A 58-year-old man with a 2-year history of exertional chest pain presents with acute substernal pressure. Vital signs: BP 165/95 mmHg, HR 102 bpm, RR 16, SpO2 98% on room air. He takes sublingual nitroglycerin, which relieves symptoms within 3 minutes. Troponin is negative. He denies dyspnea. Which hemodynamic change most directly contributes to this drug's benefit in stable angina?
- A)Inhibition of platelet aggregation only
- B)Reduced preload from venodilationGABARITO
- C)Marked slowing of AV nodal conduction
- D)Increased afterload from arteriolar constriction
- E)Direct increase in myocardial contractility
Explicação
Nitroglycerin is converted to nitric oxide, which increases cGMP and causes predominant venodilation. Reduced venous return lowers preload and myocardial oxygen demand, which relieves anginal pain. Ver explicação completa e trilha adaptativa →