What criterion forbids nitroglycerin administration in a chest pain patient?

What criterion forbids nitroglycerin administration in a chest pain patient?

• A. SBP <100
• B. SBP <120
• C. SBP <90
• D. SBP <80

Answer: (A)

Nitroglycerin works mainly by dilating veins, which lowers preload and can also lower afterload. In a chest pain patient you want to keep enough pressure to maintain coronary and overall perfusion. If the systolic blood pressure is below 100 mmHg, giving nitroglycerin can drop BP further into a dangerous range, risking inadequate heart perfusion and possible shock or fainting. That safety cutoff is why a systolic BP under 100 is a contraindication to nitroglycerin in this context. Lower thresholds (like 90 or 80) are also unsafe, but the limit emphasized in this item is 100, so any SBP below that means nitroglycerin should not be given.

Nitroglycerin works mainly by dilating veins, which lowers preload and can also lower afterload. In a chest pain patient you want to keep enough pressure to maintain coronary and overall perfusion. If the systolic blood pressure is below 100 mmHg, giving nitroglycerin can drop BP further into a dangerous range, risking inadequate heart perfusion and possible shock or fainting. That safety cutoff is why a systolic BP under 100 is a contraindication to nitroglycerin in this context. Lower thresholds (like 90 or 80) are also unsafe, but the limit emphasized in this item is 100, so any SBP below that means nitroglycerin should not be given.