88 research outputs found

    Abnormalities of sodium handling and of cardiovascular adaptations during high salt diet in patients with mild heart failure.

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    BACKGROUND: Sodium retention and hormonal activation are fundamental hallmarks in congestive heart failure. The present study was designed to assess the ability of patients with asymptomatic to mildly symptomatic heart failure and no signs or symptoms of congestion to excrete ingested sodium and to identify possible early abnormalities of hormonal and hemodynamic mechanisms related to sodium handling. METHODS AND RESULTS: The effects of a high salt diet (250 mEq/day for 6 days) on hemodynamics, salt-regulating hormones, and renal excretory response were investigated in a balanced study in 12 untreated patients with idiopathic or ischemic dilated cardiomyopathy and mild heart failure (NYHA class I-II, ejection fraction < 50%) (HF) and in 12 normal subjects, who had been previously maintained a 100 mEq/day NaCl diet. In normal subjects, high salt diet was associated with significant increases of echocardiographically measured left ventricular end-diastolic volume, ejection fraction, and stroke volume (all P < .001) and with a reduction of total peripheral resistance (P < .001). In addition, plasma atrial natriuretic factor (ANF) levels increased (P < .05), and plasma renin activity and aldosterone concentrations fell (both P < .001) in normals in response to salt excess. In HF patients, both left ventricular end-diastolic and end-systolic volumes increased in response to high salt diet, whereas ejection fraction and stroke volume failed to increase, and total peripheral resistance did not change during high salt diet. In addition, plasma ANF levels did not rise in HF in response to salt loading, whereas plasma renin activity and aldosterone concentrations were as much suppressed as in normals. Although urinary sodium excretions were not significantly different in the two groups, there was a small but systematic reduction of daily sodium excretion in HF, which resulted in a significantly higher cumulative sodium balance in HF than in normals during the high salt diet period (P < .001). CONCLUSIONS: These results show a reduced ability to excrete a sodium load and early abnormalities of cardiac and hemodynamic adaptations to salt excess in patients with mild heart failure and no signs or symptoms of congestion

    Low-voltage area ablation in addition to pulmonary vein isolation in patients with atrial fibrillation: a systematic review and meta-analysis

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    Background: Low-voltage area (LVA) ablation, in addition to pulmonary vein isolation (PVI), has been proposed as a new strategy in patients with atrial fibrillation (AF), but clinical trials have shown conflicting results. We performed a systematic review and meta-analysis to assess the impact of LVA ablation in patient undergoing AF ablation (PROSPERO-registered CRD42024537696). Methods: Randomized clinical trials investigating the role of LVA ablation in addition to PVI in patients with AF were searched on PubMed, Embase, and the Cochrane Library from inception to 22 April 2024. Primary outcome was atrial arrhythmia recurrence after the first AF ablation procedure. Secondary endpoints included procedure time, fluoroscopy time, and procedure-related complication rate. Sensitivity analysis including only patients with LVA demonstration at mapping and multiple subgroups analyses were also performed. Results: 1547 patients from 7 studies were included. LVA ablation in addition to PVI reduced atrial arrhythmia recurrence (odds ratio [OR] 0.65, 95% confidence interval [CI] 0.52-0.81, p &lt; 0.001) with a number needed to treat to prevent recurrence of 10. No difference in procedure time (mean difference [MD] -5.32 min, 95% CI -19.01-8.46 min, p = 0.45), fluoroscopy time (MD -1.10 min, 95% CI -2.48-0.28 min, p = 0.12) and complication rate (OR 0.81, 95% CI 0.40-1.61, p = 0.54) was observed. Consistent results were demonstrated when considering only patients with LVA during mapping and in prespecified subgroups for AF type (paroxysmal vs. persistent), multicentric vs. monocentric trial, and ablation strategy in control group. Conclusions: In patients with AF, ablation of LVAs in addition to PVI reduces atrial arrhythmia recurrence without a significant increase in procedure time, fluoroscopy time, or complication rate

    Perspectives in noninvasive imaging for chronic coronary syndromes

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    Both the latest European guidelines on chronic coronary syndromes and the American guidelines on chest pain have underlined the importance of noninvasive imaging to select patients to be referred to invasive angiography. Nevertheless, although coronary stenosis has long been considered the main determinant of inducible ischemia and symptoms, growing evidence has demonstrated the importance of other underlying mechanisms (e.g., vasospasm, microvascular disease, energetic inefficiency). The search for a pathophysiology-driven treatment of these patients has therefore emerged as an important objective of multimodality imaging, integrating "anatomical" and "functional" information. We here provide an up-to-date guide for the choice and the interpretation of the currently available noninvasive anatomical and/or functional tests, focusing on emerging techniques (e.g., coronary flow velocity reserve, stress-cardiac magnetic resonance, hybrid imaging, functional-coronary computed tomography angiography, etc.), which could provide deeper pathophysiological insights to refine diagnostic and therapeutic pathways in the next future

    Right ventricular free-wall scar: an exceptional source of post-infarction ventricular tachycardia. A case report

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    Abstract Background  In patients with coronary artery disease, ventricular tachycardia (VT) is usually related to left ventricular (LV) post-infarction scars. Case summary A case of a 78-year-old man with post-infarction VT originating from the right ventricular (RV) free wall is described. Following recurrent episodes of VT with left bundle branch block morphology and left superior axis deviation, a patient with prior myocardial infarction was submitted to catheter ablation. Two areas of abnormal bipolar electrograms were observed at 3D electroanatomical mapping: one located at the basal aspect of the posterior and postero-septal LV, and the other one extending from the antero-lateral to the posterior mid-basal RV free wall. Ventricular late potentials (LPs) were recorded within both scars, but only pacing from those located in the RV resulted in long stimulus-to-QRS latency and optimal pace-mapping. Accordingly, this substrate was deemed the culprit of the clinical VT. Radiofrequency catheter ablation aimed at eliminating all LPs recorded from both scars was effective in preventing VT recurrences at follow-up. Discussion A post-infarction RV free-wall scar may exceptionally be responsible of VT occurrence. Right ventricular mapping should be considered in selected cases based on 12-lead electrocardiogram VT morphology and prior RV infarct. </jats:sec

    Risk of adverse events in gastrointestinal endoscopy: Zero-inflated Poisson regression mixture model for count data and multinomial logit model for the type of event

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    Background and aims We analyze the possible predictive variables for Adverse Events (AEs) during sedation for gastrointestinal (GI) endoscopy. Methods We consider 23,788 GI endoscopies under sedation on adults between 2012 and 2019. A Zero-Inflated Poisson Regression Mixture (ZIPRM) model for count data with concomitant variables is applied, accounting for unobserved heterogeneity and evaluating the risks of multi-drug sedation. A multinomial logit model is also estimated to evaluate cardiovascular, respiratory, hemorrhagic, other AEs and stopping the procedure risk factors. Results In 7.55% of cases, one or more AEs occurred, most frequently cardiovascular (3.26%) or respiratory (2.77%). Our ZIPRM model identifies one population for non-zero counts. The AE-group reveals that age &gt;75 years yields 46% more AEs than age &lt;66 years; Body Mass Index (BMI) ≥27 27% more AEs than BMI &lt;21; emergency 11% more AEs than routine. Any one-point increment in the American Society of Anesthesiologists (ASA) score and the Mallampati score determines respectively a 42% and a 16% increment in AEs; every hour prolonging endoscopy increases AEs by 41%. Regarding sedation with propofol alone (the sedative of choice), adding opioids to propofol increases AEs by 43% and adding benzodiazepines by 51%. Cardiovascular AEs are increased by age, ASA score, smoke, in-hospital, procedure duration, midazolam/fentanyl associated with propofol. Respiratory AEs are increased by BMI, ASA and Mallampati scores, emergency, in-hospital, procedure duration, midazolam/fentanyl associated with propofol. Hemorrhagic AEs are increased by age, in-hospital, procedure duration, midazolam/fentanyl associated with propofol. The risk of suspension of the endoscopic procedure before accomplishment is increased by female gender, ASA and Mallampati scores, and in-hospital, and it is reduced by emergency and procedure duration. Conclusions Age, BMI, ASA score, Mallampati score, in-hospital, procedure duration, other sedatives with propofol increase the risk for AEs during sedation for GI endoscopy. </jats:sec

    Ab initio molecular modeling of 13C NMR chemical shifts of polymers. 2. Propene-norbornene copolymers

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    A methodology based on ab initio DFT computations as well as on molecular mechanics has been devised for helping the elucidation of the microstructure of polymers through the interpretation of their 13C NMR spectra and has been applied to the case of propene-norbornene (P-N) copolymers. In a first step, a rotational-isomeric-state model of the chain of these copolymers has been achieved. The results of molecular mechanics calculations on various model compounds were checked and corrected by means of ab initio DFT computations at high level of theory. In general, good agreement was found between the results obtained with Allinger's MM2 force field and with the quantum-mechanical method B3LYP/6-31G**. Then, theoretical 13C chemical shifts for two basic compounds were obtained according to the GIAO (gauge including atomic orbitals) method, using a large basis set and Adamo and Barone's functional. The theoretical chemical shifts averaged over the RIS populations provided rather unambiguous indications for interpreting the 13C NMR signals observed in spectra of isotactic (P-N) copolymers with mid-low norbornene content. Thus, only with the help of these calculations was it possible to achieve a first unambiguous assignment of each of the seven major N signals in the complex spectra of P-N copolymers. This methodology may turn out to be of general utility, in particular for those macromolecular systems where empirical relationships between conformation and chemical shifts are not available

    Clinical use of transoesophageal atrial stimulation in terminating ventricular tachycardia

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    This study was performed to evaluate whether transoesophageal atrial pacing could also stop ventricular tachycardias with low rates and no haemodynamic impairment. Prior to resorting to ventricular endocardial pacing, seven male patients, aged between 15 and 73 years, were treated by transoesophageal atrial pacing for 10 spontaneous episodes of sustained ventricular tachycardia at rates between 105 and 160 beats per minute, without haemodynamic impairment. When atrial pacing did not allow ventricular capture, atropine sulphate was administered. Transoesophageal atrial pacing led to ventricular capture in seven episodes, which made overdriving possible, and blocked six episodes of ventricular tachycardia. In no case did transoesophageal atrial pacing lead to an acceleration of ventricular tachycardia or to degeneration into ventricular fibrillation. Transoesophageal atrial pacing can block low-rate sustained ventricular tachycardias (≤ 150 beats per minute). For low-rate sustained ventricular tachycardias without haemodynamic impairment, transoesophageal atrial pacing can thus be used as the method of choice thanks to its good ratio of risk to efficiency. © 1990
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