A 62-year-old man with a 10-year history of hypertension presents to the clinic complaining of progressive dyspnea on exertion for 3 months, waking at night short of breath, and swelling in both ankles that worsens throughout the day. On examination, his jugular venous pressure is elevated at 8 cm H₂O, his point of maximal impulse is displaced laterally to the 6th intercostal space, and a low-pitched S3 gallop is appreciated. Vital signs are notable for a blood pressure of 152/94 mmHg and heart rate of 92 bpm. Chest X-ray demonstrates pulmonary edema with bilateral infiltrates and cardiomegaly. Transthoracic echocardiography shows a left ventricular ejection fraction of 32% with global wall hypokinesis. Serum creatinine is 1.4 mg/dL (baseline 0.9 mg/dL). Which of the following mechanisms best explains the pathophysiology of sodium and water retention in this patient?

  1. A)Suppression of antidiuretic hormone by elevated B-type natriuretic peptide
  2. B)Renal hypoperfusion with subsequent activation of the renin-angiotensin-aldosterone system and sympathetic nervous systemGABARITO
  3. C)Primary hyperaldosteronism secondary to adrenal adenoma
  4. D)Direct toxic effects of circulating TNF-α and IL-6 on the proximal tubule
  5. E)Excessive secretion of atrial natriuretic peptide causing increased tubular sodium reabsorption

Explicação

In systemic heart failure with reduced ejection fraction, decreased cardiac output leads to renal hypoperfusion. This triggers compensatory activation of the renin-angiotensin-aldosterone system (RAAS) and sympathetic nervous system. Angiotensin II causes pref... Ver explicação completa e trilha adaptativa →

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