Collaborative work in a complex case of Fontan for treating intra-atrial reentrant tachycardia and severe aortic stenosis: a case report.

Background: Intra-atrial reentrant tachycardia (IART) is a frequent arrhythmia in patients with Fontan circulation. Although its supraventricular origin, such arrhythmia can be poorly tolerated as it leads to haemodynamic impairment. Concomitant assessment of pressure/volume overload of cardiac chambers due to valvular disease or residual shunts is necessary. Case summary: We report the case of a 33-year-old male with Fontan extracardiac conduit, suffering from IART with initial poor haemodynamic tolerance. He had a medical history of pulmonary atresia with intact ventricular septum and Type 0 bicuspid aortic valve, with a total of four cardiac surgeries. Echocardiography demonstrated a severe impairment of the univentricular ejection fraction and a critical aortic stenosis. Given the limited medical treatment options of the arrhythmia and the risks of another heart surgery, both IART ablation and transcatheter aortic valve replacement (TAVR) were performed during the same procedure. The IART critical isthmus located in the antero-lateral region of the extracardiac conduit was effectively treated with radiofrequency. Rapid pacing during TAVR was provided by a catheter placed in the unique ventricle via a transconduit puncture. The aortic valve was deployed with minimal para-valvular regurgitation and a satisfactory transvalvular gradient. At follow-up, the univentricular ejection fraction normalized and no arrhythmic episode was recorded in absence of anti-arrhythmic drugs. Discussion: This case highlights the need of a collaborative approach for treating complex cases of adult congenital heart disease, suffering from both electrophysiological and haemodynamic disorders. This combination offered an elegant and safest solution for treating concomitantly a life-threatening arrhythmia and an aortic stenosis.

Clinical impact of ventilator-associated pneumonia in patients with the acute respiratory distress syndrome: a retrospective cohort study.

BACKGROUND: The clinical impact and outcomes of ventilator-associated pneumonia (VAP) have been scarcely investigated in patients with the acute respiratory distress syndrome (ARDS). METHODS: Patients admitted over an 18-month period in two intensive care units (ICU) of a university-affiliated hospital and meeting the Berlin criteria for ARDS were retrospectively included. The association between VAP and the probability of death at day 90 (primary endpoint) was appraised through a Cox proportional hazards model handling VAP as a delay entry variable. Secondary endpoints included (i) potential changes in the PaO2/FiO2 ratio and SOFA score values around VAP (linear mixed modelling), and (ii) mechanical ventilation (MV) duration, numbers of ventilator- and vasopressor-free days at day 28, and length of stay (LOS) in patients with and without VAP (median or absolute risk difference calculation). Subgroup analyses were performed in patients with COVID-19-related ARDS and those with ARDS from other causes. RESULTS: Among the 336 included patients (101 with COVID-19 and 235 with other ARDS), 176 (52.4%) experienced a first VAP. VAP induced a transient and moderate decline in the PaO2/FiO2 ratio without increase in SOFA score values. VAP was associated with less ventilator-free days (median difference and 95% CI, - 19 [- 20; - 13.5] days) and vasopressor-free days (- 5 [- 9; - 2] days) at day 28, and longer ICU (+ 13 [+ 9; + 15] days) and hospital (+ 11.5 [+ 7.5; + 17.5] days) LOS. These effects were observed in both subgroups. Overall day-90 mortality rates were 35.8% and 30.0% in patients with and without VAP, respectively (P = 0.30). In the whole cohort, VAP (adjusted HR 3.16, 95% CI 2.04-4.89, P < 0.0001), the SAPS-2 value at admission, chronic renal disease and an admission for cardiac arrest predicted death at day 90, while the COVID-19 status had no independent impact. When analysed separately, VAP predicted death in non-COVID-19 patients (aHR 3.43, 95% CI 2.11-5.58, P < 0.0001) but not in those with COVID-19 (aHR 1.19, 95% CI 0.32-4.49, P = 0.80). CONCLUSIONS: VAP is an independent predictor of 90-day mortality in ARDS patients. This condition exerts a limited impact on oxygenation but correlates with extended MV duration, vasoactive support, and LOS.

Electrical Stimulation in the Claustrum Area Induces a Deepening of Isoflurane Anesthesia in Rat.

The role of the claustrum in consciousness and vigilance states was proposed more than two decades ago; however, its role in anesthesia is not yet understood, and this requires more investigation. The aim of our study was to assess the impact of claustrum electrical stimulation during isoflurane anesthesia in adult rats. The claustrum in the left hemisphere was electrically stimulated using a bipolar tungsten electrode inserted stereotaxically. In order to monitor the anesthetic depth, the electrocorticogram (ECoG) was recorded before, during, and after claustrum stimulation using frontal and parietal epidural electrodes placed over the left hemisphere. After reaching stabilized slow-wave isoflurane anesthesia, twenty stimuli, each of one second duration with ten seconds interstimulus duration, were applied. ECoG analysis has shown that, after a delay from the beginning of stimulation, the slow-wave ECoG signal changed to a transient burst suppression (BS) pattern. Our results show that electrical stimulation of the claustrum area during slow-wave isoflurane anesthesia induces a transitory increase in anesthetic depth, documented by the appearance of a BS ECoG pattern, and suggests a potential role of claustrum in anesthesia.

Left Atrial Strain for Predicting Atrial Fibrillation Onset in Hypertensive Patients.

INTRODUCTION: We aimed to find new predictive parameters for atrial fibrillation (AF) onset in hypertensive patients using two-dimensional (2D) conventional and speckle tracking echocardiography of the left atrium (LA). METHODS: One hundred and eight patients with essential hypertension (HTN) were prospectively enrolled, from which 67 patients had no other important comorbidities (HTN group), while 41 patients had a recent AF episode, but were in sinus rhythm at the moment of enrollment (HTN and AF group). LA diameters and maximal volume, LV mass, LV ejection fraction and diastolic function were assessed through 2D conventional echocardiography. Moreover, peak longitudinal and contractile strain of LA walls (PALS and PACS, respectively) were analyzed by speckle tracking technique. Patients were followed up for 1 year and recurrent 24-h rhythm monitoring was done, in order to identify atrial fibrillation. RESULTS: Age and time from diagnosis of HTN were higher in HTN and AF group than in HTN group (68.02 ± 19 years versus 57.2 ± 1.52 years, p = 0.001 and 62.2 ± 9.2 months versus 40.4 ± 6.4 months, p = 0.04). All LA diameters and LA maximal volume were significantly larger in HTN and AF group (for LA antero-posterior diameter p = 0.02, for all the rest p < 0.0001). LV ejection fraction was preserved in both groups, being significantly lower in HTN and AF patients (58.44 ± 0.79 versus 60.75 ± 0.57, p = 0.02). LV mass was higher in HTN and AF group and these patients had also a more severe diastolic dysfunction, (E/A ratio 1.8 ± 0.51 versus 0.9 ± 0.02, p = 0.04) and lower septal and lateral A' velocities (p < 0.0001 and p = 0.002). The peak LA longitudinal and contractile strain values were also significantly lower in HTN and AF group versus HTN group (for all p < 0.0001). Among the echocardiographic parameters, we identified PALS and PACS as predictors for AF, with a good discriminating capacity (AUC = 0.88 for PALS and AUC = 0.86 for PACS). CONCLUSIONS: Compared to patients with isolated hypertension, patients with hypertension and AF display several echocardiographic differences. Among them, LA strain parameters could be useful predictors of AF occurrence in hypertensive patients.

ECoG spectrum changes at different xenon-isoflurane anaesthesia depths.

BACKGROUND AND AIMS: The purpose of this study is to assess the frontal and parietal ECoG spectrum (gamma range) changes during isoflurane and combined xenon-isoflurane anaesthesia in rats. METHODS: Experiments were carried out on four adult male Sprague-Dawley rats (250-300 g). The anaesthesia was induced with isoflurane and maintained with isoflurane and a xenon-isoflurane mixture. The rats were maintained at two different anaesthetic depths: light (isoflurane anaesthesia) and deep (isoflurane and xenon-isoflurane anaesthesia). The frontal and the parietal cortical activity was assessed by computing the median frequency, spectral edge frequency and functional connectivity between these two areas during light and deep anaesthesia. RESULTS: We noticed a decrease in cortical connectivity under deep isoflurane anaesthesia and an increase in connectivity under deep xenon-isoflurane anaesthesia. Moreover, during xenon-isoflurane anaesthesia, a trend of regularity of electro-cortical activity was present compared with isoflurane anaesthesia. CONCLUSIONS: Xenon-isoflurane deep anaesthesia demonstrated a series of specific ECoG features regarding frontoparietal functional connectivity (gamma range connectivity increase) and regularity of the electrocortical activity compared with isoflurane anaesthesia.

Changes of cortical connectivity during deep anaesthesia.

BACKGROUND AND AIMS: The aim of this study was to evaluate the frontal intracortical connectivity during deep anaesthesia (burst-suppression). METHODS: Experiments were carried out on 5 adult Sprague Dawley rats. The anaesthesia was induced and maintained with isoflurane. Following the induction of anaesthesia, rats were placed in a stereotactic instrument. A hole was drilled in the skull over the frontal cortex and electrodes were inserted in order to record the local field potentials. Rats were maintained in deep level anaesthesia (burst-suppression). The cortical connectivity was assessed by computing the coherence spectra. The frontal intracortical connectivity was calculated during burst, suppression (non-burst) and slow wave anaesthesia periods. RESULTS: The global cortical connectivity (0.5-100 Hz) was 0.61 ± 0.078 during the burst periods compared to 0.55 ± 0.032 (p < 0.05) during the suppression periods and 0.55 ± 0.015 (p < 0.05) during slow wave anaesthesia. CONCLUSIONS: The global cortical connectivity increased during the burst periods compared to the suppression periods and slow wave anaesthesia. This increase in the cortical synchronization might be due to the subcortical origin of the bursts.