Thrombolysis Based on Post-Arrest Echo Showing RV Dilatation
Thrombolysis should not be administered based solely on post-arrest echocardiographic findings of right ventricular dilatation without additional evidence of massive pulmonary embolism causing hemodynamic compromise. 1
Assessment of Suspected PE in Cardiac Arrest
- Right ventricular dilatation alone on post-arrest echocardiography is insufficient to justify thrombolysis, as it may be caused by various conditions including chronic pulmonary hypertension, right ventricular infarction, or acute right heart strain from the arrest itself 1
- Bedside cardiac ultrasonography should be considered in unstable patients with suspected PE prior to CT, but should not be the sole basis for thrombolytic therapy 1
- Disproportionate sparing of the RV apex (McConnell's Sign) may suggest acute PE in the appropriate clinical setting, but other etiologies such as RV infarct can have a similar echocardiographic pattern 1
Criteria for Thrombolysis in Suspected PE
Thrombolysis may be justified based on echocardiographic evidence only when:
For patients with confirmed massive PE and hemodynamic instability, thrombolysis is recommended as a Class I indication 1
Risk Stratification for PE
- Patients with suspected PE should be risk-stratified using validated clinical risk scores such as PESI or sPESI 1
- Measurement of RV:LV ratio on CT or assessment of RV function on echocardiography alone is not sufficient for risk stratification 1
- When RV dilatation is identified on imaging in otherwise low-risk patients, laboratory cardiac biomarkers (BNP, NT-proBNP, hsTnI or hsTnT) should be measured 1
- Normal biomarker values may help identify truly low-risk patients; elevated biomarkers should prompt inpatient admission for observation 1
Evidence Against Routine Thrombolysis for RV Dysfunction
- In patients with massive PE but stable hemodynamics and RV dysfunction, thrombolysis has not shown clear survival benefits and carries significant bleeding risks 2
- A study of 128 patients with massive PE, stable hemodynamics, and RV dysfunction found no mortality benefit with thrombolysis, while 15.6% of thrombolysis patients suffered bleeding complications (4.7% intracranial) and 6.25% died 2
- Thrombolysis during CPR for undifferentiated cardiac arrest has not shown improvement in outcomes compared to placebo 3
Alternative Approaches
- For patients with intermediate-risk PE (PESI class III) with RV dysfunction, consider repeating assessment of RV function with echocardiography or biomarkers before deciding on therapy 1
- Catheter-based interventions may be considered as an alternative to thrombolysis when there are contraindications to thrombolysis or when emergency surgical thrombectomy is unavailable 1
- Low-dose catheter-directed ultrasound-accelerated thrombolysis has shown promise in reversing RV dilatation with potentially lower bleeding risk than systemic thrombolysis 4
Clinical Pitfalls to Avoid
- Avoid administering thrombolytics based solely on RV dilatation without considering other clinical parameters and risk factors 1
- Do not confuse RV infarction with PE as both can present with RV dilatation on echocardiography 1
- The prognostic value of RV dysfunction markers alone (by echo, CT, or biomarkers) has limited clinical usefulness in risk stratification, with unsatisfactory positive and negative likelihood ratios 5
- Recognize that RV dilatation may be a pre-existing condition in patients with chronic cardiopulmonary disease rather than an acute finding 1
In summary, while RV dilatation on post-arrest echocardiography may suggest PE, thrombolysis should only be considered when there is additional evidence of hemodynamic compromise and high clinical suspicion for PE, with the understanding that the bleeding risks are substantial.