K and Mg Dyshomeostasis in Acute Hyperadrenergic Stressor States.

Acute stressor states are linked to neurohormonal activation that includes the adrenergic nervous system. Elevations in circulating epinephrine and norepinephrine unmask an interdependency that exists between K and Mg based on their regulation of a large number of Mg-dependent Na-K-ATPase pumps present in skeletal muscle. The hyperadrenergic state accounts for a sudden translocation of cations into muscle with the rapid appearance of hypokalemia and hypomagnesemia.

Pleural effusion leading to right atrial collapse.

Rapid accumulation of pericardial fluid can lead to tamponade, resulting in cardiac chambers' collapse, which can lead to hemodynamic and clinical instability, potentially needing emergent pericardiocentesis. Pleural effusion should also be considered as a potential, if rare, cause of cardiac chambers' collapse and possibly cardiac tamponade. This phenomenon has clinical implications because hemodynamically unstable patients with moderate to large pleural effusion may actually need thoracentesis instead of massive volume resuscitation, inotropic agents, or pericardiocentesis.

Streptococcus pneumoniae-associated pneumonia, meningitis, and endocarditis: a case of Austrian syndrome.

Streptococcus pneumoniae is the leading cause of hospitalization in cases of community-acquired pneumonia and meningitis in adults. It is also an uncommon cause of endocarditis in the antibiotic era. The occurrence of these three entities in one individual is rare, forming a triad termed Austrian syndrome.

Disturbances in calcium metabolism and cardiomyocyte necrosis: the role of calcitropic hormones.

A synchronized dyshomeostasis of extra- and intracellular Ca(2+), expressed as plasma ionized hypocalcemia and excessive intracellular Ca(2+) accumulation, respectively, represents a common pathophysiologic scenario that accompanies several diverse disorders. These include low-renin and salt-sensitive hypertension, primary aldosteronism and hyperparathyroidism, congestive heart failure, acute and chronic hyperadrenergic stressor states, high dietary Na(+), and low dietary Ca(2+) with hypovitaminosis D. Homeostatic responses are invoked to restore normal extracellular [Ca(2+)](o), including increased plasma levels of parathyroid hormone and 1,25(OH)(2)D(3).

A dyshomeostasis of electrolytes and trace elements in acute stressor states: impact on the heart.

Acute stressor states are associated with a homeostatic activation of the hypothalamic-pituitary-adrenal axis. A hyperadrenergic state follows and leads to a dyshomeostasis of several intra- and extracellular cations, including K, Mg, and Ca. Prolongation of myocardial repolarization and corrected QT interval (QTc) of the ECG are useful biomarkers of hypokalemia and/or hypomagnesemia and should be monitored to address the adequacy of cation replacement.