Abnormal response to short acting pulmonary vasodilator +
Elevated pulmonary artery pressure +
Increased pulmonary capillary wedge pressure
Increased pulmonary vascular resistance
Intrapulmonary shunt
Pulmonary embolism +
An embolus (that is, an abnormal particle circulating in the blood) located in the pulmonary artery and thereby blocking blood circulation to the lung. Usually the embolus is a blood clot that has developed in an extremity (for instance, a deep venous thrombosis), detached, and traveled through the circulation before becoming trapped in the pulmonary artery.