Optic nerve haemangioblastoma in association with von Hippel-Lindau syndrome: case report and literature review.

Optic nerve haemangioblastoma (ONH) is an uncommon, benign, non-meningothelial, mesenchymal tumour of unclear origin. Most are associated with von Hippel-Lindau (VHL) syndrome (71%), and only 40 cases have been reported in the medical literature. Most of the patients develop non-specific visual symptoms, including decreased visual acuity and/or loss of visual fields, exophthalmos, trigeminal neuralgia, and retroorbital pain. Optic nerve sheath meningioma and optic nerve glioma are among the differential diagnoses that may be considered in this location. Contrast-enhanced MRI is considered an optimal diagnostic tool, which helps to determine some characteristics that guide towards an adequate diagnosis and treatment. We present a 42-year-old patient with a history of VHL syndrome in whom a cerebellar lesion and optic nerve lesions were evidenced, and we did a review of the literature and case analysis.

Hallucinations in patients with obstructive sleep apnea-hypopnea syndrome: report of 3 cases.

Hallucinations are false sensory perceptions that occur in the absence of an external stimulus. Three cases of hallucinations related to obstructive sleep apnea-hypopnea syndrome are reported, 2 of which improved with the initiation of continuous positive airway pressure therapy. So far there are no published reports in the literature that account for this relationship in the absence of primary or structural mental pathology. All 3 reported patients had visual hallucinations that were uncomfortable and frightening. Polysomnography showed moderate-to-severe obstructive sleep apnea-hypopnea syndrome with severe oxygen desaturation. Initiation of continuous positive airway pressure therapy achieved control of hallucinations in 2 patients during follow-up. Very little information is available on the coexistence of obstructive sleep apnea-hypopnea syndrome and hallucinations. Observational and experimental studies are required to clarify whether there is a causal relationship between the 2 pathologies as well as the therapeutic role that continuous positive airway pressure may have. CITATION: Venegas MA, Montoya JS. Hallucinations in patients with obstructive sleep apnea-hypopnea syndrome: report of 3 cases. J Clin Sleep Med. 2024;20(1):165-167.

Lumbosacral Traumatic Spondylolisthesis L5 to S1-Classification and Surgical Management of a Difficult Presentation.

INTRODUCTION: Lumbosacral traumatic spondylolisthesis L5-S1 is a rare clinical entity that compromises the stability of the L5 vertebra by displacing it anteriorly, laterally, or posteriorly on the S1 vertebral body secondary to osteotendinous and/or articular compromise of this segment due to trauma. This pathology is difficult to classify and manage; although surgical management remains the gold standard, short- and long-term results in the literature are scarce and highly variable. PATIENT PRESENTATION: We present the case of a 53-year-old patient with lumbar trauma due to a free fall from a height of 6 meters. The fall resulted in cauda equina syndrome secondary to lumbosacral traumatic spondylolisthesis L5-S1, which required immediate surgical management. INTERVENTION AND OUTCOME: For surgical management, we used a posterior approach for L5-S1 transpedicular screw fixation, spinal decompression, bilateral root foraminotomy of L5, and L5-S1 open transforaminal lumbar interbody fusion with open reduction. After the operation, the patient reported immediate improvement of postoperative lower extremities pain and was discharged on the third postoperative day after achieving clinical improvement with physical therapy and bladder rehabilitation exercises. CONCLUSION: Lumbosacral traumatic spondylolisthesis L5-S1 is an unusual pathology that requires further study as there is currently no standardized classification. Surgical management is the gold standard and includes open reduction with short transpedicular screw fixation in segment L5-S1 and other surgical interventions such as extension to the pelvis with iliac screws, screws to the L4 vertebral body, and use of lumbar interbody fusion cages.

Deep Brain Stimulation for Obsessive-Compulsive Disorder: Optimal Stimulation Sites.

BACKGROUND: Deep brain stimulation (DBS) is a promising treatment option for treatment-refractory obsessive-compulsive disorder (OCD). Several stimulation targets have been used, mostly in and around the anterior limb of the internal capsule and ventral striatum. However, the precise target within this region remains a matter of debate. METHODS: Here, we retrospectively studied a multicenter cohort of 82 patients with OCD who underwent DBS of the ventral capsule/ventral striatum and mapped optimal stimulation sites in this region. RESULTS: DBS sweet-spot mapping performed on a discovery set of 58 patients revealed 2 optimal stimulation sites associated with improvements on the Yale-Brown Obsessive Compulsive Scale, one in the anterior limb of the internal capsule that overlapped with a previously identified OCD-DBS response tract and one in the region of the inferior thalamic peduncle and bed nucleus of the stria terminalis. Critically, the nucleus accumbens proper and anterior commissure were associated with beneficial but suboptimal clinical improvements. Moreover, overlap with the resulting sweet- and sour-spots significantly estimated variance in outcomes in an independent cohort of 22 patients from 2 additional DBS centers. Finally, beyond obsessive-compulsive symptoms, stimulation of the anterior site was associated with optimal outcomes for both depression and anxiety, while the posterior site was only associated with improvements in depression. CONCLUSIONS: Our results suggest how to refine targeting of DBS in OCD and may be helpful in guiding DBS programming in existing patients.

Treatment of intertrochanteric fractures using cephalomedullary nail: One or two cephalic screws?

OBJECTIVES: To determine the incidence of cut-out, cut-in, cut-through, Z-effect, and reverse Z-effect in two cephalomedullary nail (CMN) systems: one with single cephalic screw fixation and the other with dual-screw fixation using a lag screw and an anti-rotation screw. METHODS: A retrospective study from a cohort of patients was conducted between January 2017 and August 2019 in patients with intertrochanteric fractures treated with osteosynthesis using CMN. RESULTS: One hundred ninety-six patients with intertrochanteric fractures who met the inclusion criteria were recruited. The median age was 81 years [interquartile range (IQR) 12]. Seventy-six percent had fractures classified as Orthopaedic Trauma Association/Arbeitsgemeinschaft für Osteosynthesefragen (OTA/AO) 31A2. Twenty-one mechanical complications occurred, 8.7% (17) was cut-out with a single cephalic screw CMN and 2% (4) was Z-effect with a dual-screw CMN non-integrated. The median tip-apex distance (TAD) was 19.4 mm (IQR 10.8) in patients who experienced cut-out and 19 mm (IQR 10) in those who experienced Z-effect. The median time to cut-out occurrence was 39,5 days (IQR 47,5), while the median time to Z-effect was 90 days (IQR 86). CONCLUSIONS: The incidence of osteosynthesis failure using CMN is more frequent in patients treated with a single cephalic screw CMN. LEVEL OF EVIDENCE: Therapeutic, Level III.

Early-Phase Perceptions of COVID-19's Impact on Ophthalmology Practice Patterns: A Survey from the Pan-American Association of Ophthalmology.

Purpose: The COVID-19 pandemic affected medical practice worldwide due to interventions to prevent spreading. Its effect on ophthalmology practices in Latin America has not yet been explored. We aimed to assess the perceptions about the pandemic from countries' ophthalmological national and subspecialty retina societies affiliated to the Pan-American Association of Ophthalmology (PAAO). Patients and Methods: A survey-based study of leaders of national ophthalmological and retinal societies was conducted. The survey was sent by email to 30 societies, from which 20 responded (12 countries, 66.6% response rate). It included closed- and open-ended questions about (1) operational capacity and precautions, (2) telemedicine and virtual care, (3) procedures, and (4) post-pandemic considerations. Results: There was a marked decline in ophthalmology patient visits (80-95%) and elective surgeries (90%) during 2020 compared to before the pandemic. Precautions like temperature checks, mask usage, and social distancing were widely implemented while personal protective equipment (PPE) availability varied. Telemedicine use was limited due to lack of experience with it. Reopening plans focused on maintaining precautions and gradually resuming activities. Economic and security concerns were raised, and adherence to guidelines was emphasized. Respondents acknowledged the need to adapt to a "new normal". Long duration drugs, fewer imaging studies, and shorter wait times were preferred; however, availability of long duration drugs was limited. Conclusion: The pandemic impacted ophthalmology in Latin America, with reduced patient visits, procedures, and surgeries. Delayed treatment and complications were likely the result of the pandemic.

Self-Supported Spray-Coated NiFe-LDH Catalyst on a Stainless Steel Substrate for Efficient Oxygen Evolution Reaction.

In the quest for more efficient and cost-effective electrocatalytic systems, careful selection of catalysts and substrates plays a pivotal role. This study introduces an approach by synthesizing and depositing NiFe-layered double hydroxide (NiFe-LDH) catalysts on commercial AISI 304 substrates by using a low-temperature spray-coating technique. Through systematic investigations, the influence of processing conditions, such as the synthesis, ultrasonic power for having a stable nanoparticle's dispersion, and spray cycle optimization on the electrochemical and morphological properties of the coatings, is thoroughly explored. The results showcase exceptional catalytic performance, achieving an overpotential of 230 mV at 10 mA/cm2, with enhanced stability even at high current densities of 500 mA/cm2. The study highlights the significance of meticulous processing optimization and presents a scalable methodology that holds great potential for developing catalysts for oxygen evolution reactions (OER) and facilitates their integration into industrial processes.

Clinical Characteristics and Outcomes of Patients Hospitalized with Epidermolysis Bullosa: A Retrospective Population-Based Observational Study in Spain (2016-2021).

(1) Background: Epidermolysis bullosa (EB) comprises a group of rare skin diseases. We assessed diagnostic procedures, comorbidity profiles, length of hospital stay (LOHS), costs, and in-hospital mortality (IHM) associated with EB. (2) Methods: A retrospective, population-based observational study was performed using the Spanish National Hospital Discharge Database. Hospitalized patients with EB in Spain were identified for the period 2016 to 2021. (3) Results: A total of 677 hospitalizations were identified among 342 patients with a diagnosis of EB. Fifty percent of patients had at least one readmission during the 6-year follow-up. Notably, rehospitalizations were more common among patients aged 2-17 years. The most prevalent comorbidity was digestive disorders, which were associated with the frequency of esophageal dilatation procedures and percutaneous endoscopic gastrostomy. The longest LOHS was recorded for the 0- to 1-year age group. IHM increased with age, and the difference was statistically significant. The prevalence of malignant neoplasm was 36.88%, with cutaneous squamous cell carcinoma being the most frequent. The overall cost per hospitalized patient was estimated to be EUR 10,895.22 (SD EUR 13,394.81), with significant variations between age groups. (4) Conclusions: Readmissions are very frequent among people with EB. We observed a higher LOHS in the 0- to 1-year age group, while the highest rates of IHM were observed in patients older than 50 years. There was a substantial prevalence of comorbidities, namely, digestive disorders, infectious diseases, and especially cancer.

Opportunistic AI-enabled automated bone mineral density measurements in lung cancer screening and coronary calcium scoring CT scans are equivalent.

Rationale and objectives: We previously reported a novel manual method for measuring bone mineral density (BMD) in coronary artery calcium (CAC) scans and validated our method against Dual X-Ray Absorptiometry (DEXA). Furthermore, we have developed and validated an artificial intelligence (AI) based automated BMD (AutoBMD) measurement as an opportunistic add-on to CAC scans that recently received FDA approval. In this report, we present evidence of equivalency between AutoBMD measurements in cardiac vs lung CT scans. Materials and methods: AI models were trained using 132 cases with 7649 (3 mm) slices for CAC, and 37 cases with 21918 (0.5 mm) slices for lung scans. To validate AutoBMD against manual measurements, we used 6776 cases of BMD measured manually on CAC scans in the Multi-Ethnic Study of Atherosclerosis (MESA). We then used 165 additional cases from Harbor UCLA Lundquist Institute to compare AutoBMD in patients who underwent both cardiac and lung scans on the same day. Results: Mean±SD for age was 69 ± 9.4 years with 52.4% male. AutoBMD in lung and cardiac scans, and manual BMD in cardiac scans were 153.7 ± 43.9, 155.1 ± 44.4, and 163.6 ± 45.3 g/cm3, respectively (p = 0.09). Bland-Altman agreement analysis between AutoBMD lung and cardiac scans resulted in 1.37 g/cm3 mean differences. Pearson correlation coefficient between lung and cardiac AutoBMD was R2 = 0.95 (p < 0.0001). Conclusion: Opportunistic BMD measurement using AutoBMD in CAC and lung cancer screening scans is promising and yields similar results. No extra radiation plus the high prevalence of asymptomatic osteoporosis makes AutoBMD an ideal screening tool for osteopenia and osteoporosis in CT scans done for other reasons.

A Universal Antigen-Ranking Method to Design Personalized Vaccines Targeting Neoantigens against Melanoma.

Background: The main purpose of this article is to introduce a universal mathematics-aided vaccine design method against malignant melanoma based on neoantigens. The universal method can be adapted to the mutanome of each patient so that a specific candidate vaccine can be tailored for the corresponding patient. Methods: We extracted the 1134 most frequent mutations in melanoma, and we associated each of them to a vector with 10 components estimated with different bioinformatics tools, for which we found an aggregated value according to a set of weights, and then we ordered them in decreasing order of the scores. Results: We prepared a universal table of the most frequent mutations in melanoma ordered in decreasing order of viability to be used as candidate vaccines, so that the selection of a set of appropriate peptides for each particular patient can be easily and quickly implemented according to their specific mutanome and transcription profile. Conclusions: We have shown that the techniques that are commonly used for the design of personalized anti-tumor vaccines against malignant melanoma can be adapted for the design of universal rankings of neoantigens that originate personalized vaccines when the mutanome and transcription profile of specific patients is considered, with the consequent savings in time and money, shortening the design and production time.

Ventajas y limitaciones del modelo de lucha de Axel Honneth. Una puesta en práctica en Colombia / Advantages and limitations of Axel Honneth's struggle model. An implementation in Colombia

Este artículo revisa el modelo teórico de lucha elaborado por Axel Honneth en su libro La lucha por el reconocimiento, a partir de ejemplos prácticos de movimientos sociales contemporáneos y cercanos a nuestro contexto. De tal forma, pretende responder a cuestiones tales como las motivaciones para el surgimiento de la acción colectiva, sus formas de articulación y cómo pueden ser dirimidas aquellas situaciones en que distintas exigencias morales se ven enfrentadas entre sí. Para ello, se estudia el alcance explicativo, no sólo de la noción de lucha, sino también de las ideas de moral, amor, menosprecio e integridad personal (o identidad) que defiende el autor.

This article reviews the theoretical model of struggle developed by Axel Honneth in his book The Struggle for Recognition, from practical examples of contemporary social movements close to our context. In this way, it aims to answer questions such as the motivations for the emergence of collective action, its forms of articulation and how those situations in which different moral demands confronted with each other can be resolved. To do this, the explanatory scope is studied, not only of the notion of stru-ggle, but also of the ideas of morality, love, disparagement and personal integrity (or identity) that the author defends.

Alternativas de manejo intervencionista en el síndrome de Budd-Chiari. Serie de casos y revisión de la literatura / Interventional management alternatives in Budd-Chiari syndrome. Series of cases and review of the literature

La obstrucción en el tracto de salida del flujo venoso hepático, también conocida como síndrome de Budd-Chiari, es una condición infrecuente que causa congestión hepática, hipertensión portal, ne-crosis de los hepatocitos y, eventualmente, falla hepática aguda o crónica. Actualmente, el manejo de esta condición representa un reto para el médico, quien debe estar preparado para determinar la mejor alternativa entre las diferentes opciones terapéuticas disponibles. Este artículo pretende ilus-trar las alternativas del manejo intervencionista de esta enfermedad, a través de una serie de casos de pacientes tratados en el servicio de Radiología Intervencionista de un hospital de referencia de la ciudad de Medellín, entre 2011 y 2017.

Hepatic venous outflow tract obstruction, also known as Budd-Chiari syndrome, is a rare condition that causes hepatic congestion, portal hypertension, hepatocyte necrosis and eventually acute or chronic liver failure. Currently, the management of this condition represents a challenge for the physi-cian, who must be prepared to determine the best alternative among the different therapeutic options available. This article aims to illustrate the alternatives of interventional management of this disease, through a series of cases of patients treated in the Interventional Radiology service of a referral hos-pital in the city of Medellin, between 2011 and 2017.

Influence of Beetroot Juice Ingestion on Neuromuscular Performance on Semi-Professional Female Rugby Players: A Randomized, Double-Blind, Placebo-Controlled Study.

PURPOSE: Beetroot juice (BRJ) is considered an ergogenic aid with good to strong evidence for improving human performance in sport modalities with similar demands to rugby. However, most of the studies were realized in male athletes with limited evidence in female athletes. Thus, the aim of this study was to explore the acute ingestion of BRJ in female rugby players. METHODS: Fourteen semi-professional female rugby players (25.0 ± 3.7 years) belonging to a team from the First Spanish Female Rugby Division participated in this study. Participants were randomly divided into two groups that realized a neuromuscular battery after BRJ (140mL, 12.8 mmol NO3-) or placebo (PLAC, 140 mL, 0.08 mmol NO3-) ingestion on two different days separated by one week between protocols. The neuromuscular test battery consisted of a countermovement jump (CMJ), isometric handgrip strength (i.e., dominant), 10-m and 30-m sprint, agility t-test and Bronco test. Afterwards, participants reported a rate of perception scale (6-20 points) and side effects questionnaire associated with BRJ or PLAC ingestion. RESULTS: Statistically significant improvements were observed in CMJ (7.7%; p = 0.029; ES = 0.62), while no differences were reported in dominant isometric handgrip strength (-1.7%; p = 0.274; ES = -0.20); 10-m and 30-m sprint (0.5-0.8%; p = 0.441-0.588; ES = 0.03-0.18); modified agility t-test (-0.6%; p = 0.503; ES = -0.12) and Bronco test (1.94%; p = 0.459; ES = 0.16). CONCLUSIONS: BRJ ingestion could improve neuromuscular performance in the CMJ test, while no differences in sprint (10-m and 30-m sprint test), agility, isometric handgrip strength and endurance performance (i.e., Bronco test) were reported.

Phenolic diterpenes from Rosemary supercritical extract inhibit non-small cell lung cancer lipid metabolism and synergise with therapeutic drugs in the clinic.

Lung cancer is one of the most deadly and common cancers in the world. The molecular features of patient's tumours dictate the different therapeutic decisions, which combines targeted therapy, chemotherapy, and immunotherapy. Altered cellular metabolism is one of the hallmarks of cancer. Tumour cells reprogram their metabolism to adapt to their novel requirements of growth, proliferation, and survival. Together with the Warburg effect, the role of lipid metabolism alterations in cancer development and prognosis has been highlighted. Several lipid related genes have been shown to promote transformation and progression of cancer cells and have been proposed as biomarkers for prognosis. Nevertheless, the exact mechanisms of the regulation of lipid metabolism and the biological consequences in non-small cell lung cancer (NSCLC) have not been elucidated yet. There is an urgent necessity to develop multidisciplinary and complementary strategies to improve NSCLC patients´ well-being and treatment response. Nutrients can directly affect fundamental cellular processes and some diet-derived ingredients, bioactive natural compounds and natural extracts have been shown to inhibit the tumour growth in preclinical and clinical trials. Previously, we described a supercritical extract of rosemary (SFRE) (12 - 16% composition of phenolic diterpenes carnosic acid and carnosol) as a potential antitumoral agent in colon and breast cancer due to its effects on the inhibition of lipid metabolism and DNA synthesis, and in the reduction of resistance to 5-FluoroUracil (5-FU). Herein, we demonstrate SFRE inhibits NSCLC cell bioenergetics identifying several lipid metabolism implicated targets. Moreover, SFRE synergises with standard therapeutic drugs used in the clinic, such as cisplatin, pemetrexed and pembrolizumab to inhibit of cell viability of NSCLC cells. Importantly, the clinical relevance of SFRE as a complement in the treatment of NSCLC patients is suggested based on the results of a pilot clinical trial where SFRE formulated with bioactive lipids (PCT/ES2017/070263) diminishes metabolic and inflammatory targets in peripheral-blood mononuclear cells (PBMC), such as MAPK (p=0.04), NLRP3 (p=0.044), and SREBF1 (p=0.047), which may augment the immune antitumour function. Based on these results, SFRE merits further investigation as a co-adjuvant in the treatment of NSCLC. Clinical trial registration: ClinicalTrials.gov Identifier NCT05080920.

Correlation between the cervical sagittal alignment and spine - pelvic sagittal alignment in asymptomatic adults.

Background: Although there are studies that adequately document the linear correlation between pelvic incidence (PI), sacral slope, lumbar lordosis, and thoracic kyphosis, few have analyzed the pelvic-spine correlation including the cervical spine. Methods: This is a cross-sectional study, wherein the cervical spine was evaluated using radiography and computed tomography (CT) scans, the lumbosacral spine and the pelvis was evaluated using radiography, in adult patients without spinal pathology. Using the Surgimap tool, cervical and spinopelvic parameters were calculated by several investigators. To evaluate the correlation between cervical and spinopelvic parameters, Spearman's coefficient was calculated. To evaluate the concordance correlation of the measured parameters of cervical sagittal alignment on tomography and conventional radiography, Lin's coefficient was calculated and Bland-Altman plots were performed. Results: A total of 51 healthy adults were included in a follow-up from January 2019 to December 2020. Cervical sagittal alignment and sagittal spinopelvic alignment were assessed using radiography, and a correlation was observed between T1 slope (T1S) and lumbar mismatch (coefficient of 0.28, P = 0.047). Then, cervical sagittal alignment was evaluated using CT and sagittal spinopelvic alignment using radiography, and no correlation was observed between PI and thoracic inlet angle or cervical mismatch with lumbar mismatch. Conclusion: In asymptomatic patients, in whom cervical sagittal alignment and spinal-pelvic alignment were evaluated, only a positive correlation was found between lumbar mismatch and T1S, which lacks clinical significance. No concordance was identified between lumbar mismatch and cervical mismatch. Therefore, it is inferred that there is an independence between the sagittal spine-pelvic alignment with respect to the sagittal cervical alignment.

A new approach to obtain kinetic parameters of corn cob pyrolysis catalyzed with CaO and CaCO3.

A new approach is proposed to obtain the kinetic parameters of biomass pyrolysis mixed with calcium catalyst. This approach involves the optimization of least squares (LS) with the Coats-Redfern integral method to avoid mathematical biases that may appear when applying the linear regression approach. The method was applied to the TGA data of pyrolysis of corn cob and corn cob mixed with 20 or 40 % by weight of CaO or CaCO3 under N2 atmosphere at temperatures between 25 and 700 °C. For raw cob, r2 reaches 0.997. For corn cob mixed with 20 % by weight of CaO or CaCO3, r2 reached 0.996-0.998, and for 40 % by weight, r2 reached 0.836-0.957. Applying this method, the activation energy (EA) value of the raw cob pyrolysis is 58.35 kJ mol-1, while the addition of CaO or CaCO3 increases the EA to 69.33 and 66.07 kJ mol-1, respectively. The method is simple to use and allows reliable values of kinetic parameters.

Sex Modulates Cardiovascular Effects of Icodextrin-Based Peritoneal Dialysis Solutions.

Background/Aims: Some previous observations have noted that after six months of peritoneal dialysis (PD) treatment with icodextrin solutions, blood pressure (BP) and NT-proBNP tend to return to baseline values. This may be due to accumulation of icodextrin products that exert a colloid osmotic effect, which drives water into the bloodstream, causing the rise in blood pressure. Since icodextrin is metabolized by α-Amylase and its gene copies are lower in females than in males, we hypothesized icodextrin metabolites reach higher concentrations in females and that cardiovascular effects of icodextrin are influenced by sex. Methods: Secondary analysis of a RCT comparing factors influencing fluid balance control in diabetic PD patients with high or high average peritoneal transport receiving icodextrin (n = 30) or glucose (n = 29) PD solutions. Serum icodextrin metabolites, osmolality, body composition and Inferior Vena Cava (IVC) diameter were measured at baseline, and at 6 and 12 months of follow-up. Results: After six months of treatment, icodextrin metabolites showed higher levels in females than in males, particularly G5-7 and >G7, serum osmolality was lower in females. In spite of reduction in total and extracellular body water, ultrafiltration (UF) was lower and IVC diameter and BP increased in females, suggesting increment of blood volume. Conclusion: Females undergoing PD present with higher levels of icodextrin metabolites in serum that may exert an increased colloid-osmotic pressure followed by less UF volumes and increment in blood volume and blood pressure. Whether this could be due to the lesser number of α-Amylase gene copies described in diabetic females deserves further investigation.

Accuracy of Delta Capnography for the Prediction of Pulmonary Vein Occlusion During Cryoablation for Atrial Fibrillation.

The purpose of this study was to quantify the relationship between a drop in end-tidal carbon dioxide (etCO2) and occlusion of pulmonary veins (PVs) to find a delta etCO2 (ΔetCO2) able to predict occlusion during PV isolation (PVI) by cryoballoon. We designed a prospective registry. Paroxysmal atrial fibrillation patients who underwent cryoballoon PVI were included. Capnography was performed. Occlusion was tested by injection. A comparison between ΔetCO2 and occlusion was performed. Eighteen subjects (138 injections) were included. A drop of >3.5 mmHg predicted occlusion of the PV (sensitivity, 80%; specificity, 86.7%). A ΔetCO2 of ≥3.5 mmHg during inflation of the cryoballoon in each PV directly correlates with PV balloon occlusion.