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Objective: Unfavourable effects of sleep-disordered breathing (SDB) in heart failure (HF) are mainly mediated by impaired sympathetic activity. Few data are available on SDB and cardiac adrenergic impairment evaluated at myocardial level. The aim of the study was to assess the relationship between SDB, cardiac sympathetic innervation assessed by 123 I-metaiodobenzylguanidine ( 123 I-MIBG) imaging and prognosis in HF., Methods: Observational, prospective study enrolling patients with HF and reduced systolic function. Patients underwent nocturnal cardiorespiratory monitoring to assess SDB presence by apnoea/hypopnoea index (AHI), and 123 I-MIBG imaging to calculate heart-to-mediastinum (H/M) ratios and washout rate. Patients were prospectively followed for 29±18 months for the combined endpoint of cardiovascular death and HF hospitalisation., Results: Ninety-four patients (66.1±9.8 years; left ventricular ejection fraction 32±7%) were enrolled; 72 (77%) showed SDB and, compared with non-SDB, significantly reduced early (1.67±0.22 vs 1.77±0.13; p=0.019) and late H/M ratios (1.50±0.22 vs 1.61±0.23; p=0.038). Dividing patients into two groups according to SDB severity, patients with a moderate-severe disturbance (AHI >15; n=43) showed significantly worse survival for the composite study outcome (log-rank test, p=0.001) with respect to patients with mild or no disorder (AHI ≤15; n=51). Adding SDB variables to the already known prognostic role of 123 I-MIBG imaging, we observed a worse survival in patients with both SDB and H/M impairment., Conclusions: Patients with systolic HF and SDB show more impaired cardiac adrenergic innervation assessed by 123 I-MIBG imaging, and more adverse prognosis compared with HF patients without SDB., Competing Interests: Competing interests: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Pulmonary arterial hypertension (PAH) in adult patients with congenital heart disease (CHD) is associated with increased morbidity and mortality. The present review aims to discuss the clinical applications of invasive and non-invasive diagnostic modalities and to describe the strengths and weaknesses of each technique. Chest radiograph is an inexpensive investigation providing information on pulmonary arterial and hilar dilatation, pruning of peripheral pulmonary arteries and cardiomegaly. Transthoracic two-dimensional and Doppler echocardiography is the most widely used imaging tool. It provides information on cardiac anatomy and an estimate of haemodynamics and biventricular remodelling and function. In addition, echocardiography is valuable in assessing prognosis and monitoring the efficacy of therapy. Structural and functional changes associated with CHD-PAH, mainly affecting the right ventricle and pulmonary circulation, may represent an ideal target for evaluation with cardiac magnetic resonance. This non-invasive imaging modality has a low biological impact. CT plays an important role for patients with limited echocardiographic windows and those who are unable to undergo MRI (claustrophobia, poor compliance, presence of a pacemaker/implantable cardioverter defibrillator). It is the modality of choice for detailed assessment of pulmonary vessel obstruction or thrombosis. Finally, heart catheterisation remains the gold standard for diagnosing and confirming PAH in patients with CHD and for shunt evaluation. The diagnostic assessment of CHD-PAH requires great expertise and a deep knowledge of both CHD and PAH pathophysiology and should take place in a tertiary centre, where multiple data can be appropriately integrated and applied clinically., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Cardiac sympathetic activity can be assessed by (123)I-labelled meta-iodobenzylguanidine (MIBG) scintigraphy. Abnormalities of sympathetic cardiac activity have been shown in patients with heart failure, resulting in reduced MIBG uptake. Abnormal MIBG uptake predicts cardiac death, arrhythmias and all-cause mortality in patients with heart failure with a prognostic power incremental to that of conventional risk markers, and may identify patients at low risk of arrhythmias despite current guideline indications for implantable cardioverter defibrillator or patients at high risk for arrhythmias not fulfilling implantable cardioverter defibrillator indications. Prospective outcome studies are needed to assess whether MIBG imaging will have an impact on the mortality and morbidity of patients with heart failure.

Objective: To evaluate the effects of chronic coronary occlusion on the accuracy of low dose dobutamine echocardiography in predicting recovery of dysfunctional myocardium after revascularisation., Design: Retrospective study., Setting: Tertiary referral centre., Patients: 53 consecutive patients with >/= 70% stenosis of the left anterior descending coronary artery (LAD) and regional ventricular dysfunction (group 1, non-occluded LAD; group 2, occluded LAD) who underwent dobutamine echocardiography., Interventions: 26 patients underwent coronary artery bypass grafting and 27 had percutaneous transluminal coronary angioplasty., Main Outcome Measures: Baseline studies before revascularisation included cross sectional echocardiography at rest and during dobutamine infusion (5-10 microgram), and coronary angiography. The dobutamine study was performed mean (SD) 35 (28) days before revascularisation. Echocardiography at rest was repeated 90 (48) days after revascularisation., Results: Of 296 dysfunctional segments, 63 in group 1 (43%; 63/146) and 69 in group 2 (46%; 69/150) (NS) improved at follow up. Mean (SD) regional wall motion score index decreased from 1.97 (0.48) (95% confidence interval (CI) 1.01 to 2.93) before revascularisation to 1.74 (0.52) (95% CI 0.70 to 2.78) at follow up in group 1 (p = 0.001), and from 2.12 (0.41) (95% CI 1.30 to 2.98) to 1.88 (0.36) (95% CI 1.16 to 2.60) in group 2 (p = 0.0006). In group 1, sensitivity (87% v 52%; p < 0.0001), negative predictive value (88% v 65%; p = 0.001), and accuracy (77% v 64%; p = 0.01) were all significantly higher than in group 2, despite the angiographic evidence of collaterals in patients with occluded vessels., Conclusions: Dobutamine echocardiography shows reduced sensitivity in predicting recovery of dysfunctional myocardium supplied by totally occluded vessels. Thus caution should be used in selecting such patients for revascularisation on the basis of a viability assessment made in this way.