Pulmonary Edema With or Without Peripheral Edema

And the Difference is Critically Important

This ECG is from a patient with known coronary artery disease and a known ejection fraction of 25%. He presented to the emergency department with pulmonary edema, but the key issue is that he had no peripheral or sacral edema when he arrived. He also had no chest discomfort.

Please note the use of the term “discomfort” and not “pain” as discussed previously. (1) The ECG showed only very slight inferior wall ST segment elevations, and the patient’s initial troponin was negative. He was evaluated by the interventional cardiology fellow who recommended observation. My consult team saw the patient in the morning after his second cardiac troponin T was elevated to over 500. We pushed for prompt angiography because he had “pulmonary edema without peripheral edema.” Angiography showed a total right coronary artery occlusion, which was treated by primary angioplasty because we wanted to preserve as much cardiac function as possible in a man whose heart was already compromised.

This case illustrates several Rules of Cardiology, as follows:

1. Patients who present with pulmonary edema but without peripheral edema should be suspected to be having an acute cardiac event. Clearly a patient with a chronic ejection fraction of 25% could develop pulmonary edema. But that pulmonary edema should be the result of gradually accumulating fluid to the point where it “bubbles over” into pulmonary edema. So patients chronic heart failure and acute pulmonary edema should also have peripheral edema.

2. Please note the clever use of “bubbles over” because pulmonary edema is usually white and foamy with bubbles. The bubbles are produced because the fluid comes from the alveolae and contains surfactant. Surfactant reduces surface tension in the alveolae to keep them open and also reduces surface tension in pulmonary edema fluid to make bubbles.

3. The initial cardiac troponin can be normal especially when the culprit artery is totally occluded. A study of 925 acute ST segment elevation MIs reported that only 73% of the patients had troponin I values above the 99^th percentile when they presented to the emergency department.(2) Patients presenting within two hours of symptom onset were more likely to have normal troponins, but even among those patients presenting later, only 16% had an elevated troponin. The study’s authors suggested that abrupt and persistent coronary occlusion prevents troponin release from the myocardium.(1) I tell trainees that cardiologists are like workers at the sewage treatment plant. Neither knows that there is any xxxx in the system if the pipes are clogged and/or nobody flushes the toilet.

4. Avoid making or excluding a diagnosis on the basis of one test or one parameter, such as relying on only one troponin value. If the story is not a good story for an acute cardiac event and there are no ECG changes, one troponin has been shown to be quite reliable for excluding an acute MI. (3) But in general, use the whole picture in any clinical scenario to make a conclusion.

5. Small ECG changes, especially segmental ST segment elevation, should not be overlooked in the appropriate clinical setting. I tell my trainees that “big cardiologists look for small ECG changes.”

6. By the way, as a refresher, peripheral edema is not excluded in bedridden patients until you check the sacrum for edema. I remain convinced that Sir Isaac Newton was on to something.(4)

The most important lesson: There is pulmonary edema with, and pulmonary edema without, peripheral edema. Pulmonary edema without peripheral edema should always make you look hard for an acute cardiac event.

1. https://pauldthompsonmd.substack.com/p/no-more-pain

2. Wereski R, et. al. High-Sensitivity Cardiac Troponin Concentrations at Presentation in Patients With ST-Segment Elevation Myocardial Infarction. JAMA Cardiol. 2020 Aug 12;5(11):1302–1304. PMID: 32785613

3. Body R, et.al. The Use of Very Low Concentrations of High-sensitivity Troponin T to Rule Out Acute Myocardial Infarction Using a Single Blood Test. Acad Emerg Med. 2016 Sep;23(9):1004-13. PMID: 27178492

4. https://pauldthompsonmd.substack.com/p/check-out-that-butt

Dr. Francis Kiernan reviewed this for me and made helpful suggestions.