Author: Sana Ullah, MB ChB, FRCA - Children’s Medical Center, Dallas
An 11-month-old male infant with severe pulmonary valve stenosis and estimated peak systolic gradient of 110 mmHg presents for balloon pulmonary valvuloplasty. Immediately following balloon valvuloplasty, the vital signs are as follows: heart rate 165 beats per minute, blood pressure 53/21, and oxygen saturation 60%. Which of the following measures is the MOST APPROPRIATE next step in his management?
Correct!
Wrong!
Question of the Week 338
This patient has developed a rare but serious complication colloquially known as a “suicide right ventricle” or dynamic right ventricular infundibular obstruction following balloon pulmonary valvuloplasty. Severe pulmonary valve stenosis can result in significant right ventricular hypertrophy and in particular right infundibular hypertrophy. An acute relief of the valvar gradient can suddenly unmask a previously unknown infundibular gradient leading to dynamic right ventricular outflow tract obstruction. The pathophysiology is similar to left ventricular outflow tract obstruction in the setting of hypertrophic cardiomyopathy. The mainstay of treatment is to reduce the heart rate and contractility with a beta blocker such as esmolol, labetalol, or propranolol. The decrease in contractility allows for improved ventricular filling during diastole. Beta blockade with oral propranolol may be necessary for a period of time after balloon valvuloplasty to allow for ventricular remodeling. In this case, esmolol is the appropriate treatment due to the fast onset of action given severe oxygen desaturation and hypotension.
In this case, an epinephrine bolus would not be helpful because the oxygen desaturation and hypotension are due to right ventricular infundibular obstruction rather than ventricular dysfunction. An epinephrine bolus would increase contractility and likely worsen the signs of infundibular obstruction.
Although this patient likely has right ventricular diastolic dysfunction, a milrinone bolus would acutely produce systemic vasodilation and thereby worsen hypotension.
Inhaled nitric oxide would not be indicated in the treatment of right ventricular infundibular obstruction as it would reduce pulmonary arterial pressure rather than relieve infundibular obstruction.
References:
1) Khambatta H, Velado M, Gaffney J, Schechter W, Casta A. Management of right ventricular tract reactivity following pulmonary valve dilation after general anesthesia: experience of a medical mission. Pediatric Anesthesia. 2006; 16(10): 1087-1089.
2) Ben-Shachar G, Cohen M, Sivakoff M, Portman M, Riemenschneider T, Van Heeckeren D. Development of infundibular obstruction after percutaneous pulmonary balloon valvuloplasty. J Am Coll Cardiol. 1985; 5(3): 754-756.
3) Tharpar MK, Rao PS. Significance of infundibular obstruction following balloon valvuloplasty for valvar pulmonic stenosis. Am Heart J. 1989; 118: 99-103.
In this case, an epinephrine bolus would not be helpful because the oxygen desaturation and hypotension are due to right ventricular infundibular obstruction rather than ventricular dysfunction. An epinephrine bolus would increase contractility and likely worsen the signs of infundibular obstruction.
Although this patient likely has right ventricular diastolic dysfunction, a milrinone bolus would acutely produce systemic vasodilation and thereby worsen hypotension.
Inhaled nitric oxide would not be indicated in the treatment of right ventricular infundibular obstruction as it would reduce pulmonary arterial pressure rather than relieve infundibular obstruction.
References:
1) Khambatta H, Velado M, Gaffney J, Schechter W, Casta A. Management of right ventricular tract reactivity following pulmonary valve dilation after general anesthesia: experience of a medical mission. Pediatric Anesthesia. 2006; 16(10): 1087-1089.
2) Ben-Shachar G, Cohen M, Sivakoff M, Portman M, Riemenschneider T, Van Heeckeren D. Development of infundibular obstruction after percutaneous pulmonary balloon valvuloplasty. J Am Coll Cardiol. 1985; 5(3): 754-756.
3) Tharpar MK, Rao PS. Significance of infundibular obstruction following balloon valvuloplasty for valvar pulmonic stenosis. Am Heart J. 1989; 118: 99-103.
