Abstract 8958: The Role of Right Ventricular Dysfunction/Venous Congestion in Cardiac-Renal Interactions
Introduction: It has been thought that the primary driver of renal dysfunction (RD) in heart failure (HF) is diminished renal perfusion secondary to reduced cardiac output. However, this relationship has not been confirmed in recent clinical studies. Rather, strong associations between RD and right ventricular (RV) dysfunction/venous congestion have been identified.
Hypothesis: If RV dysfunction/venous congestion are causative of HF induced RD, the addition of RV dysfunction to a standard left ventricular (LV) HF model should produce incremental RD, independent of changes in cardiac output.
Methods: Eleven swine were chronically instrumented with intravascular catheters, intra-cardiac pressure transducers, and vascular flow probes on the ascending aorta and renal artery. After 2 weeks of recovery, biventricular failure was induced by serial microembolization of the pulmonary vascular bed (2-3 mg/kg of 65 micron glass spheres, times 6 infusions) followed by ventricular pacing at 170 BPM (RV+LV group, n=7). The remaining 4 pigs served as a pacing only control (LV group). Measurements of cardiac and renal parameters were made in the conscious state at baseline and after 2 weeks of pacing.
Results: Baseline renal and cardiac parameters were similar between groups. After 2 weeks of pacing, LV end diastolic pressure was increased and LV dP/dT and cardiac output were decreased (p<0.05), however these parameters did not differ between groups (p≥ 0.19 for all). Notably, right atrial pressure was significantly higher (LV group=4.7 ± 1.3 vs. RV+LV group= 12.1 ± 1.1 mmHg, p=0.02) and renal blood flow was significantly lower in the RV+LV group (LV=144.0 ± 3.2 vs. RV+LV= 94.4 ± 16.0 ml/min, p=0.03) despite a similar mean cardiac output between groups (LV group=3.8 ± 0.3 vs. RV+LV group=4.0 ± 0.4 l/min, p=0.76).
Conclusion: Despite a comparable degree of LV dysfunction and similar reductions in cardiac output, conscious swine with biventricular dysfunction had a disproportionate impairment in renal perfusion. These results provide mechanistic support for human observational studies linking RV dysfunction/venous congestion with RD.
- © 2011 by American Heart Association, Inc.