Medication Summary
The majority of patients with tetralogy of Fallot (TOF) require no medical therapy prior to undergoing surgical repair. In rare instances, medications may be needed to treat ductal patency in severely cyanotic neonates and signs of congestive heart failure in patients with a minimal degree of right ventricular outflow tract obstruction.
Hypercyanotic spells are initially treated with nonpharmacologic means, including knee-chest position, supplemental oxygen, and volume expansion. In more severe episodes, additional pharmacologic interventions may include beta-blocker therapy to reduce right ventricular infundibular spasm and alpha-1 agonists to increase systemic vascular resistance.
In/outpatient medications
Most patients are on no medications prior to surgical repair. Beyond the initial postoperative period, most patients are also are on no medications. Select patients may require medication to treat ventricular dysfunction, congestive heart failure, or cardiac arrhythmias.
Vasodilators
Class Summary
The use of a vasodilator will reduce systemic vascular resistance, allowing more forward flow, improving cardiac output.
Alprostadil (Prostin VR Pediatric)
Severely cyanotic neonates may require prostaglandin E1 to maintain ductal patency in order to provide adequate pulmonary blood flow.
Intravenous prostaglandin E1 may be continued until the time of surgical palliation.
Diuretics
Class Summary
Loop diuretics decrease plasma volume and edema by causing diuresis. The reduction in plasma volume and stroke volume associated with diuresis decreases cardiac output and, consequently, blood pressure.
Furosemide (Lasix)
Patients with a minimal degree of right ventricular outflow tract obstruction may show signs and symptoms of pulmonary overcirculation. In these patients, diuretic therapy can be initiated to treat signs of congestive heart failure.
Alpha1 Agonists
Class Summary
These agents improve the hemodynamic status by increasing myocardial contractility and heart rate, resulting in increased cardiac output. They also increase peripheral resistance by causing vasoconstriction. Increased cardiac output and increased peripheral resistance lead to increased blood pressure.
Phenylephrine
Phenylephrine is used to increase systemic vascular resistance.
Beta-Blockers, Beta-1 Selective
Class Summary
These agents inhibit chronotropic, inotropic, and vasodilatory responses to beta-adrenergic stimulation.
Metoprolol (Lopressor, Toprol XL)
Beta-blocker therapy is used to reduce right ventricular infundibular spasm.
Hypercyanotic spells are initially treated with nonpharmacologic means, including knee-chest position, supplemental oxygen, and volume expansion. In more severe episodes, additional pharmacologic interventions may include beta-blocker therapy to reduce right ventricular infundibular spasm and phenylephrine to increase systemic vascular resistance.
