Can isosorbide dinitrate be given to a patient with chest pain and tachycardia?

Management of Chest Pain with Tachycardia: Isosorbide Dinitrate Administration

Isosorbide dinitrate (Sorbitrate) should not be administered to this patient with chest pain, blood pressure of 110/76 mmHg, and tachycardia (pulse 120) due to the risk of severe hypotension and worsening tachycardia.

Rationale for Withholding Nitrates in This Case

Contraindications Present

• Tachycardia: The patient's heart rate of 120 bpm represents a clear contraindication to nitrate therapy. According to American Heart Association and American College of Cardiology guidelines, nitrates are contraindicated in patients with tachycardia (>100 bpm) in the absence of heart failure 1.

• Borderline Blood Pressure: While the patient's systolic BP of 110 mmHg is not below the absolute contraindication threshold of 90 mmHg, it presents a significant risk factor given the presence of tachycardia. Nitrates can cause unpredictable blood pressure responses, especially in patients with tachycardia 1.

Physiological Concerns

• The combination of tachycardia and nitrate administration could lead to:
  • Further reduction in diastolic filling time
  • Decreased coronary perfusion
  • Risk of hypotension and cardiovascular collapse
  • Reflex tachycardia worsening the existing tachycardia

Alternative Management Approach

Immediate Assessment

1. Obtain a 12-lead ECG immediately to assess for STEMI or other ischemic changes 1
2. Assess oxygen saturation and provide supplemental oxygen if <94% 1
3. Administer aspirin 160-325 mg (chewed) unless contraindicated 2, 1

Initial Pharmacotherapy

• Consider beta-blockers if no contraindications exist, as they can help manage both the tachycardia and chest pain 2, 1
• Morphine sulfate (2-4 mg IV with increments of 2-8 mg repeated at 5-15 minute intervals) for ongoing ischemic pain unresponsive to other measures 2, 1

Monitoring and Further Management

• Continuous cardiac monitoring
• Serial ECGs and cardiac biomarkers
• Consider early coronary angiography if acute coronary syndrome is diagnosed 1

Special Considerations

Nitrate Use in Chest Pain - When Appropriate

If the patient's condition changes and nitrates become appropriate (heart rate <100 bpm, adequate blood pressure):

• Initial dose of sublingual nitroglycerin is 0.3-0.4 mg every 5 minutes up to 3 doses 1
• Isosorbide dinitrate may be used only if the patient fails to respond to sublingual nitroglycerin 3
• Monitor blood pressure after each dose 1

Common Pitfalls to Avoid

1. Administering nitrates despite tachycardia - this can precipitate severe hypotension and cardiovascular collapse
2. Focusing only on chest pain relief without addressing the underlying tachycardia
3. Delaying ECG acquisition - an immediate ECG is essential for diagnosis and management planning
4. Overlooking other causes of chest pain with tachycardia - consider pulmonary embolism, pneumothorax, or aortic dissection

Conclusion

The European Society of Cardiology Task Force on Management of Chest Pain recommends that nitrates should be used liberally to decrease ischemia, but only when appropriate 2. In this case, the patient's tachycardia (pulse 120) represents a clear contraindication to nitrate therapy, and alternative approaches should be pursued for managing the chest pain.