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.

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.

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.

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.

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.

Low risk of pulmonary valve implantation after a policy of transatrial repair of tetralogy of Fallot delayed beyond the neonatal period: the Melbourne experience over 25 years.

OBJECTIVES: The study sought to evaluate the late outcomes of a policy of transatrial repair delayed beyond the neonatal period. BACKGROUND: Long-term outcomes of transatrial repair of tetralogy of Fallot are unknown. METHODS: The records of 675 consecutive patients undergoing a transatrial repair of tetralogy of Fallot between 1980 and 2005 were reviewed, their follow-up updated and survival confirmed from national death registries. One-third (220 of 675) had undergone previous palliation. Median age at repair was 2 years in the first 8 years, and 1 year from 1988 onward. A transannular incision was performed in 75% of cases and autologous pericardium was the material used to patch this incision in 92% of cases. RESULTS: There were 7 hospital deaths (1%). Eight patients died during follow-up (2 sudden unexpected and 6 noncardiac deaths). Mean follow-up was 11.7 ± 6.3 years. Twenty-five years' survival was 97% (95% confidence interval [CI]: 95% to 98%). Twenty-five years' freedom from implantation of a valved conduit was 84.6% (95% CI: 77.8% to 89.5%). By multivariable analysis, prior palliation and younger age at repair were predictive of implantation of a valved conduit (hazard ratio: 2.4, 95% CI: 1.3 to 4.6, p = 0.008; hazard ratio: 0.70, 95% CI: 0.50 to 0.96, p = 0.03, respectively). CONCLUSIONS: During long-term follow-up, transatrial repair of tetralogy of Fallot was associated with a minimal risk of sudden death and low rate of reintervention for right ventricular dilation and residual outflow tract obstruction.

Association of left ventricular motion and central augmentation index in healthy young men.

BACKGROUND: Central blood pressure is a determinant of cardiovascular outcome; however, it can be described by parameters other than systolic and diastolic pressure with central augmentation index (AIx) often utilized. Although generally considered as determined by peripheral pressure wave reflection, not all data are consistent with this interpretation of AIx. We hypothesized that the motion of the heart during systole may influence central pressure waveform morphology, including the AIx. METHOD: We studied the carotid pressure waveform, aortic stiffness and endothelial function in 20 healthy young men (full data available in 19). Arterial stiffness was measured by carotid femoral pulse wave velocity (cfPWV), endothelial function by peripheral arterial plethysmography (PAPl) and central blood pressure waveform by carotid applanation tonometry. Basal cardiac motion was assessed with pulsed wave tissue Doppler imaging of the septal mitral annulus. RESULTS: Carotid AIx decreased after the administration of glyceryl trinitrate by 11.3 ± (sem) 4.6% (P = 0.02); however, time to the inflection point (Ti) did not change. During systolic contraction at both baseline and after glyceryl trinitrate, time to peak annular systolic velocity was directly related to, and always preceded, carotid Ti (R(2) = 0.81; P < 0.01). Carotid Ti and AIx were not related to cfPWV or endothelial function. CONCLUSION: In fit young men, rather than only being a consequence of arterial properties Ti, and therefore central AIx, may be substantially determined by left ventricular systolic function. These findings question the interpretation of central AIx as a measure of pressure wave reflection and aortic stiffness and potentially impact its interpretation in diagnosis and treatment of cardiovascular risk.

Cardiac and sympathetic activation are reduced in children with Down syndrome and sleep disordered breathing.

STUDY OBJECTIVES: Sleep disordered breathing (SDB) occurs at an increased incidence in children with Down Syndrome (DS) compared to the general pediatric population. We hypothesized that, compared with typically developing (TD) children with SDB, children with DS have a reduced cardiovascular response with delayed reoxygenation after obstructive respiratory events, and reduced sympathetic drive, providing a potential explanation for their increased risk of pulmonary hypertension. DESIGN: Beat-by-beat heart rate (HR) was analyzed over the course of obstructive events (pre, early, late, post-event) and compared between groups. Also compared were the time for oxygen resaturation post-event and overnight urinary catecholamines. SETTING: Pediatric sleep laboratory. PATIENTS: Sixty-four children aged 2-17 y referred for investigation of SDB (32 DS; 32 TD) matched for age and obstructive apnea/hypopnea index. MEASUREMENT AND RESULTS: Children underwent overnight polysomnography with overnight urine collection. Compared to TD children, those with DS had significantly reduced HR changes post-event during NREM (DS: 21.4% ± 1.8%, TD: 26.6% ± 1.6%, change from late to post-event, P < 0.05). The time to resaturation post-event was significantly increased in the DS group (P < 0.05 for both NREM and REM sleep). Children with DS had significantly reduced overnight urinary noradrenaline (P < 0.01), adrenaline (P < 0.05) and dopamine levels (P < 0.01) compared with TD children. CONCLUSION: Children with DS and SDB exhibit a compromised acute cardio-respiratory response and dampened sympathetic response to SDB compared with TD children with SDB. These data may reflect autonomic dysfunction in children with DS that may place them at increased risk for cardiovascular complications such as pulmonary hypertension.

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.

Increased sympathetic activity in children with obstructive sleep apnea: cardiovascular implications.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with increased sympathetic activity and hypertension in adults. We tested the hypothesis that children with OSA also have increased sympathetic activity as measured by overnight urinary catecholamines, and that this increase is related to the severity of OSA and to blood pressure (BP). METHODS: Seventy snoring children referred for assessment of sleep disordered breathing and 26 healthy non-snoring control children (age range: 3-12 years, 59 M/37 F) were studied. Overnight polysomnography was performed coincident with a 12h overnight urine collection. Urinary catecholamine levels were determined using high performance liquid chromatography (noradrenaline, adrenaline and dopamine, with levels adjusted for creatinine excretion). Simple linear and stepwise multiple linear regressions were used to determine the independent associations between catecholamine levels and age, gender, BMI z-score, systolic BP z-score, diastolic BP z-score, and apnea hypopnea index (AHI). RESULTS: Simple linear regressions revealed significant associations between noradrenaline and AHI (r = 0.32) and age (r = -0.20, p < 0.05 for both). Significant associations were also found between adrenaline and AHI (r = 0.27) and age (r = -0.25, p < 0.05 for both). Systolic BP z-score and diastolic z-score were both significantly associated with adrenaline (r = 0.22 and r = 0.20 respectively, p < 0.05 for both). Multivariate analysis revealed that only AHI was a significant independent predictor of noradrenaline (model R(2) = 0.10, p = 0.001). Similarly, only AHI and age were significant independent predictors of adrenaline (model R(2) = 0.12, p < 0.05). CONCLUSIONS: This study demonstrates that levels of overnight urinary noradrenaline and adrenaline are related to the severity of OSA in children. These data indicate that children with OSA have increased sympathetic tone that may contribute to the cardiovascular consequences of the condition.

Diagnostic accuracy of noninvasive coronary angiography with 320-detector row computed tomography.

We sought to evaluate the diagnostic accuracy of noninvasive coronary angiography using 320-detector row computed tomography, which provides 16-cm craniocaudal coverage in 350 ms and can image the entire coronary tree in a single heartbeat, representing a significant advance from previous-generation scanners. We evaluated 63 consecutive patients who underwent 320-detector row computed tomography and invasive coronary angiography for the investigation of suspected coronary artery disease. Patients with known coronary artery disease were excluded. Computed tomographic (CT) studies were assessed by 2 independent observers blinded to results of invasive coronary angiography. A single observer unaware of CT results assessed invasive coronary angiographic images quantitatively. All available coronary segments were included in the analysis, regardless of size or image quality. Lesions with >50% diameter stenoses were considered significant. Mean heart rate was 63 ± 7 beats/min, with 6 patients (10%) in atrial fibrillation during image acquisition. Thirty-three patients (52%) and 70 of 973 segments (7%) had significant coronary stenoses on invasive coronary angiogram. Seventeen segments (2%) were nondiagnostic on computed tomogram and were assumed to contain significant stenoses on an "intention-to-diagnose" analysis. Sensitivity, specificity, and positive and negative predictive values of computed tomography for detecting significant stenoses were 94%, 87%, 88%, and 93%, respectively, by patient (n = 63), 89%, 95%, 82%, and 97%, respectively, by artery (n = 260), and 87%, 97%, 73%, and 99%, respectively, by segment (n = 973). In conclusion, noninvasive 320-detector row CT coronary angiography provides high diagnostic accuracy across all coronary segments, regardless of size, cardiac rhythm, or image quality.

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.

Cardiovascular magnetic resonance-derived aortic distensibility: validation and observed regional differences in the elderly.

OBJECTIVE: Applanation tonometry evaluation of pulse wave velocity is widely accepted as the 'gold standard' method for noninvasively assessing arterial stiffness. Newer noninvasive tools such as cardiovascular magnetic resonance can also evaluate arterial stiffness, but have not been validated. The aim of this study was to validate cardiovascular magnetic resonance-derived aortic distensibility with pulse wave velocity and to investigate age-related changes in regional aortic distensibility. METHODS: Ten young (20-30 years) and ten old (60-70 years) patients underwent applanation tonometry assessment of pulse wave velocity. Cardiovascular magnetic resonance measurements of arterial stiffness were evaluated by aortic distensibility (10-3 mmHg-1) at three separate locations, the ascending aorta, proximal descending aorta and distal descending aorta. RESULTS: Pulse wave velocity correlated strongly with aortic distensibility measurements at each site: ascending aorta R2 = 0.57, proximal descending aorta R2 = 0.60 and distal descending aorta R2 = 0.72. As expected, the old cohort had significantly increased aortic stiffness compared with the young cohort (P < 0.01). Post-hoc comparison showed an increase in proximal stiffness in the old cohort compared with the young cohort (P = 0.018). CONCLUSION: Cardiovascular magnetic resonance-derived aortic distensibility is an accurate measure of arterial stiffness and can evaluate regional stiffness through the aorta. Furthermore, our results suggest that aortic stiffening may preferentially occur in the proximal aortic segments in the elderly.

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.