Mean Recording Time Research Articles

PO-626-07 VALIDATION OF A PORTABLE DEVICE FOR HF-ECG IN ISCHEMIA DETECTION DURING CORONARY BALLOON INFLATION IN ANGIOPLASTY - BRINGING THE PHYSIOLOGY LAB TO THE BEDSIDE !

High frequency QRS (HfQRS) analysis for rapid assessment of myocardial ischemia has never been evaluated owing to the logistical challenges of signal recording. We aim to evaluate, in a pilot study, the correlation between the HFQRS changes recorded on a novel wearable Sydäntek 12 lead ECG patch with balloon inflation induced ischaemia. To document utility of a portable device, Sydäntek, in ECG and HFECG during multiple balloon inflations. 10 patients (M:F = 8:2) undergoing coronary intervention for medically refractory chronic stable angina were screened for enrollment into the study ; 9/10 patients underwent the final recording. 1 patient was excluded owing to signal noise in the device due to reluctance in chest preparation. The mean recording time per case was 60+/-15 mins. ECG including HfQRS was recordable continuously during all intended times, using Sydäntek at 2k samples/secs. In 33 balloon inflation ischemia episodes , changes were seen on the HFQRS onset ∼ 10 secs, offset ∼45 secs after deflation . No significant changes were seen in the conventional ECG analysed for these upto ∼45 secs . Decrease in the amplitude of the HFQRS, and decrease in the real time RMS voltage of QRS in leads V2-V5 and the presence of RAZ ( reduced amplitude zone ) were considered to be changes suggestive of ischemia. RAZ disappeared ∼45 secs after the balloon deflation. The mean total ischemic was 1 +/-0.5 min per patient per balloon inflation. In this study , all 9 of the conventional ECGs were reported independently by 2 docs as not having significant ST-T changes of ischaemia. RAZ presence in HFQRS was seen in all 33 of complete coronary artery occlusion by balloon, in our study .There was reduction in the amplitude of HFQRS(mean 12+/-1 μV) and RMSv2-v5 (mean 7+/-0.5 μV) from the baseline during the inflation. Post intervention, both of the above parameters had a mean increase of 22+/-1 μV and 10+/-0.3 μV respectively. HFQRS measured using our novel, portable real time 12 lead ECG recording patch can reliably detect onset of coronary ischemia in a complete coronary occlusion even in absence of ST -T changes in 12 lead ECG . We submit this proof of concept for use in detecting ischemia in a variety of clinical situations including chest pain triage and post intervention monitoring.

474 Phenotyping of patients with Moderate to Severe OSA on Polysomnography after Negative Home Sleep Apnea Testing

Abstract Introduction Polysomnography (PSG) is the gold standard for the diagnosis of obstructive sleep apnea (OSA). Given cost, insurance restrictions and in some cases limited access to sleep center testing, the use of home based sleep apnea testing is becoming increasingly more common. A proportion of patients with technically adequate HSAT who are negative end up having significant disease on PSG. The characteristics of patients who are found to have moderate to severe sleep apnea on polysomnogram (PSG) after a negative home sleep apnea test (HSAT) are not known. We aim to phenotype these patients. Methods We conducted a retrospective chart review from March 2018 to February 2020. A total of 953 adult patients (18 years old and older) underwent HSAT, 248 tests resulted negative (apnea-hypopnea index <5/h). Out of the negative HSAT, 17 patients had moderate to severe obstructive sleep apnea on PSG. Those were included for analysis. Data on patient characteristics such as age, body mass index (BMI), gender, STOP-BANG, ESS and comorbidities was gathered. Respiratory disturbance index, recording time, flow time, oximetry time on HSAT was recorded. PSG recording time, baseline AHI, supine AHI and non-supine AHI were also noted. Technically inadequate HSAT were excluded from analysis. Results The percentage of patients with negative HSAT who were found to have moderate to severe sleep apnea on PSG and were included for analysis was 6.85% (n17). Mean age was 41 years. Mean BMI was 33 kg/m2. Common comorbidities were hypertension (29%), asthma (17.6 %), depression (17.6%), anxiety (11.7%) and reflux (5.9%). Average ESS was 11.7 and STOP-BANG was 3.8. The mean recording time was 477 minutes, flow time 391 minutes and oximetry time was 426 minutes on HSAT. Average PSG recording time was 433 minutes. Average AHI was 24 with supine being 33.2/h and non-supine 17.9/h. Conclusion A proportion of patients with negative HSAT have moderate to severe OSA on follow-up polysomnogram. These patients were young, with lower-class obesity, more positional OSA, and no associated complex comorbidities. Re-evaluation of current diagnostic algorithms and further research is needed to phenotype this at-risk group, as first-line PSG may be more cost-effective and efficient. Support (if any):

Association of Ventricular Arrhythmias With Dementia

We performed a cross-sectional analysis to determine whether nonsustained ventricular tachycardia (NSVT) and premature ventricular contractions (PVCs) were associated with dementia in a population-based study. We included 2,517 (mean age 79 years, 26% Black) participants who wore a 2-week ambulatory continuous ECG recording device in 2016 to 2017. NSVT was defined as a wide-complex tachycardia ≥4 beats with a rate >100 bpm. We calculated NSVT and PVC burden as the number of episodes per day. Dementia was adjudicated by experts. We used logistic regression to assess the associations of NSVT and PVCs with dementia. The mean recording time of the Zio XT Patch was 12.6 ± 2.6 days. There were 768 (31%) participants with NSVT; prevalence was similar in White and Black participants. There were 134 (6.5%) dementia cases (5% in White, 10% in Black participants). After multivariable adjustment, there was no overall association between NSVT and dementia; however, there was a significant race interaction (p < 0.001). In Black participants, NSVT was associated with a 3.67 times higher adjusted odds of dementia (95% confidence interval [CI] 1.92-7.02) compared to those without NSVT, whereas in White participants NSVT was not associated with dementia (odds ratio [95% CI] 0.64 [0.37-1.10]). In Black participants only, a higher burden of PVCs was associated with dementia. Presence of NSVT and a higher burden of NSVT and PVCs are associated with dementia in elderly Black people. Further research to confirm this novel finding and to elucidate the underlying mechanisms is warranted.

Abstract MP16: Incremental Diagnostic Yield of 4 Weeks versus 2 Weeks of Ambulatory Heart Rhythm Monitoring for the Detection of Subclinical Atrial Fibrillation: The Atherosclerosis Risk in Communities (ARIC) Study

Introduction: Subclinical atrial fibrillation (AF) has been associated with greater stroke risk; however, subclinical AF can be intermittent, and hence hard to detect. Little is known about the diagnostic yield of extending electrocardiogram (ECG) monitoring beyond 2 weeks on subclinical AF detection, particularly among individuals without a clinical indication. Hypothesis: Extending ECG monitoring from 2 weeks to 4 weeks will increase detection of AF Methods: We included ARIC study participants who attended visit 6 (2016-2017), without a history of AF, and who wore a leadless, ambulatory ECG monitor (Zio® XT Patch by iRhythm Technologies Inc.) twice, each time for up to a maximum of 2 weeks. AF history was based on ARIC ascertainment (hospitalization codes through 2016, ECGs at prior ARIC visits 1-5) or self-reported AF at visit 6. AF on the Zio® XT Patch was defined as an irregularly irregular rhythm with absent P-waves lasting ≥30 seconds. Results: We included 387 ARIC participants (mean ± SD aged 79 ± 4 years, 54% female, 11% non-white race). Mean recording time was 13.3 ± 1.7 days for the first Ziopatch, 13.1 ± 2.0 for the second patch, and 26.4 ± 2.9 for the combined 4 weeks. Based on ≤2 weeks of monitoring, the prevalence of subclinical AF was 2.6% (95% CI: 1.0-4.2%; n=10); this increased to 4.4% (95% CI: 2.4-6.4%; n=17) with ≤4 weeks of monitoring. Thus, the incremental diagnostic yield of 4 weeks versus 2 weeks of monitoring was 70% (95% CI: 41.6-98.4%). The mean time to first AF episode was 10.5 ± 8.0 days with a median of 13.4 days (IQR=2.0-19.7). Cumulative yield of AF detection over the monitoring time is shown in the Figure . Conclusions: Among elderly community-dwelling individuals, extending ECG monitoring from 2 weeks to 4 weeks increased detection of AF. These findings help inform the debate on ECG screening for subclinical AF; however, more research is needed to define the optimal duration of ECG monitoring time.

Abstract P024: Nonsustained Ventricular Tachycardia is Independently Associated With Lower Cognitive Function: The Atherosclerosis Risk in Communities (ARIC) Study

Introduction: -- Atrial fibrillation is associated with greater cognitive decline and increased risk of dementia. Little is known about whether other arrhythmias, such as nonsustained ventricular tachycardia (NSVT), are associated with cognition. We aimed to assess the cross-sectional association of NSVT with cognitive test scores in the Atherosclerosis Risk in Communities (ARIC) study. Methods: We included 1367 (mean age, 79 ± 5 years; 55% female; 19% non-white race) participants who underwent cognitive tests and ≥2 days of heart rhythm recording using the Zio ® Patch (a non-invasive, leadless, 2-week ambulatory continuous ECG recording device by iRhythm Technologies, Inc.) in July 2013-February 2017. NSVT was defined as a wide complex tachycardia &gt;4 beats with a rate &gt;100 beats per minute. Burden was calculated as the number of NSVT episodes divided by recording time and split on the median into higher burden and lower burden. Cognitive domain-specific factor scores consisted of tests of memory, executive function and language. We used multiple linear regression to assess the association of NSVT with standardized z-scores of each cognitive domain. Results: The mean recording time of the Zio ® Patch was 12.6 ± 2.5 days. There were 399 (29%) participants with NSVT recorded, ranging from 0.5-439 episodes per week (median = 0.59; interquartile range = 0.51-1.50). Presence of NSVT was associated with lower memory and lower executive function, but not impaired language (Table). The associations were restricted to participants with higher burden of NSVT compared to those without NSVT (-0.22 z-score units, 95% confidence interval (CI) -0.41, -0.04 for memory, and -0.23, 95%CI -0.41, -0.05 for executive function) (Table). Conclusion: Presence and higher burden of NSVT are independently associated with lower cognitive function, specifically executive function and memory. Further research is warranted to elucidate the underlying mechanism.

Long term electroencephalography in preterm neonates: Safety and quality of electrode types

ObjectivesThe objective of this study was to compare gold cup and hydrogel electrodes for frequency of electrode replacement, longevity of the original electrodes after initial placement, recording quality, and skin safety issues in long-term EEG studies in preterm neonates. MethodsWe performed a prospective trial with newborns born at ≥23 weeks and ≤30 weeks of gestational age (GA). Two mirror image EEG electrode arrays were utilized on consecutive subjects, where gold cup electrodes alternated with hydrogel electrodes. ResultsOur sample included 50 neonates with mean GA of 27 (±1) weeks. The mean recording time was 84 (±15) hours. No difference was present in the frequency of replacement of either type across the total recording time (p = 0.8). We collected the time at which electrodes were first replaced, and found that hydrogel electrodes showed a longer uninterrupted recording time of 28(±2) hours vs. 20(±2) hours for gold cup electrodes (p = 0.01). Recording quality was similar in either type (p = 0.2). None of the patients experienced significant skin irritation from a discrete electrode. ConclusionLong-term EEG studies can be performed with either gold cup or hydrogel electrodes, validating the safety and quality of both electrode types. SignificanceHydrogel electrodes are a reasonable alternative for use in long-term EEG studies in preterm neonates.

Automated real-time detection of tonic-clonic seizures using a wearable EMG device.

ObjectiveTo determine the accuracy of automated detection of generalized tonic-clonic seizures (GTCS) using a wearable surface EMG device.MethodsWe prospectively tested the technical performance and diagnostic accuracy of real-time seizure detection using a wearable surface EMG device. The seizure detection algorithm and the cutoff values were prespecified. A total of 71 patients, referred to long-term video-EEG monitoring, on suspicion of GTCS, were recruited in 3 centers. Seizure detection was real-time and fully automated. The reference standard was the evaluation of video-EEG recordings by trained experts, who were blinded to data from the device. Reading the seizure logs from the device was done blinded to all other data.ResultsThe mean recording time per patient was 53.18 hours. Total recording time was 3735.5 hours, and device deficiency time was 193 hours (4.9% of the total time the device was turned on). No adverse events occurred. The sensitivity of the wearable device was 93.8% (30 out of 32 GTCS were detected). Median seizure detection latency was 9 seconds (range −4 to 48 seconds). False alarm rate was 0.67/d.ConclusionsThe performance of the wearable EMG device fulfilled the requirements of patients: it detected GTCS with a sensitivity exceeding 90% and detection latency within 30 seconds.Classification of evidenceThis study provides Class II evidence that for people with a history of GTCS, a wearable EMG device accurately detects GTCS (sensitivity 93.8%, false alarm rate 0.67/d).

Full-Shift Trunk and Upper Arm Postures and Movements Among Aircraft Baggage Handlers.

The present study assessed full-shift trunk and upper arm postural exposure amplitudes, frequencies, and durations among Swedish airport baggage handlers and aimed to determine whether exposures differ between workers at the ramp (loading and unloading aircraft) and baggage sorting areas. Trunk and upper arm postures were measured using inclinometers during three full work shifts on each of 27 male baggage handlers working at a large Swedish airport. Sixteen of the baggage handlers worked on the ramp and 11 in the sorting area. Variables summarizing postures and movements were calculated, and mean values and variance components between subjects and within subject (between days) were estimated using restricted maximum likelihood algorithms in a one-way random effect model. In total, data from 79 full shifts (651h) were collected with a mean recording time of 495min per shift (range 319-632). On average, baggage handlers worked with the right and left arm elevated >60° for 6.4% and 6.3% of the total workday, respectively. The 90th percentile trunk forward projection (FP) was 34.1°, and the 50th percentile trunk movement velocity was 8° s(-1). For most trunk (FP) and upper arm exposure variables, between-subject variability was considerable, suggesting that the flight baggage handlers were not a homogeneously exposed group. A notable between-days variability pointed to the contents of the job differing on different days. Peak exposures (>90°) were higher for ramp workers than for sorting area workers (trunk 0.6% ramp versus 0.3% sorting; right arm 1.3% ramp versus 0.7% sorting). Trunk and upper arm postures and movements among flight baggage handlers measured by inclinometry were similar to those found in other jobs comprising manual material handling, known to be associated with increased risks for musculoskeletal disorders. The results showed that full-shift trunk (FP) and, to some extent, peak arm exposures were higher for ramp workers compared with sorting workers.

97-04: Detection of supraventricular and ventricular arrhythmias by external loop recorder in patients with and without history of heart disease

Background: external loop recorders (ELRs) yield higher arrhytmias detection than conventional multilead Holter monitoring, expecially if patients complain intermittent symptoms. In our centre we evaluated since January 2015 until January 2016, 31 patients with symptoms from possible arrhytmias or known heart disease who needed a risk stratification by ELR (Spiderflash-SORIN). The aim of the study was to verify usefulness of ELR in different clinical settings presenting in routine outpatient activity. Results: Age of our population ranged from 7 to 77 years old; main indication for ELR positioning was palpitations (14/31 pts, 45%), other other were:previous AIT/ischaemic events or Brugada Syndrome or previous AVNRT (2/31 for each cathegory), vertigo/syncope or pastAF (4/31 for both cathefory), ARVD or previous Ventricular tachycardia or previous atrial tachycardia (1/31 each one). 74% of them had normal basal ecg (23/31), 1 had postmyocardial infarction (postMI) ECG, 2 showed ectopic ventricular beats (EVB), 1 ectopic supraventricular beats (ESB), 2 were Brugada patients, 1 was an ARVD patient, 1 had RBBB. Spiderflash events recordings were critically evaluated from an electrophysiology technician and formally flagged as supraventricular or ventricular event by physician; a global amount of 41 diagnostic ecg strips were isolated, that allowed a diagnosis in 93% of patients altought a mismatch between symptom complained during ELR recording time and “real finding” was present: this means that ELR performed a diagnosis regardless patients'status. The mean recording time was 17,93 ± 4,58 days.We evaluated the events recorded automatically by ELR and those acquired after patients activation, and calculated the ratio between events confirmed by technician and physician to the whole events recorded. We found that automated records had a mean ratio “true to useless” higher than events triggered by symptoms: 0,28 ± 0,36 vs 0,12 ± 0,25 for automated and symptoms tracing respectively, p = 0,027; Fig1.Detection rate of ELR was similar for supraventricolar and ventricular events (p = 0,24) for each patient group. And when the indication to ELR was vertigo/syncope or palpitation both venticular and supraventricular events were found (p = 0,36); Tab1. We evaluated also the amount of event detected according to clinical status, and we found that patients prone to ventricular arrhythmias (Brugada patients, ARVD, VT history) had less probablity of supraventricular records than patients with history of supraventricular arrhythmias (past AF, pastAT, pastAVNRT, former AIT or thromboembolic event): patient with history of supraventricular tachycardias or ischaemic event had confirmed or newly diagnosed a supraventricular tachycardia, p = 0,035 (Chi squared for tables“true values” and “expected values”, DistXsq for probability calculation), Tab1. Conclusions: ELR-Spiderflash allowed a diagnosis of supraventricular tachycardia or ectopic vetricular beats in majority of patients who complained palpitations; perfomed a diagnosis of AF in patients wih history of AIT or systemic emboli; confirmed diagnosis of supraventricular tachycardias in those who had history of such arrhythmias; is useful in risk stratification in patients prome to ventricular events.

L’évaluation de la fonction ventriculaire gauche, avec une caméra à semi-conducteurs et un protocole à faible dose

IntroductionNew gamma camera technology with Cadmium-Zinc-Telluride (CZT) semiconductor detectors provides better myocardial perfusion imaging (MPI) resolution and, given the detector's high-sensitivity (better spatial and energy resolution), it reduces imaging time and radiopharmaceutical doses (better detection sensitivity). The purpose of this study was to evaluate the left ventricular function parameters obtained by a fast low-dose clinical protocol on a CZT camera (D-SPECT), compared to the measurement on cardiac magnetic resonance imaging. MethodsWe retrospectively included patients who underwent MPI on D-SPECT camera with a low-dose of Sestamibi-99mTc (120MBq for stress and 360MBq at rest for a patient of 75kg weight), and a cardiac magnetic resonance imaging, with a time less than two months. The left ventricular function was obtained at rest, with 8-frame reformatted, and analysis was performed using Quantitative Gated SPECT (QGS®) software. ResultsSeventy-seven patients were included and their mean ejection fraction (EF) was 45±13% at MRI. For D-SPECT recording, mean activity within heart area was 527±104kcps, for mean recording time 3.5±2.2min and mean of the total activity was 420±185MBq (effective dose: 3.7±1.6mSv). Correlation between D-SPECT and MRI was very good for EF (r=0.88), end-diastolic volume (EDV, r=0.90) and end-systolic volume (ESV, r=0.96), but with an underestimation of all these parameters by the D-SPECT (on average, 5% absolute value for EF, and −16% and −24% in relative values for respectively ESV and EDV). ConclusionThe evaluation of left ventricular function using the D-SPECT camera and with a fast low-dose protocol correlates well with that obtained by cardiac MRI, in the same patient. EF and ventricular volumes are however underestimated, in agreement with that previously documented with conventional Anger cameras.

Sleep-wake evaluation from whole-night non-contact audio recordings of breathing sounds.

Study ObjectivesTo develop and validate a novel non-contact system for whole-night sleep evaluation using breathing sounds analysis (BSA).DesignWhole-night breathing sounds (using ambient microphone) and polysomnography (PSG) were simultaneously collected at a sleep laboratory (mean recording time 7.1 hours). A set of acoustic features quantifying breathing pattern were developed to distinguish between sleep and wake epochs (30 sec segments). Epochs (n = 59,108 design study and n = 68,560 validation study) were classified using AdaBoost classifier and validated epoch-by-epoch for sensitivity, specificity, positive and negative predictive values, accuracy, and Cohen's kappa. Sleep quality parameters were calculated based on the sleep/wake classifications and compared with PSG for validity.SettingUniversity affiliated sleep-wake disorder center and biomedical signal processing laboratory.PatientsOne hundred and fifty patients (age 54.0±14.8 years, BMI 31.6±5.5 kg/m2, m/f 97/53) referred for PSG were prospectively and consecutively recruited. The system was trained (design study) on 80 subjects; validation study was blindly performed on the additional 70 subjects.Measurements and ResultsEpoch-by-epoch accuracy rate for the validation study was 83.3% with sensitivity of 92.2% (sleep as sleep), specificity of 56.6% (awake as awake), and Cohen's kappa of 0.508. Comparing sleep quality parameters of BSA and PSG demonstrate average error of sleep latency, total sleep time, wake after sleep onset, and sleep efficiency of 16.6 min, 35.8 min, and 29.6 min, and 8%, respectively.ConclusionsThis study provides evidence that sleep-wake activity and sleep quality parameters can be reliably estimated solely using breathing sound analysis. This study highlights the potential of this innovative approach to measure sleep in research and clinical circumstances.

The efficacy of Watch PAT in obstructive sleep apnea syndrome diagnosis.

Polysomnography is currently considered as the gold standard for the diagnosis of obstructive sleep apnea syndrome (OSAS). But high expense and the backlog of the sleep centers have resulted in a search for an alternative method of diagnosis. The aim of this study is to assess the efficacy and reliability of Watch PAT as an alternate option in OSAS diagnosis. The patients have worn a Watch PAT(®) 200 device in the sleep laboratory during a standard polysomnography. The correlation in REM and Non-REM AHI scores, sleep periods and the mean O2 saturation percentage between Watch PAT and PSG sleep studies were assessed. There was a statistically significant very strong correlation between PSG and Watch PAT AHI scores (Spearman's rho = 0.802 p < 0.001). The mean recording time with PSG and Watch PAT was 463.06 ± 37.08 and 469.33 ± 72.81 min, respectively, and there was no statistically significant difference (p = 0.068). However, there was a statistically significant difference between two methods regarding the average sleep time and REM sleep period. No statistically significant difference was revealed in the mean O2 saturation percentage (p < 0.001). Watch PAT is an efficient device and is considered to be an adjunctive diagnostic method for PSG in diagnosis of OSAS.

Inability of single resting arterial blood gas to predict significant hypoxaemia in chronic obstructive pulmonary disease

While point measurement of resting arterial partial pressure of oxygen (P(a)O(2)) is the traditional gold-standard for assessment of oxygenation in chronic obstructive pulmonary disease (COPD), 24-h oximetry may identify further patients with clinically significant hypoxaemia. We aimed to describe the relationship between these two parameters and identify other correlated variables. All patients registered with the Barwon Health Hospital Admission Risk Program from 1 March to 31 October 2008 for the diagnosis of COPD were identified. The main inclusion criteria were obstructive spirometry, clinical stability and moderate resting hypoxaemia (P(a)O(2) 56-70 mmHg). All patients underwent 24-h oximetry, arterial blood gas, spirometry, anthropometry and telephone questionnaire, and 23 patients also completed polysomnography. Inclusion criteria were met in 35 of 287 patients. Mean recording time was 23.5 h, representing 97% of intended oximetry time. Nineteen patients (54%) spent greater than 30% of recorded oximetry time below 90%. There was a moderate inverse correlation between time below 90% saturations and P(a)O(2) (r=-0.40, P= 0.02), with body mass index (BMI) the only other independent predictor of the primary outcome identified (r= 0.39, P= 0.02). Correlations were similar for waking hours considered separately. However, for sleeping oximetry, BMI and age were the only independent predictors of time below 90%. Polysomnography demonstrated a high prevalence of rapid eye movement-related hypoventilation and obstructive sleep apnoea syndrome. Many patients with moderate hypoxaemia on resting P(a)O(2) desaturate significantly on ambulatory oximetry. The correlation between P(a)O(2) and proportion of saturations below 90% is moderate and similar to BMI, but this pattern does not hold during sleeping hours.

Wireless ambulatory pH studies: manometric or endoscopic guidance?

Wireless pH studies are widely used to assess the presence and severity of gastroesophageal reflux disease. We hypothesized that sedation or air insufflation during a preceding endoscopy may systematically alter results. A retrospective review of ambulatory pH studies completed between January 2008 and April 2010 was performed. The pH capsule was placed 6 cm above the endoscopically determined location of the squamocolumnar junction or 5 cm above the manometrically localized upper border of the lower esophageal sphincter (LES). A total of 356 patients (65% women) underwent pH studies using the BRAVO system (GIVEN Imaging, Yoqneam, Israel). In 186 patients (E-P), the capsule was placed during endoscopy. In 170 patients (M-P), capsule placement was based on manometric determination of LES boundaries using pharyngeal anesthesia only. Endoscopic placement was successful in all cases, whereas two patients could not tolerate capsule insertion with topical anesthesia only. The mean recording time did not differ between the two groups (E-P: 2468 ± 38 min; M-P: 2415 ± 40 min). The number of patients with abnormal findings on day 1 but normal results for day 2 was similar with 15% for E-P compared with 11% for M-P. However, there was a significant difference in total acid exposure times between days 1 and 2 for endoscopically (day 1: 7.3 ± 1.2; day 2: 4.8 ± 0.5; P < 0.01), but not manometrically based placement (day 1: 7.7 ± 0.7; day 2: 7.2 ± 0.6). There was no difference in the number of symptoms between days or groups (E-P day 1:13.4 ± 1.3; E-P day 2: 16.0 ± 1.6; M-P day 1: 14.1 ± 2.1; M-P day 2: 15.7 ± 2.0). Similarly, the symptom sensitivity index did not differ significantly between days and groups (E-P: day 1: 4.1 ± 0.5; day 2: 5.9 ± 0.8; M-P: day 5.3 ± 0.8; day 2: 5.7 ± 0.8). The majority of patients tolerate insertion of a wireless pH monitoring capsule without sedation. Unsedated placement did not negatively affect total recording times. Although endoscopy resulted in higher acid exposure on day one it did not significantly increase the overall fraction of abnormal tests. If confirmed in prospective studies, the more consistent findings and a potential to lower cost favor manometrically guided capsule placement.

Amplitude-integrated electroencephalographic activity is suppressed in preterm infants with high scores on illness severity

Background The neonatal acute physiology score, SNAP-II, reflects the severity of illness in newborns. In term newborns, amplitude integrated EEG (aEEG), is depressed following asphyxia. In preterm infants aEEG is discontinuous, and therefore more difficult to assess compared to term infants. Aims Our first aim was to investigate whether assessing aEEG amplitudes by calculating amplitude centiles was consistent with assessment by pattern recognition. Our second aim was to investigate whether the aEEGs of preterm infants were influenced by SNAP-II. Study Design and Subjects We recorded aEEGs in 38 infants with a mean gestational age of 29.7 weeks (26.0–31.8 weeks) during the first five days of life. The mean recording time was 130 min. The aEEGs were assessed by pattern recognition, by calculating Burdjalov score, and by calculating the mean values of the 5th, 50th, and 95th centiles of the aEEG amplitudes. Illness severity was determined within the first 24 h. Results We assessed 151 recordings and found strong correlations between the 5th and 50th amplitude centiles and the Burdjalov scores ( r = 0.71, p < 0.001 and r = 0.47, p < 0.001, respectively). The 5th and 50th amplitude centiles correlated with SNAP-II ( r = − 0.34, p < 0.0001 and r = − 0.27, p = 0.001). These correlations were the strongest on the first day of life ( r = − 0.55, p = 0.005 and r = − 0.47, p = 0.018, respectively). The 5th and the 50th amplitude centiles were best predicted by gestational age, SNAP-II, and low blood pressure. Conclusions Severe illness as measured by the SNAP-II, and low blood pressure had a negative influence on the aEEGs of preterm infants.

Heart rate variability: An index of brain processing in vegetative state? An artificial intelligence, data mining study

Objective Brain processing at varying levels of functional complexity has been documented in vegetative state. In this study, data mining procedures are applied to identify significant changes in heart rate variability (an emerging objective descriptor of autonomic correlates of brain activation) in response to complex auditory stimuli with emotional value (music). Methods The heart rate of subjects in vegetative state from brain damage ( n = 6) or spontaneous hemorrhage ( n = 3) and 16 healthy controls was recorded while they passively listened to four pre-selected music samples by different authors (mean recording time: 3 m and 36 s ± 24 s). The parametric and non-parametric frequency spectra were computed on the heart rate, spectra were compared within/across subjects and music authors, and the spectra descriptors were entered into a 1-R rules data mining procedure (WEKA software Leave One Out and Ten Fold Cross validation). The procedure independently classified the heart rate spectral patterns of both patients and controls and the emotions reported by healthy subjects as “ positive” or “ negative”. Results In both healthy controls and vegetative state subjects, the power spectra while passively listening to music differed from baseline when compared irrespective of the music authorship and from each other when compared across music samples. Data mining sorted the nu_LF (normalized parameter unit of the spectrum low frequency range) as the significant descriptor of heart rate variability in the conditions of the study. The nu_LF classification of the healthy controls’ HRV changes in response to music replicated that based on subjective reports with 75–93.7% accuracy. Conclusions Although preliminary, these findings suggest that autonomic changes with possible emotional value can be induced by complex stimuli also in vegetative state, with implications on the residual responsiveness of these subjects. Significance Heart rate variability descriptors and data mining methods appear applicable to investigate brain function in the absence of consciousness.

A pilot study of sound levels in an Australian adult general intensive care unit

High technology and activity levels in the intensive care unit (ICU) lead to elevated and disturbing sound levels. As noise has been shown to affect the ability of patients to rest and sleep, continuous sound levels are required during sleep investigations. The aim of this pilot study was to develop a robust protocol to measure continuous sound levels for a larger more substantive future study to improve sleep for the ICU patient. A review of published studies of sound levels in intensive care settings revealed sufficient information to develop a study protocol. The study protocol resulted in 10 usable recordings out of 11 attempts to collect pilot data. The mean recording time was 17.49 +/- 4.5 h. Sound levels exceeded recommendations made by the World Health Organization (WHO) for hospitals. The mean equivalent sound level (LAeq) was 56.22 +/- 1.65 dB and LA90 was 46.8 +/- 2.46 dB. The data reveal the requirement for a noise reduction program within this ICU.

Esophageal Capsule Endoscopy vs. EGD for the Evaluation of Portal Hypertension: A French Prospective Multicenter Comparative Study

Esophagogastroduodenoscopy (EGD) is the standard method for the diagnosis of esophago-gastric varices. The aim of this prospective multicenter study was to evaluate the PillCam esophageal capsule endoscopy (ECE) for this indication. Patients presenting with cirrhotic or noncirrhotic portal hypertension underwent ECEfollowed by EGD at the time of diagnosis. Capsule recordings were blindly read by two endoscopists. A total of 120 patients (72 males, mean age: 58 years; mean Child-Pugh score: 7.2) were included. Esophageal varices were detected in 74 patients. No adverse event was observed after either EGD or ECE. Seven (6%) patients were unable to swallow the capsule. The mean recording time was 204 s (range 1-876). Sensitivity, specificity, negative predictive value, and positive predictive value of ECE for the detection of esophageal varices were 77%, 86%, 69%, and 90%, respectively. Sensitivity, specificity, negative and positive predictive values of ECE for the indication of primary prophylaxis (esophageal varices > or = grade 2 and/or red signs) were 77, 88, 90, and 75%, respectively, and 85% of the patients were adequately classified for the indication (or not) of prophylaxis. Interobserver concordance for ECE readings was 79.4% for the diagnosis of varices, 66.4% for the grading of varices, and 89.7% for the indication of prophylaxis. This large multicenter study confirms the safety and acceptable accuracy of ECE for the evaluation of esophageal varices. ECE might be proposed as an alternative to EGD for the screening of portal hypertension, especially in patients unable or unwilling to undergo EGD.

Diagnosis of small-bowel pathology using paired capsule endoscopy with two different devices: a randomized study

Capsule endoscopy is an established technique in the evaluation of obscure gastrointestinal bleeding. The primary aim of the study is to compare the diagnostic yield of the two different capsule endoscopes. Patients with signs of mid-gastrointestinal bleeding after negative upper endoscopy and colonoscopy studies were included. Patients were randomized to undergo two capsule endoscopies using different capsule endoscopes (Given Pillcam SB and Olympus EndoCapsule) in random order. Forty patients (18 women, 22 men) were included in the study. All EndoCapsules reached the colon within the mean recording time of 591 +/- 52 minutes, whereas 33 out of 40 PillCam SB reached the colon within the mean recording time of 471 +/- 27 minutes. Lesions were detected in 31 patients: with both devices in 24, only by PillCam SB in 2, and, conversely, only by EndoCapsule in 5 (not significant). With regard to lesions with high bleeding potential (P2 lesions), PillCam SB detected them in 22 patients, EndoCapsule in 25 patients (not significant). In all four cases of intestinal P2 lesions that were not detected by the PillCam SB but were detected by the EndoCapsule, the PillCam SB had not reached the cecum. In this study there was a statistically nonsignificant trend for the EndoCapsule to detect more bleeding sources in patients with suspected small bowel bleeding than did the PillCam SB, which may have been due to the longer recording times with the currently available EndoCapsule.

Randomized Study to Diagnose Small Bowel Pathology Using Paired Capsule Endoscopy with Two Different Devices

Background: Capsule endoscopy is widely used as a diagnostic procedure in the evaluation of obscure gastrointestinal bleeding. In the past, only one capsule endoscope was commercially available (Pillcam SB, GivenImaging). Olympus Medical Systems has recently developed a capsule endoscope (EndoCapsule) that uses different technology and produces higher resolution images. The primary aim of the study is to compare the diagnostic yield of the two different capsule endoscopes. Patients and Mehtods: Patients with signs of gastrointestinal bleeding and negative upper endoscopy and colonoscopy were included in the study. After written informed consent, the patients were randomized to have two capsule endoscopies using different capsule endoscopes (Given Pillcam SB and Olympus EndoCapsule) in random order. The time intervall between the end of the first capsule examination and the start of the bowel preparation for the second procedure was at least one day. Results: 26 patients (10 women, 16 men; mean age 67.2 ± 10.5 years) with obscure gastrointestinal bleeding were included in the study. All capsule examinations were carried out without any complications. All Olympus Endocapsules reached the colon within the available mean recording time of 593 ± 62 minutes. In contrast, 5/26 Given capsules did not pass the ileocecal valve during the recording time (475 ± 92 minutes). With the Olympus device a bleeding source in the small bowel was detected in 16 patients (angiodysplasia n = 14, multiple ulcera n = 1, acitve bleeding n = 1) compared to 12 patients (angiodysplasia n = 11, active bleeding n = 1) using the Given device. In 3 out of the 4 patients with a definitive bleeding source seen by the Olympus capsule and not by the Given Capsule, in case when the Given Pillcam did not reach the cecum. Conclusion: In this study the Olympus Endoscapsule detected more bleeding sources in patients with obscure gastrointestinal bleeding than the Given Pillcam SB. A possible reason ist the longer recording time of the Olympus Endocapsule due to the optimized battery power with a longer recording time.