Background
Recent studies have examined hemodynamic changes with stressors such as isometric handgrip and rapid atrial pacing in heart failure with preserved ejection fraction (HFpEF), but little is known regarding left ventricular (LV) pressure-volume responses during dynamic exercise.
Objective
Assess LV hemodynamic responses to dynamic exercise in patients with HFpEF.
Methods and Results
Twenty subjects with normal EF and exertional dyspnea underwent invasive hemodynamic assessment during dynamic exercise to evaluate for suspected HFpEF. LV end-diastolic pressure (LVEDP) was elevated at rest (>15mmHg, n=18) or with exercise (≥20mmHg, n=20) in all, consistent with HFpEF. Heart rate, blood pressure, arterial elastance and cardiac output increased with exercise (all p<0.001). Minimal and mean LV diastolic pressures increased by 43–56% with exercise (both p<0.0001), despite a trend toward reduction in LV end-diastolic volume (p=0.08). Diastolic filling time was abbreviated with increases in heart rate, and the proportion of diastole that elapsed prior to estimated complete relaxation increased (p<0.0001), suggesting inadequate relaxation reserve relative to the shortening of diastole. LV diastolic chamber elastance acutely increased 50% during exercise (p=0.0003). Exercise increases in LV filling pressures correlated with changes in diastolic relaxation rates, chamber stiffness and arterial afterload but were not related to alterations in preload volume, heart rate, or cardiac output.
Conclusion
In patients with newly-diagnosed HFpEF, LV filling pressures increase during dynamic exercise in association with inadequate enhancement of relaxation and acute increases in LV chamber stiffness. Therapies that enhance diastolic reserve function may improve symptoms of exertional intolerance in patients with hypertensive heart disease and early HFpEF.
Background We provide the first multicenter analysis of patients cared for by eight Pulmonary Embolism Response Teams (PERTs) in the United States (US); describing the frequency of team activation, patient characteristics, pulmonary embolism (PE) severity, treatments delivered, and outcomes. Methods We enrolled patients from the National PERT Consortium™ multicenter registry with a PERT activation between 18 October 2016 and 17 October 2017. Data are presented combined and by PERT institution. Differences between institutions were analyzed using chi-squared test or Fisher's exact test for categorical variables, and ANOVA or Kruskal-Wallis test for continuous variables, with a two-sided P value < 0.05 considered statistically significant. Results There were 475 unique PERT activations across the Consortium, with acute PE confirmed in 416 (88%). The number of activations at each institution ranged from 3 to 13 activations/month/1000 beds with the majority originating from the emergency department (281/475; 59.3%). The largest percentage of patients were at intermediate–low (141/416, 34%) and intermediate–high (146/416, 35%) risk of early mortality, while fewer were at high-risk (51/416, 12%) and low-risk (78/416, 19%). The distribution of risk groups varied significantly between institutions ( P = 0.002). Anticoagulation alone was the most common therapy, delivered to 289/416 (70%) patients with confirmed PE. The proportion of patients receiving any advanced therapy varied between institutions ( P = 0.0003), ranging from 16% to 46%. The 30-day mortality was 16% (53/338), ranging from 9% to 44%. Conclusions The frequency of team activation, PE severity, treatments delivered, and 30-day mortality varies between US PERTs. Further research should investigate the sources of this variability.
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