Can pulmonary embolism (PE) be an intermittent condition?

Can Pulmonary Embolism Come and Go?

Pulmonary embolism (PE) does not typically "come and go" in the sense of spontaneously resolving and recurring, but rather can present with fluctuating or intermittent symptoms that may give this impression to patients. 1

Understanding PE Symptom Patterns

Pulmonary embolism presents with symptoms that can vary in intensity and may appear to wax and wane, leading to potential confusion about the nature of the condition:

• Sudden onset dyspnea is the most common symptom (present in 78-81% of patients) 2
• Pleuritic chest pain affects 39-56% of patients and may fluctuate with breathing 2
• Fainting or syncope occurs in 22-26% of cases and can be intermittent 2
• Hemoptysis is less common (5-7%) but distinctive 2

At least one of these symptoms is reported by 94% of PE patients, with only 1% being truly asymptomatic 2.

Why PE May Appear to "Come and Go"

Several mechanisms explain why PE symptoms might seem intermittent:

1. Multiple successive emboli: The European Society of Cardiology guidelines note that massive PE may be preceded by smaller PEs in the weeks before diagnosis, with autopsy studies showing multiple PEs and infarcts of different ages in 15-60% of cases 1. These sequential embolic events can create a pattern of symptoms that worsen and improve.

2. Compensatory mechanisms: The body may temporarily adapt to the vascular obstruction, masking symptoms until decompensation occurs.

3. Variable obstruction: Partial dissolution or fragmentation of clots can temporarily improve blood flow, leading to symptom fluctuation.

4. Misattribution of symptoms: Patients may attribute PE symptoms to other conditions like anxiety or musculoskeletal pain, especially when symptoms temporarily subside.

Clinical Implications

The fluctuating nature of PE symptoms contributes to its underdiagnosis. According to the European Society of Cardiology, only 7% of patients who die from PE were correctly diagnosed before death 1. This highlights the danger of dismissing intermittent symptoms.

Diagnostic Approach for Suspected PE with Fluctuating Symptoms

When evaluating patients with intermittent cardiopulmonary symptoms:

• Maintain high clinical suspicion: Consider PE in any patient with suggestive symptoms, even if they come and go 3
• Use validated clinical prediction tools: Apply the Wells score or revised Geneva score to assess PE probability 3
• Perform appropriate testing: Order D-dimer testing in patients with low or intermediate probability; proceed directly to imaging in high-probability cases 3
• Remember that PE can be recurrent: Previous PE history increases risk for subsequent events 1

Important Caveats

• Don't wait for "classic" presentation: The absence of persistent symptoms does not rule out PE 4
• Consider alternative diagnoses: Fluctuating cardiopulmonary symptoms may represent other serious conditions requiring evaluation
• Beware of silent PE: Some cases remain asymptomatic until a major event occurs 1
• Recognize that untreated PE has high mortality: Without treatment, mortality approaches 30% 1

Bottom Line

While PE itself doesn't spontaneously resolve and recur, its symptoms can fluctuate, creating the impression that it "comes and goes." This pattern contributes to delayed diagnosis and treatment. Any unexplained, intermittent cardiopulmonary symptoms—especially sudden dyspnea, chest pain, syncope, or hemoptysis—should prompt consideration of PE in the differential diagnosis and appropriate diagnostic testing.