From the Guidelines
Cardioversion can be performed in a patient with a saddle pulmonary embolism (PE) if they have hemodynamic instability due to an arrhythmia like atrial fibrillation, with initiation of therapeutic-dose parenteral anticoagulation before cardioversion, if possible, as suggested by the Chest guideline and expert panel report 1. The priority is to stabilize the patient, and if the arrhythmia is contributing to hemodynamic compromise, cardioversion may be necessary despite the PE.
- Before cardioversion, anticoagulation should be initiated if not already in place, typically with intravenous unfractionated heparin at a loading dose of 80 units/kg followed by 18 units/kg/hour, adjusted to maintain an aPTT of 1.5-2.5 times normal.
- For the cardioversion itself, start with synchronized electrical cardioversion at 120-200 joules for biphasic defibrillators or 200 joules for monophasic devices. The presence of a saddle PE increases the risk of right heart strain and hemodynamic collapse, so have vasopressors readily available (norepinephrine 0.1-0.5 mcg/kg/min or epinephrine 0.05-0.5 mcg/kg/min) and consider having ECMO capabilities on standby if available. The rationale for proceeding with cardioversion despite the PE is that restoring normal sinus rhythm may improve cardiac output and hemodynamic stability, which is particularly important in a patient already compromised by a large PE, as noted in the context of antithrombotic therapy for atrial fibrillation 1. Key considerations include:
- The need for urgent cardioversion in the setting of hemodynamic instability
- The importance of initiating anticoagulation before cardioversion, if possible, without delaying emergency intervention 1
- The potential benefits of cardioversion in improving cardiac output and hemodynamic stability in a patient with a saddle PE.
From the Research
Patient Considerations for Cardioversion
- A patient with saddle pulmonary embolism (PE) may have various treatment options, but the decision to undergo cardioversion depends on their individual condition and stability 2.
- Saddle PE is a rare type of venous thromboembolism that can cause circulation collapse and sudden death, and its management is crucial to prevent further complications 3, 4.
- The clinical presentation and outcomes of patients with saddle PE can vary widely, and some may require thrombolytics or catheter thrombectomy even if they are hemodynamically stable 5.
Treatment Options for Saddle PE
- Anticoagulation is the initial therapy for patients with PE, and the use of vasopressors, inotropes, pulmonary artery vasodilators, and mechanical ventilation can stabilize critically ill patients 2.
- Thrombolytic therapy is the recommended definitive treatment for patients with massive PE, but its use in sub-massive PE should be weighed against the increased risk of life-threatening hemorrhage 2.
- Surgical embolectomy and catheter-based therapies are options for patients with contraindications to anticoagulation and thrombolytic therapy, and may be considered for those with high-risk sub-massive PE 2, 6.
Cardioversion Considerations
- There is no direct evidence to suggest that cardioversion is a standard treatment option for patients with saddle PE, and its use would depend on the individual patient's condition and the presence of any underlying arrhythmias.
- The primary focus of treatment for saddle PE is to stabilize the patient and prevent further complications, and cardioversion may not be a priority in the initial management of these patients 3, 4, 5, 2, 6.