Amyloidosis and the Syncopal Enigma

Background: Syncope is a common presenting complaint in the outpatient setting and requires a thoughtful and meticulous approach to history-taking skills. This is crucial in discerning cardiac versus non-cardiac etiologies, underscoring the pivotal role of healthcare professionals in the diagnostic process.

Case report: This is a case of a 76-year-old male who presented to the primary care clinic following an episode of syncope with abrupt loss of consciousness. Given the presentation, there was a high suspicion of cardiac etiology, and further testing was pursued. An electrocardiogram (ECG) demonstrated normal sinus rhythm with a pre-existing first-degree atrioventricular (AV) block. The Holter monitor was without sustained arrhythmias. A dobutamine stress echocardiogram was negative for myocardial ischemia, though a resting transthoracic echocardiogram demonstrated findings consistent with cardiac amyloidosis. Further evaluation with cardiology confirmed the diagnosis of transthyretin (ATTR) cardiac amyloidosis. He was initiated on appropriate treatment and underwent a dual chamber implantable cardioverter defibrillator (ICD) given his presentation. The patient ultimately succumbed to his disease 5 years after his diagnosis.

Conclusion: If the cardiac etiology of syncope is suspected, further cardiac structural evaluation is necessary. Cardiac amyloidosis, although rare, is a cause of cardiogenic syncope that should not be overlooked. It should be considered in the differential diagnosis in the appropriate clinical setting, highlighting the need for a broad and comprehensive approach to diagnosis.