A 62-year-old man is found dead in his hotel room. He was traveling for work and had checked into the hotel the night prior. No other history is available. Autopsy examination is performed; the lung findings shown below are determined to be the cause of death.
Show Explanatory Sources
Which of the following is the most likely inciting event that led to this patient's death?
Show Explanatory Sources
This patient's autopsy shows a large thromboembolism lodged in the right pulmonary artery; he most likely died from a massive pulmonary embolism (PE) that originated as a lower extremity deep vein thrombosis. Massive PE can lead to sudden occlusion of >50% of the pulmonary arterial circulation, causing a rapid increase in pulmonary vascular resistance and right ventricular (RV) pressure load. This can result in acute RV dysfunction and inability to pump blood through the pulmonary circulation to the left side of the heart. With a marked decrease in left ventricular preload (left ventricular end-diastolic volume) there is a sudden loss of cardiac output.
Depending on the degree of compensation for the loss of cardiac output, patients can experience lightheadedness, syncope, or sudden cardiac death (SCD). Less commonly, acute PE may also cause SCD due to cardiac arrhythmia induced by RV strain and ischemia.
(Choice A) Coronary atheromatous plaque rupture leads to acute myocardial infarction; SCD can result due to ventricular arrhythmia (ie, ventricular tachycardia, ventricular fibrillation) triggered by myocardial ischemia/infarction. There would not be evidence of thromboembolism in the pulmonary arteries.
(Choices C and D) Malignant tumor may erode into a bronchial artery, resulting in acute hemorrhage, or it may erode into a bronchus resulting in airway obstruction. Neither of these scenarios is likely to cause SCD. Bronchial artery hemorrhage would likely present with hemoptysis and, if fatal, would be evidenced by blood or thrombus in the airways on gross pathology. Bronchial airway obstruction is likely to present with respiratory difficulty or distress.
(Choice E) Sleep-related upper airway obstruction occurs in obstructive sleep apnea, which may cause SCD due to hypoxemia-related cardiac arrhythmia. However, there would not be evidence of thromboembolic disease on autopsy.
Educational objective:
Massive pulmonary embolism can lead to sudden cardiac death (SCD) due to a sudden loss of cardiac output. Less commonly, SCD may result from cardiac arrhythmia triggered by right ventricular strain and ischemia.