Pathophysiology Of Constriction Exaggerated Ventricular Interdependence: • Limited Cardiac Filling due to Fixed Volume → Septum Shifts L/R to Accommodate RV/LV Filling During Inspiration/Expiration • Rapid Early Ventricular Filling and then Abrupt Cessation due to Stiff Pericardium: ↑ E-Wave Velocity + ↓ A-wave (E/A > 1) • In addition to Intrathoracic-lntracardiac Pressure Disassociation → Exaggerated Ventricular Interdependence during Resp → • Variation in Inflow Across A-V Valves → > 25% ↓ Peak MV Velocity and >40% ↑ Peak TV Velocity During Inspiration (opposite Exp.) Intrathoracic-lntracardiac Dissociation: • Normal - Under normal circumstances, the change in intrathoracic pressure with respiration is transmitted to the intrapericardial (heart chambers) structures and extra- pericardial (pulmonary vasculature) equally → MV Inflow Gradient Remains Constant Through Respiration. With inspiration, the intrathoracic pressure ↑ and with expiration ↓ • Constriction - With constriction, the ↓ intrathoracic pressure is transmitted to the extra-pericardial pulmonary capillaries but constriction limits the ↓ intrathoracic pressure being transmitted to the heart chambers. ↓ MV Inflow Gradient During Inspiration. With inspiration, the intrathoracic pressure ↓ and with expiration ↑ - Karan Desai MD @karanpdesai via CardioNerds @cardionerds #constriction #constrictive #pericarditis #pathophysiology #cardiology #dissociation
