Most Common Symptom in Pulmonary Embolism
Dyspnea (shortness of breath) is the most common symptom of pulmonary embolism, occurring in 80-89% of patients with PE. 1
Clinical Presentation of Pulmonary Embolism
Pulmonary embolism presents with a constellation of symptoms, but dyspnea is consistently the most frequently reported:
- Dyspnea (shortness of breath): 80-89% of cases 1
- Chest pain: 40-60% of cases 1
- Tachypnea (respiratory rate >20/min): 70% of cases 1
- Tachycardia: Common but variable frequency 1
- Syncope or pre-syncope: Less common but important as it may indicate severe PE 2
- Hemoptysis: Relatively uncommon (5-7%) 1, 3
According to the European Society of Cardiology guidelines, dyspnea may be acute and severe in central PE, while in small peripheral PE, it may be mild and transient 2. In patients with pre-existing heart failure or pulmonary disease, worsening dyspnea may be the only symptom indicative of PE 2.
Characteristics of Dyspnea in PE
The nature of dyspnea in PE has specific characteristics:
- Often sudden in onset (reported in approximately 80% of cases) 3
- May be the sole presenting symptom, especially in central PE 2
- Can range from mild to severe depending on the extent of embolism 2
- May be progressive over several weeks in some cases 2
Important Clinical Considerations
It's crucial to note that:
No single symptom has sufficient sensitivity or specificity to rule in or rule out PE 1, which highlights the importance of clinical probability assessment using validated tools like the Wells Score or Revised Geneva Score.
While dyspnea is the most common symptom, up to 1% of patients may be asymptomatic at diagnosis 3.
PE can be easily missed because symptoms are non-specific. The European Society of Cardiology notes that in 90% of cases, suspicion of PE is raised by clinical symptoms such as dyspnea, chest pain, and syncope, either singly or in combination 2.
Hypoxemia is frequent in PE, but up to 40% of patients may have normal arterial oxygen saturation, and 20% may have a normal alveolar-arterial oxygen gradient 2.
Clinical Pitfalls to Avoid
- Don't rely on a single symptom: While dyspnea is the most common symptom, its absence doesn't rule out PE.
- Don't overlook PE in patients with pre-existing cardiopulmonary disease: Worsening dyspnea may be the only new symptom 2.
- Don't wait for all classic symptoms: At least one of the four main symptoms (dyspnea, chest pain, fainting/syncope, or hemoptysis) is reported in 94% of PE cases 3.
- Don't miss PE in asymptomatic patients: Autopsy studies show that many fatal PEs were unrecognized and undiagnosed before death 4.
In summary, while dyspnea is the most common symptom of PE, clinicians should maintain a high index of suspicion for PE in patients presenting with any combination of the common symptoms, particularly when risk factors for venous thromboembolism are present.