13 research outputs found
Habitat partitioning and vulnerability of sharks in the Great Barrier Reef Marine Park
Sharks present a critical conservation challenge, but little is known about their spatial distribution and vulnerability, particularly in complex seascapes such as Australia's Great Barrier Reef Marine Park (GBRMP). We review (1) the distribution of shark species among the primary habitats of the GBRMP (coral reefs, inshore/shelf, pelagic and deep-water habitats) (2) the relative exploitation of each species by fisheries, and (3) how current catch rates interact with their vulnerability and trophic index. Excluding rays and chimaeras, we identify a total of 82 shark species in the GBRMP. We find that shark research in the GBRMP has yielded little quantitative information on most species. Reef sharks are largely site-fidelic, but can move large distances and some regularly use non-reef habitats. Inshore and shelf sharks use coastal habitats either exclusively or during specific times in their life cycle (e.g. as nurseries). Virtually nothing is known about the distribution and habitat use of the GBRMP's pelagic and deep-water sharks. At least 46 species (53.5 %) are caught in one or more fisheries, but stock assessments are lacking for most. At least 17 of the sharks caught are considered highly vulnerable to exploitation. We argue that users of shark resources should be responsible for demonstrating that a fishery is sustainable before exploitation is allowed to commence or continue. This fundamental change in management principle will safeguard against stock collapses that have characterised many shark fisheries
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Electrocardiographic patterns of ventricular arrhythmias in arrhythmogenic right ventricular dysplasia/cardiomyopathy
Ventricular arrhythmias in patients with ARVD/C are common. Differentiation between idiopathic VT and ARVD is of utmost importance. Baseline sinus rhythm electrocardiography as well as electrocar- diographic differences during ventricular arrhythmias (VT
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Physician Accuracy in Interpreting Potential ST-Segment Elevation Myocardial Infarction Electrocardiograms
Recognizing Belhassen Ventricular Tachycardia and Preventing Its Misinterpretation as Supraventricular Tachycardia: An Unusual Case Report
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Physician Accuracy in Interpreting Potential ST-Segment Elevation Myocardial Infarction Electrocardiograms
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Comparison of radionuclide angiographic synchrony analysis to echocardiography and magnetic resonance imaging for the diagnosis of arrhythmogenic right ventricular cardiomyopathy
Background Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heritable arrhythmia syndrome entailing a high risk of sudden cardiac death. Discernment from benign arrhythmia disorders, particularly right ventricular outflow tract ventricular tachycardia (RVOT VT), may be challenging, providing an impetus to explore alternative modalities that may facilitate evaluation of patients with suspected ARVC. Objective We evaluated the role of equilibrium radionuclide angiography (ERNA) as a diagnostic tool for ARVC. Methods ERNA measures of ventricular synchrony - synchrony (S) and entropy (E) - were examined in patients with ARVC (n = 16), those with RVOT VT (n = 13), and healthy controls (n = 49). The sensitivity and specificity of ERNA parameters for ARVC diagnosis were compared with those of echocardiography (ECHO) and cardiovascular magnetic resonance (CMR). Results ERNA right ventricular synchrony parameters in patients with ARVC (S = 0.91 ± 0.07; E = 0.61 ± 0.1) differed significantly from those in patients with RVOT VT (S = 0.99 ± 0.01 [P =.0015]; E = 0.46 ± 0.05 [P <.001]) and healthy controls (S = 0.97 ± 0.02 [P =.003]; E = 0.48 ± 0.07 [P =.001]). The sensitivity of ERNA synchrony parameters for ARVC diagnosis (81%) was higher than that for ECHO (38%; P =.033) and similar to that for CMR (69%; P =.162), while specificity was lower for ERNA (89%) than that for ECHO and CMR (both 100%; P =.008). Conclusion ERNA right ventricular synchrony parameters can distinguish patients with ARVC from controls with structurally normal hearts, and its performance is comparable to that of ECHO and CMR for ARVC diagnosis. These findings suggest that ERNA may serve as a valuable imaging tool in the diagnostic evaluation of patients with suspected ARVC