A new approach to improve the hemodynamic assessment of cardiac function independent of respiratory influence

Abstract

Cardiovascular and respiratory systems are anatomically and functionally linked; inspiration produces negative intrathoracic pressures that act on the heart and alter cardiac function. Inspiratory pressures increase with heart failure and can exceed the magnitude of ventricular pressure during diastole. Accordingly, respiratory pressures may be a confounding factor to assessing cardiac function. While the interaction between respiration and the heart is well characterized, the extent to which systolic and diastolic indices are affected by inspiration is unknown. Our objective was to understand how inspiratory pressure affects the hemodynamic assessment of cardiac function. To do this, we developed custom software to assess and separate indices of systolic and diastolic function into inspiratory, early expiratory, and late expiratory phases of respiration. We then compared cardiac parameters during normal breathing and with various respiratory loads. Variations in inspiratory pressure had a small impact on systolic pressure and function. Conversely, diastolic pressure strongly correlated with negative inspiratory pressure. Cardiac pressures were less affected by respiration during expiration; late expiration was the most stable respiratory phase. In conclusion, inspiration is a large confounding influence on diastolic pressure, but minimally affects systolic pressure. Performing cardiac hemodynamic analysis by accounting for respiratory phase yields more accuracy and analytic confidence to the assessment of diastolic function.

The local mechanosensitive response of primary cardiac fibroblasts is influenced by the microenvironment mechanics

“…1 d, f) and a force-induced calcium response was detected. At these forces, by considering half area of the bead surface as the contact area 25 , the pressure applied ranges from 4 to 9 kPa, which is compatible with the physiological pressures reported for the cardiac cycle 26 , 27 .…”

Free-Breathing and Single-Breath Hold Compressed Sensing Real-Time MRI of Right Ventricular Function in Children with Congenital Heart Disease

“…In our examination protocols, the RMB images were always acquired at the end of expiration, whereas with FB protocols, the data acquisition was conducted in multiple breathing phases. Since inspiration causes negative intrathoracic pressure, the ventricular functional parameters might be affected as well [26]. However, in our study, this methodical particularity of the CS imaging technique did not impair the reliability of the measurement results.…”