A 62-year-old man with a 10-year history of hypertension presents with progressive dyspnea on exertion, orthopnea, and bilateral ankle edema over the past 3 months. Physical examination reveals a displaced point of maximal impulse, an S3 gallop, and crackles at bilateral lung bases. Echocardiography shows a left ventricular ejection fraction of 35%. Which of the following neurohormonal mechanisms is primarily responsible for the progressive worsening of his condition?
- A)Reduced angiotensin II production decreasing peripheral vascular resistance
- B)Decreased sympathetic nervous system activity reducing cardiac contractility
- C)Activation of the renin-angiotensin-aldosterone system leading to sodium retention and vasoconstrictionGABARITO
- D)Inhibition of antidiuretic hormone secretion promoting excessive diuresis
- E)Increased natriuretic peptide levels causing severe hyponatremia
Explicação
In systolic heart failure, reduced cardiac output activates compensatory mechanisms including RAAS activation. Increased angiotensin II causes vasoconstriction and aldosterone-mediated sodium and water retention, initially maintaining perfusion pressure but ul... Ver explicação completa e trilha adaptativa →