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Background: The purpose of the current study was to define exercise-induced changes in indices of left ventricular (LV) systolic and diastolic properties in patients with chronic heart failure (HF), compare these changes in patients with HF and a reduced ejection fraction (EF) versus HF and a preserved EF, and compare the hemodynamic responses to activities of daily living with symptom-limited upright exercise., Methods and Results: Subjects with HF and a preserved EF (n=8) and subjects with HF and a reduced EF (n=5) underwent symptom-limited Naughton protocol treadmill exercise tests. Implantable hemodynamic monitor data and echocardiographic data were obtained before exercise and at peak exercise. Implantable hemodynamic monitor data were obtained during activities of daily living during a 24-hour time period. In patients with HF and a reduced EF, limited exercise time (639±164 seconds) was associated with a marked rise in right ventricular systolic, diastolic, and estimated pulmonary artery diastolic (ePAD) pressures and an increase in LV end diastolic volume (EDV). LV systolic properties, namely EF, end systolic elastance, stroke work, and preload recruitable stroke work, all decreased. The ePAD/EDV ratio increased; to a large extent, this was dependent on an increase in EDV. By contrast, in HF and a preserved EF, limited exercise time (411±128 seconds) and the marked rise in right ventricular systolic, diastolic, and ePAD pressures were associated with no change in LV EDV. LV systolic properties increased or were unchanged; ePAD/EDV ratio increased during exercise, but the increase was independent of a change in EDV. The ranges of right ventricular systolic, diastolic, and ePAD pressures during activities of daily living were higher than the ranges of these values during the exercise stress test., Conclusions: Although exercise limitations were similar between HF and a reduced EF and HF and a preserved EF, there were significant differences in exercise-induced changes in LV systolic and diastolic properties. These differences likely reflect the different pathophysiologies of these clinical syndromes of HF.

Aims: To compare haemodynamic responses during the 6-min walk test (6MWT) and daily living activities in heart failure (HF) patients., Methods and Results: Eighteen HF patients received an implantable haemodynamic monitor, which continuously measured heart rate (HR), estimated pulmonary artery diastolic pressure (ePAD), and several right ventricular (RV) pressure parameters. During the 6MWT, haemodynamics were assessed at rest and peak exercise. Ambulatory values were measured as the daily minimum, maximum, and median, averaged over the 14-day period surrounding each 6MWT. During the 6MWT, HR increased from 71 +/- 17 to 101 +/- 20 b.p.m. and ePAD from 20 +/- 5 to 34 +/- 8 mmHg. Daily minimum values were significantly lower and daily maximum values higher compared with rest and peak exercise. Patients with a walked distance above the median (402 m) had lower resting HR (64 +/- 10 vs. 77 +/- 20, P = 0.001) and ePAD (18 +/- 4 vs. 21 +/- 7, P = 0.022) compared to patients with walked distances below the median; values at peak exercise were similar. This pattern was also observed during the ambulatory periods., Conclusion: Ranges of HR and RV pressures are significantly larger during daily living activities compared with 6MWT in HF patients. Haemodynamic characteristics of patients with greater exercise capacity include lower resting HR and RV pressures and are similar during the 6MWT and daily life.

Background: Care and management of patients with congestive heart failure (CHF) is a major health-care challenge. The value of acute hemodynamic data in assessing heart failure has been questioned in some studies, while more intensive hemodynamic monitoring has been reported to improve patient care in others. A series of patient studies are reported here that were conducted to identify device requirements and verify the feasibility of continuous hemodynamic monitoring in CHF patients and devices for remote transfer and use of these data., Methods and Results: The results of four separate studies in 68 CHF patients who received systems for chronic hemodynamic monitoring between 1992 and the present are reviewed. One early study was with five patients followed for 7-16 months and another study was with nine patients followed for 4-22 months. A third study included 21 patients followed up to 39 months, and the fourth study included 32 patients implanted in 1998-99 with many of them still in follow-up. These studies support the technical feasibility of implanted devices and the external instrumentation required to transfer and manage the collected data. They also support the long-term stability and accuracy of these systems. Three additional acute studies conducted with 30 patients and chronic data from 53 of the 68 patients with the implanted systems are presented that support the feature included in the newer monitors--the ability to reliably estimate pulmonary artery diastolic pressures from the right ventricular pressure signal., Conclusions: Development of implantable technology to measure several hemodynamic variables in ambulatory CHF patients is feasible. External instrumentation needed to remotely acquire data from the implanted devices has been verified. The potential to eliminate the uncertainties associated with the use of acute, invasive hemodynamics and the ability to evaluate long-term ambulatory hemodynamic patterns is provided. These findings set the stage for determining the potential clinical value of these systems in impacting the care of chronic CHF patients.