Vomiting as a Heart Attack Symptom: Atypical Presentation and Mechanisms

While chest pain/pressure is the hallmark heart attack (MI) symptom, vomiting can occur, particularly in inferior/posterior MI, women, elderly, and diabetics. It is an atypical but clinically significant presentation.

Mechanisms

1. Vagal Activation: Inferior wall ischemia → stimulates vagal afferents (via Bezold-Jarisch reflex) → nausea/vomiting, bradycardia, hypotension.
2. Visceral Afferent Convergence: Cardiac and gastric afferents converge in spinal cord (T1–T4) → referred nausea/vomiting.
3. Hemodynamic Compromise: Reduced cardiac output → splanchnic hypoperfusion → gastric stasis, nausea.
4. Medication Side Effects: Nitroglycerin, morphine, ACE inhibitors can cause nausea.
5. Psychogenic: Anxiety/fear response to acute event.

Clinical Implications

• Do not dismiss vomiting as "just indigestion" or "flu" in high-risk patients (age >50, diabetes, hypertension, smoking, family history).
• ECG is mandatory for any adult with unexplained nausea/vomiting + risk factors.
• Inferior MI (II, III, aVF) most associated with vomiting; check right-sided leads (V4R) for RV involvement.
• Diabetics: Autonomic neuropathy masks chest pain → vomiting may be predominant symptom.

Differential for Vomiting + Chest Discomfort

• Acute coronary syndrome (MI, unstable angina)
• Aortic dissection (tearing pain, vomiting)
• Pulmonary embolism (pleuritic pain, hypoxia, vomiting)
• Pericarditis (positional pain)
• Esophageal rupture (Boerhaave – vomiting then pain)
• Acute gastritis/pancreatitis/cholecystitis

Action

Call 911 for chest pain, pressure, squeezing, radiation to arm/jaw/back, dyspnea, diaphoresis, syncope – with or without vomiting. Chew 325 mg aspirin if not allergic. Time is muscle.