PVCs and Left Axis Deviation: Clinical Significance and Management

Definition and Clinical Significance

Left axis deviation (LAD) is defined as a mean frontal plane QRS axis between -30° and -90°, with moderate LAD (-30° to -45°) and marked LAD (-45° to -90°), according to the American College of Cardiology 1
LAD commonly indicates left anterior fascicular block, left ventricular hypertrophy, or cardiomyopathies, as stated by the American Heart Association 1
In athletes, LAD is classified as a "borderline" ECG finding that may warrant additional investigation, especially when combined with other abnormalities, according to the American College of Cardiology 2, 3

≥2 PVCs on a standard 10-second ECG tracing is considered abnormal and requires further evaluation, as recommended by the American College of Cardiology 2, 3
High PVC burden (>10-15%) can induce or worsen cardiomyopathy and left ventricular dysfunction, according to the American Heart Association 4
Multiple PVCs (≥2) on standard ECG, PVC burden >10-15% on ambulatory monitoring, wide QRS duration of PVCs (>160 ms), and multifocal PVCs are concerning features that require urgent evaluation, as stated by the American College of Cardiology 2, 3, 4

Obtain 24-hour Holter monitoring to quantify PVC burden, as recommended by the American Heart Association 4
Perform echocardiography to assess for structural heart disease, such as left ventricular hypertrophy or cardiomyopathy, according to the American College of Cardiology 1, 4
Exercise stress testing is essential to evaluate exercise capacity and detect ischemia, as stated by the American College of Cardiology 1, 4

In athletes, LAD may indicate pathological rather than physiological left ventricular hypertrophy, according to the American College of Cardiology 1
PVCs are uncommon in athletes (<1% on 12-lead ECG), so their presence warrants investigation, as recommended by the American Heart Association 4
The combination of two borderline findings (LAD + PVCs) mandates additional investigation in athletes, according to the American College of Cardiology 2, 3

Treatment becomes necessary when symptomatic PVCs are present, PVC burden >10-15% with risk of cardiomyopathy development, PVCs are associated with documented structural heart disease, or evidence of left ventricular dysfunction develops, as stated by the American Heart Association 4