Chiari's network: Normal anatomic variant or risk factor for arterial embolic events?

Objectives.This study was performed to assess the prevalence of Chiari's network in patients undergoing transesophageal echocardiography and to determine whether this anomaly is associated with other cardiac lesions or is characterized by typical clinical findings.Background.Chiari's network is a congenital remnant of the right valve of the sinus venosus. It has been found in 1.3% to 4% of autopsy studies and is believed to be of little clinical consequence.Methods.Video recordings of 1,436 consecutive adult patients evaluated by transesophageal echocardiography over a 30-month period were reviewed for the presence of Chiari's network. Echocardiographic contrast studies had been performed in all patients with Chiari's network and were compared with those of 160 consecutive patients without a Chiari net, serving as a control group.Results.Chiari's network was present in 29 of 1,436 patients (prevalence 2%). A frequently associated finding was a patent foramen ovale in 24 (83%) of the 29 patients with Chiari's network versus 44 (28%) of 160 control patients (p < 0.001). Intense right-to-left shunting occurred significantly more often in patients with Chiari's network than in control patients (16 [55%] of 29 patients vs. 19 [12%] of 160 control patients, p < 0.001). Another frequent association was an atrial septal aneurysm in 7 (24%) of 29 patients. The indication for transesophageal echocardiography was a suspected cardiac source of arterial embolism in 24 (83%) of 29 patients with a Chiari net, 13 of whom (54%) had recurrent embolic events. Chiari's network was significantly more common in patients with unexplained arterial embolism than in patients evaluated for other indications (24 [4.6%] of 522 patients vs. 5 [0.5%] of 914 patients, p < 0.001). Potential causes for arterial embolism were present in 9 of the 24 patients with a Chiari net and embolic events (atrial septal aneurysm in 7, cerebrovascular lesion in 2). In 15 (62%) of 24 patients only a patent foramen ovale could be identified. Three patients had deep venous thrombosis and pulmonary embolism at the time of arterial embolism; none had a thrombus detected within the network.Conclusions.In patients undergoing transesophageal echocardiography, the prevalence of Chiari's network was 2%, which is consistent with autopsy studies. By maintaining an embryonic right atrial flow pattern into adult life and directing the blood from the inferior vena cava preferentially toward the interatrial septum, Chiari's network may favor persistence of a patent foramen ovale and formation of an atrial septal aneurysm and facilitate paradoxic embolism

Simultaneous measurement of pulmonary venous flow by intravascular catheter Doppler velocimetry and transesophageal doppler echocardiography: Relation to left atrial pressure and left atrial and left ventricular function

Objectives.The aim of our study was to compare measurements of pulmonary venous flow velocity obtained either by transesophageal Doppler echocardiography or by intravascular catheter Doppler velocimetry. Furthermore, the relation among pulmonary venous flow velocity, left atrial compliance and left atrial pressure was evaluated.Background.Data about the relation between left atrial pressure and pulmonary venous flow velocity are controversial.Methods.A total of 32 patients undergoing elective open heart surgery for coronary artery bypass grafting were included prospectively in the study. Pulmonary venous flow velocity (Doppler catheter) and left atrial pressure (microtip pressure transducer) were recorded simultaneously with recordings of pulmonary venous flow velocity obtained by transesophageal Doppler echocardiography.Results.Agreement between Doppler catheter and Doppler echocardiographic measurements of pulmonary venous flow velocity (n = 18 patients) was analyzed using the Bland-Altmann technique. The 95% limits of agreement were −0.16 to +0.11 m/s for systolic peak velocity, −0.14 to +0.09 m/s for diastolic peak velocity and −0.12 to +0.10 m/s for atrial peak velocity. The closest agreement between both methods was found for the ratio of systolic to diastolic peak velocity, the ratio of systolic to diastolic flow duration and the time from Q deflection on the electrocardiogram to maximal flow velocity. Mean left atrial pressure was strongly correlated with the ratio of systolic to diastolic peak velocity (r = −0.829), systolic velocity-time integral (r = −0.653), time to maximal flow velocity (r = 0.844) and the ratio of systolic to diastolic flow duration (r = −0.556). The ratio of systolic to diastolic peak velocity and the time to maximal flow velocity were identified as strong independent predictors of mean left atrial pressure. Left atrial compliance was not found to be an independent predictor of mean left atrial pressure.Conclusions.Flow velocity in the left upper pulmonary vein can be reliably recorded by transesophageal pulsed wave Doppler echocardiography. Our data reveal further evidence that mean left atrial pressure can be estimated by the pattern of pulmonary venous flow velocity

Implications of troponin testing in clinical medicine

During the past decade considerable research has been conducted into the use of cardiac troponins, their diagnostic capability and their potential to allow risk stratification in patients with acute chest pain. Determination of risk in patients with suspected myocardial ischaemia is known to be as important as retrospective confirmation of a diagnosis of myocardial infarction (MI). Therefore, creatine kinase (CK)-MB - the former 'gold standard' in detecting myocardial necrosis - has been supplanted by new, more accurate biomarkers.Measurement of cardiac troponin levels constitute a substantial determinant in assessment of ischaemic heart disease, the presentations of which range from silent ischaemia to acute MI. Under these conditions, troponin release is regarded as surrogate marker of thrombus formation and peripheral embolization, and therefore new therapeutic strategies are focusing on potent antithrombotic regimens to improve long-term outcomes. Although elevated troponin levels are highly sensitive and specific indicators of myocardial damage, they are not always reflective of acute ischaemic coronary artery disease; other processes have been identified that cause elevations in these biomarkers. However, because prognosis appears to be related to the presence of troponins regardless of the mechanism of myocardial damage, clinicians increasingly rely on troponin assays when formulating individual therapeutic plans

Increased NAD(P)H oxidase-mediated superoxide production in renovascular hypertension: Evidence for an involvement of protein kinase C

Increased NAD(P)H oxidase-mediated superoxide production in renovascular hypertension: Evidence for an involvement of protein kinase C.BackgroundAngiotensin II infusion has been shown to cause hypertension and endothelial dysfunction and to increase superoxide (O-·2) production in vascular tissue, mainly via an activation of nicotinamide adenine dinucleotide (phosphate) [NAD(P)H]-dependent oxidase, the most significant O-·2 source in endothelial and/or smooth muscle cells. With these studies, we sought to determine whether endothelial dysfunction in renovascular hypertension is secondary to an activation of these oxidases.MethodsEndothelial function in aortas from rats with two kidney-one clip (2K-1C) hypertension and age-matched controls was assessed using isometric tension studies in organ chambers. Changes in vascular O-·2 production were measured using lucigenin-enhanced chemiluminescence and electron spin resonance spectroscopy.ResultsIn hypertensive animals, relaxation to endothelium-dependent (acetylcholine) and endothelium-independent nitrovasodilators (nitroglycerin) was impaired. Constriction to a direct activator of protein kinase C (PKC) phorbol ester 12,13 dibutyrate (PDBu) was enhanced, and vascular O-·2 was significantly increased compared with controls. Vascular O-·2 was normalized by the PKC inhibitor calphostin C, by the inhibitor of flavin-dependent oxidases, diphenylene iodonium, and recombinant heparin-binding superoxide dismutase, whereas inhibitors of the xanthine oxidase (oxypurinol), nitric oxide synthase (NG-nitro-L-arginine) and mitochondrial NADH dehydrogenase (rotenone) were ineffective. Studies of vascular homogenates demonstrated that the major source of O-·2 was a NAD(P)H-dependent oxidase. Incubation of intact tissue with PDBu markedly increased O-·2, the increase being significantly stronger in vessels from hypertensive animals as compared with vessels from controls. Endothelial dysfunction was improved by preincubation of vascular tissue with superoxide dismutase and calphostin C.ConclusionsWe therefore conclude that renovascular hypertension in 2K-1C rats is associated with increased vascular O-·2 leading to impaired vasodilator responses to endogenous and exogenous nitrovasodilators. Increased vascular O-·2 is likely secondary to a PKC-mediated activation of a membrane-associated NAD(P)H-dependent oxidase

The BDS checklist as measure of illness severity:A cross-sectional cohort study in the Danish general population, primary care and specialised setting

Objective The bodily distress syndrome (BDS) checklist has proven to be useful in the diagnostic categorisation and as screening tool for functional somatic disorders (FSD). This study aims to investigate whether the BDS checklist total sum score (0–100) can be used as a measure of physical symptom burden and FSD illness severity.Design Cross-sectional.Setting Danish general population, primary care and specialised clinical setting.Participants A general population cohort (n=9656), a primary care cohort (n=2480) and a cohort of patients with multiorgan BDS from specialised clinical setting (n=492).Outcome measures All data were self-reported. Physical symptoms were measured with the 25-item BDS checklist. Overall self-perceived health was measured with one item from the 36-item Short-Form Health Survey (SF-36). Physical functioning was measured with an aggregate score of four items from the SF-36/SF-12 scales ‘physical functioning’, ‘bodily pain’ and ‘vitality’. Emotional distress was measured with the mental distress subscale (SCL-8) from the Danish version of the Hopkins Symptom Checklist-90. Illness worry was measured with the six-item Whiteley Index.Results For all cohorts, bifactor models established that despite some multidimensionality the total sum score of the BDS checklist adequately reflected physical symptom burden and illness severity. The BDS checklist had acceptable convergent validity with measures of overall health (r=0.25–0.58), physical functioning (r=0.22–0.58), emotional distress (r=0.47–0.62) and illness worry (r=0.36–0.55). Acceptability was good with a low number of missing responses to items (&lt;3%). Internal consistency was high (α ≥0.879). BDS score means varied and reflected symptom burden across cohorts (13.03–46.15). We provide normative data for the Danish general population.Conclusions The BDS checklist total sum score can be used as a measure of symptom burden and FSD illness severity across settings. These findings establish the usefulness of the BDS checklist in clinics and in research, both as a diagnostic screening tool and as an instrument to assess illness severity