From the Guidelines
The workup for transpulmonary shunting should begin with cross-sectional imaging using CMR or CTA to delineate pulmonary venous connections, as recommended by the 2018 AHA/ACC guideline for the management of adults with congenital heart disease 1. The initial assessment may also include echocardiography, which can identify potential shunts and anomalous veins, particularly in patients with excellent acoustic windows. However, CMR and CTA are superior for evaluating extracardiac vascular anatomy.
- Key components of the workup include:
- Cross-sectional imaging with CMR or CTA to delineate pulmonary venous connections
- Echocardiography to identify potential shunts and anomalous veins
- Invasive hemodynamic assessment in higher-risk patients to directly measure pressures, quantify shunt magnitude, and measure pulmonary arterial resistance and responsiveness to pulmonary vasodilator therapy
- The choice of imaging modality depends on the individual patient's condition and the suspected underlying cause of the shunt.
- Invasive hemodynamic assessment is especially important in adult patients who are being considered for surgical correction, as it can provide valuable information on the severity of the shunt and the patient's suitability for surgery.
- The 2018 AHA/ACC guideline recommends that surgical repair be considered in patients with symptoms referable to the shunt, multiple anomalous veins, and a moderate or large left-to-right shunt 1.
- Pulmonary hypertension is a significant risk factor for adverse outcomes with surgery, and its presence should be carefully evaluated during the workup.
- The workup should be tailored to the individual patient's needs, taking into account their medical history, symptoms, and underlying condition.
- A comprehensive approach to the workup, including a combination of non-invasive and invasive tests, can help guide appropriate management decisions and improve patient outcomes.
From the Research
Transpulmonic Shunting Workup
The workup for transpulmonic shunting typically involves several diagnostic steps to evaluate the patient's condition and determine the best course of treatment.
- Diagnostic imaging: This may include echocardiography, cardiac catheterization, or other imaging modalities to visualize the shunt and assess its function 2, 3.
- Hemodynamic assessment: This involves measuring blood pressure, oxygen saturation, and other parameters to evaluate the patient's cardiovascular status 4.
- Laboratory tests: Blood tests may be ordered to evaluate the patient's overall health and detect any potential complications 5.
Diagnostic Techniques
Several diagnostic techniques can be used to evaluate transpulmonic shunting, including:
- Echocardiography with agitated saline contrast injection: This technique can help diagnose intrapulmonary arteriovenous shunting by visualizing the flow of contrast bubbles through the pulmonary veins 6.
- Cardiac catheterization: This procedure involves inserting a catheter into the heart to measure blood pressure, oxygen saturation, and other parameters, and to visualize the shunt 2, 3.
- Imaging modalities: Other imaging modalities, such as MRI or CT scans, may be used to evaluate the shunt and assess its function 5, 4.
Shunt Evaluation
The evaluation of transpulmonic shunting involves assessing the shunt's function, including:
- Shunt patency: The shunt's ability to remain open and allow blood flow 2, 3.
- Shunt flow: The amount of blood flowing through the shunt 4.
- Shunt pressure: The pressure gradient across the shunt 4.
- Complications: Potential complications, such as thrombosis, stenosis, or infection, must be evaluated and managed accordingly 2, 3, 5.