What is likely seen on cardiac catheterization (cardiac cath) in a 17-year-old male with no personal or family history of cardiac disease, presenting with chest pain, elevated troponins, and ST elevation in multiple leads?

Spontaneous Coronary Artery Dissection is Most Likely Seen on Cardiac Catheterization in This Young Patient

In a 17-year-old male with chest pain, elevated troponins, and ST elevation in multiple leads but no cardiac history or drug use, spontaneous coronary artery dissection (SCAD) is the most likely finding on cardiac catheterization.

Diagnostic Reasoning

When evaluating this young patient with signs of myocardial infarction but no traditional risk factors, the clinical presentation strongly suggests a non-atherosclerotic cause. The key features guiding this diagnosis include:

• Young age (17 years)
• No personal or family cardiac history
• No drug use (ruling out cocaine-induced vasospasm)
• Positive troponins indicating myocardial damage
• ST elevation in multiple leads suggesting acute myocardial injury

Differential Diagnosis Based on Catheterization Findings

1. Spontaneous Coronary Artery Dissection (SCAD):

   • Most likely finding given the patient's age and lack of risk factors
   • Typically presents with chest pain, elevated troponins, and ST elevation
   • Often affects otherwise healthy young individuals without atherosclerotic disease

2. Normal coronary arteries with myocarditis:

   • Second most likely possibility
   • However, the ST elevation in multiple leads is more consistent with SCAD

3. Coronary artery thrombosis without underlying atherosclerosis:

   • Less likely without predisposing factors

Evidence Supporting SCAD Diagnosis

The 2018 ESC guidelines describe cases of SCAD presenting with ST-segment elevation and elevated troponins 1. In the guideline case example, a 44-year-old female with minimal risk factors presented with acute chest pain and showed ST-segment elevation with elevated troponins. Coronary angiography revealed coronary artery dissection with no evidence of atherosclerosis 1.

SCAD predominantly affects women (>90% of cases) but can occur in men, particularly young men without traditional risk factors 2. The most common presenting symptom is chest discomfort (96% of cases), and all patients present with myocardial infarction, with approximately 24% having STEMI 2.

Management Implications

The identification of SCAD on cardiac catheterization has important management implications:

• Conservative management is often preferred in stable SCAD patients
• Revascularization (PCI or CABG) is indicated only if there is:
  • Ongoing ischemia
  • Involvement of a major coronary territory
  • Hemodynamic instability

Potential Pitfalls and Caveats

1. Misdiagnosis risk: SCAD can be mistaken for atherosclerotic disease, leading to inappropriate interventions that may worsen dissection.

2. Catheterization risks: The diagnostic procedure itself carries a small risk of iatrogenic coronary dissection, which can mimic spontaneous dissection 3, 4, 5.

3. Alternative diagnoses to consider:

   • Myocarditis (would show normal coronaries but with ventricular wall motion abnormalities)
   • Stress cardiomyopathy (Takotsubo) in the setting of extreme stress
   • Coronary vasospasm (though less likely with persistent ST elevation)

Conclusion for Clinical Decision-Making

When performing cardiac catheterization on this young patient, the cardiologist should be prepared to identify the characteristic angiographic appearance of SCAD, which typically shows:

• A radiolucent flap within the coronary lumen
• Multiple lumens
• Contrast staining of the arterial wall
• Diffuse smooth narrowing that can be mistaken for vasospasm

The absence of atherosclerotic plaque in other coronary segments would further support this diagnosis.