) = 10.275 vs 4.293, p<0.05). CONCLUSION: Ischaemic aetiology of HF is an independent predictor of higher cardiovascular mortality and hospitalisation after CRT. This may implicate the progressive nature of coronary heart disease leading to a worse outcome despite similar short-term benefits of CRT.

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AIMS: To evaluate whether short-axis function plays a part in determining left ventricular (LV) geometric and functional improvement after cardiac resynchronisation therapy (CRT). METHODS AND RESULTS: 39 patients who received CRT were enrolled. 2D speckle tracking echocardiography was performed at baseline and three months after CRT to assess mean systolic circumferential (epsilon-circum), radial (epsilon-radial) and longitudinal (epsilon-long) strain and torsion. Responders of reverse remodelling (n = 21) had higher baseline mean epsilon-circum than non-responders (p<0.05), who also had improvement in mean epsilon-circum and mean epsilon-radial (both p<0.05) after CRT. Also, the increase in mean epsilon-circum correlated with increase in ejection fraction (r = 0.57, p<0.001) and decrease in mid-cavity width (r = -0.52, p = 0.001). A baseline mean epsilon-circum of >or=6.5% predicted a gain in ejection fraction >or=5%, with a sensitivity of 73% and a specificity of 71%. The baseline epsilon-long was not different between the two groups, and remained unchanged after CRT. The torsion did not improve in responders, but was worsened in non-responders (p<0.05). CONCLUSIONS: The improvement of LV short-axis function but not long-axis function or torsion contributes to the improvement in LV global function and geometry at three-month follow up. A relatively preserved mean epsilon-circum of >or=6.5% might be useful to predict favourable responses after CRT.

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BACKGROUND: Several two-dimensional (2-D) tissue Doppler imaging (TDI) echocardiographic techniques have proved useful to identify responders to cardiac resynchronisation therapy (CRT). Recently a 3-D probe allowing simultaneous acquisition of TDI data in three imaging planes became available. OBJECTIVE: To evaluate the value of triplane TDI to predict reverse left ventricular (LV) remodelling after CRT. METHODS: Sixty patients with heart failure, scheduled for CRT, underwent triplane echocardiography with simultaneous TDI acquisition before and 6 months after implantation. From the triplane dataset a 3-D LV volume was generated and LV volumes and ejection fraction were calculated. Intraventricular dyssynchrony was quantitatively analysed by evaluating time from onset of the QRS complex to peak myocardial systolic velocity in 12 LV segments from the triplane dataset and calculation of the standard deviation (Ts-SD-12). Clinical response was defined as an improvement of at least one New York Heart Association class. Reverse LV remodelling was defined as >/=15% decrease of LV end-systolic volume at 6 months' follow-up. RESULTS: Responders to CRT had significantly more LV dyssynchrony at baseline than non-responders (mean (SD) Ts-SD-12: 42 (14) vs 22 (12), p<0.001). A cut-off value of 33 ms for baseline Ts-SD-12, acquired from the triplane TDI dataset, yielded a sensitivity of 89% with a specificity of 82% to predict clinical response to CRT; sensitivity and specificity to predict reverse LV remodelling were 90% and 83%, respectively. CONCLUSION: Triplane TDI echocardiography predicts clinical response and reverse LV remodelling 6 months after CRT implantation.

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An 81-year-old Chinese woman presented with a 1-week history of increasing facial puffiness. She had 2:1 second-degree heart block and a permanent pacemaker that had been inserted 3 years previously because of syncopal episodes. Physical examination revealed facial plethora, dilated upper trunk veins, and oedematous upper limbs suggestive of superior vena cava obstruction syndrome. This was confirmed on urgent computed tomographic scan of the thorax. There was no evidence of extrinsic compression or formation of intraluminal thrombus. The underlying aetiology was a pacemaker-induced fibrotic stricture that was successfully treated with balloon venoplasty. At 3-month follow-up, the patient remained symptom-free with normal pacemaker function.

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