From the Guidelines
Yes, "Resp. >50%" refers to respiratory variation in tricuspid regurgitation where the regurgitant flow increases by more than 50% during inspiration, which is a normal physiological behavior of right-sided heart valves. This finding is significant in the context of tricuspid regurgitation (TR), a condition that affects 2.7% of patients attending for routine transthoracic echocardiography, with an increased prevalence amongst females and the elderly 1. During inspiration, negative intrathoracic pressure increases venous return to the right heart, which increases right ventricular volume and pressure, leading to greater tricuspid regurgitation during inspiration compared to expiration.
This respiratory variation is an important diagnostic feature that helps distinguish tricuspid regurgitation from mitral regurgitation, as left-sided valve pathologies typically don't show this degree of respiratory variation. When evaluating tricuspid regurgitation with Doppler echocardiography, finding this respiratory variation (>50% increase during inspiration) confirms the right-sided origin of the regurgitant jet and is consistent with normal right heart physiology rather than indicating a pathological process. Key points to consider in the management of TR include:
- Significant TR is frequently associated with right ventricular injury, functional impairment, and poor outcomes, with 1-year all-cause mortality rates of 29.5% for moderate TR and 45.6% for severe TR 1.
- Despite poor prognosis, TR is undertreated, with only 10% of patients with severe TR and congestive heart failure undergoing surgery, despite at least one indication for intervention in 30% 1.
- Management of pulmonary hypertension and loop diuretics may reduce volume overload and improve symptoms, but no medical treatment strategies have been shown to significantly impact outcomes 1.
Given the poor outcomes associated with significant TR, early recognition and intervention are crucial to improve morbidity, mortality, and quality of life. Therefore, it is essential to accurately diagnose and manage TR, taking into account the respiratory variation in tricuspid regurgitation, to provide optimal care for patients with this condition.
From the Research
Tricuspid Regurgitation
- Tricuspid regurgitation (TR) is a condition where the tricuspid valve does not close properly, allowing blood to flow back into the right atrium 2, 3.
- The condition can be primary or secondary, with secondary TR being the most prevalent, resulting from maladaptive right ventricular remodeling secondary to pulmonary hypertension or atrial fibrillation 3.
- Significant TR can lead to worsening prognosis, regardless of the underlying etiology, and should be addressed as a separate therapeutic target 3, 4.
Diagnosis and Treatment
- Echocardiography can assess the TR etiology and severity, measure right atrial and ventricular size and function, estimate pulmonary pressure, and characterize left ventricular disease 2.
- Management of TR includes diuretics, ACE inhibitors, and aldosterone antagonists, as well as surgical annuloplasty or valve replacement in patients with progressive right ventricular dilatation without severe left ventricular dysfunction and pulmonary hypertension 2, 5.
- Transcatheter repair or replacement is an emerging therapy for high-risk patients with TR who would otherwise have a dismal clinical prognosis 2, 3, 4.
Respiratory Variation in Tricuspid Regurgitation
- There is no direct evidence in the provided studies to support the statement that respiratory variation in tricuspid regurgitation refers to the backflow being more pronounced during inspiration.
- However, it is known that TR can be affected by respiratory cycles, and further research may be needed to fully understand the relationship between respiratory variation and TR 3, 4.