What is Pulmonary Wedge Tracing (PWT) in Echocardiography (Echo)?

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Last updated: April 4, 2025View editorial policy

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From the Research

In echocardiography, PWT stands for posterior wall thickness, which refers to the measurement of the thickness of the left ventricular posterior wall, typically taken during diastole and is an important parameter in assessing left ventricular structure and function. This measurement is crucial in diagnosing and managing various cardiovascular conditions, including left ventricular hypertrophy, which can be caused by conditions such as hypertension, aortic stenosis, or hypertrophic cardiomyopathy 1. The normal range for posterior wall thickness is generally 6-11 mm in adults.

Importance of PWT Measurement

The measurement of PWT is usually obtained using M-mode or 2D echocardiography and is often evaluated alongside other parameters like interventricular septal thickness and left ventricular internal dimensions to provide a comprehensive assessment of cardiac structure. Accurate measurement of PWT is essential for proper diagnosis and management of various cardiovascular conditions. According to a study published in 2019, the measurement of posterior wall thickness can be used to calculate relative wall thickness, which has prognostic value in patients with acute decompensated heart failure 2.

Clinical Implications

An increased PWT may indicate left ventricular hypertrophy, and echocardiography is an invaluable tool in the diagnosis and follow-up of patients with hypertrophic cardiomyopathy 1. The measurement of PWT can also be used to guide catheter ablation in patients with atrial fibrillation, particularly in those with rare anatomical variants such as confluent inferior pulmonary veins 3.

Measurement Techniques

The measurement of PWT can be performed using different techniques, including M-mode and 2D echocardiography. A study published in 1991 compared echocardiographic and anatomic measurements of left ventricular wall thickness and found that echocardiographic measurements corresponded closely to anatomic measurements of total wall thickness including trabeculae 4. Another study published in 1979 found that echocardiographic measurement of posterior wall thickness accurately reflected the anatomical dimension 5.

Recent Findings

A recent study published in 2024 found that the posterior wall thickness of the confluent inferior pulmonary veins measured by left atrial intracardiac echocardiography was significantly thinner than the left atrial posterior wall thickness in non-CIPV patients, highlighting the need for special care during ablation in patients with this rare anatomical variant 3. Therefore, accurate measurement of PWT is crucial in clinical practice, and echocardiography remains a valuable tool in the diagnosis and management of cardiovascular conditions.

References

Research

Echocardiography in hypertrophic cardiomyopathy diagnosis, prognosis, and role in management.

European journal of echocardiography : the journal of the Working Group on Echocardiography of the European Society of Cardiology, 2009

Research

Posterior wall thickness of the confluent inferior pulmonary veins measured by left atrial intracardiac echocardiography: implications for catheter ablation.

Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing, 2024

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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