When the Heart Affects the Shoulder: An Overlooked Connection between Cardiac Amyloidosis and Shoulder Pain: A Case Report

Case Diagnosis: Right shoulder pain secondary to amyloid deposition.

Case Description or Program Description: A 77-year-old male with heart failure secondary to cardiac amyloidosis has chronic right shoulder pain without an inciting event. The pain, which has progressively worsened and is now excruciating, is aggravated by any shoulder movement and has not responded to conservative management nor to intra-articular steroid injections.

Setting: Secondary Care

Assessment/Results: A comprehensive physical examination revealed no asymmetry or deformities in bilateral shoulders. Tenderness was present in the right subacromial area and lateral deltoid, with range of motion limited in all planes and strength diminished due to pain. The patient only experienced pain relief when the right arm was at rest. Sensation was preserved, and no abnormal neurovascular findings were present. X-ray imaging showed degenerative changes and calcific peritendinitis. MRI showed tendinosis of supraspinatus muscle, bursitis, and osteoarthritis of acromioclavicular joint.

Discussion (relevance): Amyloidosis is characterized by the abnormal deposition of proteins in tissue. Symptoms vary by organ involvement, with restrictive cardiomyopathy being a notable manifestation. This case highlights a rare case of right shoulder pain, suggestive of transthyretin deposition in the shoulder soft tissues. Clinicians should maintain a high level of suspicion, as this condition may be misdiagnosed as osteoarthritis or rotator cuff pathology. Correctly identifying amyloidosis is essential, as it can severely impact the patient's quality of life and symptoms are often resistant to typical treatments. Early surgical intervention may be needed to improve function, even when imaging reveals minimal changes, since amyloid deposits are usually not detected on standard scans.

Conclusions: This case highlights shoulder pain from amyloid deposition, a rare cause secondary to the uncommon condition of amyloidosis. Its impact on symptoms may be overlooked. Amyloid deposits can lead to significant pain and disability and conservative treatments may be ineffective, making early surgical intervention essential to improve the patient's quality of life.