Cardiovascular research
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Cardiovascular research · May 1997
Right ventricular dysfunction persists following brief right ventricular pressure overload.
Acute pulmonary hypertension may cause right ventricular (RV) contractile failure. While it has been assumed that restoration of normal loading conditions after acute pulmonary hypertension is sufficient for complete recovery of RV function, this has not been rigorously examined. The purpose of this study was to test the hypothesis that acute RV pressure overload produces RV contractile dysfunction that persists following restoration of control loading conditions. ⋯ Acute pulmonary hypertension causes RV contractile dysfunction that persists at least 2 h after restoration of control loading conditions. Contractile dysfunction is not attributable to RV ischemia during pressure overload.
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Cardiovascular research · May 1997
Acute and persistent effects of a 46-kilometer wilderness trail run at altitude: cardiovascular autonomic modulation and baroreflexes.
To test the hypothesis that prolonged physical exercise induces long-lasting effects on blood pressure and heart rate we studied 17 endurance runners before and after the 1995 Sandia Wilderness Crossing Research Run (46 km of rocky trails, average altitude 2500 m). ⋯ The acute effects of prolonged exertion are associated with a relative increase in sympathetic activity. Twenty-four hours after this race an increased sensitivity to vagal and reduced sensitivity to sympathetic baroreflex stimulation was found. In this field study at altitude we found long-lasting effects on cardiovascular autonomic modulation after physical exertion.