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Butts RJ, Chowdhury SM, Baker GH, Bandisode V, Savage AJ, Atz AM. Effect of Sildenafil on Pressure-Volume Loop Measures of Ventricular Function in Fontan Patients. Pediatr Cardiol 2016; 37:184-91. [PMID: 26409473 PMCID: PMC4833409 DOI: 10.1007/s00246-015-1262-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 08/27/2015] [Indexed: 12/11/2022]
Abstract
UNLABELLED Sildenafil has been reported to improve exercise capacity in Fontan patients, but the physiologic mechanisms behind these findings are not completely understood. The objective of this study was to study the acute effect of sildenafil on pressure-volume loop (PVL) measures of ventricular function in Fontan patients. Patients after Fontan operation who were presenting for a clinically indicated catheterization were enrolled. Patients were randomized in a double-blinded fashion to receive placebo (n = 9) or sildenafil (n = 10) 30-90 min prior to catheterization. PVLs were recorded using microconductance catheters at baseline and after infusion of dobutamine (10 mcg/kg/min). The primary outcome was change in ventriculoarterial (VA) coupling. For the entire cohort, VA coupling trended toward improvement with dobutamine (1.4 ± 0.4 to 1.8 ± 0.9, p = 0.07). End-systolic elastance showed improvement (2.6 ± 0.9 to 3.8 ± 1.4 mmHg m(2)/ml, p < 0.01) with dobutamine infusion. The cohorts had similar VA coupling at baseline (p = 0.32), but the sildenafil cohort trended toward having less of an improvement in VA coupling with dobutamine stress (p = 0.06). There were no differences between PVL measures of systolic or diastolic function between treatment groups, both at baseline and after dobutamine infusion. Patients with Fontan circulation had improved contractility and trended toward improvement in VA coupling with dobutamine stress. Acute sildenafil administration was not associated with improved PVL measurements of ventricular function in this population. These results suggest that clinical improvements seen with administration of sildenafil in Fontan patients are not associated with an acute improvement in ventricular function. CLINICAL TRIAL REGISTRATION www.clinicaltrials.gov ; Clinicaltrials.gov Identifier: NCT01815502.
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Affiliation(s)
- Ryan J. Butts
- Division of Cardiology, Department of Pediatrics, Medical University of South Carolina, 165 Ashley Avenue, MSC 915, Charleston, SC 29425, USA
| | - Shahryar M. Chowdhury
- Division of Cardiology, Department of Pediatrics, Medical University of South Carolina, 165 Ashley Avenue, MSC 915, Charleston, SC 29425, USA
| | - George H. Baker
- Division of Cardiology, Department of Pediatrics, Medical University of South Carolina, 165 Ashley Avenue, MSC 915, Charleston, SC 29425, USA
| | - Varsha Bandisode
- Division of Cardiology, Department of Pediatrics, Medical University of South Carolina, 165 Ashley Avenue, MSC 915, Charleston, SC 29425, USA
| | - Andrew J. Savage
- Division of Cardiology, Department of Pediatrics, Medical University of South Carolina, 165 Ashley Avenue, MSC 915, Charleston, SC 29425, USA
| | - Andrew M. Atz
- Division of Cardiology, Department of Pediatrics, Medical University of South Carolina, 165 Ashley Avenue, MSC 915, Charleston, SC 29425, USA
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