Exertional chest pain is sometimes more than just coronary atherosclerosis.

CLINICAL CASE: A 64-year-old male, with cardiovascular risk factors and previous history of bilateral carpal tunnel syndrome, presented with exertional retrosternal pain. The resting echocardiogram was unremarkable. A stress echocardiogram with dobutamine revealed hypokinesis of the inferior wall, associated with angina, followed by ventricular tachycardia. The coronary angiography revealed slow flow, a dominant right coronary artery with non-obstructive atherosclerosis and a left anterior descending artery with intermediate lesions in mid and distal segments. The invasive functional evaluation, including fractional flow reserve, thermodilution coronary flow reserve and index of microvascular resistance, led to the diagnosis of microvascular angina, treated with calcium channel blockers and transdermal nitrate, giving symptom relief.

EVOLUTION: Three years later he developed complete atrioventricular block and a dual chamber pacemaker was implanted. Shortly after, the patient developed progressive symmetrical tetraparesis, associated with marked muscle atrophy, hand numbness, orthostatic hypotension and dysphagia. The neurology workup led to the diagnosis of familial amyloidotic polyneuropathy, with the Val30Met mutation in the transthyretin gene. The following year he developed congestive heart failure. The echocardiogram showed moderate concentric left ventricular hypertrophy with preserved ejection fraction. A 99mTc-DPD Scintigraphy showed significant myocardial tracer uptake, leading to a diagnosis of TTR amyloid infiltration.

DISCUSSION: Patients with exertional angina and microvascular disease should be kept under close surveillance, as they may have systemic disease with cardiac involvement. Carpal tunnel syndrome, in the context of undiagnosed cardiac disease, should trigger suspicion of cardiac amyloidosis.