How to diagnose left ventricular hypertrophy (LVH) on an electrocardiogram (ECG)?

From the Guidelines

Diagnosing hypertrophy on an ECG involves looking for specific voltage criteria and pattern changes that indicate enlargement of heart chambers, with the most recent and highest quality study suggesting the use of increased QRS voltage in precordial leads (S wave in V1 + R wave in V5 or V6 > 35 mm) or limb leads (R wave in aVL > 11 mm) for left ventricular hypertrophy (LVH) 1. To diagnose hypertrophy on an ECG, several key points should be considered:

• For left ventricular hypertrophy (LVH), look for increased QRS voltage in precordial leads (S wave in V1 + R wave in V5 or V6 > 35 mm) or limb leads (R wave in aVL > 11 mm) 1.
• Additional signs of LVH include left axis deviation, prolonged QRS duration, ST depression and T wave inversion in lateral leads (the "strain pattern") 1.
• Right ventricular hypertrophy (RVH) presents with right axis deviation, tall R waves in right precordial leads (R:S ratio > 1 in V1), deep S waves in left precordial leads, and possible right bundle branch block pattern 1.
• Atrial hypertrophy shows as P wave abnormalities: left atrial enlargement produces wide, notched P waves (>0.12 seconds) in lead II and biphasic P waves in V1, while right atrial enlargement shows tall, peaked P waves (>2.5 mm) in leads II, III, and aVF 1. It is essential to remember that ECG has moderate sensitivity but high specificity for hypertrophy, so findings should be correlated with clinical context and considered in conjunction with other diagnostic tools, such as echocardiography, for confirmation when hypertrophy is suspected but ECG criteria aren't fully met 1.

From the Research

Diagnosing Hypertrophy in ECG

To diagnose hypertrophy in an ECG, several factors and criteria can be considered, as discussed in various studies 2, 3, 4.

• The ECG diagnosis of left ventricular hypertrophy (LVH) is predominantly based on the QRS voltage criteria, which includes increased QRS complex amplitude in defined leads 3.
• However, the classical ECG diagnostic paradigm has been criticized for its low sensitivity, with increased QRS amplitude only observed in a minority of patients with LVH 3.
• Alternative criteria, such as the Sokolow-Lyon, Romhilt-Estes, or Cornell criteria, assess changes in the amplitude and/or duration of the QRS complex to quantify LV mass 4.
• Studies have shown that LVH can result from diverse etiologies and is characterized by pathological changes in myocardial tissue characteristics beyond a pure increase in cardiomyocytes 4.
• Myocardial tissue characterization by cardiovascular magnetic resonance imaging (CMR) can detect and quantify the extent and severity of focal or diffuse myocardial fibrosis, edema, inflammation, and other conditions 4.

ECG Criteria for LVH

The following ECG criteria can be used to diagnose LVH:

• Increased QRS voltage, including increased QRS complex amplitude in defined leads 2, 3
• Prolonged duration of QRS complex 2
• Left axis deviation 2
• Prolonged intrinsicoid deflection 2
• Left bundle branch block (LBBB) and left anterior fascicular block (LAFB) patterns 2
• Pseudo-normal ECG findings 2

Limitations of ECG Diagnosis

The ECG diagnosis of LVH has several limitations, including:

• Low sensitivity of voltage criteria 3
• Limited ability to detect pathological changes in myocardial tissue characteristics 4
• Need for additional diagnostic tools, such as CMR, to quantify LV mass and detect myocardial fibrosis and other conditions 4