Respiratory Variation Across the Tricuspid Valve in Constrictive Pericarditis
Yes, there is significant respiratory variation across the tricuspid valve in constrictive pericarditis, with >25% variation in flow velocities being a diagnostic hallmark of this condition. 1
Pathophysiologic Mechanism
The respiratory variation occurs because the thickened, non-compliant pericardium creates a fixed total cardiac volume within which both ventricles must compete for space. 2 During inspiration:
- Increased venous return to the right heart causes the interventricular septum to shift leftward, compressing the left ventricle 2
- The right ventricle expands at the expense of left ventricular filling due to ventricular interdependence within the constrained pericardial space 2
- Tricuspid inflow velocity increases during inspiration while mitral inflow velocity reciprocally decreases 1, 3
This creates the characteristic reciprocal respiratory variation where right-sided and left-sided filling patterns move in opposite directions with respiration. 3
Diagnostic Criteria
The European Society of Cardiology guidelines establish >25% respiratory variation across the atrioventricular valves as a key diagnostic criterion for constrictive pericarditis. 1 Specifically:
- Tricuspid inflow E velocity increases with inspiration in constrictive pericarditis 3
- This variation is reciprocal to mitral inflow changes, which decrease with inspiration 1, 3
- The magnitude of variation (>25%) distinguishes constrictive pericarditis from normal physiology 1
Clinical Application and Caveats
Important limitations exist that can mask or alter this finding:
- Patients with increased atrial pressures or mixed constriction-restriction may demonstrate <25% respiratory changes 1
- Atrial fibrillation makes diagnosis difficult, though hepatic vein flow patterns remain useful even when atrioventricular flow velocity patterns are inconclusive 1
- A provocation test with head-up tilting or sitting position to decrease preload may unmask constrictive physiology when respiratory variation is initially absent 1
During mechanical ventilation, the pattern reverses: positive pressure ventilation causes tricuspid inflow velocities to increase during mechanical inspiration (opposite to spontaneous breathing), representing an 18-28% change that maintains diagnostic utility. 4
Complementary Diagnostic Features
Beyond tricuspid valve respiratory variation, constrictive pericarditis demonstrates:
- Ventricular septal shift with respiration (respiratory bounce) 5
- Hepatic vein expiratory diastolic reversal ratio ≥0.79 5
- Preserved or increased medial mitral annular e' velocity (≥9 cm/s) 5
The combination of ventricular septal shift with either elevated medial e' or prominent hepatic vein reversal achieves 87% sensitivity and 91% specificity for constrictive pericarditis. 5