From the Guidelines
Low voltage complexes on an ECG are most commonly caused by conditions such as obesity, emphysema, pericardial effusion, and amyloidosis, which can attenuate or dampen the electrical signals of the heart. These conditions can lead to a decrease in the amplitude of the QRS complexes, resulting in low voltage complexes. According to the European Society of Cardiology guidelines 1, low QRS voltage can be caused by various factors, including:
- Obesity
- Emphysema
- Pericardial effusion
- Amyloidosis It is essential to correlate low voltage complexes with clinical findings and consider additional diagnostic testing, such as echocardiography or cardiac magnetic resonance (CMR), to identify the underlying cause. The European Society of Cardiology guidelines 1 recommend echocardiography/CMR, chest X-ray, and further imaging (CMR, 99mTc-DPD scan) and endomyocardial biopsy for amyloidosis. Technical factors, such as improper lead placement or equipment calibration issues, should also be considered and ruled out.
From the Research
Causes of Low Voltage Complexes on ECG
The causes of low voltage complexes on the electrocardiogram (ECG) are variable and can be due to several underlying conditions. Some of the possible causes include:
- Cardiac amyloidosis, a rare condition that can lead to low voltage complexes on ECG, as highlighted in a case study published in the Singapore medical journal 2
- Large pericardial effusion with cardiac tamponade, a life-threatening condition that can cause low voltage complexes on ECG, as discussed in a case study published in the Singapore medical journal 2 and The Nurse practitioner 3
- Myocardial infarction (MI), although not directly linked to low voltage complexes, can cause changes in the ECG reading, including low voltage complexes, as described in an article published in Cell biochemistry and biophysics 4
- Pericarditis, inflammation of the pericardium, can also cause low voltage complexes on ECG, as discussed in articles published in The Journal of cardiovascular nursing 5 and Primary care 6
Underlying Conditions
These underlying conditions can be critical and may require immediate medical attention. A 12-lead ECG showing low voltage should be a red flag to providers, as it can be caused by several serious conditions, including cardiac tamponade and myocardial infarction, as highlighted in The Nurse practitioner 3 and Cell biochemistry and biophysics 4.
Diagnostic Procedures
Diagnostic procedures such as echocardiogram, coronary angiography, and X-ray of the heart and blood vessels can be performed to observe the narrowing of coronary arteries and to diagnose underlying conditions, as described in Singapore medical journal 2 and Cell biochemistry and biophysics 4.