What is a maternal electrocardiogram (ECG)?

From the Guidelines

A MAT ECG is a crucial diagnostic tool for monitoring the electrical activity of a pregnant woman's heart, and it should be performed in accordance with the latest guidelines to ensure the best possible outcomes for both maternal and fetal health. When interpreting a MAT ECG, it is essential to consider the physiological changes that occur during pregnancy, such as increased heart rate and blood volume, which can affect cardiac function 1. Some key points to consider when interpreting a MAT ECG include:

• A slight leftward axis deviation and minor ST-segment changes are normal findings during pregnancy 1
• Sinus tachycardia, 15° left axis deviation due to diaphragmatic elevation, T wave changes, T wave inversion in lead III and aVF, and non-specific ST changes are common ECG findings in pregnant women 1
• Atrial and ventricular ectopic beats can also be observed in normal pregnancy 1
• It is crucial to differentiate between normal physiological changes and potential cardiac issues, such as arrhythmias or ischemia, which may affect both maternal and fetal health 1
• Echocardiography is recommended in pregnant patients with unexplained or new cardiovascular signs or symptoms, and cardiovascular magnetic resonance (without gadolinium) should be carried out if additional information is required 1
• The test is non-invasive, painless, and poses no risk to the developing fetus, making it a safe diagnostic tool throughout pregnancy 1. In terms of guidelines, the American College of Cardiology/American Heart Association Task Force on Assessment of Diagnostic and Therapeutic Cardiovascular Procedures (Committee on Electrocardiography) recommends that an ECG be performed during the initial evaluation of patients with known cardiovascular disease, dysfunction, or arrhythmia 1. However, the most recent and highest quality study 1 provides more specific guidance on the interpretation of MAT ECGs in pregnant women, emphasizing the importance of considering physiological changes and differentiating between normal and abnormal findings.

From the Research

Maternal ECG

• Maternal ECG removal from non-invasive fetal ECG recordings is important for accurate diagnosis of fetal well-being 2
• A novel method for removal of the mECG signal from abdominal recordings has been presented, which is an extension of the linear prediction method 2
• The presented method is capable of a more accurate removal of the mECG signal for all simulated abdominal recordings with respect to the linear prediction method 2

Echocardiography in Pregnancy

• Echocardiography is a safe and effective diagnostic tool indicated in pregnant women with cardiac symptoms or women with known cardiac disease 3
• Echocardiography is the single most important clinical tool to diagnose and manage heart disease during pregnancy 3
• Echocardiography is able to characterize cardiac structural abnormalities and corresponding hemodynamic changes, identifies heart diseases that are poorly tolerated in pregnancy, and helps select patients who may require a cesarean delivery because of hemodynamic instability 3
• The American College of Cardiology Foundation (ACCF) appropriateness criteria for obtaining echocardiography can be applied to pregnant women with consideration for additional risk factors such as multiparity, tobacco use, and postpartum status 4

Maternal Cardiac Function

• Evaluation of maternal cardiac function has not been previously available to obstetrical healthcare providers using diagnostic ultrasound equipment used for fetal evaluation 5
• A technique for evaluation of maternal cardiac function using a cardiac probe placed in the suprasternal notch to image and measure the descending aorta diameter and the velocity time integral using pulsed and continuous wave Doppler ultrasound has been described 5
• This technique allows for computation of maternal left ventricular preload, afterload, contractility, and blood flow, and can be used to select appropriate hypertensive medication on the basis of the results of the evaluation of the maternal left ventricle 5