Original Article

Single-beat estimation of the left ventricular end-diastolic pressure-volume relationship in heart failure patients

Ellen A ten Brinke¹, Daniel Burkhoff², Robert J Klautz¹, Carsten Tschöpe³, Martin J Schalij¹, Jeroen J Bax¹, Ernst E van der Wall¹, Robert A Dion¹, Paul Steendijk^1,*

¹ Leiden University Medical Center, Netherlands;
² Columbia University, New York City, United States;
³ Charité-University, Berlin, Netherlands

Correspondence to: Paul Steendijk, Cardiology, Leiden University Medical Center, PObox 9600, Leiden, 2300RC, Netherlands; p.steendijk{at}lumc.nl

Accepted 5 October 2009

Aims: A method to predict the end-diastolic pressure-volume relationship (EDPVR) from a single beat was tested in heart failure patients.

Methods and results: Patients (NYHA III-IV) scheduled for mitral annuloplasty (n=9) or ventricular restoration (n=10) and patients with normal left ventricular function undergoing CABG (n=12) were instrumented with pressure-conductance catheters to measure pressure-volume loops pre- and post-surgery. Data obtained during vena cava occlusion provided directly-measured EDPVRs. Baseline end-diastolic pressure (Pm) and volume (Vm) were used for single-beat prediction of EDPVRs. Root-mean-squared-error (RMSE) between measured and predicted EDPVRs, was 2.79±0.21mmHg. Measured vs. predicted end-diastolic volumes (EDV) at pressure levels 5, 10, 15 and 20mmHg showed tight correlations (R2: 0.69-0.97). Bland-Altman analyses indicated overestimation at 5mmHg (bias: pre-surgery 44mL (95% CI: 29 to 58mL); post-surgery 35mL (23 to 47mL)) and underestimation at 20mmHg (bias: pre-surgery -57mL (-80 to -34mL); post-surgery -13mL (-20 to -7.0mL)). EDVs were significantly different between groups and between conditions, but these differences were not dependent on the method (i.e. measured vs. predicted). RMSEs were not different between groups or conditions, nor dependent on Vm or Pm, indicating that EDPVR prediction was equally accurate over a wide volume range.

Conclusions: Single-beat EDPVRs obtained from hearts spanning a wide range of sizes and conditions accurately predicted directly-measured EDPVRs with low RMSE. Single-beat EDPVR indices correlated well with directly-measured values, but systematic biases were present at low and high pressures. The single-beat method facilitates less invasive EDPVR estimation, particularly when coupled with emerging noninvasive techniques to measure pressures and volumes.

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