Weight Management Interventions for Adults With Idiopathic Intracranial Hypertension: A Systematic Review and Practice Recommendations.

BACKGROUND AND OBJECTIVES: Idiopathic intracranial hypertension (IIH) is associated with obesity; however, there is a lack of clinical consensus on how to manage weight in IIH. The aim of this systematic review was to evaluate weight loss interventions in people with IIH to determine which intervention is superior in terms of weight loss, reduction in intracranial pressure (ICP), benefit to visual and headache outcomes, quality of life, and mental health. METHODS: A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and registered with PROSPERO (CRD42023339569). MEDLINE and CINAHL were searched for relevant literature published from inception until December 15, 2022. Screening and quality appraisal was conducted by 2 independent reviewers. Recommendations were graded using Scottish Intercollegiate Guidelines Network methodology. RESULTS: A total of 17 studies were included. Bariatric surgery resulted in 27.2-27.8 kg weight loss at 24 months (Level 1- to 1++). Lifestyle weight management interventions resulted in between 1.4 and 15.7 kg weight loss (Level 2+ to 1++). Bariatric surgery resulted in the greatest mean reduction in ICP (-11.9 cm H2O) at 24 months (Level 1++), followed by multicomponent lifestyle intervention + acetazolamide (-11.2 cm H2O) at 6 months (Level 1+) and then a very low-energy diet intervention (-8.0 cm H2O) at 3 months (Level 2++). The least ICP reduction was shown at 24 months after completing a 12-month multicomponent lifestyle intervention (-3.5 cm H2O) (Level 1++). Reduction in body weight was shown to be highly correlated with reduction in ICP (Level 2++ to 1++). DISCUSSION: Bariatric surgery should be considered for women with IIH and a body mass index (BMI) ≥35 kg/m2 since this had the most robust evidence for sustained weight management (grade A). A multicomponent lifestyle intervention (diet + physical activity + behavior) had the most robust evidence for modest weight loss with a BMI <35 kg/m2 (grade B). Longer-term outcomes for weight management interventions in people with IIH are required to determine whether there is a superior weight loss intervention for IIH.

Evaluation of a technique to measure heart rate variability in anaesthetised cats.

Analysis of heart rate (HR) and heart rate variability (HRV) are powerful tools to investigate cardiac diseases, but current methods, including 24-h Holter monitoring, can be cumbersome and may be compromised by movement artefact. A commercially available data capture and analysis system was used in anaesthetised healthy cats to measure HR and HRV during pharmacological manipulation of HR. Seven healthy cats were subjected to a randomised crossover study design with a 7 day washout period between two treatment groups, placebo and atenolol (1mg/kg, IV), with the efficacy of atenolol to inhibit ß1 adrenoreceptors challenged by epinephrine. Statistical significance for the epinephrine challenge was set at P<0.0027 (Holm-Bonferroni correction), whereas a level of significance of P<0.05 was set for other variables. Analysis of the continuous electrocardiography (ECG) recordings showed that epinephrine challenge increased HR in the placebo group (P=0.0003) but not in the atenolol group. The change in HR was greater in the placebo group than in the atenolol group (P=0.0004). Therefore, compared to cats pre-treated with placebo, pre-treatment with atenolol significantly antagonised the tachycardia while not significantly affecting HRV. The increased HR in the placebo group following epinephrine challenge was consistent with a shift of the sympathovagal balance towards a predominantly sympathetic tone. However, the small (but not significant at the critical value) decrease in the normalised high-frequency component (HFnorm) in both groups of cats suggested that epinephrine induced a parasympathetic withdrawal in addition to sympathetic enhancement (increased normalised low frequency component or LFnorm). In conclusion, this model is a highly sensitive and repeatable model to investigate HRV in anaesthetised cats that would be useful in the laboratory setting for short-term investigation of cardiovascular disease and subtle responses to pharmacological agents in this species.

Congenital supravalvular mitral stenosis in 14 cats.

OBJECTIVES: To describe the clinical features of congenital supravalvular mitral stenosis (SVMS) in cats. BACKGROUND: Supravalvular mitral stenosis is an uncommon congenital cardiac defect that has not been previously reported in a series of cats. ANIMALS: 14 cats with SVMS. METHODS: Medical records, relevant diagnostic studies and preserved pathology specimens were reviewed. RESULTS: Cats were presented over a wide age range (5 months-10 years; median 3 years); males (n = 9) and the Siamese breed were over-represented. Presenting complaints included respiratory distress (n = 6), hindlimb paralysis due to aortic thromboembolism (n = 5) and asymptomatic heart murmur (n = 3). Echocardiographic examination often identified pulmonary hypertension (PHT) (n = 7) and concurrent cardiac abnormalities (n = 7), especially partial atrioventricular septal defect (PAVSD) (n = 4). Status 12 months following diagnosis was known for 9 cats; 8 of these had died or were euthanized. CONCLUSIONS: Cats with SVMS are usually presented as young adults for respiratory signs attributable to congestive heart failure, aortic thromboembolism or incidental murmur identification. Congestive heart failure, PHT and concurrent congenital cardiac abnormalities (specifically PAVSD) are common. Long-term prognosis for symptomatic cats is poor.

Cardiac effects of pulmonary disease.

Pulmonary hypertension (PHT) is the primary cardiac consequence of pulmonary disease. It develops as alveolar hypoxia of pulmonary disease, coupled with vasoactive and mitogenic substances released from pulmonary endothelial and vascular smooth muscle cells damaged by the primary disease process, mediates arterial vasoconstriction and vascular remodeling to raise pulmonary vascular resistance. Independent of the underlying pulmonary disease, PHT produces clinical signs of respiratory distress, exercise intolerance, syncope, and right heart failure. Diagnosis of PHT is made by estimation of pulmonary artery pressures by means of continuous-wave Doppler echocardiographic assessment of tricuspid or pulmonic regurgitant flow velocity. Treatment of PHT is directed at the underlying pulmonary disease but may also aim to attenuate pulmonary artery pressure and limit the clinical sequelae of PHT. No treatments are of proven benefit in veterinary patients; irrespective of the nature of the inciting pulmonary disease, the prognosis is often grave.