Mechanical circulatory support for the treatment of children with acute fulminant myocarditis.

BACKGROUND: Viral myocarditis may follow a rapidly progressive and fatal course in children. Mechanical circulatory support may be a life-saving measure by allowing an interval for return of native ventricular function in the majority of these patients or by providing a bridge to transplantation in the remainder. METHODS: A retrospective chart review of 15 children with viral myocarditis supported with extracorporeal membrane oxygenation (12 patients) or ventricular assist devices (3 patients) was performed. RESULTS: All patients had histories and clinical findings consistent with acute myocarditis. The median age was 4.6 years (range 1 day-13.6 years) with a median duration of mechanical circulatory support of 140 hours (range 48-400 hours). Myocardial biopsy tissue demonstrated inflammatory infiltrates or necrosis, or both, in 8 (67%) of the 12 patients who had biopsies. Overall survival was 12 (80%) of 15 patients, with 10 (83%) survivors of extracorporeal membrane oxygenation and 2 (67%) survivors of ventricular assist device support. Nine (60%) of the 15 patients were weaned from support, with 7 (78%) survivors; the remaining 6 patients were successfully bridged to transplantation, with 5 (83%) survivors. All survivors not undergoing transplantation are currently alive with normal ventricular function after a median follow-up of 1.1 years (range 0.9-5.3 years). CONCLUSION: Eighty-percent of the children who required mechanical circulatory support for acute myocarditis survived in this series. Recovery of native ventricular function to allow weaning from support can be anticipated in many of these patients with excellent prospects for eventual recovery of full myocardial function.

Initial intravenous gammaglobulin treatment failure in Kawasaki disease.

OBJECTIVES: To determine initial intravenous gammaglobulin (IVIG) treatment failures in Kawasaki disease (KD) and to report the outcome of retreatment and our use of pulse intravenous (IV) methylprednisolone and cyclophosphamide in patients with persistent KD. STUDY DESIGN: Retrospective analysis of the treatment and response of children with KD over 3 years. RESULTS: Fifty (77%) of 65 patients completely responded to a single treatment with IVIG (2 g/kg). Fifteen patients (23%) required retreatment; 10 patients fully responded but 5 had persistent disease (3 developed coronary aneurysms and 4 developed coronary artery thrombosis). Four of these 5 patients with persistent disease were treated with pulse IV methylprednisolone and 2 were also treated with IV cyclophosphamide. There was no progression of coronary aneurysms and no deaths. No initial patient characteristics predicted IVIG treatment failure or the development of coronary aneurysms. CONCLUSION: Nearly 23% of patients with KD may require retreatment and 8% may develop coronary aneurysm. Additional antiinflammatory therapy, such as IV methylprednisolone and IV cyclophosphamide, may be helpful in treating persistent KD.

A child with valproic acid-associated carnitine deficiency and carnitine-responsive cardiac dysfunction.

Valproic acid enhances renal losses of carnitine esters and leads to decreased plasma free carnitine concentrations in many patients receiving valproic acid therapy. However, decreased serum carnitine levels are of unclear pathologic significance, and most children manifest no symptoms of carnitine deficiency. We report a child with valproic acid-associated carnitine deficiency who had severe cardiac dysfunction develop that resolved with carnitine replacement therapy.

Video viewing as an alternative to sedation for young subjects who have cardiac ultrasound examinations.

Sedation is often required for extended or quantitative echocardiographic examination of young patients. To test the hypothesis that patient viewing of entertaining videotapes during echocardiographic examinations would reduce the need for sedation and that Doppler pressure gradients so obtained would correspond satisfactorily with subsequent catheterization pressure gradients, 38 patients (age, 5 to 64 months; mean age, 18.6 months) with a variety of cardiac defects were studied. Because of excessive activity, resistance, fear, or crying, all of these patients would have normally been sedated. Instead, an age-appropriate videotape was used for patient viewing. In 35 of 38 patients, complete examinations were obtained with video viewing with no sedation. Twelve study patients later underwent catheterization while receiving sedation. The Doppler pressure gradients obtained while patients were viewing videotapes corresponded well with catheterization (r = 0.94). However, those pressure gradients were higher than those obtained with catheterization (mean, 8.3 mm Hg), but there was only one significant discrepancy of 22 mm Hg. In this series, complete examinations were obtained without sedation in 92% of subjects who would have normally required sedation (p less than 0.001), with minimal reduction in the accuracy of prediction of subsequent sedated catheterization pressure gradients. This suggests that near baseline conditions existed while patients were viewing television. Video viewing during echocardiographic examinations appears to be advantageous.

Naturally corrected double-outlet right ventricle with biventricular outflow tract obstruction.

A 5-year-old girl had presyncopal episodes associated with exertion. Diagnostic evaluation revealed a combination of congenital abnormalities: double-outlet right ventricle with apparent "natural correction" of a large subaortic ventricular septal defect and severe biventricular outflow tract obstruction. Intraoperative and postoperative studies confirmed satisfactory relief of the biventricular outflow tract obstruction.

Comparison of high pulse repetition frequency and continuous wave Doppler echocardiography for velocity measurement and gradient prediction in children with valvular and congenital heart disease.

To compare the ability of high pulse repetition frequency and continuous wave Doppler echocardiography to detect the peak velocity of a jet flow disturbance and to predict pressure gradients accurately, two groups of children with valvular or congenital heart disease were examined using both Doppler techniques. The use study group included 84 children or adolescents (aged 1 day to 19 years) who underwent examination in the echocardiography laboratory with both Doppler techniques in a randomized sequence. The peak velocity recorded with high pulse repetition frequency Doppler echocardiography was compared with the peak velocity recorded with the continuous wave technique. The accuracy study group included 41 children or adolescents (aged 1 day to 16 years) who underwent examination with both Doppler techniques at the time of cardiac catheterization. Doppler pressure gradients were calculated from the peak velocity using the simplified Bernoulli equation and were compared with peak instantaneous gradients and peak to peak gradients measured at catheterization. In the use study, a high correlation was found between peak velocities detected by high pulse repetition frequency and continuous wave Doppler echocardiography (r = 0.94, SEE = 0.28 m/s). In the accuracy study, close correlations were found between measured peak to peak pressure gradients and pressure gradients calculated from continuous wave (r = 0.95, SEE = 7.9 mm Hg) and high pulse repetition frequency Doppler echocardiography (r = 0.94, SEE = 8.7 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)

Doppler pressure gradient estimation in children. Accuracy, effect of activity and exercise, and the need for sedation during examination.

Noninvasive estimation of pressure drop has been shown to be an accurate and useful application of Doppler echocardiography. Most accuracy series have used patient-sedated catheterization gradient measurements as the standard of reference. Doppler gradient estimates, however, are commonly made without sedation of the patient when hemodynamics may differ from those present at catheterization. We questioned whether "unsedated" Doppler gradient estimates would correlate in a useful way with "sedated" catheter measurements, Doppler gradient estimates would vary with patient activity, exercise or crying, and Doppler gradient estimates made using chloral hydrate sedation would prove useful in predicting sedated catheter measurements. Twenty-five infants and children were examined under conditions 1 and 2 above, and 20 under condition 3. Sedated Doppler estimates, performed at the time of catheterization corresponded closely with catheter measurements (r = 0.97, SEE = 4.8), confirming the accuracy of the Doppler method. Gradients estimated by Doppler without sedation, or with activity, correlated poorly with sedated catheter measurements (SEE = 16.2, SEE = 34.9, respectively). Use of chloral hydrate sedation for Doppler estimates resulted in good correlation with subsequent sedated catheter measurements. The results demonstrate marked increases in noninvasive Doppler pressure gradient estimates under conditions other than sedation. Clinicians tend to think in terms of sedated catheter gradients as the standard of reference for evaluation of severity and need for surgery. Ultrasonic data can only be used if Doppler estimates are performed under similar physiologic conditions; in children this requires sedation.

Tetralogy of Fallot: selective staged management.

One hundred twenty-four patients with tetralogy of Fallot have undergone either primary total repair (61), shunt and later repair (30), or an initial shunt (33). The mean ratio of pulmonary anulus to descending thoracic aorta increased from 0.80 +/- 0.25 before the shunt to 1.22 +/- 0.26 before the repair (p less than 0.0001). The mean ratio in the primary repair group was 1.23 +/- 0.25. A transannular patch was necessary in only six of 91 patients (6.6%). Postrepair right ventricular/left ventricular pressure ratio averaged 0.50 +/- 0.11 in the shunt plus repair group and 0.43 +/- 0.12 in the primary repair group. Only four patients had a right ventricular/left ventricular pressure ratio less than 0.65. A significant inverse linear relationship existed between this ratio and the pulmonary anulus size measured at operation and normalized for the patient's height (p less than 0.01). Postoperative complications occurred in 21% of patients after a shunt and 20% of patients after open heart repair. The early mortality was 0.8% (1/124). An initial shunt in patients with a small pulmonary anulus can result in an increased anulus size and better hemodynamic result with frequent avoidance of a transannular patch. Staged repair may result in improved overall mortality rates.

Severe superior vena cava syndrome and hydrocephalus after the Mustard procedure: findings and a new surgical approach.

Some degree of obstruction of the superior vena cava is common after the Mustard operation for transposition of the great arteries. This can cause superior vena cava syndrome, which in extreme cases may lead to hydrocephalus in young children. While revision of the intra-atrial baffle can be performed, this procedure is associated with significant morbidity and mortality and may not resolve the problem. We describe an alternative operative approach in a group of patients who had superior vena cava syndrome after the Mustard procedure: anastomosis of the innominate vein to the left atrial appendage. This procedure is not complicated to perform and is safe; symptoms were relieved in all patients.

Cardiac localization of transvascular bioptome using 2-dimensional echocardiography.

Two-dimensional (2-D) echocardiography was added to standard fluoroscopic localization of transvascular endomyocardial biopsy in 7 children with heart muscle disease whose ages were 6 months to 18 years. One left ventricular and 11 right ventricular biopsies were carried ot without complications using the fluoroscopic-echocardiographic technique. Two-dimensional echocardiographic monitoring has the advantages of reducing radiation exposure and providing anatomic information about intracardiac structures as well as bioptome localization. Lateral beam spread and reverberation artifacts represent potential problems with 2-D echocardiography, but they did not cause significant difficulties in this study.

Echocardiography: M-mode and two-dimensional methods.

We review the basic similarities and differences of currently used M-mode and two-dimensional (2D) echocardiography. Discrete categories of disease are used to show the relative strengths of M-mode and 2D methods. The format of 2D echocardiography is well suited to analyze congenital heart disease, consequences of coronary artery disease, and distortions of anatomy due to acquired heart disease. Rapid structure movement is preserved with M-mode recording, facilitating detailed analysis of motion. The vast clinical experience with M-mode echocardiography can now be augmented by 2D echocardiography, but combination of 2D and M-mode methods is optimal for understanding each type of ultrasound recording and for best serving the patient.

Two-dimensional echocardiographic features of bicuspid aortic valve.

The two-dimensional cross-sectional echocardiographic diagnosis of bicuspid aortic valves is described and compared with results of M-mode echocardiograms. Aortic valve anatomy was determined in 19 selected patients by angiography, and confirmed in five by direct surgical visualization. Using an eccentricity index (EI) of 1.3 or greater as diagnostic of bicuspid aortic valve, M-mode correctly identified anatomy in 14 of 19 valves (74 percent), although EI varied in several patients. For two-dimensional diagnosis of bicuspid aortic valve, short axis cross section was preferred, and criteria included number of cusps seen in real time motion, irregularity of folding of cusp margins, and location of commissural insertions. Two-dimensional echocardiography correctly identified anatomy in 18 of 19 valves (95 percent). Long axis cross section disclosed valvular doming in all 8 patients in whom doming was observed angiographically, correlating with hemodynamic findings. Two-dimensional echocardiography aids in the detection of bicuspid aortic valve in a suspected population, can give an estimate of valve gradients, and explains variability in M-mode findings. As such, two-dimensional echocardiography is a valuable tool in the noninvasive diagnosis of the bicuspid aortic valve.

Two dimensional echocardiographic assessment of patients with bioprosthetic valves.

The clinical utility of two dimensional echocardiography in assessing bioprosthetic and left ventricular function was studied in 40 consecutive patients 1 week to 60 months after valve replacement surgery. These patients were referred to obtain normal baseline studies as well as to evaluate complications:suspected endocarditis, embolic phenomena and congestive heart failure of unknown cause. Independent M mode echocardiograms were also obtained in each patient. Confirmation of ultrasonic studies was by cardiac catheterization with angiography, surgery and pathologic study in 10 patients; cardiac catheterization with angiography alone in 7 patients; surgery and pathologic study in 3 patients; autopsy in 3 patients; blood cultures to confirm or exclude endocarditis in 10 patients; and confirmation on clinical grounds in 7 patients. Technically adequate two dimensional studies were recorded in 39 of 40 subjects. Two dimensional echocardiography accurately assessed 15 of 16 patients with an abnormal bioprosthetic valve and a normal left ventricle (1 of 16 patients had a false positive two dimensional echocardiogram); 8 of 8 patients suspected to have prosthetic valve or left ventricular dysfunction but who were normal; 7 of 7 patients with a normal prosthesis and an abnormal left ventricle; the one patient with an abnormal valve and left ventricle; and 7 of 7 clinically normal patients who were referred for baseline studies. In summary, the two-dimensional echocardiogram demonstrated a 97 percent diagnostic accuracy rate which was significantly greater than the 67 percent (P less than 0.001) for M mode echocardiography in the same group of patients. It is concluded that two dimensional echocardiography has excellent diagnostic accuracy in assessing bioprosthetic and left ventricular function and is superior to M mode echocardiography in evaluating patients after such valve replacement.