Which of the following may be a consequence of an untreated pulmonary embolism?

A consequence of an untreated pulmonary embolism can indeed lead to cardiac arrest. This severe condition occurs when a blood clot blocks a pulmonary artery, leading to decreased blood flow to the lungs. As the lungs struggle to oxygenate the blood efficiently, other vital organs also start to suffer from inadequate oxygen supply. This insufficient perfusion can trigger arrhythmias, increase the risk of heart strain, and ultimately result in cardiac arrest if the embolism is not promptly treated. The severity and acute nature of pulmonary embolism necessitate immediate medical intervention to prevent such catastrophic outcomes.

In contrast, the other options describe scenarios that are not associated with untreated pulmonary embolism. For example, increased oxygenation and improved pulmonary function contradict the effects of an obstruction in the pulmonary artery. Decreased blood pressure does not directly relate as a realistic consequence of pulmonary embolism; instead, patients often experience increased pulmonary artery pressures due to the blockage. Understanding these implications highlights the urgency in addressing a pulmonary embolism to prevent life-threatening incidents like cardiac arrest.