Normal fluctuations in pulmonary artery pressures and cardiac output in patients with severe left ventricular dysfunction.

BACKGROUND: One barrier to accurate interpretation of changes in hemodynamic pressures and cardiac output is lack of data about what constitutes a normal fluctuation. Few investigators have examined normal fluctuations in these parameters and none have done so in patients with left ventricular dysfunction. AIMS: To describe normal fluctuations in pulmonary artery pressures and cardiac output in patients with left ventricular dysfunction. METHODS: Hemodynamically stable advanced heart failure patients (N=39; 55+/-6 years old; 62% male) with left ventricular dysfunction (mean ejection fraction 22+/-5%) were studied. Cardiac output and pulmonary artery pressures were measured every 15 min for 2 h. RESULTS: Mean+/-standard deviation fluctuations were as follows: pulmonary artery systolic pressure=7+/-4 mmHg; pulmonary artery diastolic pressure=6+/-3 mmHg; pulmonary capillary wedge pressure=5+/-3 mmHg; cardiac output=0.7+/-0.3 l/min. The coefficient of variation for fluctuations in pulmonary artery systolic pressure was 6.7%, in pulmonary artery diastolic pressure was 9.3%, in pulmonary capillary wedge pressure was 9.2%, and in cardiac output was 7.2%. CONCLUSIONS: Values that vary <8% for pulmonary artery systolic pressure, <11% for pulmonary artery diastolic pressure, <12% for pulmonary capillary wedge pressure, and <9% for cardiac output from baseline represent normal fluctuations in these parameters in patients with left ventricular dysfunction.