Hand-carried ultrasound devices in pediatric cardiology: clinical experience with three different devices in 110 patients

BACKGROUND

The aims of this study were to determine the usefulness of hand-carried ultrasound devices in pediatric cardiology and to compare the performance of three different hand-carried ultrasound devices in a pediatric cardiology outpatient clinic and intensive care unit.

METHODS

One hundred ten patients (49 male; mean age, 6.4 ± 5.2 years; range 0.1-38 years) with congenital heart defects or innocent heart murmurs were examined using Siemens Acuson P10, Siemens Acuson P50, and Philips CX 50 systems. The quality of images and the accuracy of B-mode measurements were compared with those obtained using a standard echocardiographic system (Philips iE33).

RESULTS

Fifty-nine patients were examined with the Siemens Acuson P10, 29 with the Siemens Acuson P50, and 22 with the Philips CX 50 system. There were no significant differences in B-mode measurements. The Acuson P10 system, however, showed significantly lower image quality, with 64.54% of all studies considered of excellent quality compared with 92.83% with the Acuson P50 and 95.52% with the CX 50 (P < .05) and a mean quality score (1 = fair, 5 = excellent) of 3.5 versus 4.57 with the Acuson P50 and 4.86 with the CX 50 (P < .05). This was attributed to the limited capacity for accurate diagnosis in children with body weights < 10 kg and complex heart defects.

CONCLUSION

Hand-carried ultrasound devices represent a valuable alternative to standard echocardiographic systems in pediatric cardiology. In particular, systems including all echocardiographic modalities offer unlimited versatility in outpatient and intensive care.

Paediatric heart transplantation - the impact of a ventricular assist device on operative outcomes

BACKGROUND

The use of a ventricular assist device (VAD) is a life-saving option for patients with heart failure refractory to conventional therapy.

AIM

To assess the effect of VAD on outcomes of heart transplantation in children.

METHODS

Between October 1988 and June 2009, a consecutive series of 95 children (mean age 8.6 + or - 6.7 years, range 5 days-17.9 years) underwent heart transplantation: patients in group 1 (n = 11) received VAD as a bridge to cardiac transplantation (left ventricular VAD in 4, biventricular VAD in 7), and patients in group 2 (n = 84) underwent heart transplantation without previous cardiac support using VAD. The indication for heart transplantation was cardiomyopathy/myocarditis in 66 (69.5%) of children and congenital heart disease in 29 (30.5%) patients.

RESULTS

Congenital heart disease was diagnosed more often in group 2 than in group 1 (p = 0.047). The two groups did not differ significantly with respect to age, weight and parameters of preoperative liver and kidney function (except for aspartate aminotransferase activity, p = 0.020). The mean waiting time for transplantation was 64.2 + or - 87.4 days (range 1-443 days) and did not differ between the groups. The mean follow-up was 6.8 + or - 5.4 years (range 1 day-17.6 years). Mortality during long-term follow-up was 9.1% (n = 1) in group 1 and 20.2% (n=17) in group 2 (p = 0.632). We found no significant differences in postoperative ventilatory support time (p = 0.773), duration of hospital stay (p = 0.853), and incidence of acute rejection episodes (p = 0.575).

CONCLUSIONS

The use of VAD as a bridge to heart transplantation in children with severe heart failure had no negative effect on treatment outcomes.

Unique technique of surgery in an unusual variety of Scimitar syndrome: a case report

Scimitar syndrome is a rare congenital anomaly characterized by total or partial anomalous pulmonary venous drainage of the right lung to the inferior vena cava. We present a seven year old girl with a systolic murmur who was diagnosed as having a Scimitar syndrome with unusual drainage of the right pulmonary veins. The unique technique of surgery in this patient was appropriate to the unusual, previously not described anatomy.

Successful ABO-incompatible heart transplantation in a child despite blood-group sensitization after ventricular assist device support

In the first two yr of life blood-group incompatible (ABO-incompatible) heart transplantation can be performed leading to immune tolerance to donor blood group. Antibody titers should be below 1:4. VAD use is correlated with sensitization toward blood-group antigens. A boy was diagnosed with dilated cardiomyopathy at nine months of age and listed for 0-compatible transplantation. Progressive heart failure required implantation of a left VAD. His listing was extended for ABO-incompatible transplantation despite antibody titers of 1:32 anti-A and 1:8 anti-B. After 26 days on VAD, he was transplanted with a B donor heart. No hyperacute or acute rejection occurred in 12 months post-transplant. Anti-B antibodies rose to a maximum of 1:2. No use of rituximab or plasmapheresis was required. There are no signs of graft vasculopathy. This indicates that inclusion criteria for ABO-incompatible transplantation may be extended to immediate cases. This is the first case with a healthy immune system to show signs of tolerance development after ABO-incompatible heart transplantation with increased prior antibody titers and without specific treatment.

Ventricular assist device as a bridge to heart transplantation in children

The ventricular assist device (VAD) is a life-saving option for patients in heart failure refractory for conventional therapy. The aim of study was to assess the influence of VAD on heart transplantation (HT) outcome in children <16 years. Between October 1988 and August 2008, 73 children underwent HT: Group 1 (n=9) who received VAD as bridge to HT (left ventricular - 4, biventricular - 5), and Group 2 (n=64), without previous VAD. Diagnoses included cardiomyopathy (n=50 (68.5%)) and congenital heart defects (n=23 (31.5%)). Retrospective analysis of perioperative and long-term follow-up data was performed. The mean follow-up was 7.22+/-4.7 years. The diagnosis of cardiomyopathy appeared more often in Group 1 (P=0.074), but the difference was not significant. The two groups did not differ with respect to age (P=0.123) and weight (P=0.183). Mortality in long follow-up was: 11.1% (n=1) in Group 1 and 14.1% (n=9) in Group 2 (P=0.782). Analysis of preoperative end-organs function did not reveal significant differences between groups. There was also no significant differences with respect to waiting time for transplant (P=0.948), postoperative ventilatory support time (P=0.677), duration of hospital stay (P=0.711) and incidence of acute rejection episodes (P=0.156). VAD used as a bridge for HT in children does not negatively influence the outcome.

Relation of increased short-term variability of QT interval to congenital long-QT syndrome

Apart from clinical symptoms the diagnosis and risk stratification in long-QT syndrome (LQTS) is usually based on the surface electrocardiogram. Studies have indicated that not only prolongation of the QT interval but also an increased short-term variability of QT interval (STV(QT)) is a marker for a decreased repolarization reserve in patients with drug-induced LQTS. The aims of this study were to determine if STV(QT) (1) is higher in patients with LQTS compared with controls, (2) if this effect is more pronounced in a high-risk LQTS population, and (3) could increase the diagnostic power of the surface electrocardiogram in identifying mutation carriers. Forty mutation carriers were compared with age- and gender-matched control subjects in the absence of beta-receptor-blocking agents. Lead II or V(5) RR and QT intervals from 30 consecutive beats were manually measured. STV(QT) was determined from Poincaré plots of QT intervals (STV(QT) = Sigma|QTn + 1 - QTn|/[30 x radical2]). Compared with controls, patients with LQTS had a prolonged QTc interval (449 +/- 41 vs 411 +/- 32 ms, p = 0.00049) and increased STV(QT) (6.4 +/- 3.2 vs 4.1 +/- 1.6 ms, p = 0.005). In patients with the highest risk of clinical events, defined as a QTc interval >500 ms or symptoms before beta-blocker therapy, STV(QT) was 9 +/- 4 ms. QTc interval had a sensitivity of 43% and a specificity of 97% in identifying mutation carriers (thresholds 450 ms for men and 460 ms for women). Receiver operator characteristic analysis showed that an STV(QT) of 4.9 ms was the optimal cut-off value to predict mutation carriers. When incorporating an STV(QT) >4.9 ms for those whose QTc interval was within the normal limits, sensitivity to distinguish mutation carriers increased to 83% with a specificity of 68%, so that another 15 mutation carriers could be identified. In conclusion, these are the first results in humans showing that STV(QT) is increased in congenital LQTS, this effect is increased in patients with symptoms before therapy, and, hence, STV(QT) could prove to be a useful noninvasive additive marker for diagnostic screening to bridge the gap before results of genetic testing are available.

ALCAPA with the ectopic orifice at the non-facing sinus: successful anatomic repair by creation of an autologous extrapulmonary tunnel

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital defect. This anomaly leads to a coronary hypoperfusion phenomenon and to substantial left ventricular dysfunction caused by abnormal perfusion of the left ventricle. The optimal surgical management of such cases is not clearly established. Here, we report the successful anatomic repair of ALCAPA arising from the non-facing sinus of Valsalva of the pulmonary artery in a 5-kg patient. In order to perform the repair, we created an autologous extrapulmonary tunnel (from a pulmonary artery flap and autologous pericardium), which we implanted into the ascending aorta. Because of post-cardiotomy heart failure, we implanted an extracorporeal membrane oxygenation device during the same procedure. After recovery of the failing heart, the device was easily ex-planted, and the patient was discharged from the hospital on postoperative day 30.

Prenatal diagnosis of a long QT syndrome by fetal magnetocardiography in an unshielded bedside environment

OBJECTIVE

The potentially life threatening long QT syndrome should be diagnosed during pregnancy to improve perinatal care.

METHODS

A patient with a family history for a hereditary long QT syndrome presented at 30 weeks of her first pregnancy with fetal bradycardia and a narrow oscillation bandwidth on cardiotocography without structural abnormalities of the fetal heart. Fetal magnetocardiography was performed with a prototype biomagnetometer/gradiometer device in a magnetically unshielded environment. The cardiac time intervals were determined in the averaged PQRST complex.

RESULTS

The QT time and the frequency-corrected QTc showed a marked prolongation to 380 ms and 0.52 s, respectively. The findings were confirmed in the postnatal electrocardiogram after spontaneous term delivery in a perinatal center. The causative mutation on chromosome 11 had been passed on to the newborn from his mother.

CONCLUSION

Bedside fetal magnetocardiography revealed the exact diagnosis of the long QT syndrome in a period of the gestation when the fetus was electrically isolated by the vernix caseosa that hinders electrocardiography. To patients at risk of fetal cardiac abnormalities, magnetocardiography can be offered as a non-invasive diagnostic bedside procedure. The diagnosis should trigger closer surveillance and delivery in a perinatal center.

[15-year-old patient with decompensated heart failure and tachycardia with negative P-waves in inferior ECG recordings. An indication for heart transplantation?]

A 15-year-old girl was admitted with signs of severe cardiac failure. There were no symptoms of cardiac insufficiency 4 weeks before hospital admission. She presented with permanent supraventricular tachycardia with negative P-waves in leads II, III and aVF, the heart rate was 150 beats per minute. The electrophysiological examination showed a permanent junctional reentry tachycardia. A postero-septal accessory pathway could be eliminated successfully by radiofrequency catheter ablation. Immediately after the procedure cardiac function deteriorated with slight decrease of the strongly reduced cardiac output. Intensive care and application of dobutamine led to clinical stability. During a follow-up of two years the young patient showed permanent sinus rhythm and an age related physical strain. This case report documents the rapid and severe manifestation of cardiac failure owing to permanent junctional reentry tachycardia in a 15-year-old girl. She was referred for consideration of heart transplantation. Invasive electrophysiological treatment led to permanent sinus rhythm with improvement of left ventricular function.

Effect of cardiopulmonary bypass on myocardial function, damage and inflammation after cardiac surgery in newborns and children

Postoperative measurement of cardiac troponin I, creatine kinase and procalcitonin reflects myocardial damage and systemic inflammatory response after cardiac surgery with cardiopulmonary bypass in children. Pulse-contour cardiac output technique is a less invasive tool for determining postoperative cardiac function.

OBJECTIVE

The aim of our study was to investigate myocardial lesions and systemic inflammatory response after cardiac surgery with cardiopulmonary bypass in children suffering from congenital heart defects.

METHODS

The elevation of cardiac troponin I (cTnI), creatine kinase (CK) and procalcitonin (PCT) was evaluated in relationship to duration of aortic cross-clamping, incisional trauma and cardiac bypass temperature in 37 paediatric patients. To assess postoperative cardiac function, the cardiac index was measured in 7 children using the PiCCO (pulse contour cardiac output) technique.

RESULTS

CTnI and PCT both peaked on the day of surgery and slowly decreased postoperatively in case of an uncomplicated course. The median values of both parameters differed significantly from the day of surgery until the fourth postoperative day in children with an aortic cross-clamping time (CCT) longer than 80 minutes or after ventriculotomy in comparison to patients with shorter clamping times or atriotomy only. CK values showed similar results, but were less significant than cTnI. A relationship between cTnI, CK or PCT and the body temperature during cardiopulmonary bypass was not found. The cardiac indices (CI) measured by the PiCCO technique in the first 48 hours after surgery showed normal values.

CONCLUSION

In summary, perioperative measurement of cTnI, CK and PCT reflects myocardial damage and systemic inflammatory response and allows an improved peri- and postoperative management. PiCCO technique is an excellent, less invasive tool to determine postoperative cardiac function.