From the Guidelines
Low QRS voltage in precordial leads alone is not a contraindication to surgery. This electrocardiogram (ECG) finding should be evaluated in the context of the patient's overall clinical picture rather than viewed as an isolated barrier to surgical intervention. According to the 2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery 1, 2, a preoperative resting 12-lead ECG is reasonable for patients with known coronary heart disease or other significant structural heart disease, except for low-risk surgery. Low QRS voltage may be caused by various conditions including obesity, emphysema, pericardial effusion, hypothyroidism, infiltrative cardiomyopathies (like amyloidosis), or myocardial scarring.
Key Considerations
- Before surgery, patients with this finding should undergo a comprehensive cardiac evaluation to determine if there is underlying heart disease that might increase surgical risk.
- This evaluation may include:
- Echocardiography
- Stress testing
- Other cardiac imaging as appropriate
- The anesthesiologist and surgeon should be informed about this ECG finding so they can monitor the patient appropriately during surgery.
- If the workup reveals significant cardiac disease, the surgical team may need to modify the anesthetic approach or surgical plan, but the presence of low voltage QRS complexes by itself would not prevent proceeding with necessary surgery.
Clinical Approach
The focus should be on identifying and addressing any underlying cardiac condition that might be causing the ECG finding rather than canceling surgery based solely on this finding. As stated in the guidelines, routine preoperative resting 12-lead ECG is not useful for asymptomatic patients undergoing low-risk surgical procedures 1, 2. Therefore, the decision to proceed with surgery should be based on a comprehensive assessment of the patient's overall health and risk factors, rather than the presence of low QRS voltage in precordial leads alone.
From the Research
Low QRS Voltage in Precordial Leads and Surgery
- There is no direct evidence to suggest that low QRS voltage in precordial leads is a contraindication to surgery 3, 4, 5, 6, 7.
- Low QRS voltage can be caused by various factors, including cardiac and extracardiac conditions, and its presence may indicate underlying cardiac disease 3.
- The prevalence of low QRS voltage in precordial leads is relatively low, ranging from 12.3% to 13% in patients with cardiac amyloidosis 4, 5.
- Low QRS voltage is associated with adverse outcomes, including increased risk of in-hospital death or discharge against medical advice, particularly in patients with cardiac amyloidosis or other cardiomyopathies 4, 5, 6.
- The diagnostic accuracy of low QRS voltage for cardiac amyloidosis is limited, and other ECG criteria, such as the voltage/mass ratio, may be more useful in diagnosing the condition 7.
Clinical Implications
- Low QRS voltage in precordial leads may indicate severe cardiac dysfunction and increased risk of adverse outcomes, but it is not a direct contraindication to surgery 5, 6.
- Patients with low QRS voltage in precordial leads should undergo thorough evaluation and risk assessment before undergoing surgery, taking into account their underlying cardiac condition and other comorbidities 5, 6.
- Further studies are needed to investigate the clinical significance of low QRS voltage in precordial leads and its implications for surgical risk assessment and management 5.