Cardiac Amyloidosis Disguised as Atrial Flutter: A Case Report.

Cardiac amyloidosis (CA) is a rare form of infiltrative cardiomyopathy (IC) that frequently leads to heart failure (HF). Its symptoms can range from minimal to significant shortness of breath, palpitations, leg swelling, and chest discomfort. Early diagnosis and treatment are crucial in preventing the further progression of the disease and improving outcomes. This case report describes a 63-year-old male with no prior medical history who presented with severe dyspnea, palpitations, and chest heaviness. Initially diagnosed with atrial flutter, he was later confirmed to have cardiac amyloidosis through a thorough workup with multimodality imaging. The patient was started on guideline-directed medical therapy (GDMT) and discharged home with a follow-up from a heart failure specialist. An outpatient workup confirmed the diagnosis of amyloidosis with a positive pyrophosphate scan. At a seven-month follow-up, the workup for extra-cardiac involvement was negative, and the ejection fraction (EF) had improved. This case highlights the importance of a high index of suspicion and a thorough workup in cases of suspected cardiac amyloidosis to achieve early diagnosis and prevent disease progression.