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PATIENT CASE

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A 62-year-old man with a history of nonischemic cardiomyopathy presents with worsening shortness of breath, orthopnea, lower extremity edema, and weight gain. He is diagnosed with acute on chronic systolic heart failure. Attempts at diuresis with furosemide 80 mg intravenously (IV) twice daily are unsuccessful, and his renal function worsens. Right heart catheterization reveals elevated filling pressures and low cardiac output. He is started on inotropes and continuous furosemide infusion with improvement in his symptoms and renal function.

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INTRODUCTION

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  • Right heart catheterization (RHC) can be used for a variety of clinical indications in critically ill patients; use in decompensated heart failure is among the most common.

  • Allows direct measurement of right atrial, right ventricular, and pulmonary artery pressures.1

  • Can also estimate left atrial pressure by measuring the pulmonary capillary wedge pressure.

  • Cardiac output can be estimated using automated thermodilution techniques or calculated using the Fick method.

  • Samples of mixed venous blood can be used to quantify oxygen consumption.

  • Value of RHC in heart failure remains controversial.2

    • Unnecessary in most patients who present with acute decompensated heart failure but can provide valuable information in select patients.

    • Randomized ESCAPE trial showed no benefit (or increased risk) in mortality or days alive out of the hospital with use of RHC.3

    • ESCAPE did not enroll all consecutive patients because many physicians would not enroll patients and risk a 50% chance of not having a pulmonary artery catheter.

  • Based on the ESCAPE trial, routine RHC in heart failure is not recommended. However, it can be useful in a subset of advanced heart failure patients.

  • The 2013 American College of Cardiology/American Heart Association heart failure guideline suggests RHC be performed in patients with respiratory distress or impaired systemic perfusion when clinical assessment is inadequate.

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PRESSURES

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RIGHT ATRIAL PRESSURE

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  • “Filling pressure” of the right heart reflecting venous return to the right atrium (RA) during ventricular systole and right ventricular end-diastolic pressure.

  • Waveform normally has 3 distinct positive waves and 2 negative descents (Figure 2-1).

    • a wave reflects pressure increase at atrial contraction.

    • x descent reflects fall in pressure during atrial relaxation.

    • c wave (generally small) reflects pressure increase due to bulging of tricuspid valve into the RA during ventricular isovolumetric contraction.

    • v wave is increased atrial pressure from passive blood return to the atria while the tricuspid valve remains closed.

    • y descent reflects fall in atrial pressure as the tricuspid valve opens and blood rushes from the atrium to the ventricle.

    • a wave is usually slightly larger than the v wave.

  • Normal RA pressure is 3 to 7 mm Hg (Table 2-1).

  • Characteristic RA pressure waveforms:

    • Tricuspid regurgitation can result in tall v waves due to blood regurgitated into the RA during systole (Figure 2-2).

    • Atrial fibrillation results in loss of normal a waves due to lack of organized atrial activity.

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