What electrocardiogram (ECG) findings suggest mild left ventricular hypertrophy (LVH)?

From the Guidelines

Mild left ventricular hypertrophy (LVH) on ECG is best suggested by increased QRS voltage, particularly in the precordial leads, with criteria such as the Sokolow-Lyon criteria (R waves in V5 or V6 exceeding 25-30 mm or S waves in V1 or V2 plus R waves in V5 or V6 greater than 35 mm) or the Cornell voltage criteria (S wave in V3 plus R wave in aVL >20 mm in women or >28 mm in men) being the most commonly used indicators 1.

ECG Findings for Mild LVH

The ECG findings that suggest mild LVH include:

• Increased QRS voltage in the precordial leads
• Slight left axis deviation
• Prolonged QRS duration (usually less than 120 ms in mild cases)
• Delayed intrinsicoid deflection in lateral leads
• ST segment depression and T wave inversion in the lateral leads (V5, V6, I, aVL), though these may be minimal in mild LVH These findings are based on the American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society recommendations for the standardization and interpretation of the electrocardiogram 1.

Diagnostic Criteria

The diagnostic criteria for LVH based on QRS voltage have evolved over the years, with the Sokolow-Lyon criteria and the Cornell voltage criteria being the most widely used. However, it is essential to note that these criteria have limited sensitivity, and mild LVH may be missed on ECG alone 1.

Clinical Application

In clinical practice, the diagnosis of mild LVH should be made with caution, considering the limited sensitivity of the ECG criteria. The use of multiple criteria, such as the Sokolow-Lyon and Cornell voltage criteria, may be helpful in increasing the diagnostic accuracy. Additionally, the interpretation of ECG findings should take into account the patient's clinical context, including age, gender, and body habitus, as these factors can influence QRS voltages 1.

From the Research

ECG Findings for Mild Left Ventricular Hypertrophy

The ECG diagnosis of left ventricular hypertrophy (LVH) is predominantly based on the QRS voltage criteria, which includes the increased QRS complex amplitude in defined leads 2, 3. However, the low sensitivity of voltage criteria has been repeatedly documented, and various clinical conditions associated with LVH produce considerable diversity of electrical properties alterations, thereby modifying the resultant QRS patterns 3, 4.

QRS Patterns in LVH

The spectrum of QRS patterns observed in LVH patients is quite broad, including:

• Left axis deviation
• Left anterior fascicular block
• Incomplete and complete left bundle branch blocks
• Q waves
• Fragmented QRS
• QRS complex can be within normal limits 3, 5

Effect of Anatomic and Electric Remodeling

The increase in left ventricular mass (LVM) does not affect the QRS voltage proportionally, and LVM and type of hypertrophy are not the only determinants of the QRS patterns 5. The conduction velocity slowing results in a spectrum of QRS patterns, including increased QRS voltage and duration, left axis deviation, and prolonged intrinsicoid deflection 5, 4.

ECG Criteria for LVH

The ECG criteria for LVH include:

• Voltage criteria
• Repolarization abnormalities
• Left atrial abnormality
• Ventricular conduction time 6 An increase in echocardiogram-derived LVM has a significant effect on all 4 ECG criteria, with the frequency of voltage criteria for LVH increasing as LVM progressively increases 6.