Objectives: Severe idiopathic tricuspid regurgitation (TR) occurs in the aged, but the mechanism of TR is unclear and there is little information on atrial abnormalities associated with this condition. This study retrospectively analyzed patients with severe functional TR presenting with common clinical features suggesting a distinct syndrome.
Methods: Eleven patients with severe functional TR were identified by reviewing the records of 16,235 consecutive patients. All patients had undergone clinical evaluation including echocardiography, electrocardiography and laboratory data.
Results: The median age of patients with severe functional TR was 78 years. All had a long-standing history of atrial fibrillation (median duration, 23 years). Clinical features are characterized by severe functional TR due to annular dilation, markedly dilated right atrium, episodes of right-sided heart failure, absent or diminished fibrillation waves on electrocardiogram, bradycardia probably due to partial atrial standstill, and decreased atrial natriuretic peptide secretion. During long-term follow up, right atrial size progressively increased in association with worsening TR.
Conclusions: Severe functional TR occurs with long-standing atrial fibrillation and causes right-sided heart failure. The TR is caused by tricuspid valve systolic coaptation loss due to tricuspid annular dilation associated with atrial dilation. This condition is associated with atrial abnormalities, such as atrial standstill and impaired atrial natriuretic peptide secretion. We propose that atrial remodeling associated with atrial fibrillation is central to the occurrence of the syndrome.