Antral Area Research Articles

The rationale for the recommendations of the European Paediatric Fasting Guideline: Improving paediatric anaesthesia and perioperative medicine.

The rationale for the recommendations of the European Paediatric Fasting Guideline: Improving paediatric anaesthesia and perioperative medicine.

Study of Prevalence of H Pylori Infection in Dyspeptic Patients

Background: Helicobacter pylori infection occurs worldwide, affecting more than half of the world population. The clear aetiology of dyspeptic symptoms is still unclear but helicobacter infection is main contributing factor for it we investigated Helicobacter pylori prevalence in dyspepsia. Methods: 100 cases of dyspepsia attended Adichunchanagiri hospital and research center, studied over a period of 18 months (January 2020 to June 2021), were subjected to upper gastrointestinal endoscopy, during which 4 biopsies, two each from the antrum and the pathological areas were taken. Two biopsy specimens, one of the antral area and the other of the pathological finding were immediately inoculated into freshly prepared urea broth containing phenol red as the indicator. Positive test for Helicobacter pylori was indicated by change in colour of the medium from yellow to pink or red. The other two biopsy specimens were sent for routine histopathology. The case was taken as Helicobacter pylori positive when the rapid urease test and/or histopathological examination were positive. Results: Out of 100 dyspeptic patients who were included in the study, there were 65 male patients and 35 female patients. In which 71 patients were found to have been infected with Helicobacter pylori (71%). Conclusion: In this study, we found that in Dyspepsia the Helicobacter pylori was consistently associated and its well proved with various studies done in past and present. Thus we conclude Helicobacter pylori infection definitely have role in the aetiopathogenesis of dyspepsia. Keywords: Giemsa; Helicobacter Pylori; Peptic ulcer disease; Urease; Ulcerative dyspepsia.

Ultrasound assessment of gastric contents prior to placental delivery: A prospective multicentre cohort study

BackgroundThere is ongoing debate regarding the optimal general anaesthetic technique for manual removal of the placenta after vaginal delivery. Using ultrasound examination of the gastric antrum, this study aimed to assess the change in gastric contents during vaginal delivery and to determine the prevalence of stomach at risk for pulmonary aspiration in the immediate postpartum period before placental delivery. MethodsIn this prospective multicentre cohort study, antral ultrasonography was performed at full cervical dilatation within the thirty minutes preceding the beginning of expulsive efforts and after vaginal birth, before placental delivery. High-risk gastric content was defined as the visualisation of any solid content in the antrum or antral cross-sectional area in the semi-recumbent position (SR-CSA) > 608 mm². ResultsTwenty-six women were included and analysed. There was a significant decrease in both the proportion of patients with solid gastric content and the SR-CSA between the two-ultrasound examinations. Twenty-one patients (80.8%) exhibited a decrease in the SR-CSA during vaginal delivery. The prevalence of stomach at risk for pulmonary aspiration was significantly lower after vaginal delivery than before vaginal delivery (23.1% vs. 57.7%, P = 0.0004). ConclusionOur results suggest that gastric emptying is at least partially preserved during vaginal birth. Nevertheless, almost a quarter of women did have high-risk gastric content in the immediate postpartum period. Point-of-care antral ultrasonography may be of interest for the fast assessment of the gastric content status when a general anaesthesia is required for manual removal of retained placenta.

A Review of Current Literature of Interest to the Office-Based Anesthesiologist

A Review of Current Literature of Interest to the Office-Based Anesthesiologist

Abstract 10208: Quantitative Comparison of Ablation Area Created by the Conventional- and Larger-Sized Visually Guided Laser Balloon

Introduction: The visually guided laser balloon (VGLB) ablation catheter has been designed to facilitate pulmonary vein (PV) isolation in patients with atrial fibrillation (AF). Because VGLB is characterized by a compliant and variable diameter balloon, the balloon at the larger inflation size can isolate wider-area circumferential PV antrum. Though the importance of a wider circumferential isolation of PVs, which includes a large portion of the left atrial posterior wall (LAPW), has been suggested in several studies, the extension of the isolation area created by the new VGLB technique remains to be elucidated. We report the quantitative examination of the isolation areas after the conventional- and larger-sized VGLB ablation. Methods: Fifty-five patients with AF who underwent VGLB ablation were enrolled in this prospective study. An electroanatomic map of the left atrium was obtained with the PENTARAY catheter and the CARTO-3 system before and after PV isolation using conventional-sized VGLB. The isolation areas were extended by the larger-sized VGLB ablation and remapped in the same way. As demonstrated in figure, the isolation areas were measured after each ablation. Results: After PV isolation using the conventional-sized VGLB, the mean left- and right-sided antral PV surface areas of ablation were 13.5±2.9 cm 2 and 16.4±3.7 cm 2 , respectively. The total area of LAPW ablation was 10.9±2.1 cm 2 (45.6±9.3% of the posterior wall). On the other hand, they were 18.6±4.0 cm 2 , 23.7±5.2 cm 2 and 16.3±2.8 cm 2 (65.9±11.2%) after ablation with the larger-sized VGLB. These results revealed that the new VGLB technique yielded statistically greater areas of isolation than the conventional-sized VGLB. Conclusions: The larger VGLB ablation technique can create a significantly wider antral PV and LAPW isolation than the conventional-sized VGLB. The resulting LAPW debulking may be greater than the other balloon-based ablation lesions that have been reported previously.

Evaluation of gastric contents using ultrasound in full-term pregnant women fasted for 8h: a prospective observational study.

We aimed to evaluate the gastric volume and contents after an 8-h fasting period in full-term, non-laboring, pregnant women following a standardized meal. In this prospective observational study, we included full-term pregnant women scheduled for elective cesarean delivery. The participants were instructed to fast after a standardized meal (apple juice, bread, and cheese). Participants were scanned in the semi-recumbent and right-lateral positions 8h after the standardized meal. The primary outcome was the proportion of patients with gastric volume > 1.5mLkg-1 calculated by two equations. Secondary outcomes included the antral cross-sectional area and gastric volume. Data are expressed as frequency (%, 95% confidence interval [CI]), mean ± standard deviation (95% CI of the mean), or median (quartiles) as appropriate. Forty-one women were available for the final analysis. For the primary outcome, one participant (2.4%, 95% CI of 0.06 to 12.8%) had gastric volume > 1.5mLkg-1, and none had solids in the antrum. For the secondary outcomes, the mean (95% CI of the mean) of the antral cross-sectional area was 2.11 ± 0.72 (1.88 to 2.34) cm2 and 4.08 ± 1.80 (3.51 to 4.65) cm2 during the semi-recumbent and right-lateral position, respectively. The median (quartiles) gastric volume was 0.53 (0.32, 0.66) mLkg-1 and 0.33 (0.13, 0.52) mLkg-1 as estimated by Perlas et al. and Roukhomovsky et al. equations, respectively. After 8-h fasting following a standardized meal, full-term pregnant non-laboring women are less likely to have a high residual gastric volume.

Endoscopic features and clinical importance of autoimmune gastritis.

Autoimmune gastritis (AIG) is a special type of chronic gastritis characterized by autoimmune disorders caused by cellular immunity, resulting in the destruction of parietal cells and production of antiparietal cell antibodies. Endoscopic findings of AIG are mainly characterized by corpus-dominant advanced atrophy. The antral area is generally considered to have no or mild atrophy; however, there are cases wherein the gastric mucosa is red or faded due to past infection with Helicobacter pylori or bile reflux. Currently, there are no diagnostic criteria for AIG in Japan, and it is important to make a diagnosis based on the presence of gastric autoantibodies and characteristic endoscopic and histological findings. AIG is associated with gastric cancer, neuroendocrine tumors (NETs), and other autoimmune diseases, such as thyroid diseases, anemia, and neurological symptoms due to impaired absorption of iron and vitamin B12 , and thus requires systemic treatment. The significance of diagnosing AIG is to include patients as a high-risk group for the development of gastric cancer and gastric NETs, provide an opportunity to detect autoimmune endocrine diseases, and initiate therapeutic intervention before anemia and neurological symptoms develop. It is important to pay close attention to the occurrence of AIG comorbidities not only at the time of AIG diagnosis but also during follow-up after detection.

Left Atrial Fibrosis after Single Shot Guided Pulmonary Vein Isolation.

Cryoballoon (CB)-based pulmonary vein isolation (PVI) is an effective treatment modality for patients with atrial fibrillation (AF) with encouraging acute and long-term outcome data. However, the size of collaterally created lesion sets adjacent to the pulmonary veins (PVs) remains unclear, especially when CB ablation is performed with individualized time-to-isolation (TTI) protocols. This study seeks to investigate the extension of lesions at the posterior wall and the roof of the left atrium (LA). Thirty patients with paroxysmal or persistent AF underwent ablation with a fourth-generation CB. The individual freeze-cycle duration was set at TTI + 120 s. A total of 120 PVs were identified, and all were successfully isolated. A three-dimensional electroanatomical high-density (HD) mapping of the LA was performed in every patient before and after PVI. The surface areas of the posterior wall and LA roof were measured and compared with lesion extension after PVI. After CB ablation, 65.6 ± 16.9% of the posterior wall and 75.4 ± 18.4% of the LA roof remained unablated. In addition, non-antral lesion formation was observed in every patient in at least one PV. After CB ablation, anterior antral parts of the superior PVs showed the greatest unablated areas compared with the other antral areas. HD re-mapping after CB-based PVI demonstrated that major regions of the posterior wall and roof remained electrically normal and unaffected. Unablated antral areas were localized predominantly in the anterior segments of the superior PVs and may be partly responsible for AF recurrence.

Gastric emptying of preoperative carbohydrate in elderly assessed using gastric ultrasonography: A randomized controlled study.

Background:Preoperative carbohydrate loading enhances postoperative recovery and reduces patient discomfort. However, gastric emptying of liquids can be delayed in elderly populations. Therefore, this study aimed to evaluate the gastric emptying of 400 mL of a carbohydrate drink ingested 2 hours before surgery in elderly patients.Methods:In this prospective, randomized controlled study, patients aged >65 years were allocated to either fast from midnight (nil per os [NPO] group, n = 29) or drink 400 mL of a carbohydrate drink 2 hours before surgery (carbohydrate group, n = 29). The gastric antrum was assessed using ultrasonography in the supine position, followed by the right lateral decubitus (RLD) position. The gastric antrum was graded as grade 0 (fluid not seen in both positions), grade 1 (fluid only seen in the RLD position), and grade 2 (fluid seen in both positions). The gastric antral cross-sectional area (CSA) and aspirated residual gastric volume were measured.Results:In 58 patients, the incidence of grade 2 stomach was 13.8% in NPO group and 17.2% in carbohydrate group (P = .790). The gastric antral CSA in the supine position was larger in carbohydrate group than in NPO group (4.42 [3.72–5.18] cm2 vs 5.31 [4.35–6.92] cm2, P = .018). The gastric antral CSA in the RLD position was not different in NPO and carbohydrate groups (P = .120). There was no difference in gastric volume (2 [0–7.5] vs 3 [0–13.4], P = .331) in NPO group versus carbohydrate group.Conclusion:The incidence of grade 2 stomach was not different between NPO group and carbohydrate group in elderly patients.

Systematic Review and Meta-analysis of Histological Gastric Biopsy Aspects According to the Updated Sydney System in Children.

A descriptive and comparative study of gastric histological aspects according to the updated Sydney classification (USC), obtained from Helicobacter pylori-positive versus H pylori-negative children referred for upper gastrointestinal endoscopy. The Prisma method was used to perform a systematic review and meta-analysis. Selection criteria were based on following key words USC, H pylori, children, endoscopy, or biopsy. Publication biases were assessed according to the Newcastle-Ottawa Scale, and a meta-regression analysis was done. The study was registered on the PROSPERO platform. Between 1994 and 2017, 1238 references were found; 97 studies were retained for the systematic review with a total number of 25,867 children; 75 studies were selected for the meta-analysis concerning 5990 H pylori-infected and 17,782 uninfected children.H pylori-positive versus H pylori-negative children, according to the USC, showed significantly higher relative risk for gastric antral and corpus chronic inflammation, presence of neutrophils, and of lymphoid follicles, and gastric mucosa atrophy, whereas, intestinal metaplasia showed a significantly higher RR only in antral biopsies. The meta-regression analysis showed that H pylori-positive versus H pylori-negative children had significantly higher risk only for corpus activity according to age, recurrent abdominal pain, and geographical area of low H pylori prevalence. H pylori infection in children was associated with higher relative risk for gastric antral and corpus chronic inflammation, presence of neutrophils, lymphoid follicles, and rare gastric mucosa atrophy, whereas, rare intestinal metaplasia was only significantly higher in the antral area.

Gastric emptying time of two different quantities of clear fluids in children: A double-blinded randomized controlled study.

Perioperative pulmonary aspiration risk increases with increased preoperative gastric volume; hence traditionally, healthy children are kept fasted overnight before surgery. Current guidelines recommend 2-h clear fluids fasting prior to anesthesia. However, emerging evidence favors allowing 3ml/kg clear fluids up to 1-h before anesthesia. We compared the gastric volume and gastric emptying time after ingestion of 3ml/kg and 5ml/kg of clear fluids. The present study enrolled 44 children, aged between 6 and 14years. On the day of surgery, baseline gastric volume was estimated using ultrasound and patients were randomly allocated into two groups of equal number, that is, Group 3 and Group 5 (patients received 3ml/kg and 5ml/kg 5% Dextrose respectively). Repeated gastric ultrasound was performed at every 5min until the gastric volume reached baseline levels. The primary objective of the study was to compare gastric emptying time. Secondary objectives included comparison of antral cross-sectional area and gastric volume. The demographic profile, preoperative fasting duration for clear fluids, and baseline gastric volume were comparable between groups. In both groups, compared to baseline the antral cross-sectional area and gastric volume increased significantly following fluid ingestion and then decreased exponentially to reach baseline within 1-h. The median (IQR) (range) gastric emptying time (minutes) [35.0 (28.8, 40.0) (20.0-45.0) in group 3 and 40.0 (28.8, 45.0) (20.0-50.0) in group 5] and emptying half-time (minutes) [17.0 (15.7, 21.5) (14.4-24.0) in group 3 and 18.6 (16.0, 22.0) (15.1-23.8) in group 5] were comparable [median difference -5 (95% CI -7.8 to 2.1) and -1.5 (95% CI -2.3 to 1.0), respectively] (p=.16 and p=.44, respectively). As the gastric volume returned to baseline within 1-h even after ingesting 5ml/kg clear fluids, the preoperative fasting time can be reduced to 1-h and healthy children undergoing elective procedure can be safely allowed to drink up to 5ml/kg clear fluids.

Left paratracheal pressure versus cricoid pressure for successful laryngeal mask airway insertion in adult patients: a randomized, non-inferiority trial.

Cricoid pressure (CP) is used to prevent pulmonary aspiration of regurgitated gastric contents and gastric insufflation during positive-pressure ventilation. However, CP impedes the successful insertion of laryngeal mask airway (LMA). Left paratracheal pressure (LPP), a maneuver of applying backward digital force at the lower left paratracheal level, was recently introduced as an alternative to CP. We assessed whether LPP is non-inferior to CP in successful LMA insertion on the first attempt in adult patients undergoing general anesthesia. In this non-inferiority randomized controlled trial, 108 patients undergoing general anesthesia were randomly allocated to receive either LPP or CP during LMA insertion. The primary outcome was the success rate of LMA insertion on the first attempt. The margin of non-inferiority was defined as 15%. The success rate of LMA insertion on the first attempt was 68.5% (37/54) in the LPP group and 51.9% (28/54) in the CP group (P=0.077) with between-group difference of 16.7% (two-sided 95% CI, -1.9% to 35.2%). Time for successful device insertion was comparable in the two groups (P=0.355), whereas LMA insertion was easier in the LPP group than in the CP group (P=0.001). There was no significant difference between the two groups for change in antral cross-sectional area measured before and after mask ventilation (P=0.081). No serious complication was evident in any group. This randomized clinical trial demonstrated the non-inferiority of LPP over CP in the success rate of LMA insertion on the first attempt in adult patients undergoing general anesthesia.

Prediction of gastric fluid volume by ultrasonography in infants undergoing general anaesthesia

BackgroundPoint-of-care ultrasonography can estimate gastric contents and volume to assess the risk of pulmonary aspiration; however, its use in infants has not been well validated. We aimed to develop a predictive model for estimating gastric fluid volume using ultrasonography in infants. MethodsThis prospective observational study enrolled 200 infants (≤12 months) undergoing general anaesthesia. After anaesthetic induction, while preserving spontaneous respiration, we measured gastric antral cross-sectional area using ultrasonography in both the supine and right lateral decubitus positions. We then suctioned the gastric content and measured its volume. The primary outcome was development of a gastric fluid volume prediction model with multiple regression analysis. Agreement between the predicted volume and the suctioned volume was evaluated using a Bland–Altman plot. ResultsOverall, 192 infants were included in the final analysis. Pearson correlation analysis showed that the gastric antral cross-sectional area in the supine (P<0.001; correlation coefficient: 0.667) and right lateral decubitus (P<0.001; correlation coefficient: 0.845) positions and qualitative antral grade (P<0.001; correlation coefficient: 0.581) correlated with suctioned volume. We developed a predictive model: predicted volume (ml)=–3.7+6.5 × (right lateral decubitus cross-sectional area [cm2])–3.9 (supine cross-sectional area [cm2])+1.7 × grade (P<0.01). When comparing the predicted volume and suctioned volume, the mean bias was 0.01 ml kg−1 and the limit of agreement was –0.58 to 0.62 ml kg−1. ConclusionsGastric fluid volume can be estimated using a predictive model based on ultrasonography data in infants. Clinical trial registrationNCT03155776.

Ultrasound Assessment of Gastric Emptying in Premature Infants Treated With Non-Invasive Ventilatory Support.

Nasal continuous positive airway pressure (CPAP) introduces positive pressure of air into both the trachea and stomach, which may affect gastric emptying. The rate of gastric emptying can be estimated by ultrasound (US) in neonates by two validated techniques: "antral cross-sectional area" (ACSA, two-dimensional estimate of the surface area at the gastric antrum), and "spheroid gastric volume" (spheroid, three-dimensional estimate of the stomach volume). To compare gastric emptying rates in neonates on machine-derived nasal CPAP (MD-nCPAP, Avea and RAM cannula) with those on bubble CPAP (bCPAP, Fisher Paykel and Babi.Plus nasal prongs). Ultrasound measurements of the amount of the milk in the stomach were performed before feeding and at 1, 2, and 3 hours after the start of feeding, using both the ACSA and spheroid methods. Rates of gastric emptying were calculated during the "early" (1-2 hours) and "late" (2-3 hours) phases after feeding. We recruited 32 infants (25-34 weeks gestational age, full enteral tube feedings, on nasal CPAP). Seventeen infants were treated with MD-nCPAP (median birth weight 1015 g [interquartile range (IQR): 870-1300], gestational age 28 weeks [IQR: 27-29], postnatal age 20 days [IQR: 14-28]), whereas 15 infants were treated with bCPAP (median birth weight 960 g [IQR: 855-1070], gestational age 27 weeks [IQR: 26-28], postnatal age 17 days [IQR: 15-25]). Gastric emptying rates (% emptied/min) were significantly faster in the "early" compared to the "late" phase for all infants. There were no significant differences in the rates of gastric emptying (either "early" or "late") or volumes of gastric residuals between infants receiving MD-nCPAP or bCPAP, measured by either method. Although no feeding intolerance was seen in either group, the volumes of residual gastric contents measured by both methods were higher than the volumes traditionally considered abnormal when obtained by gastric tube aspiration. Gastric emptying is faster during the "early" compared to the "late" phase. Gastric emptying rates are not different in infants receiving MD-nCPAP versus bCPAP. The presence of large residual gastric contents in infants who are tolerating feedings challenges the value of traditional gastric aspiration for the assessment of feeding tolerance in infants.

Does ultrasonographic assessment of gastric antrum correlate with gastric residual volume in critically ill patients? A prospective observational study.

This study aimed to evaluate the relationship between ultrasonographic gastric antral measurements and aspirated gastric residual volume (GRV) in mechanically ventilated critically ill patients receiving enteral nutrition (EN). This prospective observational study included 56 enterally-fed critically ill patients in one-year period. All imaging procedures were done at 30-degree head-of-bed elevation and supine position on epigastric region of abdomen with 2.5-6MHz convex-array probe just before routine GRV aspiration. The antral cross-sectional area (CSA) was calculated by measuring the anteroposterior (dAP) and craniocaudal diameters (dCC) of the gastric antrum. Total 283 ultrasonographic gastric antrum imaging procedures were done. In only eight (2.82%) attempts, the antrum could not be visualized due to inhibition from intra-gastric air or gas in the surrounding intestinal lumen. The calculated mean antral CSA was 568.15 ± 348.37 mm2 (103.43-2,846.30). The antral CSA correlated significantly with aspirated GRV, and the antral CSA increased linearly with increasing aspirated GRV (R2 = 0.73, p < 0.0001). In Receiver operating characteristic (ROC) analysis of antral CSA ≥ 920 mm2 (mean + 1*SD) for estimating aspirated GRV, the area under the curve (AUC) was 0.848 (95% CI, 0.76 ~ 0.93) (p < 0.0001), and ROC analysis of antral CSA to discriminate aspirated GRV ≥ 250mL showed a significant relation (AUC = 0.969, 95% CI 0.94 ~ 0.99, p < 0.0001). Ultrasonographic measurement of gastric antral CSA is an easy and reliable bedside procedure to estimate GRV in critically ill patients receiving EN in 30-degree head-of-bed elevation and supine position. Trial registration number: NCT04413474, date of registration: June 17, 2020, retrospectively registered.

Gastric Volume Changes in Preterm Neonates during Intermittent and Continuous Feeding-GRV and Feeding Mode in Preterm Neonates.

Background: We aimed to evaluate gastric volume changes during intermittent milk feeds (IMF) and continuous milk feeds (CMF) in very premature neonates (VPN), with gastric residual volume (GRV) based on antral cross-sectional area (ACSA) measurements and to examine if there were differences in GRV between the two feeding methods. Methods: A randomized prospective clinical trial with crossover design was conducted in 31 preterm neonates (gestational age < 30 weeks). Gastric volume was assessed twice in each neonate (during IMF and CMF feeding), at 7 specific time points during a 2-h observation period by measuring ACSA changes via the ultrasound (U/S) method. Results: There was a significantly different pattern of gastric volume changes between the two feeding methods. GRV, expressed as the median percentage of ACSA measurement at 120 min relative to the higher ACSA measurement during IMF, was found to be 3% (range 0–25%) for IMF and 50% (range 15–80%) for CMF. Neonates fed with IMF had a shorter mean gastric emptying time compared to those fed with CMF (p = 0.0032). No signs of feeding intolerance were recorded in either group during the period of observation. Conclusions: Our results showed that gastric volume changes and gastric emptying time in VPN, based on ACSA measurement changes, depend on the milk feeding method. No gastrointestinal complications/adverse events were noted with GRV up to 80% with CMF.

The effect of high-dose versus low-dose epidural fentanyl on gastric emptying in nonfasted parturients: A double-blinded randomised controlled trial.

Epidural fentanyl doses above 100 μg have been shown, using the paracetamol absorption test, to reduce gastric emptying in fasted labouring women. To investigate the effect of fentanyl dose on gastric emptying in nonfasted labouring women using gastric ultrasonography. A double-blinded randomised controlled study. A tertiary medical centre in Tel Aviv, Israel between 30 July 2020 and 11 October 2020. Eighty labouring women with cervical dilation 5 cm or less, at least 18 years age, at least 37 weeks gestation with a singleton pregnancy and cephalad foetus. Women randomised to high (>100 μg) or low (<100 μg) cumulative epidural fentanyl had ultrasound gastric content assessment, measuring antral cross-sectional area (CSA) at epidural placement and 2 h thereafter (T2 h). The primary outcome was CSA at T2 h comparing high-dose versus low-dose fentanyl. Secondary outcomes included change in CSA between baseline and T2 h. Sub-group analysis compared stomach content at T2 h according to baseline stomach content, empty (CSA <381 mm2) or full (CSA ≥381 mm2), and high-dose versus low-dose fentanyl. Data from 80 women were analysed; 63 had empty and 17 had full stomach at baseline. There was no significant difference in CSA at T2 h between high-dose, mean 335 ± SD 133 mm2, versus low-dose fentanyl, mean 335 ± SD 172 mm2, P = 0.991. Change in CSA baseline to T2 h was 46 ± SD 149 mm2 for high and 49 ± SD 163 mm2 for low-dose group, P = 0.931. The subgroup analysis according to baseline stomach content showed no statistically significant differences in CSA at T2 h. The CSA at T2 h was similar for women who received high-dose versus low-dose epidural fentanyl, measured by ultrasound, in our nonfasted labouring cohort. Clinicaltrials.gov number: NCT04202887.

Impact of the size of non-ablated left atrial posterior wall area on outcomes after extensive encircling pulmonary vein isolation.

The aim of this study was to evaluate the impact of the size of the isolated surface area and non-ablated left atrial posterior area after extensive encircling pulmonary vein isolation (EEPVI) for non-paroxysmal atrial fibrillation (AF) on arrhythmia recurrence. This study included 132 consecutive persistent AF patients who underwent EEPVI guided by Ablation Index (AI). The isolated antral surface area (IASA) excluding the pulmonary veins, the non-ablated left atrial (LA) posterior wall surface area (PWSA), the ratio of IASA to LA surface area (IASA/LA ratio), and the ratio of PWSA to LA surface area (PWSA/LA ratio) were assessed using CARTO3 and the association with AF and atrial tachycardia (AT) recurrence was examined. At a mean follow-up of 13.2 ± 7.3months, sinus rhythm was maintained in 115 (87%) patients. In the univariate Cox regression analysis, the factors that significantly predicted AT/AF recurrence were a history of heart failure, a higher CHA2DS2-VASc score, a larger LA diameter, and a larger PWSA/LA ratio. Multivariate Cox regression analysis revealed that the independent predictors of AT/AF recurrence were LA diameter [hazard ratio (HR) 1.120 per 1mm increase; 95% confidence interval (CI) 1.006-1.247; P = 0.039] and PWSA/LA ratio (HR 1.218 per 1% increase; 95% CI 1.041-1.425; P = 0.014). Receiver operating characteristics curve analysis yielded an optimal cut-off value of 8% for the PWSA/LA ratio. The Kaplan-Meier survival curve showed that patients with a larger PWSA/LA ratio had poorer clinical outcomes (Log-rank P = 0.001). A larger PWSA/LA ratio was associated with a high AT/AF recurrence rate in patients with non-paroxysmal atrial fibrillation.

Does pulsed field ablation regress over time? A quantitative temporal analysis of pulmonary vein isolation

The tissue specificity of pulsed field ablation (PFA) makes it an attractive energy source for pulmonary vein (PV) isolation (PVI). However, beyond each PFA lesion's zone of irreversible electroporation and cell death, there may be a surrounding zone of reversible electroporation and cell injury that could potentially normalize with time. The purpose of this study was to assess whether the level of electrical PVI that is observed acutely after PFA regresses over time. In a clinical trial, patients with paroxysmal atrial fibrillation underwent PVI using a biphasic PFA waveform delivered through a dedicated, variably deployable multielectrode basket/flower catheter. Detailed voltage maps were created using a multispline diagnostic catheter immediately after PFA and again ∼3 months later in a prospective, protocol-specified reassessment procedure. We analyzed 20 patients who underwent PFA with durable PVI and available maps from both time points. To compare the ablated zones, the left- and right-sided PV antral isolation areas and nonablated posterior wall area were quantified and the distances between left and right PV low-voltage edges were measured. A comparison of voltage maps immediately after PFA and at a median of 84 days (interquartile range 69-90 days) later revealed that there was no significant difference in either the left- and right-sided PV antral isolation areas or nonablated posterior wall area. The distances between low-voltage edges on the posterior wall were also not significantly different between the 2 time points. This study demonstrates that the level of PV antral isolation after PFA with a multielectrode PFA catheter persists without regression.

Ultrasound assessment of gastric volumes of thick fluids: Validating a prediction model.

Enteral nutrition is essential in the treatment of critically ill patients. Current methods to monitor enteral nutrition such as aspiration of residual volume may be inaccurate. Gastric ultrasonography estimates total gastric fluid volume using the Perlas model, but this model is validated for clear fluids only, and its accuracy for measuring thick fluids is unknown. The primary aim of this study was to evaluate the Perlas model for gastric volume estimation of enteral nutrition, a thick fluid product. A single-centre, single blinded, randomised controlled study. Single university hospital, from May to July 2019. Seventy-two healthy fasted volunteers were randomly allocated to different fluid volume groups. Participants randomly ingested predetermined volumes between 50 and 400 ml of a feeding-drink (Nutricia Nutridrink). Following a standardised gastric ultrasound scanning protocol, a blinded sonographer measured the antral cross-sectional area in the supine and right-lateral decubitus positions. Measurements were performed at baseline, 5 min postingestion and 20 min postingestion. Gastric volumes were predicted using the previously established Perlas model and compared with total gastric fluid volumes after ingestion of the study drink. The Perlas model underestimated the volume of thick gastric fluid and yielded a suboptimal fit for our data. However, antral cross-sectional area and total gastric thick fluid volumes were significantly correlated (Pearson's correlation coefficient 0.73, P < 0.01). A new model was fitted to predict gastric volumes of thick fluids, using the antral cross-sectional area (cm2) in the right-lateral decubitus position: Volume (ml) = 79.38 + 13.32 x right-lateral cross-sectional area. The Perlas model for clear gastric fluid volume estimation is suboptimal for thick fluid volume assessment and an alternative model is presented. Netherlands Trial Register Trial NL7677, Registration date: 16 April 2019; https://www.trialregister.nl/trial/7677.