atrial pressure

atrial pressure increases when :

• a wave : atrial contraction
• c wave: as ventricle contracts - due probably to bulging of AV valve into atria
• v wave: increases slowly at atrium fills with blood from periphery

atrial pressure reduces when :

• x descent: atrium relaxes and tricuspid valve is pulled downwards
• y descent : tricuspid valve opens and blood flows into right ventricle