1. The Role of Isoproterenol in Pulmonary Artery Hypertension of Unknown Etiology (Primary) 
Eulo Lupi-Herrera, M.D., David Bialostozky, M.D., Angel Sobrino, M.D. 
CHEST 
Volume 79, Issue 3, Pages (March 1981)
DOI: /chest
Copyright © 1981 The American College of Chest Physicians Terms and Conditions

2. FIGURE 1 Clinical and ECG findings, case 4, asymptomatic.
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Copyright © 1981 The American College of Chest Physicians Terms and Conditions

3. FIGURE 2
Changes in systolic pulmonary artery pressure (SPAP) observed after (A) infusion or sublingual administration of isoproterenol.
CHEST  , DOI: ( /chest )
Copyright © 1981 The American College of Chest Physicians Terms and Conditions

4. FIGURE 3
Relationship between mean pulmonary artery pressure (PAP) and cardiac index (CI) before (B) and after (A) isoproterenol. Significant p values obtained.
CHEST  , DOI: ( /chest )
Copyright © 1981 The American College of Chest Physicians Terms and Conditions

5. FIGURE 4
Relationship between cardiac index (CI) and pulmonary arteriolar resistance (PAR) before (B) and after (A) infusion or sublingual administration of isoproterenol. Decrease of PAR normal or close to normal in cases 4 and 6.
CHEST  , DOI: ( /chest )
Copyright © 1981 The American College of Chest Physicians Terms and Conditions