Nitrate Effect on Exercise Capacitance

Children's Hospital Medical Center, Cincinnati20 enrolled

Overview

The investigators will investigate the safety and preliminary efficacy of ISDN therapy to reduce venous congestion and improve exercise tolerance in children and adults after the Fontan operation. This will be accomplished by recruiting 15 Fontan physiology patients from the Cincinnati Children's Fontan clinic and University of Kentucky Pediatric Cardiology clinic for the investigation. The investigators will non-invasively measure both central venous pressures at rest and during graded cardiopulmonary exercise testing. In addition the study team will obtain a measurement of liver stiffness before and after a 4-week regimen of ISDN therapy. Patients will be seen twice in clinic, once before and after ISDN therapy, and phone calls will be made to ensure safety, compliance, and make appropriate alterations to medications throughout the study period. Pre- and post-intervention central venous pressure and exercise tolerance will be compared.

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Fontan

Interventions

Eligibility

Sex: ALLMin age: 9 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Underlying Fontan physiology * On a stable medication regimen for the past 3 months * Nine years of age or older Exclusion Criteria: * Pregnant or nursing * Prior hospitalization for heart failure in past year * Presence of uncontrolled arrhythmias within the past 6 months * Non-cardiac conditions which significantly limited exercise * Moderate or severe ventricular dysfunction by echocardiogram or cardiac MRI * Currently treated with a phosphodiesterase-5 inhibitor or organic nitrates * Concurrent enrollment in other investigational drug trial * End stage Liver Disease (ESLD)

Outcomes

Primary Outcomes

Number of Participants Who Experience an Adverse Reaction to the Study Medication During the Study Enrollment Period.

Potential adverse side effects of study medication (isosorbide dinitrate) will be monitored throughout study period. Study medication will be titrated to a maximal dose of 30mg dependent on the patient tolerance. Patient tolerance is defined by frequency of known risk factors to the study medication (headaches, hypotension, and syncope).