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The article presents information on a study which analyzes the impact of exercise and altitude-induced increase in pulmonary artery pressures on left ventricular (LV) diastolic function in patients with high-altitude pulmonary edema (HAPE). The study included 29 HAPE susceptible (HAPE-S) and 10 control subjects.

Study objective: To investigate the prognostic value of oxygen uptake (VO[sub 2]) kinetics during low-intensity exercise in patients with congestive heart failure. Design: Prospective cohort study. Setting: Tertiary care center. Patients: One hundred forty-six consecutive patients (128 men) with chronic heart failure, followed up for a mean (± SD) duration of 25 ± 15 months. Measurements: A treadmill exercise test was performed with "breath by breath" gas-exchange monitoring. VO[sub 2] kinetics were defined as the O[sub 2] deficit (ie, ΔVO[sub 2] × time[rest to steady state] - ΣVO[sub 2][rest to steady state]) and mean response time (MRT) lie, O[sub 2] deficit/ΔVO[sub 2]]. Cardiac death, urgent cardiac transplantation, and hospitalization due to worsening heart failure were considered as the end points. Results: Thirty patients (21%) died, 11 patients (8%) underwent urgent transplantation, and 32 patients (22%) were hospitalized. In univariate analysis, MRT was the most powerful predictor of survival, survival free of urgent transplantation, and survival free of hospitalization (hazard ratios [HRs] per 10 s, 1.65, 1.72, and 1.61, respectively; all p < 0.0001). The predictive value of MRT exceeded that of peak VO[sub 2] (HR per mL/kg/min, 0.90; p = 0.02, 0.91; p = 0.007, and 0.95; p = 0.08, respectively). In multivariate analysis, MRT (HR per 10 s, 1.73; p = 0.0002), resting systolic BP (HR per 10 mm Hg, 0.65; p = 0.003), and the slope of the ventilatory response to exercise (HR per 10 U, 1.68; p = 0.02) were independent predictors of survival. Conclusions: Our results suggest that VO[sub 2] kinetics are strongly related to outcome in heart failure patients. Since it has several additional advantages over peak exercise testing (eg, less timeconsuming, less demanding for the patients, less dependent on motivation, and applicable in patients with limitations other than cardiopulmonary disease), it has the potential to become a prognostic test for the assessment of heart failure patients. [ABSTRACT FROM AUTHOR]

Background: Prognostic parameters in patients with congestive heart failure (CHF) are important for guiding therapeutic options. Maximal oxygen uptake (VO[sub 2]max) is a widely used parameter for prognostic assessment in patients with CHF and correlates with exercise cardiac output; however, afterload is not taken into account. Methods: The concept of a noninvasive surrogate of cardiac power output combines exercise systolic BP (SBP), as an estimate of afterload, with VO[sub 2]max, as an estimate of exercise cardiac output neglecting preload. Thus, a variable termed exercise cardiac power (ECP) is defined as the product of VO[sub 2]max (expressed as a percent predicted value) and SBP (ECP, expressed as %mm Hg, is the product of VO[sub 2]max, expressed as percentage of predicted maximum, times systolic pressure. The prognostic value of ECP obtained during routine treadmill ergospirometry was assessed in patients referred to our heart failure clinic. Patients undergoing heart transplantation were censored at the time of transplantation. Results: One hundred fifty-four patients were followed prospectively for a mean (± SE) duration of 625 ± 32 days. Thirty-two patients (21%) died. ECP was the most powerful predictor of mortality, was the combined end point of mortality or hospitalization for worsening heart failure (all p < 0.001), and was an independent predictor in multivariate analysis. An ECP of < 5,000 %mm Hg indicated a poor prognosis with a 1-year mortality rate of 37%, whereas only 2% of the patients having an ECP of > 9,000 %mm Hg died during the first year. Conclusion: The integration of afterload and VO[sub 2]max improves the prognostic value of each indicator, and provides an easily available and independent predictor of mortality and morbidity in CHF patients. This integrative concept of cardiac hydraulic performance is superior to VO[sub 2]max and can be used in routine ergospirometry. [ABSTRACT FROM AUTHOR]

Study objectives: To determine the BP response to the Valsalva maneuver (VM) at baseline and after changes in therapy and to compare this response to the invasively measured pulmonary capillary wedge pressure (PCWP). Design: Comparison of the BP response to the VM with invasively measured PCWP. In a subset of patients, direct PCWP and pulse amplitude ratio (PAR) measurements were repeated (mean ± SD) 3.2 ± 4.5 months later after adjusting the therapy. Setting: Tertiary-care center. Patients: Forty-two stable patients (8 women; mean age, 58 ± 13 years) undergoing right heart catheterization who were in sinus rhythm. Measurements: PAR calculated between the end and the beginning of the VM using the last two beats and the first three beats of the straining phase and simultaneous measurement of PCWP. Results: There was a highly significant correlation between the invasively measured PCWP (range, 2 to 32 mm Hg) and the PAR (range, 0.28 to 1.15; R² = 0.75; p < 0.001). In addition, changes of PCWP during follow-up (-16 to 13 mm Hg) were well-correlated (R² = 0.93; p < 0.001; n = 11) with changes in PAR (-0.44 to 0.47). The administration of medication (eg, β-blockers, amiodarone, angiotensin-converting enzyme inhibitor, and digoxin) did not influence the results. Conclusions: PCWP and changes during therapy can be estimated noninvasively by measuring the PAR during the VM with acceptable accuracy in stable patients with cardiac conditions. Thus, this method may be a useful tool in detecting an elevated PCWP and hemodynamic response to therapy. [ABSTRACT FROM AUTHOR]