Sympathetically Mediated Changes in Capacitance: Redistribution of the Venous Reservoir as a Cause of Decompensation

“To be accepted as a paradigm, a theory must seem better than its competitors, but it need not, and in fact never does, explain all the facts with which it can be confronted.” Thomas Kuhn, The Structure of Scientific Revolutions ### Heard on Rounds “A 57-year-old patient with a history of heart failure states that she began experiencing worsening shortness of breath 4 days prior to admission, with lower extremity edema developing 1 day prior to admission. She is compliant with her medications, though has had similar admissions previously. She states that her weight at home increased by “a couple of pounds” 2 days ago and that she increased her diuretic dose but her symptoms worsened. She says that she generally adheres to her low salt diet, but admits to eating pretzels 5 days ago. The physical examination showed BP 136/84, HR 94, weight 3 lbs above baseline, elevated JVP, basilar rales, and 1+ pedal edema.” As the intern finishes the presentation, the Senior expresses surprise that the patient's weight had increased only 3 pounds, and comments about salt and volume overload leading to acute decompensated heart failure (ADHF). The Attending adds that recent data reveal that many patients presenting with ADHF have minimal or no weight gain, but that there is no clear mechanism to explain this phenomenon. They set in place plans for diuresis, increasing vasodilators, and further patient education. On the surface, there is nothing remarkable about this case, and the usual approaches to treat this entity have remained remarkably consistent since the advent of loop diuretics over 50 years ago: salt restriction, patient education, uptitration of medications if not already at optimal doses, and diuresis. However, approximately 1 in 4 such patients are readmitted to the hospital within 30 days,1 and the disease continues to progress. It is clear …