High Voltage
High voltage – probable left ventricular hypertrophy (LVH); criteria:
- S in V1 plus R in V5-6 (whichever is the larger) ≥ 35 mm
- sensitive but not specific; the larger the sum the more specific
- or R in aVL ≥ 13 mm
- specific but not sensitive
- or R in I plus S in III ≥ 27 mm
- intermediate sensitivity-specificity
- LAE, LAD, ST-T abnormalities (strain pattern): LVH more likely
- QRS voltages may be higher in normal young and thin individuals
- Unexplained high voltage: check amplification (r/o 20 mm/mV)
Low Voltage
- QRS amplitude <5 mm in all limb leads; <10 mm in all chest leads
Variable Voltage
- Proceed to alternans