Relative adrenal insufficiency in severe congestive heart failure with preserved systolic function: a case report

Hypothalamic Dysfunction and Multiple Sclerosis: Implications for Fatigue and Weight Dysregulation

Signs and symptoms of multiple sclerosis are usually attributed to demyelinating lesions in the spinal cord or cerebral cortex. The hypothalamus is a region that is often overlooked yet controls many important homeostatic functions, including those that are perturbed in multiple sclerosis. In this review we discuss how hypothalamic dysfunction may contribute to signs and symptoms in people with multiple sclerosis. While dysfunction of the hypothalamic-pituitary-adrenal axis is common in multiple sclerosis, the effects and mechanisms of this dysfunction are not well understood. We discuss three hypothalamic mechanisms of fatigue in multiple sclerosis: (1) general hypothalamic-pituitary-adrenal axis hyperactivity, (2) disordered orexin neurotransmission, (3) abnormal cortisol secretion. We then review potential mechanisms of weight dysregulation caused by hypothalamic dysfunction. Lastly, we propose future studies and therapeutics to better understand and treat hypothalamic dysfunction in multiple sclerosis. Hypothalamic dysfunction appears to be common in multiple sclerosis, yet current studies are underpowered and contradictory. Future studies should contain larger sample sizes and standardize hormone and neuropeptide measurements.

Does Accidental Overcorrection of Symptomatic Hyponatremia in Chronic Heart Failure Require Specific Therapeutic Adjustments for Preventing Central Pontine Myelinolysis?

This review aims at summarizing essential aspects of epidemiology and pathophysiology of hyponatremia in chronic heart failure (CHF), to set the ground for a practical as well as evidence-based approach to treatment. As a guide through the discussion of the available evidence, a clinical case of hyponatremia associated with CHF is presented. For this case, the severe neurological signs at presentation justified an emergency treatment with hypertonic saline plus furosemide, as indicated. Subsequently, as the neurological emergency began to subside, the reversion of the trend toward hyponatremia overcorrection was realized by continuous infusion of hypotonic solutions, and administration of desmopressin, so as to prevent the very feared risk of an osmotic demyelination syndrome. This very disabling complication of the hyponatremia correction is then briefly outlined. Moreover, the possible advantages related to systematic correction of the hyponatremia that occurs in the course of CHF are mentioned. Additionally, the case of tolvaptan, a vasopressin receptor antagonist, is concisely presented in order to underline the different views that have led to different norms in Europe with respect to the USA or Japan as regards the use of this drug as a therapeutic resource against the hyponatremia.

Vasopressin Receptor Antagonists for the Correction of Hyponatremia in Chronic Heart Failure: An Underutilized Therapeutic Option in Current Clinical Practice?

In the congestive heart failure (CHF) setting, chronic hyponatremia is very common. The present review aims at addressing topics relevant to the pathophysiology of hyponatremia in the course of CHF as well as its optimal treatment, including the main advantages and the limitations resulting from the use of the available dietary and pharmacological measures approved for the treatment of this electrolytic trouble. A narrative review is carried out in order to represent the main modalities of therapy for chronic hyponatremia that frequently complicates CHF. The limits of usual therapies implemented for CHF-related chronic hyponatremia are outlined, while an original analysis of the main advancements achieved with the use of vasopressin receptor antagonists (VRAs) is also executed. The European regulatory restrictions that currently limit the use of VRAs in the management of CHF are substantially caused by financial concerns, i.e., the high costs of VRA therapy. A thoughtful reworking of current restrictions would be warranted in order to enable VRAs to be usefully associated to loop diuretics for decongestive treatment of CHF patients with hyponatremia.

Vasopressin receptor antagonists in patients with chronic heart failure

In this brief review, the pathophysiology of hyponatremia and its clinical significance in the course of chronic heart failure (CHF) are illustrated. Moreover, issues concerning the optimal treatment for hyponatremia during CHF are addressed and discussed. In addition, advantages and limitations resulting from the use of vasopressin receptor antagonists, drugs that have recently emerged as the best available resource against hyponatremia, are highlighted.

A preliminary investigation into adrenal responsiveness and outcomes in patients with cardiogenic shock after acute myocardial infarction

PURPOSE

This study investigated the significance of baseline cortisol levels and adrenal response to corticotropin in shocked patients after acute myocardial infarction (AMI).

METHODS

A short corticotropin stimulation test was performed in 35 patients with cardiogenic shock after AMI by intravenously injecting of 250 μg of tetracosactrin (Synacthen). Blood samples were obtained at baseline (T0) before and at 30 (T30) and 60 (T60) minutes after the test to determine plasma total cortisol (TC) and free cortisol concentrations. The main outcome measure was in-hospital mortality and its association with T0 TC and maximum response to corticotropin (maximum difference [Δ max] in cortisol levels between T0 and the highest value between T30 and T60).

RESULTS

The in-hospital mortality was 37%, and the median time to death was 4 days (interquartile range, 3-9 days). There was some evidence of an increased mortality in patients with T0 TC concentrations greater than 34 μg/dL (P=.07). Maximum difference by itself was not an independent predictor of death. Patients with a T0 TC 34 μg/dL or less and Δ max greater than 9 μg/dL appeared to have the most favorable survival (91%) when compared with the other 2 groups: T0 34 μg/dL or less and Δ max 9 μg/dL or less or T0 34 μg/dL or higher and Δ max greater than 9 μg/dL (75%; P=.8) and T0 greater than 34 μg/dL and Δ max 9 μg/dL or less (60%; P=.02). Corticosteroid therapy was associated with an increased mortality (P=.03). There was a strong correlation between plasma TC and free cortisol (r=0.85).

CONCLUSIONS

A high baseline plasma TC was associated with a trend toward increased mortality in patients with cardiogenic shock post-AMI. Patients with lower baseline TC, but with an inducible adrenal response, appeared to have a survival benefit. A prognostic system based on basal TC and Δ max similar to that described in septic shock appears feasible in this cohort. Corticosteroid therapy was associated with adverse outcomes. These findings require further validation in larger studies.