[The treatment of postoperative junctional ectopic tachycardia].

OBJECTIVE

To evaluate treatment of junctional ectopic tachycardia after cardiac surgery.

MATERIAL AND METHODS

Twenty-seven patients (5.5 % of 488 patients who underwent surgery) were treated for junctional ectopic tachycardia between 1994 and 1998. There were 14 boys and 13 girls with a mean age of 11 11 months. Seven suffered from tetralogy of Fallot, seven from ventricular septal defect, six from atrioventricular septal defect, three from transposition of the great vessels and the remaining four had other complex heart diseases. The mean initial frequency was 186 27 beats/min. Crystalloid cardioplegia was applied in 274 patients (1994-1996) and 20 patients (7.4 %) showed junctional ectopic tachycardia. Hematic cardioplegia was performed in 214 patients (1997-1998) and seven patients (3.2 %) developed junctional ectopic tachycardia. Of the 33 patients who were treated during the surgical procedure with high mean doses of sympathomimetic catecholamine agents, 27 (81 %) developed tachycardia. Tachycardia developed 8.24 7 hours after surgery (range: 1-24 hours) in 25 patients and after 4 and 5 days in the remaining two patients. The mean duration of tachycardia was 4 days.

RESULTS

In all patients rectal temperature was reduced to 32-34 C. Nineteen patients (70 %) showed a quick response (1-2 hours), although the technique was effective as an isolated procedure in only one patient. Sympathomimetic catecholamine level was reduced to 2-5 g/kg/min in 20 patients but this was effective in 14 (70 %). In 15 patients intravenous amiodarone was also administered and was effective in 11 patients (73 %). Finally, intravenous propafenone was administered to 5 patients. The most effective treatments were hypothermia with reduction of sympathomimetic catecholamine levels in 7 patients (100 %) or intravenous amiodarone in 4 (80 %). Tachycardia led to low cardiac output in 10 patients and only four recovered normal sinus rhythm. Eight patients died. Of these, hemorrhage in the junction area was confirmed in six patients.

CONCLUSIONS

Junctional ectopic tachycardia is favored by high levels of sympathomimetic catecholamines after surgery. On the other hand, myocardial protection with hematic cardioplegia reduces tachycardia. Moderate hypothermia with reduction of sympathomimetic agents or intravenous amiodarone reverses ectopic tachycardia.