Case 1 - Cardiorenal Syndrome - 1 - RV Failure
Patient with chronic right heart failure secondary to pulmonary hypertension frequently presents with acute kidney injury secondary to further cardiac decompensation. Junior trainees often would propose volume expansion in hope to increase LV preload to increase LV stroke volume. However, this strategy would, in fact, result in the reduction of LV preload and LV stroke volume. This is because of a physiological phenomenon called the interventricular dependence where the RV and LV influence each other via the ventricular septum.
The following images pre- and post-diuresis illustrate this phenomenon at work.
Pre-Diuresis:
Note the interventricular septum in the PSS view is flat (maybe even deviating a bit into the LV). Although this increases the end-diastolic volume of the RV which may increase RV stroke volume, it is at the expense of the ened-diastolic volume of the LV. As septum encroaches into the LV cavity, its ability to fill reduces -- diastolic dysfunction. Although the RV's stroke volume improves with compensatory volume retention, after a certain point it will reduce LV stroke volume.
The following images pre- and post-diuresis illustrate this phenomenon at work.
Pre-Diuresis:
Note the interventricular septum in the PSS view is flat (maybe even deviating a bit into the LV). Although this increases the end-diastolic volume of the RV which may increase RV stroke volume, it is at the expense of the ened-diastolic volume of the LV. As septum encroaches into the LV cavity, its ability to fill reduces -- diastolic dysfunction. Although the RV's stroke volume improves with compensatory volume retention, after a certain point it will reduce LV stroke volume.
Post-Diuresis Day 3:
As volume was removed, the pressure and volume within his venous system and, hence, RV reduced. Note the interventricular septum in the PSS view was in its normal conformation - bowing into the RV. There was filling room, diastolic capability, in the LV.
His renal function recovered to baseline with the diuresis. This indicated that his LV cardiac output increased.
As volume was removed, the pressure and volume within his venous system and, hence, RV reduced. Note the interventricular septum in the PSS view was in its normal conformation - bowing into the RV. There was filling room, diastolic capability, in the LV.
His renal function recovered to baseline with the diuresis. This indicated that his LV cardiac output increased.