The right ventricle is not just a smaller left ventricle. It is a thin-walled chamber designed to move blood through a low-pressure, low-resistance pulmonary circulation.
This matters because the right ventricle tolerates volume better than pressure. When pulmonary vascular resistance rises acutely, the right ventricle can fail quickly.
Common ICU triggers include pulmonary embolism, severe ARDS, pulmonary hypertension, hypoxic pulmonary vasoconstriction, high intrathoracic pressure, acidosis, and excessive PEEP.
As RV afterload increases, the right ventricle dilates. RV dilation increases wall tension and myocardial oxygen demand. At the same time, systemic hypotension may reduce right coronary perfusion.
This creates a dangerous spiral.