Heart Failure and Cardiac Involvement as Isolated Manifestation of Familial Form of Transthyretin Amyloidosis Resulting From Val30Met Mutation With No Clinical Signs of Polyneuropathy

Abstract

A 63-year-old white man with a 6-month history of progressive exertional dyspnea was referred for evaluation. In 1997, he presented an episode of unconsciousness as first symptom of a cardiac disease. In 2003, arterial hypertension, as well as atrioventricular block Mobitz type I, was diagnosed. A worsening of the biventricular heart failure over the last 2 years led to his admission at our clinic in 2008, with dyspnea at rest and bilateral pleural effusions. At admission, the patient appeared to be well, with a blood pressure of 142/76 mm Hg and a pulse of 97 bpm. Jugular venous pulse was not elevated, but mild bilateral edema of the lower extremities was noted. The lungs were clear to auscultation, with attenuation on the right side because of pleural effusion. The patient’s symptoms improved slightly through pharmacological therapy, but he remained in New York Heart Association functional class III heart failure. Laboratory studies revealed normal blood cell counts and electrolyte panel, with signs of load on the right side of the heart. The highest B-type natriuretic peptide was 818.6 pg/mL (normal, <100 pg/mL). The 24-hour urine protein collection was outside of normal limits at 0.27 g (normal, <0.15 g), and glomerular filtration rate according to the modified …