How Effective Leaders Harness the Future.

Human beings are fundamentally future oriented. Most of our decisions and undertakings are for the sake of a future to which we are committed or obligated. This future orientation is essential to effective leadership in health care, especially during this time of significant reform, when people are at risk of becoming cynical and disengaged. Conventional thinking holds that our effectiveness as leaders is primarily a function of what we have learned in the past-our knowledge, expertise, and experience. In contrast, the emerging model contends that our effectiveness is also a function of how the future (outcome) of our leadership challenges "shows up" for us. If, despite daunting circumstances, we can "see" an aspired future ahead, we are more likely to commit and engage. Our story of the future becomes the "narrative frame" through which we see and tackle leadership challenges today. Because organizations are fundamentally networks of conversations, an organization's ability to create new language practices is tantamount to its ability to evolve. What makes the future compelling is the embodiment of our deepest convictions and ideals in our image of the future. Because health care reform has challenged the medical profession along the entire spectrum of its traditional values and roles, working toward a unifying vision of the future has been difficult. To enroll others in creating a better future, effective leaders must underscore the purpose and importance of their work and motivate them with inspiring stories.

Precise quantification of pressure flow waveforms of a pulsatile ventricular assist device.

Unreliable quantification of flow pulsatility has hampered many efforts to assess the importance of pulsatile perfusion. Generation of pulsatile flow depends upon an energy gradient. It is necessary to quantify pressure flow waveforms in terms of hemodynamic energy levels to make a valid comparison between perfusion modes during chronic support. The objective of this study was to quantify pressure flow waveforms in terms of energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE) levels in an adult mock loop using a pulsatile ventricle assist system (VAD). A 70 cc Pierce-Donachy pneumatic pulsatile VAD was used with a Penn State adult mock loop. The pump flow rate was kept constant at 5 L/min with pump rates of 70 and 80 bpm and mean aortic pressures (MAP) of 80, 90, and 100 mm Hg, respectively. Pump flows were adjusted by varying the systolic pressure, systolic duration, and the diastolic vacuum of the pneumatic drive unit. The aortic pressure was adjusted by varying the systemic resistance of the mock loop EEP (mm Hg) = (integral of fpdf)/(integral of fdt) SHE (ergs/cm3) = 1,332 [((integral of fpdt)/(integral of fdt))--MAP] were calculated at each experimental stage. The difference between the EEP and the MAP is the extra energy generated by this device. This difference is approximately 10% in a normal human heart. The EEP levels were 88.3 +/- 0.9 mm Hg, 98.1 +/- 1.3 mm Hg, and 107.4 +/- 1.0 mm Hg with a pump rate of 70 bpm and an aortic pressure of 80 mm Hg, 90 mm Hg, and 100 mm Hg, respectively. Surplus hemodynamic energy in terms of ergs/cm3 was 11,039 +/- 1,236 ergs/cm3, 10,839 +/- 1,659 ergs/cm3, and 9,857 +/- 1,289 ergs/cm3, respectively. The percentage change from the mean aortic pressure to EEP was 10.4 +/- 1.2%, 9.0 +/- 1.4%, and 7.4 +/- 1.0% at the same experimental stages. Similar results were obtained when the pump rate was changed from 70 bpm to 80 bpm. The EEP and SHE formulas are adequate to quantify different levels of pulsatility for direct and meaningful comparisons. This particular pulsatile VAD system produces near physiologic hemodynamic energy levels at each experimental stage.