Compromise of the left ventricular filling due to bulging of the interventricular septum into the left ventricle

Can occur due to

• Physiologically during inspiration due to increased filling of the right ventricle (because of increased venous return)
• pulmonary embolism

1. Bernheim effect
2. Inspiratory decrease in systolic blood pressure and pulse volume – Mechanism
3. Pulsus paradoxus
4. Frusemide in left ventricular failure