Frequency Operative
and Prognosis of Arrhythmias After Worrection” of Tetralogy of Fallot
Guy Vaksmann, MD, Anne Fournier, MD, Andre Davignon, MD, Gilles Ducharme, PhD, Lucile Houyel, MD, and Jean-Claude Fouron, MD
Two hundred twenty-four consecutive patients operated on for tetralogy of Fallot were followed from 1 to 28 years (mean 11). Mean age at surgery was 5.3 years (range 1 to 14). Postoperative right ventricular systolic pressure was 66 mm Hg in 19 of 213 patients (9%). Fourteen patients (6%) had ventricular premature complexes on surface electrocardiograms. Seventy-nine patients underwent treadmill exercise tests, and ventricular premature complexes were induced in 17 (22%). Twenty-four-hour ambulatory monitoring in 92 patients demonstrated significant ventricular arrhythmias (2 grade 2 of the Lown classification) in 41 (45%). The frequency of ventricular arrhythmias correlated with length of follow-up and duration of cardiopulmonary bypass. No correlation was found with age at surgery, postoperative right ventricular systolic pressure and importance of conduction defects on electrocardiogram. There were no sudden or unexpected deaths during follow-up. (Am J Cardiol 1990;66:346-349)
From the Division of Pediatric Cardiology, SaintsJustine Hospital, and the University of Montreal, Mont$al, QuCbec, Canada. This study was supported in part by So&C d’Etudes et de Soins pour les Enfants Atteints de Rhumatisme Articulaire et de Cardiopathies (SESERAC), France, and was presented in part at the American Heart Association’s 61st Scientific Sessions, Washington, DC, November 1988. Manuscript received January 9, 1990; revised manuscript received and accepted March 27, 1990. Address for reprints: Anne Fournier, MD, Division of Pediatric Cardiology, Ste-Justine Hospital, 3175 &te Ste-Catherine, Montrkal, Quebec, Canada H3T lC5.
346
THE AMERICAN JOURNAL OF CARDIOLOGY VOLUME 66
entricular arrhythmias are common after repair of tetralogy of Fallot and have been recognized as a risk indicator for sudden death, which has been reported in up to 5% of patients.im5Whether all patients with ventricular arrhythmias should receive antiarrhythmic treatment or whether treatment should be reserved for patients with additional risk factors is still unresolved. This study reports our experiencewith patients operated on for tetralogy of Fallot in our institution, with special attention paid to frequency and prognosis of ventricular arrhythmias managed with an overall conservativeapproach.
V
METHODS
Two hundred twenty-four consecutivepatients who underwent correction of tetralogy of Fallot from 1960 to 1986 at Sainte-Justine Hospital and who were followed for >l year were reviewed. All patients were operated on by the samesurgical team. A systemic-to-pulmonary artery anastomosishad beencreatedbeforecorrective surgery in 139 patients; primary repair had been done in the others. Clinical status was determined in 207 patients (93%) (clinical assessmentin 197, phone evaluation in 10) during the 18 months before the end of the study (17 patients were lost to follow-up); 203 of those clinically assessed(98%) were in functional classI or II of the New York Heart Association. On chest roentgenogram the heart was usually of normal size or slightly enlarged; the mean cardiothoracic index was 0.52 f 0.07. Age at corrective surgery ranged from 1 to 14 years (mean 5.3). Duration of postoperativefollowup from surgery to evaluation was 1 to 28 years (mean 10.6). A second intracardiac procedure had been performed in 6 patients (3 for outflow tract aneurysm, 2 for residual ventricular septal defect, 1 for subaortic stenosis). Right ventricular systolic pressuremeasuredat the end of the surgical procedure after hemodynamic stabilization was available in 209 patients. In 38 patients postoperative cardiac catheterization had been done 6 months to 26 years after correction. A good correlation with a sensitivity of 89% was found between immediate postoperativeright ventricular systolic pressure and pressure measured at postoperative cardiac catheterization.6 Twelve-lead electrocardiograms recorded preoperatively, postoperatively and at each follow-up visit (average 0.9 per year) were reviewed, with special attention given to the presenceof arrhythmias or conduction defects. Complete right bundle branch block was defined as a QRS duration >O.lO second in patients younger
than 16 years of age and >O. 12 second in older patients. Left axis deviation was defined as a QRS mean frontal plane axis between -30 and - 120”. Treadmill exercise test to maximal tolerance was performed using the Bruce protocol in 79 patients. The electrocardiogram was displayed on an oscilloscope and observed for rhythm during and for 5 minutes after exercise. The test was considered positive if it induced > 1 ventricular premature complex. The mean age at surgery of this group of patients was 5.6 years with a mean follow-up of 12.6 years. Twenty-four-hour ambulatory monitoring was performed in 92 patients; in 85 patients it was done during 18 months before the end of the study. All patients were studied as outpatients. These patients do not differ from the total group for mean age at surgery (5.4 years) and mean follow-up duration (11.4 years). Ventricular arrhythmias were graded using a modification of Lown’s criteria’ proposed by Deanfield et al? grade 0 = no ventricular premature complex; grade 1 = uniform ventricular premature complexes with a peak hourly count 30 ventricular premature complexes in any hour; grade 3 = couplets or multiform ventricular premature complexes with a peak hourly count 30 in any hour; and grade 5 = ventricular tachycardia defined as 13 consecutive ventricular premature complexes with a mean rate >l lO/min. Ventricular arrhythmias were considered significant when Lgrade 2. Since 1986, 9 patients have been treated with phenytoin for significant ventricular arrhythmias. The mean duration of treatment from beginning to the last evaluation was 1.3 years. Statistical significance of proportions was determined by Fisher’s exact test and means by unpaired Student’s t test. Analysis of covariance was also used to take into account the possible confounding effects of covariables. A p value
and Prognosis of Arrhythmias After Worrection” of Tetralogy of Fallot
Guy Vaksmann, MD, Anne Fournier, MD, Andre Davignon, MD, Gilles Ducharme, PhD, Lucile Houyel, MD, and Jean-Claude Fouron, MD
Two hundred twenty-four consecutive patients operated on for tetralogy of Fallot were followed from 1 to 28 years (mean 11). Mean age at surgery was 5.3 years (range 1 to 14). Postoperative right ventricular systolic pressure was 66 mm Hg in 19 of 213 patients (9%). Fourteen patients (6%) had ventricular premature complexes on surface electrocardiograms. Seventy-nine patients underwent treadmill exercise tests, and ventricular premature complexes were induced in 17 (22%). Twenty-four-hour ambulatory monitoring in 92 patients demonstrated significant ventricular arrhythmias (2 grade 2 of the Lown classification) in 41 (45%). The frequency of ventricular arrhythmias correlated with length of follow-up and duration of cardiopulmonary bypass. No correlation was found with age at surgery, postoperative right ventricular systolic pressure and importance of conduction defects on electrocardiogram. There were no sudden or unexpected deaths during follow-up. (Am J Cardiol 1990;66:346-349)
From the Division of Pediatric Cardiology, SaintsJustine Hospital, and the University of Montreal, Mont$al, QuCbec, Canada. This study was supported in part by So&C d’Etudes et de Soins pour les Enfants Atteints de Rhumatisme Articulaire et de Cardiopathies (SESERAC), France, and was presented in part at the American Heart Association’s 61st Scientific Sessions, Washington, DC, November 1988. Manuscript received January 9, 1990; revised manuscript received and accepted March 27, 1990. Address for reprints: Anne Fournier, MD, Division of Pediatric Cardiology, Ste-Justine Hospital, 3175 &te Ste-Catherine, Montrkal, Quebec, Canada H3T lC5.
346
THE AMERICAN JOURNAL OF CARDIOLOGY VOLUME 66
entricular arrhythmias are common after repair of tetralogy of Fallot and have been recognized as a risk indicator for sudden death, which has been reported in up to 5% of patients.im5Whether all patients with ventricular arrhythmias should receive antiarrhythmic treatment or whether treatment should be reserved for patients with additional risk factors is still unresolved. This study reports our experiencewith patients operated on for tetralogy of Fallot in our institution, with special attention paid to frequency and prognosis of ventricular arrhythmias managed with an overall conservativeapproach.
V
METHODS
Two hundred twenty-four consecutivepatients who underwent correction of tetralogy of Fallot from 1960 to 1986 at Sainte-Justine Hospital and who were followed for >l year were reviewed. All patients were operated on by the samesurgical team. A systemic-to-pulmonary artery anastomosishad beencreatedbeforecorrective surgery in 139 patients; primary repair had been done in the others. Clinical status was determined in 207 patients (93%) (clinical assessmentin 197, phone evaluation in 10) during the 18 months before the end of the study (17 patients were lost to follow-up); 203 of those clinically assessed(98%) were in functional classI or II of the New York Heart Association. On chest roentgenogram the heart was usually of normal size or slightly enlarged; the mean cardiothoracic index was 0.52 f 0.07. Age at corrective surgery ranged from 1 to 14 years (mean 5.3). Duration of postoperativefollowup from surgery to evaluation was 1 to 28 years (mean 10.6). A second intracardiac procedure had been performed in 6 patients (3 for outflow tract aneurysm, 2 for residual ventricular septal defect, 1 for subaortic stenosis). Right ventricular systolic pressuremeasuredat the end of the surgical procedure after hemodynamic stabilization was available in 209 patients. In 38 patients postoperative cardiac catheterization had been done 6 months to 26 years after correction. A good correlation with a sensitivity of 89% was found between immediate postoperativeright ventricular systolic pressure and pressure measured at postoperative cardiac catheterization.6 Twelve-lead electrocardiograms recorded preoperatively, postoperatively and at each follow-up visit (average 0.9 per year) were reviewed, with special attention given to the presenceof arrhythmias or conduction defects. Complete right bundle branch block was defined as a QRS duration >O.lO second in patients younger
than 16 years of age and >O. 12 second in older patients. Left axis deviation was defined as a QRS mean frontal plane axis between -30 and - 120”. Treadmill exercise test to maximal tolerance was performed using the Bruce protocol in 79 patients. The electrocardiogram was displayed on an oscilloscope and observed for rhythm during and for 5 minutes after exercise. The test was considered positive if it induced > 1 ventricular premature complex. The mean age at surgery of this group of patients was 5.6 years with a mean follow-up of 12.6 years. Twenty-four-hour ambulatory monitoring was performed in 92 patients; in 85 patients it was done during 18 months before the end of the study. All patients were studied as outpatients. These patients do not differ from the total group for mean age at surgery (5.4 years) and mean follow-up duration (11.4 years). Ventricular arrhythmias were graded using a modification of Lown’s criteria’ proposed by Deanfield et al? grade 0 = no ventricular premature complex; grade 1 = uniform ventricular premature complexes with a peak hourly count 30 ventricular premature complexes in any hour; grade 3 = couplets or multiform ventricular premature complexes with a peak hourly count 30 in any hour; and grade 5 = ventricular tachycardia defined as 13 consecutive ventricular premature complexes with a mean rate >l lO/min. Ventricular arrhythmias were considered significant when Lgrade 2. Since 1986, 9 patients have been treated with phenytoin for significant ventricular arrhythmias. The mean duration of treatment from beginning to the last evaluation was 1.3 years. Statistical significance of proportions was determined by Fisher’s exact test and means by unpaired Student’s t test. Analysis of covariance was also used to take into account the possible confounding effects of covariables. A p value
