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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Exercise-induced pulmonary hemorrhage (EIPH) is a common occurrence in racehorses. The objective of this study was to compare pulmonary vascular pressures of healthy Thoroughbred horses with and without postexertion endoscopically detectable fresh blood in the trachea. The nasopharynx, larynx, and trachea (down to the carina) of horses were examined weekly with an endoscope 55-60 min postexertion, and the diagnosis of EIPH was confirmed by the presence of fresh blood in the trachea. Measurements of heart rate and right atrial, pulmonary arterial, and pulmonary arterial wedge pressures were made during quiet rest and during treadmill exercise performed at 14.5 m/s on a 5% uphill grade. This workload elicited maximal heart rate of the horses. Mean pulmonary capillary pressure was estimated to be halfway between the mean pulmonary arterial pressure and the mean pulmonary arterial wedge pressure. These data from 7 healthy sound exercise-trained horses that were positive on 12 consecutive occasions (at 1-wk intervals) for the postexercise presence of fresh blood in the trachea were compared with those in 8 healthy horses that were consistently negative for the evidence of fresh blood in the trachea on postexercise endoscopic examination over 12-16 wk. The heart rate and the right heart and/or pulmonary vascular pressures in the two groups of horses were similar at rest. Exercise was attended by a large significant (P < 0.05) increase in these pressures and heart rate in both groups. However, statistically significant differences between endoscopically EIPH-positive and endoscopically EIPH-negative horses for heart rate and right atrial and pulmonary vascular pressures were not found during exercise. Thus these data revealed that the magnitude of exercise-induced right atrial as well as pulmonary arterial, capillary, and venous hypertension in endoscopically EIPH-positive horses that are otherwise healthy is quite similar to that in endoscopically EIPH-negative horses during comparable exertion.
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PMID:Pulmonary vascular pressures of exercising thoroughbred horses with and without endoscopic evidence of EIPH. 890 73

We hypothesised that 22.5 mg of oral nitroglycerin would cause pulmonary vasodilation and therefore decrease pulmonary capillary pressure in horses during strenuous exercise. Six horses were assigned to exercise twice, once with no medication (control) and once with nitroglycerin (22.5 mg orally) in random order. Horses were exercised for 3 min each at 75, 90 and 100% of maximal heart rate (HRmax) with a 2 min period of walking between each period of exertion. Pulmonary artery and oesophageal pressures were recorded continuously. Subsequent analysis was carried out on the pulmonary arterial pressure signal with the oesophageal pressure subtracted, hence pulmonary vascular pressures reported in this paper approximate transmural pressures. Pulmonary arterial pressure, pulmonary arterial wedge pressure, pulmonary capillary pressure, heart rate and arterial blood gas tensions were determined for each level of exercise. Pulmonary arterial wedge and pulmonary capillary pressures were determined from the pulmonary artery waveform after dynamic occlusion of a branch of the pulmonary artery. The resulting decay in pulmonary artery pressure was submitted to an exponential curve fitting and the amplitude at the moment of occlusion on this curve was recorded as pulmonary capillary pressure. The effects of nitroglycerin on the various parameters were evaluated using a 3-way ANOVA blocked on horse treatment, and exercise intensity, followed by Tukey's multiple comparison procedure. Resting pulmonary artery pressure decreased from mean +/- s.e. 34.0 +/- 5.5 mmHg to 24.0 +/- 3.9 mmHg 5 min after administration of nitroglycerin (P < 0.05) but there were no significant effects on pulmonary capillary or wedge pressures. Nitroglycerin at this dose resulted in no significant differences in pulmonary artery, pulmonary capillary, and pulmonary wedge pressure, heart rate, arterial oxygen tension or arterial carbon dioxide tension at 75, 90 and 100% of HRmax. This dose of nitroglycerin does not appear significantly to protect the pulmonary vascular bed from exercise-induced hypertension. These data do not support the use of this dose of oral nitroglycerin in the prevention of EIPH.
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PMID:Oral nitroglycerin paste did not lower pulmonary capillary pressure during treadmill exercise. 1065 41

The objective of the present study was to ascertain whether administration of a second dose of frusemide would attenuate exercise-induced pulmonary hypertension more than a single dose. Right atrial, right ventricular and pulmonary vascular pressures were determined in 7 healthy, sound, exercise-trained Thoroughbred horses at rest and during exercise (14.2 m/s + a 3.5% uphill grade) performed at maximal heart rate (217 +/- 3 beats/min [mean +/- s.e.]). Horses were studied during the following 3 treatments in random order 7 days apart: control (no medication), frusemide single dose (250 mg i.v. 4 h pre-exercise), and frusemide double dose (250 mg i.v., 4 h pre-exercise + 250 mg i.v. 2 h pre-exercise). In the control study, exercise resulted in significant (P < 0.05) right atrial as well as pulmonary arterial, capillary and venous hypertension. In the frusemide single dose experiments, a significant (P < 0.05) attenuation of the exercise-induced rise in right atrial and pulmonary vascular pressures was observed. However, compared with frusemide single dose experiments, significant changes in the exercise-induced right atrial and pulmonary arterial, capillary and venous hypertension were not observed in the frusemide double dose experiments. Therefore, it is concluded that administration of an additional dose of frusemide is unlikely to affect the severity of EIPH in racing Thoroughbred horses more than a single dose.
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PMID:Repeated administration of frusemide does not offer an advantage over single dosing in attenuating exercise-induced pulmonary hypertension in thoroughbred horses. 1065 14