The American journal of cardiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparative evaluation of a new formulation of isosorbide dinitrate oral spray and sublingual nitroglycerin tablets.
The magnitude and time course of the hemodynamic effect of a new formulation of an aqueous solution of isosorbide dinitrate (ISDN) spray were compared with those of sublingual nitroglycerin (NTG) tablets in 12 patients with chronic congestive heart failure. The patients received, in a random order, ISDN spray, 2.5 mg, or sublingual NTG, 0.8 mg. Hemodynamic measurements were performed before and at 1, 3, 5, 10, 20, 30 and 60 minutes after each drug. ⋯ The peak effect of ISDN spray on PCWP and right atrial pressure was greater than that of NTG. Thus, the onset of the hemodynamic effect of the new formulation of ISDN spray is much more rapid than that of sublingual NTG tablets. At the doses used, the magnitude of the effect of the ISDN spray on some of the hemodynamic variables is greater than that of sublingual NTG.
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Randomized Controlled Trial Clinical Trial
A dose-finding study of the hemodynamic effect of isosorbide dinitrate spray in congestive heart failure.
A dose-finding study of the hemodynamic effect of a new formulation of isosorbide dinitrate (ISDN) spray was performed in 12 patients with chronic congestive heart failure. Doses of 1.25, 2.5, 5.0 mg and placebo, as 1 squirt, were randomly given to all patients. Hemodynamic measurements were performed by a Swan-Ganz catheter before and at 30 seconds and 1, 5, 10, 20 and 30 minutes after drug administration and every 30 minutes thereafter, until return of hemodynamic variables to baseline. ⋯ Near maximal effect was achieved by the 2.5-mg dose. Thus, 2.5 mg of ISDN spray (new formulation) dose. Thus, 2.5 mg of ISDN spray (new formulation) produces rapid, near-maximal hemodynamic improvement in patients with congestive heart failure.
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The hemodynamic manifestations of the Valsalva maneuver are in part the result of changes in the venous return accompanying changes in intrathoracic pressure. Doppler echocardiography was performed during Valsalva maneuver in 13 normal subjects. Superior vena cava flow velocities and flow velocity integrals were measured in all 13 subjects. ⋯ With release of the maneuver (phase III), there was a sudden significant increase in flow velocity integral (61 +/- 2 cm, p = 0.005 vs phase II) and superior vena cava lumen diameter. Subsequently, superior vena cava flow velocity integral returned to baseline values. This study suggests that one of the ways in which the Valsalva maneuver leads to decreased venous return may be by direct external compression of the superior vena cava.
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There are few data on oxygen transport in cardiogenic shock after acute myocardial infarction. This prospective study examined oxygen transport variables in 19 such patients and assessed their responses to treatment. Femoral and pulmonary arterial catheters were inserted before any therapy except correction of hypoxemia by mechanical ventilation in 8 patients, defibrillation (3 patients) or pacing (5 patients). ⋯ There was no correlation between cuff systolic blood pressure and mean arterial pressure before or after resuscitation. Thirteen patients survived to hospital discharge. When cardiogenic shock responds to treatment, large increases in DO2 lead to small increases in VO2 but large increases in mixed venous oxygen saturation, reflecting improved tissue oxygen availability.