system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
In an experiment, a certain gene product is known to stimulate the production of a particular hormone synthesized in the liver. This hormone, when present in increased amounts, downregulates the expression of a divalent cation transmembrane transporter located on the basolateral membranes of enterocytes. Mutations in the gene product have been linked to certain abnormalities in affected patients. Such individuals may present with darkening of the skin, cold intolerance, excessive urination, and weight loss. Patients may also present with symptoms of a cardiovascular disease as a result of this disease. Which of the following would be the first cardiac finding in affected patients?
assistant
Preload: decreased, cardiac contractility: unchanged, afterload: increased