Twenty-five years of progress in the medical treatment of pediatric and congenital heart disease.

In the past 25 years there has been a many-fold increase in the prospect that with early recognition and modern treatment the newborn with critical congenital heart disease will reach adult life in a healthy condition, prepared to earn a living and to function as a spouse and as a parent. Advancements in the medical treatment of congenital heart disease may create less public acclaim than may surgical treatment but many purely medical developments provide the basis for achieving ultimate surgical success and, by judicious use of some forms of medical treatment, operation can be avoided altogether. The eight major contributions to patient care that are discussed in this review and the 35 that are simply listed are merely examples of the many developments that have occurred in the past 25 years. These include: 1) the organization of pediatric cardiology and the contribution of volunteer health organizations, 2) continuing medical education aimed at promoting early diagnosis of congenital heart disease and prompt referral to a cardiac center, 3) advances in the technology of cardiac catheterization, 4) Rashkind's balloon atrial septostomy and other catheter manipulative procedures, 5) pharmacologic manipulation of the ductus, 6) beta-adrenergic blockade for control of a variety of problems, including paroxysmal hypoxemic attacks, certain arrhythmias and relief of symptoms in hypertrophic cardiomyopathy, 7) echocardiography, and 8) advances in arrhythmias, electrophysiologic studies and use of pacemakers.

Sudden death in a pediatric cardiology population, 1958 to 1983: relation to prior arrhythmias.

This review of sudden death in patients previously seen in a pediatric cardiology clinic attempts to identify factors that may have been predictive of sudden death. The denominator for these factors is unknown. For example, the number of patients with these possible risk factors who have well tolerated arrhythmias is not known. Further studies are planned to document the incidence of these factors in patients with similar lesions whom we continue to follow up. The following conclusions can be drawn from the study: More than three-quarters of the patients who died suddenly had severe limitation of activity, cardiac enlargement on chest radiograph or poor hemodynamic status at cardiac catheterization. The majority of patients who died suddenly had an arrhythmia in the 12 month period before death. A significant number of these arrhythmias developed for the first time in the year before death. The presence of arrhythmias was generally related to poor hemodynamic status in patients who died suddenly. Most sudden deaths occurred with the patient at rest and only approximately one-quarter occurred during participation in sports. Each cardiac diagnosis had its own specific profile of types of arrhythmias Conspicuously absent from the list of diagnoses were children with a normal heart and children with mitral valve prolapse.(ABSTRACT TRUNCATED AT 250 WORDS)

Induction of ventricular tachycardia during electrophysiologic study after repair of tetralogy of Fallot.

An association among premature ventricular complexes on routine electrocardiogram, elevated right ventricular systolic pressure and sudden death after repair of tetralogy of Fallot was previously reported. To examine this relation further, noninvasive, hemodynamic and invasive electrophysiologic data were studied in 27 patients who had undergone repair of tetralogy of Fallot 7 months to 21 years (mean 1.75 years) previously. Syncope, which had occurred in four patients, was not significantly related to ventricular arrhythmia on rest electrocardiogram, 24 hour electrocardiogram or treadmill test. All four patients with syncope had either nonsustained (two patients) or sustained (two patients) ventricular tachycardia induced at electrophysiologic study. His bundle to ventricle conduction interval was prolonged in two patients and Q to right ventricular apex interval was prolonged in three of the four patients. All four had abnormal anatomic or hemodynamic findings: two had a right ventricular systolic pressure of 70 mm Hg or more, one had right ventricular dysfunction with tricuspid insufficiency and one a septal aneurysm. The 9 patients with induced nonsustained or sustained ventricular tachycardia were then compared with the 15 patients without induced ventricular arrhythmias. Those with ventricular tachycardia had a greater prevalence of: more complex ventricular arrhythmia on 24 hour electrocardiogram (63 versus 0%, p less than 0.001), long His bundle to ventricle interval (44 versus 0%, p less than 0.001), right ventricular systolic pressure of 70 mm Hg or more (56 versus 0%, p less than 0.01) and reduced right ventricular ejection fraction (33 versus 7%, p less than 0.025). It is concluded that: 1) induction of nonsustained or sustained ventricular tachycardia was associated with a history of syncope; 2) all patients at risk for syncope could not be identified by routine electrocardiogram 24 hour electrocardiogram or treadmill test; 3) hemodynamic alterations may interact with intraventricular conduction abnormalities and predispose to ventricular tachycardia.

Application of information theory to decision analysis in potentially prostaglandin-responsive neonates.

To define settings in which use of prostaglandin E1 before transfer from a community hospital to a tertiary care center benefits neonates with possible heart disease, information theory was used to predict the probability of a favorable response to prostaglandin therapy from the limited information of clinical variables. Records of 250 patients, newborn to 7 days old, with suspected heart disease were reviewed to assess six clinical variables (cyanosis, respiratory distress, heart murmur, pulse contour, hepatomegaly and prematurity). According to the anatomic and hemodynamic cardiovascular condition, each case was categorized as to whether a favorable response to prostaglandin E1 could be anticipated. Information content of each clinical variable with respect to prostaglandin responsiveness was determined, and patients were classified according to the most informative clinical variable. Stepwise extraction of information proceeded until remaining clinical variables added no significant information. Bayes' rule gave estimates of probability of prostaglandin-responsive defect in final subgroups for use in decision analysis. Cyanosis, murmur, small volume pulses and prematurity gave information about prostaglandin-responsive defects. Decision analysis indicated that frequency of poor outcome is minimized by early prostaglandin treatment of cyanotic term infants with a murmur or poor pulses, regardless of how ill they appear, and by treating any critically ill term newborn who has either cyanosis or poor pulses. Acyanotic patients with normal pulses are best untreated with prostaglandin until after definitive diagnosis is made. Advantage to either course was not seen in some small subgroups. Information theory with decision analysis is a rigorous approach to identify relevant clinical variables and define their roles in critical decisions in pediatric cardiology.

Quantitative morphology of the aortic arch in neonatal coarctation.

It has been speculated that neonatal coarctation results from postnatal constriction of the aortic isthmus and ductus arteriosus. However, aortic arch hypoplasia is present in some neonates with coarctation and is presumed to be due to decreased aortic arch blood flow in utero. To measure the degree of aortic arch hypoplasia and to analyze the distribution of blood flow in neonatal coarctation, quantitative morphometric analysis of the great vessels from two-dimensional echocardiograms was performed in 14 neonates with isolated coarctation and 14 normal control neonates, all less than 1 month old. Measurements of the aortic valve, pulmonary valve, ascending aorta, transverse aortic arch between the carotid and subclavian arteries, aortic isthmus, descending aorta, main pulmonary artery and brachiocephalic vessels were obtained to the nearest 0.5 mm. In coarctation patients the transverse arch and isthmus were significantly smaller than in control subjects (p less than 0.001). In addition, pulmonary valve and main pulmonary artery diameters were significantly greater in neonates with coarctation than in normal neonates. Transverse arch hypoplasia and increased pulmonary valve and pulmonary artery diameters are present in neonates with coarctation. This suggests decreased aortic arch flow and increased pulmonary and ductus arteriosus flow in utero, which produce a characteristic echocardiographic appearance of transverse arch hypoplasia with a large main pulmonary artery.

Surgical management of refractory supraventricular tachycardia in infants and children.

Sixty-seven children underwent attempted surgical correction of refractory supraventricular arrhythmias using a combination of intraoperative electrophysiologic mapping followed by surgical division or cryoablation of an aberrant conduction pathway or atrial ectopic focus. The patients ranged in age from 4 months to 18 years (mean 11.4 years). Fifty-five patients (82%) had an abnormal conduction pathway crossing the atrioventricular junction (Kent bundle). Thirty-six (65%) of these 55 patients had classic Wolff-Parkinson-White syndrome with a delta wave of pre-excitation on the surface electrocardiogram. Nineteen (35%), however, demonstrated only retrograde conduction across the Kent bundle and had a normal surface electrocardiogram when tachycardia was not present. Kent bundles were isolated to the following locations: right anterior or lateral in 19 (34.5%), left posterior or lateral in 22 (40%), posteroseptal in 10 (18%), anteroseptal in 2 (4%) and both right and left in 2 (4%). Follow-up evaluation of as long as 8 years (mean 34.9 months) has shown seven immediate failures and one late recurrence of arrhythmia (14.5%). Recent refinements in technique and the use of cryoablation for septal aberrant pathways have improved these results. There have been two failures (8%) in the last 25 attempts. Twelve patients underwent surgery for an atrial ectopic focus by the following techniques: cryoablation in seven patients, excision in one patient and both excision and cryoablation in four patients. At a mean follow-up of 16.6 months, there was one late recurrence in the group with an atrial ectopic focus.(ABSTRACT TRUNCATED AT 250 WORDS)

Ventricular arrhythmias and sudden death in children.

In children, sudden death related to ventricular arrhythmias occurs virtually always in a patient with an abnormal heart. Therefore, children with ventricular tachycardia should be thoroughly investigated by anatomic cardiac catheterization and possibly electrophysiologic study. Sudden death may occur in a patient who had been relatively asymptomatic. This especially occurs in patients after repair of congenital heart disease. The patient may also never have had documented ventricular tachycardia, although most have had at least premature ventricular complexes on a Holter monitor recording. Finally, sudden death related to ventricular arrhythmias can often be prevented with vigorous medical and surgical therapy.

Doppler echocardiography in the diagnosis and management of persistent fetal arrhythmias.

Thirteen fetuses with persistent arrhythmias underwent combined noninvasive echocardiographic evaluation utilizing M-mode, two-dimensional and pulsed Doppler echocardiography. This group (Group A) was compared with 14 fetuses in which only two-dimensional and M-mode echocardiographic evaluations were performed (Group B). In both groups correct prenatal interpretation of the arrhythmia was confirmed by postnatal electrocardiograms in all surviving fetuses. Although Doppler echocardiography was not more sensitive than M-mode echocardiography in the interpretations of the arrhythmia, Doppler tracings of sufficient quality to analyze rate and rhythm were easier to obtain in all cases and provided additional information about valvular incompetence and the functional state of the fetal heart. Cardiac malformations and hydrops fetalis were commonly associated with persistent arrhythmias. Congenital heart disease occurred frequently (6 of 11) with complete atrioventricular (AV) block. Pulsed Doppler echocardiography defined the AV contraction sequence, atrial and ventricular rates and AV valve insufficiency, allowing rapid interpretation of fetal arrhythmias.

Prevention of sudden death after repair of tetralogy of Fallot: treatment of ventricular arrhythmias.

The majority of sudden deaths after repair of tetralogy of Fallot have been presumed to be due to ventricular arrhythmia; however, it remains to be demonstrated that antiarrhythmic medication reduces the incidence of sudden death. Since 1978, ventricular arrhythmias have been treated aggressively; these include any ventricular arrhythmia on routine electrocardiogram and more than 10 uniform premature ventricular complexes per hour on 24 hour electrocardiogram. A review was undertaken of 488 patients followed up for more than 1 month after repair of tetralogy of Fallot (mean follow-up time 6.1 years); 13.5% had ventricular arrhythmia on routine electrocardiogram. Ventricular arrhythmia appeared from 2 months to 21 years postoperatively (mean 7.3 years). Ventricular arrhythmias were significantly (p less than 0.01) related to: longer follow-up duration, older age at follow-up, older age at operation and higher postoperative right ventricular systolic and end-diastolic pressures. Ventricular arrhythmia on routine electrocardiogram occurred in 100% of those who later died suddenly compared with 12% of those who did not die (p less than 0.01). Treatment for ventricular arrhythmia was given to 46 patients and considered "successful" if there were fewer than 10 uniform premature ventricular complexes per hour on 24 hour electrocardiogram. A successful drug was found in 44 of the 46: 30 of 34 given phenytoin, 6 of 9 given propranolol, 1 of 7 given quinidine, 1 of 2 given disopyramide, 8 of 9 given mexiletine and 4 of 5 given amiodarone.(ABSTRACT TRUNCATED AT 250 WORDS)

Pacemaker treatment of sick sinus syndrome in children.

The sick sinus syndrome is being recognized with increasing frequency in children. Although it is sometimes benign, it can be serious or have fatal consequences. Fifty-one patients (mean age 10.5 years) underwent permanent cardiac pacing for sick sinus syndrome. Twenty patients had epicardial ventricular pacing and 12 had an epicardial atrial implant. Seven had endocardial atrial pacing, six epicardial atrioventricular (AV) sequential pacing, four epicardial universal pacing and two endocardial universal pacing. Of the 49 symptomatic patients, 45 had relief of symptoms. Eleven of 18 patients with associated tachyarrhythmias had amelioration of their tachycardia. There were no early but two late deaths unrelated to the pacemakers. Seven patients during a mean follow-up period of 26 months required reoperation for pacing lead or sensing problems. Permanent pacing for sick sinus syndrome in children is a safe and symptomatically effective procedure.

Surgery without catheterization for congenital heart defects: management of 100 patients.

Little information is available regarding the surgical mortality of children with congenital heart disease who undergo operation on the basis of clinical assessment and echocardiographic diagnosis without cardiac catheterization. If catheterization affects early surgical mortality then perhaps omitting it would improve survival. Early operative mortality of 100 patients managed with echocardiography without preoperative catheterization (Group I) was compared with that of 151 diagnosis-matched control patients who had catheterization (Group II). The catheterization (Group II) and echocardiographic (Group I) groups included patients with the following diagnoses: atrial septal defect (33 and 17 in Group II and Group I, respectively); pulmonary stenosis/pulmonary atresia (33 and 15), aortic stenosis (14 and 3), coarctation of aorta (36 and 29), patent ductus arteriosus (10 and 15) and miscellaneous (25 and 21). Age range was 1 day to 16 years (mean 3.5); 114 (45%) of the 251 patients were less than 1 year of age and 59 (29%) were less than 1 month of age. With one exception, echocardiographic diagnosis was correct when compared with findings at surgery or autopsy, or both. Surgical mortality was 18% in Group I and 9% in Group II; however, multiple logistic regression analysis adjusting for differences in age and preoperative condition showed no significant difference between the two groups with a trend toward lower mortality in Group I (p = 0.075). Echocardiography as the definitive imaging modality in selected patients with congenital heart disease is accurate and is comparable with conventional methods of preoperative diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

High-altitude pulmonary edema with absent right pulmonary artery.

High-altitude pulmonary edema potentially is fatal. Adults with unilateral absence of a right pulmonary artery are particularly susceptible to high-altitude pulmonary edema. The occurrence of high-altitude pulmonary edema was documented in a child with congenital absence of the right pulmonary artery. Improvement occurred only upon descent to low altitude. Physicians should be aware of this life-threatening condition in children ascending to high altitude, particularly in individuals with unilateral absence of a pulmonary artery.

Diagnosis, management, and long-term results of patients with congenital complete atrioventricular block.

Sixty-five patients with congenital complete atrioventricular block have been studied. The median age at time of diagnosis was 7 months with 26 infants being diagnosed prior to 1 month of age. Anatomic heart disease was present in 25/65 (39%) infants, with ventricular inversion/L-transposition of great arteries complex occurring in 20/25 infants (80%). The site of block was above the bundle of His in 11 of 18 (61%) patients studied, in the bundle of His in three of 18 (17%), and below the bundle of His in two of 18 (11%). Permanent pacemakers were implanted in 17 (26%). Ten patients (15%) have died. The highest risk was in patients with anatomic heart disease and patients diagnosed early in life.

Postoperative pericardial effusion and its relation to postpericardiotomy syndrome.

Postpericardiotomy syndrome often delays recovery from cardiac operation. Pericardial effusion is an important sequela of postpericardiotomy syndrome. To define the relationship between postpericardiotomy syndrome and pericardial effusion, we performed four to seven serial echocardiograms (echoes) between postoperative day 0 and postoperative day 10 in 40 children who had operation requiring pericardiotomy. We also performed daily physical examination on each patient for clinical evidence of postpericardiotomy syndrome. Echocardiographic signs of pericardial effusion developed in 21/40 patients (53%). The effusion was present by postoperative day 5 in 19/21 patients. Clinical signs of postpericardiotomy syndrome occurred in 18/40 patients (45%). Among the 18 patients with postpericardiotomy syndrome, 16 had echocardiographic evidence of pericardial effusion. Thus the sensitivity of the echocardiogram was 89%. The pericardial effusion always developed prior to and persisted through clinical symptoms. We conclude that (1) pericardial effusion is present in over 50% of the patients following cardiac surgery, (2) it develops early in the postoperative period, and (3) once present, the effusion is persistent and frequently followed by clinical evidence of postpericardiotomy syndrome.

Energy dose for ventricular defibrillation of children.

Transthoracic direct current shock is the recommended treatment for ventricular fibrillation in children as in adults. To determine the appropriate energy dose, data were collected from 71 defibrillation attempts in 27 children. Sixty-three of the 71 shocks (89%) were successful in terminating fibrillation. Fifty-seven shocks were within 10 watt-seconds (w-sec) above or below an energy dose of 2 w-sec/kg of body weight. Fifty-two (91%) of these were effective and five (9%) were ineffective. In every case, fibrillation was ultimately terminated by a shock of 4 w-sec/kg or less. The results of these studies suggest that an energy dose of 2 w-sec/kg (or approximately 1 w-sec/lb) is adequate to defibrillate most children weighing under 50 kg. We currently use 2 w-sec/kg and double the energy dose if the first defibrillation attempt is unsuccessful.

Long-term follow-up of patients with malformations for which definitive surgical repair has been available for 25 years or more.

The results of long-term follow-up studies of patients with five common congenital heart defects are reviewed. The lesions included are ventricular septal defect, atrial septal defect, patent ductus arteriosus, pulmonary stenosis and coarctation of the aorta. A definitive, rather than palliative, operation has been available for each of these lesions for more than 25 years. Therefore many patients who have undergone operation for one of these lesions are now reaching adulthood. Although most of these postoperative patients live a normal life, many have residuae or sequelae that require close observation or treatment. Other persistent abnormalities of the physical examination, electrocardiogram and chest radiogram are obvious but call for no precaution or treatment. We have drawn on our own experience and the published experience of others to identify those findings and historical factors that best reflect the long-term prognosis of these patients. In addition, recommendations concerning the need for continued prophylaxis against infective endocarditis, and the problems of insurability and employability of these postoperative patients are discussed.

Prognosis for the newborn with transposition of the great arteries.

To determine the prognosis for the newborn with transposition of the great arteries, the clinical course of 112 consecutive neonates with dextrotransposition was reviewed. Patients were managed with balloon atrial septostomy at initial cardiac catheterization, palliative operation if needed in the 1st year of life and Mustard's intraatrial baffle repair. The 1st month of life was the period of greatest risk (8 percent mortality rate). Between balloon septostomy and baffle repair, 14 of 103 patients at risk (14 percent) either died or had a cerebrovascular accident. The mortality rate at baffle repair was 14 percent (10 deaths in 71 patients), and there were 3 late postoperative deaths. Actuarial analysis of the data indicates that with this plan of management, approximately 50 percent of newborns with transposition of the great arteries will survive 5 years with excellent function and an additional 15 to 20 percent will survive with one or more medical handicaps.

Spectrum of cardiovascular lesions in mucocutaneous lymph node syndrome: analysis of eight cases.

Eight cases of mucocutaneous lymph node syndrome with cardiovascular complications are described. The clinical presentation in all but one patient conformed to the previously described features of this syndrome. Five patients had cardiac enlargement, six had electrocardiographic abnormalities and three had a murmur of mitral insufficiency. Each of the four patients who died had aneurysms of the coronary arteries, usually associated with organizing thrombi. In addition to involvement of the coronary arteries, the renal, mesenteric, vertebral, splenic, hepatic and iliac arteries were affected to individual cases. One patient required triple aortocoronary bypass surgery and one patient underwent excision of a brachial arterial aneurysm. Further long-term follow-up studies of the patients who have survived the acute stage of the syndrome are indicated to establish this spectrum of late complications and sequelae.

Prognosis of symptomatic coarctation of the aorta in infancy.

Medical and surgical advances have improved the outlook for infants with symptomatic coarctation of the aorta. To help predict the clinical course of individual patients and to aid in individualizing their treatment, a 10-year experience with this condition was reviewed. Of 97 infants with symptomatic coarctation, 10 had isolated defects. In these patients, medical treatment was successful and surgical intervention could be postponed to allow for growth. The 87 other patients with associated cardiac defects were generally sicker at presentation and required earlier operation. Eleven of these died before surgical correction, 10 died at the time of repair, and 13 died later. The overall survival rate after 8 years was 62%, with most deaths occurring in the first 6 months of life. Late surgical results are flawed by a 32% rate of residual coarctation. Late postoperative hypertension is uncommon, and is usually attributable to a residual coarctation.

Pulmonary artery sling.

Pulmonary artery "sling" indicates the vascular anomaly wherein the left pulmonary artery arises from the right pulmonary artery and traverses between the esophagus and trachea to enter the left lung. Respiratory symptoms may result from compression of the trachea and right mainstem bronchus by the anomalous vessel as well as by associated tracheobronchial defects. Six cases are described. The distinctive radiologic features include anterior indentation of the barium esophagogram and a characteristic pulmonary angiogram. Surgery is the usual recommended treatment for life-threatening airway obstruction, but results are often poor. In patients with less severe symptoms the physician's approach may be modified by the presence of associated intracardiac defects and intrinsic airway disease.