Differential Diagnosis

The patient's presentation with a history of peripheral arterial disease (pPAD), multiple stents, problems with restenosis, recent wound infection, a heart rate of 36, shortness of breath at night, and feelings of lightheadedness and dizziness suggests a complex clinical picture. The differential diagnoses can be categorized as follows:

• Single Most Likely Diagnosis

  • Bradycardia likely due to sick sinus syndrome or medication effect: The patient's heart rate of 36 is significantly low, especially considering they are not on beta blockers, which are known to slow heart rate. This, combined with symptoms of lightheadedness and dizziness, points towards a primary cardiac rhythm issue. The recent hospitalization and infection could also contribute to a transient or worsening condition affecting heart rate.

• Other Likely Diagnoses

  • Restenosis or new stenosis in coronary or peripheral arteries: Given the patient's history of multiple stents and problems with restenosis, it's plausible that new or worsening stenosis could be contributing to their symptoms, including shortness of breath and potentially the bradycardia if there's significant cardiac ischemia.
  • Anemia or other complications from recent wound infection: The recent wound infection could have led to anemia or sepsis, which might explain the shortness of breath and potentially contribute to a feeling of lightheadedness.
  • Heart failure: The shortness of breath at night (nocturnal dyspnea) could indicate heart failure, which might be exacerbated by or contribute to the bradycardia.

• Do Not Miss Diagnoses

  • Endocarditis: Although less likely, given the recent wound infection, endocarditis is a potentially deadly condition that could explain the patient's symptoms, including the new-onset bradycardia and shortness of breath.
  • Myocardial infarction (MI) or acute coronary syndrome (ACS): These conditions are always a concern in patients with a history of coronary artery disease and could present atypically, especially in the context of bradycardia.
  • Severe sepsis or septic shock: The recent hospitalization for a wound infection increases the risk of sepsis, which could lead to bradycardia among other symptoms due to its systemic effects.

• Rare Diagnoses

  • Neurocardiogenic syncope: This condition could potentially explain the lightheadedness and dizziness but would less likely account for the persistent bradycardia and shortness of breath.
  • Cardiac amyloidosis: A rare condition that could lead to restrictive cardiomyopathy, heart failure, and potentially bradycardia, though it would be less likely without other supporting evidence such as specific echocardiographic findings.
  • Infiltrative cardiac diseases (e.g., sarcoidosis): These could lead to conduction abnormalities, including bradycardia, but would be considered rare without additional supporting clinical or diagnostic evidence.