A wave

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