Assessment of vasodilator therapy in patients with severe congestive heart failure: limitations of measurements of left ventricular ejection fraction and volumes
Although noninvasive techniques are often used to assess the effect of vasodilator therapy in patients with congestive heart failure, it is unknown whether changes in noninvasively determined left ventricular ejection fraction, volume, or dimension reliably reflect alterations in intracardiac pressure and flow. Accordingly, we compared the acute effect of sodium nitroprusside on left ventricular volume and ejection fraction (determined scintigraphically) with its effect on intracardiac pressure and forward cardiac index (determined by thermodilution) in 12 patients with severe, chronic congestive heart failure and a markedly dilated left ventricle. Nitroprusside (infused at 1.3 +/- 1.1 (mean +/- standard deviation) microgram/kg/min) caused a decrease in mean systemic arterial, mean pulmonary arterial, and mean pulmonary capillary wedge pressure as well as a concomitant increase in forward cardiac index. Simultaneously, left ventricular end-diastolic and end-systolic volume indexes decreased, but the scintigraphically determined cardiac index did not change significantly. Left ventricular ejection fraction averaged 0.19 +/- 0.05 before nitroprusside administration and increased by less than 0.05 units in response to nitroprusside in 11 of 12 patients. The only significant correlation between scintigraphically and invasively determined variables was that between the percent change in end-diastolic volume index and the percent change in pulmonary capillary wedge pressure (r . 0.68, p . 0.01). Although nitroprusside produced changes in scintigraphically determined left ventricular ejection fraction, end-systolic volume index, and cardiac index, these alterations bore no predictable relation to changes in intracardiac pressure, forward cardiac index, or vascular resistance. Furthermore, nitroprusside produced a considerably greater percent change in the invasively measured variables than in the scintigraphically determined ones.
- Research Organization:
- Department of Internal Medicine, University of Texas Health Science Center, Dallas
- OSTI ID:
- 6529148
- Journal Information:
- Am. J. Cardiol.; (United States), Vol. 50:5
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
CARDIOVASCULAR DISEASES
THERAPY
HEART
SCINTISCANNING
VASODILATORS
BIOLOGICAL EFFECTS
BLOOD CIRCULATION
BLOOD PRESSURE
ERYTHROCYTES
PATIENTS
RADIOPHARMACEUTICALS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY
BODY FLUIDS
CARDIOVASCULAR AGENTS
CARDIOVASCULAR SYSTEM
COUNTING TECHNIQUES
DIAGNOSTIC TECHNIQUES
DISEASES
DRUGS
LABELLED COMPOUNDS
MATERIALS
ORGANS
RADIOISOTOPE SCANNING
550601* - Medicine- Unsealed Radionuclides in Diagnostics
550901 - Pathology- Tracer Techniques
551001 - Physiological Systems- Tracer Techniques