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failure. 1 , 5 In addition to the indices mentioned above, the severity of MMVD needs to be assessed using various indices, and various studies have been conducted to evaluate the severity of MMVD. 6 – 15 The pulmonary-vein-to-pulmonary-artery ratio (PV

Open access
in American Journal of Veterinary Research

pulmonary artery. RA = Right atrium. RV = Right ventricle. RPA = Right pulmonary artery. LPA = Left pulmonary artery. SVC = Supraventricular crest. 5, 10, and 15 on the sides of echocardiograms indicate the number of centimeters of field depth. At the

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in Journal of the American Veterinary Medical Association

. Results of the serum biochemical analyses were within reference limits. Consultation with the surgery department for pulmonary artery banding was recommended. The next week (8 weeks after the initial cardiac consultation), the cat was evaluated by the

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in Journal of the American Veterinary Medical Association

such as myxomatous mitral valve degeneration and myocardial disease. 1 PH may affect the cardiovascular system negatively and increases the likelihood of death. 1 , 2 Right pulmonary artery (PA) catheterization is the gold standard for diagnosing PH

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in American Journal of Veterinary Research

Pulmonary thromboembolism is a condition characterized by partial or complete obstruction of the pulmonary artery or its branches by a thrombus. 1 In humans, diagnostic tests for thromboembolic disease include assay of D-dimer concentrations

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in American Journal of Veterinary Research

glomerular filtration rate or renal biopsies were performed, the exact cause of the systemic hypertension in this patient remains speculative. ABBREVIATIONS PA Pulmonary artery RVOT Right ventricular outflow tract a. Parks Medical

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in Journal of the American Veterinary Medical Association

care and anesthetic management. Pulmonary artery thermodilution (PATD) is an invasive technique for measuring flow and pressures and is considered the “gold standard” for CO monitoring in humans and animals. 5 , 6 However, the utility of PATD in

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in American Journal of Veterinary Research
Author:

SUMMARY

Using catheter mounted microtip manometers, right atrial, pulmonary artery, and pulmonary artery wedge pressures were studied in 8 horses while they were standing quietly (rest), and during galloping at treadmill speeds of 8, 10, and 13 m/s. At rest, mean (± sem) heart rate, mean right atrial pressure, mean pulmonary artery pressure, and mean pulmonary artery wedge pressure were 37 (± 2) beats/min, 8 (± 2) mm of Hg, 31 (± 2) mm of Hg, and 18 (± 2) mm of Hg, respectively. Exercise at treadmill belt speed of 8 m/s resulted in significant (P < 0.05) increments in heart rate, right atrial pressure, pulmonary artery systolic, mean, diastolic and pulse pressures, and pulmonary artery wedge pressure. All these variables registered further significant (P < 0.05) increments as work intensity increased to 10 m/s, and then to 13 m/s. Pulmonary artery diastolic pressure was, however, not different among the 3 work intensities. During exercise at belt speed of 13 m/s, heart rate, mean right atrial pressure, mean pulmonary artery pressure, pulmonary artery pulse pressure, and mean pulmonary artery wedge pressure were 213 (± 5) beats/min, 44 (± 4) mm of Hg, 89 (± 5) mm of Hg, 69 (± 4) mm of Hg, and 56 (± 4) mm of Hg, respectively. Assuming mean intravascular pulmonary capillary pressure to be halfway between the mean pulmonary arterial and venous pressures, its value during exercise at 13 m/s may have approached 72.5 mm of Hg. Transmural pressure (intravascular minus alveolar pressure) across pulmonary capillaries may be even higher because of the large negative pleural pressure swings in galloping horses. High transmural pressures may cause stress failure of pulmonary capillaries, resulting in exercise-induced pulmonary hemorrhage.

Free access
in American Journal of Veterinary Research

Abstract

Objective

To determine whether dorsal displacesment of the soft palate (DDSP) results in pulmonary artery hypertension and leads to increases in transmural pulmonary artery pressure (TPAP); to determine whether pulmonary hypertension can be prevented by prior administration of furosemide; and to determine whether tracheostomy reduces pulmonary hypertension.

Animals

7 healthy horses.

Procedure

Horses were subjected to 3 conditions (control conditions, conditions after induction of DDSP, and conditions after tracheostomy). Horses were evaluated during exercise after being given saline (0.9% NaCI) solution or furosemide.

Results

Controlling for drug, horse, and speed of treadmill, DDSP-induced increase in intrathoracic pressure was associated with a significant increase in minimum (36 mm Hg), mean (82 mm Hg), and maximum (141 mm Hg) pulmonary artery pressure, compared with values for control horses (30, 75, and 132 mm Hg, respectively). Increases in pulmonary artery pressure did not induce concomitant increases in TPAP. Tracheostomy led to a significant reduction of minimum (53 mm Hg), and mean (79 mm Hg) TPAP pressure, compared with values for control horses (56 and 83 mm Hg, respectively). When adjusted for horse, speed of treadmill, and type of obstruction, all aspects of the pulmonary artery and TPAP curves were significantly decreased after administration of furosemide, compared with those for horses given saline (0.9% NaCI) solution.

Conclusions

DDSP was associated with increases in pulmonary artery pressure but not with increases in TPAP.

Clinical Relevance

Expiratory obstructions such as DDSP are likely to result in pulmonary hypertension during strenuous exercise, but may not have a role in the pathogenesis of exercise-induced pulmonary hemorrhage. (Am J Vet Res 1999;60:485-494).

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in American Journal of Veterinary Research

Abstract

Objective

To test the effect of heartworm infection on agonist-induced constriction of canine pulmonary artery and vein in vitro.

Procedure

Cumulative concentration-response relations to norepinephrine, serotonin, histamine, prostaglandin F2α, and the thromboxane A2 analog U-44069 were determined, using isolated rings of pulmonary artery and vein from control and heartworm-infected dogs. To determine the role of endothelial cells in histamine constriction, some rings were denuded of endothelial cells in both artery and vein.

Animals

Noninfected control and heartworm-infected dogs.

Results

There was no difference in constriction response to norepinephrine, serotonin, prostaglandin F2α, or U44069 of pulmonary artery or vein from control or heartworm-infected dogs. Histamine-induced constriction of pulmonary artery from heartworm-infected dogs was not different from control values, however, when endothelial cells were removed from control, but not heartworm-infected pulmonary artery, histamine-induced constriction was enhanced. Histamine-induced constriction of pulmonary vein from heartworm-infected dogs was significantly depressed, compared with that of control pulmonary vein. However, removal of endothelial cells in pulmonary vein from heartworm-infected, but not control dogs significantly increased constriction.

Conclusion

Heartworm infection alters histamine-induced constriction responses of pulmonary artery and vein. These changes may reflect high circulating histamine concentrations in heartworm-infected dogs, compared with that in controls. Increased circulating histamine concentrations in vivo could bring about decreased sensitivity of histamine receptors or decreases in the number of receptors expressed.

Clinical Relevance

Mast cells and histamine may be important factors in altered endothelium-mediated responses associated with heartworm disease. (Am J Vet Res 1997;58:394–397)

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in American Journal of Veterinary Research