Aortic Input Impedance during Nitroprusside Infusion
نویسنده
چکیده
Receivedfor publication 21 November 1977 and in revised form 16 April 1979. vascular load and improve ventricular function independent of aortic pressure reduction.
منابع مشابه
Aortic input impedance during nitroprusside infusion. A reconsideration of afterload reduction and beneficial action.
Beneficial effects of nitroprusside infusion in heart failure are purportedly a result of decreased afterload through "impedance" reduction. To study the effect of nitroprusside on vascular factors that determine the total load opposing left ventricular ejection, the total aortic input impedance spectrum was examined in 12 patients with heart failure (cardiac index <2.0 liters/min per m(2) and ...
متن کاملAortic input impedance in man: acute response to vasodilator drugs.
In 18 patients who underwent coronary arteriography, aortic velocity and pressure data were obtained during a control state and during either isoproterenol infusion at 1, 2 and 3 micrograms/min or graded nitroprusside infusion (average peak dose 60 micrograms/min). Impedance moduli and phase angles were derived to 10 Hz for controls states, isoproterenol at 2 micrograms/min, and at peak nitropr...
متن کاملEffects of alterations in aortic input impedance on the force-velocity-length relationship in the intact canine heart.
We studied the effects of changes in aortic input impedance on the force-velocity-length relationship of the left ventricle in sir open-chest dogs, using a right heart bypass preparation. The control relationship between wall stress and ventricular diameter or mean velocity of shortening (MVCF) was determined first by using maneuvers (changes in venous return and phenylephrine infusion) that di...
متن کاملPulse Wave Reflection: Can It Explain the Differences Between Systemic and Pulmonary Pressure and Flow Waves? A Study in Dogs
We have studied the effect of changes in pulse wave reflection on the configurations of pressure and flow in systemic and pulmonary circulation. Electromagnetic flow transducers, atrial catheters, and pacing leads were implanted in 10 dogs. In four animals, the flow transducer was placed on the pulmonary artery, in another four on the ascending aorta, and in two additional dogs on both vessels....
متن کاملInput impedance of the lower abdominal aorta in chronically instrumented fetal sheep.
Five fetal sheep (gestational age, 118 to 125 days) were instrumented to measure impedances of the lower abdominal aorta. Four days after surgery, flow and pressure pulses were recorded during control conditions and during infusion of norepinephrine (0.3 to 3 micrograms.min-1.kg-1 body weight) or angiotensin II (0.2 to 3 micrograms.min-1.kg-1). The protocol was repeated after injection of hexam...
متن کامل