RESUMEN
The newborn pig is currently the most used species in animal neonatal research. Valid non-invasive monitoring is important in particular for long-term survival of unsedated animals. In the unsedated newborn pig (n = 35, median age 24 h, range 7-48 h) we standardized two-dimensional Doppler echocardiography and determined the normal ranges for cardiac function. Probe positioning had to be adjusted to the V-shaped thorax and the mid-line position of the heart. Six out of the sixteen animals < 20 h had a patent ductus arteriosus compared with one of the twenty animals > 20 h old. One atrial septal defect (5 mm) and one small ventricular septal defect were diagnosed. The average heart size was 0.7-0.9% of body weight which is similar to human infants of the same size. The mean aortic diameter was 6.0 +/- 0.5 mm (mean +/- S.D.) and cardiac output was 0.38 +/- 0.08 l min-1; both correlate with body weight (r = 0.80 and 0.73, respectively). Tricuspid regurgitation velocity was 3.0 +/- 0.4 m s-1 (mean +/- S.D.), giving an estimated pressure gradient across the tricuspid valve of 37 +/- 9.7 mmHg. The aortic diameter and the heart weight per kg body weight are comparable to those reported for preterm neonates. The cardiac output and velocities across the four valves are more comparable with term neonates.
Asunto(s)
Animales Recién Nacidos/anatomía & histología , Animales Recién Nacidos/fisiología , Ecocardiografía , Corazón/fisiología , Porcinos/anatomía & histología , Porcinos/fisiología , Animales , Aorta/diagnóstico por imagen , Velocidad del Flujo Sanguíneo/fisiología , Gasto Cardíaco/fisiología , Conducto Arterioso Permeable/diagnóstico por imagen , Femenino , Corazón/anatomía & histología , Defectos del Tabique Interatrial/diagnóstico por imagen , Defectos del Tabique Interventricular/diagnóstico por imagen , Masculino , Tamaño de los Órganos/fisiología , Valores de Referencia , Insuficiencia de la Válvula Tricúspide/diagnóstico por imagen , Insuficiencia de la Válvula Tricúspide/fisiopatologíaRESUMEN
BACKGROUND: Nonsteroidal anti-inflammatory drugs may attenuate the antihypertensive effects of diuretics, beta-blockers, angiotensin-converting enzyme inhibitors, central alpha-agonists, and other vasodilators. Their effects on the antihypertensive efficacy of calcium channel blockers are inadequately studied in small numbers of patients but appear to be minimal. METHODS: A three-phase, randomized, double-blind, placebo-controlled multicenter study included 162 patients aged 18 to 75 years with essential hypertension. After diastolic blood pressure was controlled to 90 mm Hg or less with once-daily verapamil hydrochloride, patients received ibuprofen, naproxen, or placebo matching capsules for 3 weeks, and blood pressure, heart rate, weight, and adverse effects were evaluated. A general linear model with 95% confidence intervals was used to compare each nonsteroidal anti-inflammatory drug treatment group with the placebo group. RESULTS: No significant differences in sitting, standing, or supine blood pressure were noted with naproxen or ibuprofen compared with placebo. The percentages of patients in each treatment group with increases of 10 mm Hg or more in either systolic or diastolic blood pressure were similar. Statistically significant increases in weight were seen with both nonsteroidal anti-inflammatory drug therapies. Changes in pulse rate were not significant. The incidence of adverse effects was similar across all three treatment groups. CONCLUSIONS: The addition of naproxen or ibuprofen to the treatment of hypertensive patients in whom blood pressure is controlled by once-daily verapamil does not cause an increase in blood pressure. Verapamil may therefore offer considerable advantages in maintaining control of blood pressure in patients who regularly receive nonsteroidal anti-inflammatory drug therapy.