A 72-year-old male post-CABG presents with friction rub and chest pain. What is the likely diagnosis?

The presence of a friction rub along with chest pain in a post-CABG (Coronary Artery Bypass Grafting) patient strongly suggests a diagnosis of pericarditis. After cardiac surgery, it's not uncommon for inflammation of the pericardium, the fibrous sac surrounding the heart, to occur. This inflammation can lead to pericardial effusion or simply irritation of the pericardium, which manifests as a characteristic scratching or rubbing sound (friction rub) upon auscultation of the chest.

Chest pain associated with pericarditis is typically sharp and may be worsened by breathing or positional changes, which could fit the clinical picture presented. In contrast, acute myocardial infarction may present with chest pain but would typically be associated with different vital signs, and there wouldn’t likely be a friction rub. Pulmonary embolism would usually present with shortness of breath, tachycardia, or hemoptysis rather than a friction rub, and heart failure symptoms tend to involve fluid overload signs, such as edema or difficulty breathing, rather than a friction rub noted on examination.

Thus, given the clinical context of recent cardiac surgery and the presentation of symptoms, the likelihood of pericarditis