Table 8.
Differential diagnosis of J wave vs intraventricular conduction defect–mediated notch syndromes (IVCD).
| J wave | IVCD-induced end QRS notch | |
|---|---|---|
| Male predominance | Yes | No |
| Average age at initial presentation | Young adults | Older adults |
| Most common morphology | Dome-like smooth appearance | Relatively sharp appearance |
| Response to change in heart rate | Bradycardia- and pause-dependent augmentation of J wave, which may be accompanied by T-wave inversion | Tachycardia and prematurity-dependent augmentation of the notch |
| Structural heart diseases | Rare | Common |
| History of myocardial infarction and/or cardiomyopathy |