Key result
Atrial septal defect abolishes normal respiratory and Valsalva-induced variations in right atrial volume.
Why the study?
Assessing the complex relations between pressure and volume in the right atrium was previously hampered by difficulties in measuring atrial volume, prompting an examination of right atrial pressure-volume dynamics using an impedance catheter in patients with and without an atrial septal defect.
How do right atrial pressure-volume relations during normal respiration and the Valsalva maneuver differ between patients with and without an atrial septal defect?
Observational (n=16)
How do right atrial pressure-volume relations during normal respiration and the Valsalva maneuver differ between patients with and without an atrial septal defect?
Using a multi-electrode impedance catheter, this study demonstrates that patients with an atrial septal defect lack the normal respiratory and Valsalva-induced changes in mean right atrial volume despite exhibiting normal baseline pressure-volume loop patterns and pressure changes.
ASD patients lack normal right atrial volume variation with respiration; hypothesis-generating for right heart physiology and should not yet change practice.
Assessment of the complex relations between pressure and volume in the right atrium has been hampered in the past by difficulties in the measurement of atrial volume. Accordingly, in the present study the dynamics of right atrial pressure-volume relations were examined (with the use of an impedance catheter to measure right atrial volume) in patients with and without an atrial septal defect. Right atrial pressure and impedance volume were measured in 16 patients at the time of cardiac catheterization with the use of a multi-electrode impedance catheter to provide continuous, on-line, pressure-volume data. Eleven patients without evidence of an interatrial shunt were examined during normal respiration and during the Valsalva maneuver and contrasted with five patients with an atrial septal defect documented by oxygen saturation step-up and echocardiographic studies. Right atrial pressure-volume diagrams in patients without an atrial septal defect exhibited the normal figure eight pattern, with an A loop (atrial contraction) and a V loop (passive filling), corresponding to the A wave and V wave of right atrial pressure, respectively. During inspiration, mean right atrial pressure decreased and mean right atrial volume increased, consistent with augmented venous return. With the Valsalva maneuver, right atrial pressure increased and both right atrial stroke volume and mean right atrial volume decreased compared with baseline. Patients with an atrial septal defect demonstrated baseline pressure-volume diagrams similar to those of patients without an interatrial shunt. However, no change in mean right atrial volume occurred with either respiration or the Valsalva maneuver despite changes in right atrial pressure similar to those seen inpatients without an atrial septal defect.(ABSTRACT TRUNCATED AT 250 WORDS)
No takes yet. Share an insight, caveat, or question.
Ferguson et al. (1989) conducted an observational in Atrial septal defect (n=16). Atrial septal defect (evaluated via multi-electrode impedance catheter during normal respiration and Valsalva maneuver) vs. Patients without an interatrial shunt (n=11) was evaluated on Right atrial pressure-volume relations and mean right atrial volume changes during respiration and Valsalva maneuver. Patients with an atrial septal defect (n=5) showed no change in mean right atrial volume during respiration or Valsalva maneuver, unlike controls (n=11).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: