Acute rheumatic fever and rheumatic heart disease in children and adolescents in Victoria, Australia.

AIM: To describe the epidemiology and clinical profile of children and adolescents with acute rheumatic fever (ARF) and rheumatic heart disease (RHD) in Victoria, Australia. METHODS: A retrospective audit was undertaken of children and adolescents with ARF and RHD attending the Royal Children's and Monash Children's Hospitals in Victoria, Australia between 2010 and 2019. Potential cases were identified by searching multiple sources for relevant ICD-10-AM codes and keywords, then reviewed manually. For confirmed cases, we collected data on patient demographics, clinical features, comorbidities and management. RESULTS: Of 179 participants included, there were 108 Victorian residents and 71 non-Victorian residents. 126 had at least one episode of ARF during the study period and 128 were diagnosed with RHD. In the Victorian resident group, the overall incidence of ARF was 0.8 per 100 000 5-14 year olds. This incidence was higher in Victorian Aboriginal and/or Torres Strait Islander (3.8 per 100 000) and Pacific Islander (32.1 per 100 000) sub-populations. Of 83 Victorian residents who had an ARF episode, 11 (13%) had a recurrence. Most Victorian residents with RHD had mixed aortic and mitral valve pathology (69.4%) and moderate to severe disease (61.9%). Most non-Victorian residents were Aboriginal and/or Torres Strait Islander people (80.3%) and were commonly transferred for tertiary or surgical management of RHD (83.1%). CONCLUSIONS: ARF and RHD continue to affect the health of significant numbers of children and adolescents living in Victoria, including severe and recurrent disease. Specialised services and a register-based control program may help to prevent complications and premature death.

In utero fetal left ventricular rupture and pseudoaneurysm formation: a case report.

BACKGROUND: Cardiac ventricular aneurysms affect 1 in 200,000 live births. To the best of our knowledge, no reported cases of a left ventricular pseudoaneurym and in utero rupture exist to guide optimal management. CASE PRESENTATION: We present a case of fetal left ventricular rupture with a large pericardial effusion, cardiac tamponade and subsequent pseudoaneurysm formation with concerns for a poor prognosis. Interventional drainage of the pericardial effusion led to resolution of tamponade and significant improvement in fetal condition. A multidisciplinary team was utilised to plan birth to minimise risk of pseudoaneurysmal rupture and a catastrophic bleed at birth. CONCLUSION: For similar cases we recommend consideration of birth by caesarean section, delayed cord clamping and a prostaglandin E1 infusion, to reduce the systemic pressures on the left ventricle during transition from fetal to neonatal circulations, until definitive surgical repair. In this case, this resulted in a successful outcome.

Parent-Mediated Interventions for Children With Autism Spectrum Disorder: A Systematic Review.

OBJECTIVE: The purpose of this systematic review was to evaluate the evidence for the effectiveness of parent-mediated interventions on occupational performance of children with autism spectrum disorder (ASD). METHOD: We conducted a search of academic databases using terms such as autism spectrum disorder, parent, caregiver, and intervention. Five hundred eighty-two articles were reviewed, and 109 were selected for full-text review. The final analysis included 13 articles. RESULTS: Strong evidence was found for the efficacy of parent-mediated intervention for increasing child joint attention. Moderate evidence was found for the improvement of language scores, expressive language, nonverbal communication, initiation and response to interaction, behavior, play, adaptive functioning, ASD symptoms, and social communication. CONCLUSION: This systematic review suggests that parent-mediated interventions for children with ASD can improve various aspects of communication and ASD symptoms, with emerging support for occupational performance. Occupational therapy practitioners are well suited to facilitate these interventions to support families with children with autism.

BAR-SH3 sorting nexins are conserved interacting proteins of Nervous wreck that organize synapses and promote neurotransmission.

Nervous wreck (Nwk) is a conserved F-BAR protein that attenuates synaptic growth and promotes synaptic function in Drosophila. In an effort to understand how Nwk carries out its dual roles, we isolated interacting proteins using mass spectrometry. We report a conserved interaction between Nwk proteins and BAR-SH3 sorting nexins, a family of membrane-binding proteins implicated in diverse intracellular trafficking processes. In mammalian cells, BAR-SH3 sorting nexins induce plasma membrane tubules that localize NWK2, consistent with a possible functional interaction during the early stages of endocytic trafficking. To study the role of BAR-SH3 sorting nexins in vivo, we took advantage of the lack of genetic redundancy in Drosophila and employed CRISPR-based genome engineering to generate null and endogenously tagged alleles of SH3PX1. SH3PX1 localizes to neuromuscular junctions where it regulates synaptic ultrastructure, but not synapse number. Consistently, neurotransmitter release was significantly diminished in SH3PX1 mutants. Double-mutant and tissue-specific-rescue experiments indicate that SH3PX1 promotes neurotransmitter release presynaptically, at least in part through functional interactions with Nwk, and might act to distinguish the roles of Nwk in regulating synaptic growth and function.

Barriers to antiretroviral therapy initiation for HIV-positive children aged 2-18 months in Swaziland.

Although early antiretroviral therapy (ART) reduces HIV-related mortality in children by up to 75%, almost half of HIV-positive children younger than 1 year old in Swaziland do not initiate ART. This study was conducted to identify barriers to early ART initiation among HIV-positive infants. This was a case-control study among HIV-positive infants, aged 2 to 18 months, who either did not initiate ART (cases), or initiated ART (controls), during 18 months after testing. Multivariable logistic regression showed that infants who visited the clinic every month, or every 2 months, were 5.78 and 6.20 times more likely to initiate ART than those who visited less often (OR 5.78, 95% CI 1.82-18.33 and OR 6.20, 95% CI 1.30-29.60 respectively). Children who lived ≤30 and 31-60 minutes from the nearest clinic were 84% and 79% less likely respectively to initiate ART (OR 0.16, 95% CI 0.03-0.78 and OR 0.21, 95% CI 0.04-0.98) compared with those who lived more than 60 minutes away. Children who received immunisation after 6 months were 22.59 times more likely to initiate ART (OR 22.59, 95% CI 7.00-21.72) than those who did not. Infants of caregivers who had excellent or good relationships with their healthcare provider were 4.32 times more likely to initiate ART (OR 4.32, 95% CI 1.01-18.59) than those of caregivers who had average or poor relationships with healthcare providers. The significant predictors of ART initiation identified in this study should be regarded as priority areas for intervention among HIV-positive women in Swaziland.

How to effectively design and create a concept mobile application to aid in the management of type 1 diabetes in adolescents.

Diabetes is one of the most prevalent chronic health conditions in the world; with a range of diabetes-related mobile applications available to the public to aid in glycaemic control and self-management. Statistically, adherence to medication is extremely low in adolescents with Type 1 Diabetes Mellitus (T1DM), therefore, this paper focuses on the research and design of an interactive and educational concept mobile application aimed at early to mid-adolescents to aid in their understanding of T1DM. As visual elements are an essential part of the design, this research outlines how visual components were designed specifically for adolescents with T1DM.

Redefining expectations of long-term survival after the Fontan procedure: twenty-five years of follow-up from the entire population of Australia and New Zealand.

BACKGROUND: The life expectancy of patients undergoing a Fontan procedure is unknown. METHODS AND RESULTS: Follow-up of all 1006 survivors of the 1089 patients who underwent a Fontan procedure in Australia and New Zealand was obtained from a binational population-based registry including all pediatric and adult cardiac centers. There were 203 atriopulmonary connections (AP; 1975-1995), 271 lateral tunnels (1988-2006), and 532 extracardiac conduits (1997-2010). The proportion with hypoplastic left heart syndrome increased from 1/173 (1%) before 1990 to 80/500 (16%) after 2000. Survival at 10 years was 89% (84%-93%) for AP and 97% (95% confidence interval [CI], 94%-99%) for lateral tunnels and extracardiac conduits. The longest survival estimate was 76% (95% CI, 67%-82%) at 25 years for AP. AP independently predicted worse survival compared with extracardiac conduits (hazard ratio, 6.2; P<0.001; 95% CI, 2.4-16.0). Freedom from failure (death, transplantation, takedown, conversion to extracardiac conduits, New York Heart Association III/IV, or protein-losing enteropathy/plastic bronchitis) 20 years after Fontan was 70% (95% CI, 63%-76%). Hypoplastic left heart syndrome was the primary predictor of Fontan failure (hazard ratio, 3.8; P<0.001; 95% CI, 2.0-7.1). Ten-year freedom from failure was 79% (95% CI, 61%-89%) for hypoplastic left heart syndrome versus 92% (95% CI, 87%-95%) for other morphologies. CONCLUSIONS: The long-term survival of the Australia and New Zealand Fontan population is excellent. Patients with an AP Fontan experience survival of 76% at 25 years. Technical modifications have further improved survival. Patients with hypoplastic left heart syndrome are at higher risk of failure. Large, comprehensive registries such as this will further improve our understanding of late outcomes after the Fontan procedure.

Mal-positioned nasogastric feeding tubes: are medical students safe to identify them?

OBJECTIVES: Nasogastric tube (NGT) placement is listed against Clinical Imaging in the upcoming Medical Licensing Assessment-compulsory for every graduating UK medical student from 2025. This study aims to establish the ability of medical students to correctly identify the position of an NGT on Chest X-ray (CXR) and to evaluate a learning tool to improve student outcome in this area. METHODS: Fourth-year (MB4) and fifth-year (MB5) medical students were invited to view 20 CXRs with 14 correctly sited and 6 mal-positioned NGT. MB5 students (Intervention) were exposed to an online interactive learning tool, with MB4 students kept as control. One week later, both groups of students were invited to view 20 more CXRs for NGT placement. RESULTS: Only 12 (4.8%) of 249 MB5 students and 5 (3.1%) of 161 MB4 students correctly identified all the NGTs on CXRs. The number of students misidentifying 1 or more mal-positioned NGT as "safe to feed" was 129 (51.8%) for MB5 and 76 (47.2%) for MB4 students. This improved significantly (P < .001) following exposure to the learning tool with 58% scoring all CXRs correctly, while 28% scored 1 or more mal-positioned NGT incorrectly. Students struggled to determine if the NGT tip had adequately passed into the stomach. However, they failed to identify an NG tube in the lung ("never event") in just one out of 1,108 opportunities. CONCLUSION: Medical students' ability to determine if the NGT was in the stomach remains suboptimal despite exposure to over 60 CXRs. Feeding NGT should be formally reported before use. ADVANCES IN KNOWLEDGE: This is the first attempt at quantifying graduating medical students', and by inference junior doctors', competence in safely identifying misplaced nasogastric feeding tubes. An online, experiential learning resource significantly improved their ability.

Computed tomography stress myocardial perfusion imaging in patients considered for revascularization: a comparison with fractional flow reserve.

AIMS: Adenosine stress computed tomography myocardial perfusion imaging (CTP) is an emerging non-invasive method for detecting myocardial ischaemia. Its value when compared with fractional flow reserve (FFR), a highly accurate index of ischaemia, is unknown. Our aim was to determine the diagnostic accuracy of CTP and its incremental value when used with computed tomography coronary angiography (CTA) for detecting ischaemia compared with FFR. METHODS AND RESULTS: Forty-two patients (126 vessel territories), who had at least one ≥50% angiographic stenosis on invasive angiography considered for non-urgent revascularization, were included and underwent FFR and CT assessment, including CTP, delayed contrast enhancement scan and CTA all acquired using 320-detector row CT, and prospective ECG gating. Fractional flow reserve was determined in 86 territories subtended by vessels with ≥50% stenosis upon visual assessment. Fractional flow reserve ≤0.8 was considered to indicate significant ischaemia. Computed tomography myocardial perfusion imaging correctly identified 31/41 (76%) ischaemic territories and 38/45 (84%) non-ischaemic territories. Per-vessel territory sensitivity, specificity, positive, and negative predictive values of CTP were 76, 84, 82, and 79%, respectively. The combination of a ≥50% stenosis on CTA and perfusion defect on CTP was 98% specific for ischaemia, while the presence of <50% stenosis on CTA and normal perfusion on CTP was 100% specific for exclusion of ischaemia. Mean radiation for CTP and combined CT was 5.3 and 11.3 mSv, respectively. CONCLUSION: Computed tomography myocardial perfusion imaging is moderately accurate in identifying perfusion defects associated with ischaemia as assessed by FFR in patients considered for revascularization. In territories, where CTA and CTP are concordant, CTA/CTP is highly accurate in the detection and exclusion of ischaemia. This is achievable with acceptable radiation exposure using 320-detector row CT and prospective ECG gating.

The heart rate response to spontaneous arousal from sleep is reduced in children with Down syndrome referred for evaluation of sleep-disordered breathing.

Arousal from sleep in healthy adults is associated with a large, transient increase in heart rate (HR). Individuals with Down syndrome (DS) have attenuated cardiovascular responses to autonomic tests during wakefulness. We tested the hypothesis that the HR response to arousal from sleep is reduced in children with DS and obstructive sleep apnea (OSA) compared with healthy children. Twenty children aged 3-17 yr referred for investigation of sleep-disordered breathing (10 DS, and 10 OSA controls) matched for age and obstructive apnea/hypopnea index underwent routine overnight polysomnography. In addition, 10 nonsnoring controls from the general community were studied. Beat-by-beat HR was analyzed from 15 s pre- to 15 s post-spontaneous arousals and compared between groups using two-way ANOVA with repeated measures. Data are presented as means + or - SE. For both rapid eye movement (REM) and non-REM (NREM), arousals were associated with a significant increase in HR in all groups (peak response NREM: DS, 118 + or - 1% at 3 s; OSA controls, 124 + or - 2% at 4 s; and healthy controls, 125 + or - 3% at 4 s; and peak response REM: DS, 116 + or - 2% at 4 s; OSA controls, 123 + or - 3% at 4 s; and healthy controls, 125 + or - 4 at 4 s; P < 0.001 for all). Post hoc analysis revealed that HR in the DS group was significantly lower than both control groups at 1-4 s in NREM and at 4 to 5 s in REM (P < 0.05 for all). In conclusion, the HR response to spontaneous arousal from sleep is reduced in children with DS and OSA compared with healthy children. This attenuated cardiovascular response could be due to reduced sympathetic activation or blunted vagal withdrawal and may have implications for the child with DS and OSA.

Occlusive aortic arch thrombus in a preterm neonate.

OBJECTIVE: To present the case of an extremely preterm infant with occlusive aortic arch clot managed with low-risk therapy. DATA SOURCE: Case details were obtained from medical records and echocardiographic images from Excelera database. STUDY SELECTION: Preterm infant with occlusive clot in the aortic arch. DATA EXTRACTION AND SYNTHESIS: Demographic details (gestation age and birthweight), clinical and biochemical data (blood pressure, oxygen saturation, urine output, lactate levels, and coagulation profile) were obtained from medical records. A female infant was born at 28 wks gestation and had umbilical catheters inserted in satisfactory positions. On day 6, pre- and postductal oxygen saturation differences, a significantly higher blood pressure on right arm, and weak pulses were noted. Echocardiogram revealed an occlusive thrombus in the aortic arch distal to the innominate artery, extending into the carotid artery with retrograde flow in the left internal carotid and subclavian arteries. The distal aortic circulation was supported by ductus arteriosus shunting bidirectionally. Intravenous prostaglandin E and heparin were started, the latter was later replaced by enoxaparin. Serial echocardiograms over next 3 mos showed complete resolution of the thrombus. CONCLUSIONS: Neonatal aortic arch thrombus is extremely rare with only 3 cases previously reported--all in term infants. Therapeutic options include anticoagulation, thrombolytic therapy, and thrombectomy. The risk/benefit ratio for anticoagulation and thrombolytic therapy is unknown and must be individualized. This preterm infant was managed with low-risk therapy and had an optimal outcome.

Arterial transfer functions and the reconstruction of central aortic waveforms: myths, controversies and misconceptions.

Continuing reports in the literature regarding the potential of central pulse wave analysis in clinical practice and a recent consensus statement demonstrate the increasing interest in the clinical application of arterial transfer functions. A number of misconceptions, however, persist regarding their use. In spite of ongoing controversy, there are considerable published data that would permit users to assess the validity and accuracy of the technique. We provide a comprehensive review of available data, all of which appear to be clear and consistent. The technique does not permit accurate reconstruction of central waveforms from entirely non-invasively acquired data. We should move on from the misconception that what is being studied is central aortic data when transfer functions are applied non-invasively, and accept that it is radial waveform data that have been passed through a single mathematical transformation. We have a readily applicable, non-invasive and reproducible technique for acquiring radial waveform data, with or without the application of a generalized arterial transfer function. We must explore the potential of this technique in an analytical manner, and without untenable preconceptions, if we are to learn the secrets that it may yet reveal.

Quantitative and qualitative changes in the resting electrocardiograph after percutaneous transluminal septal myocardial ablation for the treatment of symptomatic obstructive hypertrophic cardiomyopathy.

Percutaneous Transluminal Septal Myocardial Ablation (PTSMA) may reduce symptoms in patients with obstructive hypertrophic cardiomyopathy. Limited quantitative and qualitative data exists on the effects of PTSMA on the resting electrocardiograph. We report repolarisation and conduction abnormalities and incidence of arrhythmia post-PTSMA. Twelve-lead electrocardiographs from subjects without pre-procedural pacemakers who underwent successful procedures (37 procedures, mean age 61+/-14 years) were analysed for rhythm, heart rate, PR and QTc intervals, QRS duration and left or right bundle branch block (RBBB, LBBB). Four subjects developed permanent complete AV block, 19 subjects developed new RBBB and two subjects developed new LBBB pre-discharge. At a median follow-up of 34 (range 1-84) months, no new AV block, ventricular arrhythmias or deaths occurred. Post-PTSMA PR, QRS and QTc intervals lengthened (PR 180+/-33 ms, 204+/-40 ms, QRS 105+/-20 ms, 132+/-27 ms and QTc 454+/-32 ms, 491+/-37 ms (pre- and post-PTSMA respectively, all p=0.001). Predictors of permanent complete AV block included female gender (p=0.013), older age (p=0.013) and pre-existing LBBB (p<0.001). Atrio-ventricular and intra-ventricular conduction disturbances are common post-PTSMA. A pre-existing LBBB is a risk factor for the development of complete AV block and may merit prophylactic pacemaker insertion.

Arterial pulse wave velocity but not augmentation index is associated with coronary artery disease extent and severity: implications for arterial transfer function applicability.

OBJECTIVES: The aim of this study was to test the hypothesis that coronary artery disease extent and severity are associated with central aortic pressure waveform characteristics. BACKGROUND: Although it is thought that central aortic pressure waveform characteristics, particularly augmentation index, may influence cardiovascular disease progression and predict cardiovascular risk, little is known of the relationship between central waveform characteristics and the severity and extent of coronary artery disease. METHODS: Central aortic waveforms (2F Millar pressure transducer-tipped catheters) were acquired at the time of coronary angiography for suspected native coronary artery disease in 40 patients (24 male). The severity and extent of disease were assessed independently by two observers using two previously described scoring systems (modified Gensini's stenosis and Sullivan's extent scores). Relationships between disease scores, aortic waveform characteristics, aorto-radial pulse wave velocity and subject demographic features were assessed by regression techniques. RESULTS: Both extent and severity scores were associated with increasing age and male sex (P < 0.001), but no other risk factors. Both scores were independently associated with aorto-radial pulse wave velocity (P < 0.001), which entered a multiple regression model prior to age and sex. This association was not dependent upon blood pressure. Neither score was associated with central aortic augmentation index, by either simple or multiple linear regression techniques including heart rate, subject demographic features and cardiovascular risk factors. CONCLUSIONS: Aorto-radial pulse wave velocity, but not central aortic augmentation index, is associated with both the extent and severity of coronary artery disease. This has potentially important implications for applicability of a generalized arterial transfer function.

'Generalizability' of a radial-aortic transfer function for the derivation of central aortic waveform parameters.

OBJECTIVE: Arterial transfer functions (TFs) describe the relationship between the pressure waveform at different arterial sites. Generalized TFs are used to reconstruct central aortic waveforms from non-invasively obtained peripheral waveforms and have been promoted as potentially clinically useful. A limitation is the paucity of information on their 'generalizability' with no information existing on the number of subjects required to construct a satisfactory TF, nor is adequate prospective validation available. We therefore investigated the uniformity of radial-aortic TFs and prospectively estimated the capacity of a generalized TF to reconstruct individual central blood pressure parameters. PATIENTS AND METHODS: Ninety-three subjects (64 male) were studied by simultaneous radial applanation and high-fidelity (Millar Mikro-tip catheter) direct measurement of central aortic BP during elective coronary procedures. Subjects were prospectively randomized to either a derivation or validation group. RESULTS: Increasing numbers of individual TFs from the derivation group were averaged to form a generalized TF. There was minimal change with greater than 20 TFs averaged. In the validation group, the error in most reconstructed parameters related to the absolute value of the directly measured parameter [systolic blood pressure (SBP) and pulse pressure, P<0.05; systolic pressure-time interval, subendocardial viability index, augmentation index, and times to the inflection point, peak and end systole, all P<0.01]. Aorto-radial delay was related to error in reconstructed central aortic SBP and pulse pressure (negatively) and time to peak systole (positively) (all P<0.001). Reconstruction of augmentation index was poor. DISCUSSION: Inclusion of more than 20 individual TFs in the construction of a generalized TF does not improve 'generalizability'. There appear to be systematic errors in derived central pressure waveforms and derived aortic augmentation index is inaccurate compared to the directly measured value.

Systemic inflammatory markers in acute coronary syndrome: association with cardiovascular risk factors and effect of early lipid lowering.

BACKGROUND: Evidence for statin therapy in prevention of coronary artery disease is overwhelming. In spite of theoretical benefits, any additional advantage of its early introduction in the management of acute coronary syndrome is, however, uncertain. We therefore investigated differences between plasma levels of the systemic inflammatory markers intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, C-reactive protein and interleukin-6 in patients presenting with unstable angina or acute myocardial infarction, and assessed whether the 30-day levels of these markers are influenced by early instigation of the HMG-CoA reductase inhibitor pravastatin. MATERIALS AND METHODS: 170 (134 male) patients presenting with acute coronary syndrome, but without previous statin therapy, participated. Blood was taken within 24 h of onset of ischaemic pain and again at 30 days. In all, 87 (71 male) participants were treated with pravastatin (20-40 mg daily) and 83 (63 male) with a matched placebo. RESULTS: At presentation, interleukin-6 was higher in males than in females (P=0.008) and lower in those with a pre-existing history of myocardial infarction (P=0.038). C-reactive protein and interleukin-6 were greater in myocardial infarction, but this difference was lost at 30 days. Thirty-day changes in all parameters were inversely related to level at presentation but not to treatment with pravastatin. Hypertension (P=0.011) and smoking (P=0.042) were associated with elevation of C-reactive protein with no difference between unstable angina or acute myocardial infarction. The effect of these individual factors was cumulative. CONCLUSIONS: Interleukin-6 was greater in acute myocardial infarction than in unstable angina; E-selectin was positively associated with a previous myocardial infarction and inversely related to age. We found no effect of early introduction of pravastatin on systemic inflammatory markers 30 days after acute coronary syndrome.

Use of arterial transfer functions for the derivation of central aortic waveform characteristics in subjects with type 2 diabetes and cardiovascular disease.

OBJECTIVE: Optimal blood pressure control in subjects with diabetes reduces cardiovascular complications. There is theoretical benefit in the assessment of central aortic waveforms including the augmentation index, which is taken as a putative index of stiffness. Transfer functions may be used to reconstruct aortic from radial pressure waveforms; however, a single generalized transfer function may not be appropriate for all patients. We aimed to evaluate the technique in subjects with diabetes. RESEARCH DESIGN AND METHODS: Simultaneous invasive central aortic and noninvasive radial waveforms were acquired in 19 subjects with type 2 diabetes, and a diabetes-specific transfer function was derived. Similar data were acquired from 38 age- and sex-matched subjects without diabetes. Central waveforms were reconstructed using a generalized transfer function in all patients and the diabetes-specific transfer function in individuals with diabetes. RESULTS: There was no difference between groups in measured central pressures. The error in generalized transfer function-derived systolic pressure was greater in individuals with diabetes (6 +/- 7 mmHg) (mean +/- SD) than without diabetes (2 +/- 8 mmHg) (P<0.05). Errors in other parameters were no different. The diabetes-specific transfer function reduced the error in derived systolic pressure to 0 +/- 7 mmHg in individuals with diabetes--no different than that with the generalized transfer function in individuals without diabetes. The central augmentation index reconstructed by either transfer function was unrelated to that directly measured. CONCLUSIONS: A generalized transfer function is inappropriate for the derivation of central waveforms in subjects with type 2 diabetes. Errors in subjects with diabetes might be reduced with a diabetes-specific transfer function.

Use of arterial transfer functions for the derivation of aortic waveform characteristics.

OBJECTIVE: To investigate the utility and accuracy of radial-aortic arterial transfer functions for the derivation of central blood pressure waveforms. DESIGN Prospective measurement of central and peripheral waveforms in patients undergoing coronary angiography or percutaneous coronary intervention. METHODS: Simultaneous invasive central aortic and non-invasive radial pressure waveforms were recorded in 78 subjects (61 male : 17 female). Data were applied to a single-input/single-output model for the calculation of a transfer function (TF). Individual TFs were derived by two methods and ensemble averaged TFs obtained for the group. Reverse transformation was performed using each averaged TF applied to the radial data of each subject. RESULTS: There was close linear correlation between measured aortic parameters and both radial and TF-derived aortic systolic and diastolic pressures (P < 0.001) and most other waveform parameters. However, despite small mean differences between measured and most TF-derived aortic parameters (systolic pressure 0.8-2.9 mmHg, augmentation index 4.3-5.6%), individual scatter was marked, with 95% limits of agreement of +/- 14.6 mmHg (systolic pressure) and +/- 24.4% [augmentation index (AI)]. Indeed, scatter for AI was so marked that measured and derived values were not statistically significantly correlated. CONCLUSIONS: Transfer functions may be valid for the derivation of some central aortic waveform characteristics. However, in providing neither improved reproducibility nor data on parameters not obtainable from the radial waveform, transfer function techniques may offer no additional clinical benefit. The absence of correlation between measured and TF-derived aortic AI and wide limits of agreement of other parameters should be considered if this technique is utilized in clinical practice.

Time course of plasma adhesion molecules in acute coronary syndromes.

BACKGROUND: Atherosclerosis is an inflammatory process in which adhesion molecules play an intimate role in both the initiation and progression of lesions. It is postulated that they also play a role in the presentation of acute coronary syndromes and that plasma levels thereafter may be of potential prognostic significance. The stability of sample levels under different laboratory conditions is unknown. METHODS: Stability of plasma levels was assessed in six healthy subjects under four different laboratory conditions. The time course of levels was studied in 57 patients with acute chest pain, 21 of non-cardiac aetiology, 23 unstable angina and 13 acute myocardial infarction, at mean times of 2.3, 8.2 and 17.3 h after the onset of pain. Samples were assayed for intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), P-selectin, E-selectin and C-reactive protein (CRP). RESULTS: ICAM-1, VCAM-1, P-selectin and E-selectin levels did not differ under different laboratory conditions. Levels were similar at presentation in patients with acute chest pain of non-cardiac aetiology, unstable angina or acute myocardial infarction (median levels ICAM-1 269 microg/l, VCAM-1 379 microg/l, P-selectin 167 microg/l and E-selectin 53 microg/l). Levels did not change in the 24 h following the onset of pain. CRP levels did not differ at presentation between groups (median level 2.1 mg/l), but rose more than 12 h after the onset of pain in the group with acute myocardial infarction (P < 0.05). CONCLUSION: Adhesion molecule levels are stable under normal laboratory sample handling conditions. Levels do not change in the 24 h following the onset of chest pain of non-cardiac or acute ischaemic aetiology.