The right ventricle dysfunction in the post-operative period of the heart transplantation (HTx) surgery is a frequent complication with high morbidity and mortality . In order to reduce the high pulmonary vascular resistance (PVR) and pulmonary artery pressure (PAP), often found in the patients candidates to HTx, it is, sometimes, necessary to use endovenous infusion of sodium nitroprusside (NaNTP) (the pharmacologic test), during the pre-operative hemodynamic assessment of the pulmonary circulation, in attempt to reduce the PVR and PAP to compatible levels, allowing the inclusion of these patients in the HTx program protocol. Values of PVR over 6 Wood units without drugs (such as NaNTP) or 2.5 Wood units with drugs will exclude the patient from the HTx program. Between January 1997 and January 2000, 40 patients (70% males) (mean age = 42 +/- 12), candidates to HTx were submitted to cardiac catheterization (right side). 24 patients (59%) had dilated idiopathic cardiomyopathy, 10 (25%) ischemic myocardiopathy. All were in Class IV (NYHA), with mean left ventricular ejection fraction (LVEF) of 0.21 (+/- 0.03). Continuous measurement of the cardiac output, PAP and RVP were done with the help of a special Swan-Ganz catheter. In 5 patients the pharmacologic test was interrupted owing to systemic effects of NaNTP (important drop of arterial blood pressure and cardiac output). Then, they were submitted to inhalation of 20 ppm of nitric oxide (NO), though facial mask, during 10 minutes, in three patients the RVP dropped from a mean of 7.8 (+/- 0.88) to 2.4 (+/- 0.36) Wood units and so they could be included in the transplantation program. The two other patients did not achieve RVP drops enough to be candidates to HTx, once, even though the amount of NO inhaled had reached 20, 30 and 40 ppm, the reduction of the RVP was from 8,4 (+/- 2.12) to 4,9 (+/- 0.42) Wood units. There were no deaths or complications during these producers. The NO inhalation during hemodynamic evaluation of candidates to HTx, owing to its selective vasodilator effect, allows us to identify those patients with pulmonary vascular hyperresistance, who do not respond to the use of endovenous vasodilator drugs, thus avoiding them to be excluded from the benefits of the HTx.
Nitric oxide; Vasodilator agents; Heart transplantation; Hypertension, pulmonary; Ventricular dysfunction, right; Vascular resistance; Preoperative care; Heart transplantation
