A wave
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
The a wave is an upward deflection in the right atrial pressure that occurs during right atrial contraction.
See the main page on JVP waveforms for more details.
Shown below is an image depicting the typical a wave pattern as seen on an EKG.
a = atrial contraction, occurs just before 1st heart sound and carotid pulse x = atrial relaxation c = bulging of tricuspid valve during isovolumetric contraction; x 1 = occurs during ventricular contraction pulling down the tricuspid valve “descent of the base”; v = occurs during venous filling of the atrium with a closed tricuspid valve\; y = opening of tricuspid valve and right atrium emptying
Abnormalities in the JVP Waveforms
| Absence of a wave | Atrial fibrillation |
| Flutter of a wave | Atrial flutter |
| Prominent a waves | First-degree atrioventricular block |
| Large a waves | Tricuspid stenosis, Right atrial myxoma, Pulmonary hypertension, Pulmonic stenosis |
| Absent x descent | Tricuspid regurgitation |
| Prominent x descent | Conditions associated with large a waves |
| Slow y descent | Tricuspid stenosis, Right atrial myxoma |
| Rapid y descent | Constrictive pericarditis, severe Right heart failure, Tricuspid regurgitation, Atrial septal defect |
| Absent y descent | Cardiac tamponade |