Accuracy of the Apple Watch Oxygen Saturation Measurement in Adults and Children with Congenital Heart Disease.

As new customer health devices have been spread throughout the consumer market in recent years, it now needs to be evaluated if they also fulfill the requirements of clinical use. The Apple Watch Series 6 provides a new health feature with its oxygen saturation measurement. The aim of this prospective, investigator-initiated, single-arm study was to compare transcutaneous oxygen saturation measurements using the Apple Watch 6 with the conventional method of pulse oximetry in patients with congenital heart disease. Patients of any age presenting at the Leipzig Heart Center, Department for pediatric cardiology, were included. After obtaining informed consent, the routine oxygen saturation measurement with the pulse oximeter was taken and simultaneously three measurements with the Apple Watch. A total of 508 patients were enrolled. Comparing children and adults in terms of measurement success shows a statistically significant difference with a higher proportion of unsuccessful measurements in children, but no difference concerning correct versus incorrect Apple Watch measurements. Noticeable, strapping on the watch properly around the patient's wrists significantly improved the measurements compared to a watch only laid on. The study demonstrated that oxygen saturation measurement with the Apple Watch 6 is not yet up to the medical standard of pulse oximetry, too large a proportion of the measurements remain either unsuccessful or incorrect. While a high proportion of unsuccessful measurements in children can be attributed to movement, the cause in adults usually remains unclear. Further influencing factors on a correct, or successful measurement could not be found.

Open Field Exercise Testing in Pediatric Congenital Heart Disease Patients: A Subsumption of Cardiovascular Parameters.

Heart failure is a common phenomenon in congenital heart disease patients. Cardiopulmonary exercise testing is used for a reliable assessment of heart failure but is still challenging, especially for young children. Implementing mobile cardiopulmonary exercise testing (CPET) can close that diagnostic gap. While average values for healthy children have already been published, this study aims to describe typical ranges of cardiovascular performance parameters of young children with congenital heart disease performing an 8-min running cardiopulmonary exercise test. Children aged 4-8 years with common congenital heart defects after corrective surgery (Tetralogy of Fallot; transposition of the great arteries and univentricular hearts after palliation) were included. The outdoor running protocol consisted of slow walking, slow jogging, fast jogging, and maximum speed running. Each exercise was performed for 2 min, except the last, in which children were instructed to keep up maximal speed as long as possible. A total of 78 children (45 male/33 female, mean age 6,24) with congenital heart disease participated in the study, of which 97% completed the CPET successfully. A detailed description of participating patients, including data on cardiac function and subjective fitness levels, is given to help physicians use this method to classify their patients. This study presents a typical range for cardiovascular performance parameters in a population of 4-8-year-old children with congenital heart disease tested in a newly developed outdoor running protocol for CPET.

Into the Blue: First in Man Data on Diving Physiology in Fontan Patients.

Swimming and diving are popular recreational activities. As congenital heart disease, especially patients with univentricular hearts after Fontan palliation are thought to have reduced physiologic capacities for compensation of submersion-associated physiologic demands, current guidelines put restraints on this group of patients. Although these restrictions on doctoral advice place a significant burden on affected patients, it is especially interesting that these guideline recommendations are merely based on physiologic assumptions, i.e., expert consensus. A recent study by Paech et al. presented the first in vivo data on the effects of immersion in Fontan patients, stating no major adverse events in their study group as well as comparable physiologic adaption as reported in the literature for healthy people. Yet, submersion was not reflected in this study, and the current study therefore aimed to conduct a first study for the evaluation of the effects of submersion and apnea diving in Fontan patients. A control group of healthy adults as well as patients recruited from the Heart Center Leipzig, Department of pediatric cardiology underwent a standardized diving protocol including a static as well as dynamic apnea phase. Physiologic data were recorded. This study presents the first structured data on diving physiology in Fontan patients compared to healthy probands. There were no adverse events. The physiologic response to diving seems to be comparable between healthy probands and Fontan patients. Although, healthy probands did reach a much better performance, the basic mechanisms of physiologic adaption seem comparable.

Accuracy of the Apple Watch iECG in Children With and Without Congenital Heart Disease.

The development of smart technologies paves the way for new diagnostic modalities. The Apple Watch provides an FDA approved iECG function for users from 22 years of age. Yet, there are currently no data on the accuracy of the Apple Watch iECG in children. While arrhythmias are a frequent phenomenon in children, especially those with congenital heart disease, the increasing spread of smart watches provides the possibility to use a smart watch as mobile event recorder in case of suspected arrhythmia. This may help to provide valuable information to the treating physician, without having the patient to come to the hospital. Necessary treatment adjustments might be provided without timely delay. The aim of this study was therefore to evaluate the agreement of measured values of rate, interval, and amplitude with those obtained by a diagnostic quality ECG recording to an Apple Watch iECG in children with and without congenital heart disease. In this prospective, single-arm study, consecutive patients aged 0-16 years presenting to the Heart Center Leipzig, Department for pediatric cardiology were included. After obtaining informed consent from participants' parents, a 12-lead ECG and an iECG using an Apple Watch were performed. Cardiac rhythm was classified, amplitudes and timing intervals were measured and analyzed in iECG and 12-lead ECG for comparability. These measurements were performed blinded to the patients' history by two experienced pediatric cardiologists. Patient demographic data, medical and cardiac history were assessed. 215 children between 0 and 16 years were enrolled. Comparison of amplitudes and timing intervals between ECG and iECG showed excellent correlation (K > 0.7, p < 0.01) in all parameters except for the p-waves. Automatic rhythm classification was inferior to manual interpretation of ECG / iECG, while iECG interpretation was reliable in 94.86% of cases. The study demonstrates equal quality of the Apple Watch derived iECG compared to a lead I in 12-lead ECG in children of all age groups and independent from cardiac anatomy.

The Fontan and the Sea: First-in-Man Data on Swimming and Diving Physiology in Fontan Patients.

While swimming represents a popular recreational activity, the immersion of the human body into the water requires a complex physiologic adaption of the whole cardiopulmonary and circulatory system. While this sport is regarded as beneficial, especially in cardiovascular patients, current guidelines hypothesized a possible hazardous effect of swimming and especially diving in patients with univentricular hearts after Fontan palliation. Yet, actual data to underline or contradict these assumptions are lacking. Therefore, this study aimed to conduct a first feasibility study for the evaluation of these effects on Fontan physiology and elucidate the gap of evidence currently preventing patients after Fontan palliation from being restricted from swimming or diving on doctoral advice. Patients recruited from the Heart Center Leipzig, Department of pediatric cardiology, underwent spiroergometry treadmill testing followed by a spiroergometry swimming stress test in a counter current pool. Physiologic data were recorded. A short apnea diving test was performed. The current study found similar physiologic reactions comparing treadmill and swimming exercise stress testing. Heart rate response and oxygen uptake were comparable on land and in the water. This study presents the first-in-man data on swimming and diving in Fontan patients. In this small study cohort of three Fontan patients, there were no adverse events triggered by swimming and breath-hold diving seen. Basically, the physiologic response to exercise was comparable on land and in the water.

QRS Width as a Predictor of Right Ventricular Remodeling After Percutaneous Pulmonary Valve Implantation.

Recent data showed a right ventricular dyssynchrony in patients with tetralogy of Fallot (TOF). Percutaneous pulmonary valve implantation (PPVI) has become an important procedure to treat a pulmonary stenosis and/or regurgitation of the right ventricular outflow tract in these patients. Despite providing good results, there is still a considerable number of nonresponders to PPVI. The authors speculated that electrical dysfunction of the right ventricle plays an underestimated role in the outcome of patients after PPVI. This study aimed to investigate the influence of right ventricular electrical dysfunction, i.e., right bundle branch block (RBBB) on the RV remodeling after PPVI. The study included consecutive patients after correction of TOF with or without RBBB, who had received a PPVI previously at the Heart Center of the University of Leipzig, Germany during the period from 2012 to 2015. 24 patients were included. Patients without RBBB, i.e., with narrow QRS complexes pre-intervention, had significantly better RV function and had smaller right ventricular volumes. Patients with pre-interventionally QRS width below 150 ms showed a post-interventional remodeling of the right ventricle with the decreasing RV volumes (p = 0.001). The parameters of LV function and volume as well as RV ejection fraction remained unaffected by RBBB. The presented data indicate that the QRS width seems to be a valuable parameter in the prediction of right ventricular remodeling after PPVI, as it represents both electrical and mechanical functions of the right ventricle and may serve as an additional parameter for optimal timing of a PPVI.

Left atrial appendage closure devices. Their role in 2013.

Stroke prevention is the major goal in treating patients with atrial fibrillation. Warfarin therapy, if used appropriately, is highly effective in preventing thromboembolic events, but is simultaneously burdened by a narrow therapeutic window, multiple food and drug interactions, and a substantial bleeding risk. New pharmacological agents show only a modest reduction of bleeding complications compared to warfarin. Percutaneous device left atrial appendage (LAA) closure has now been technologically advanced as an additional and potential alternative to pharmacotherapy in patients with AF. Promising randomized data are obtainable with the WATCHMAN® device, while several other devices are in various stages of clinical and preclinical development. In this article we review the current knowledge and status of this technique.

Development of an AI based automated analysis of pediatric Apple Watch iECGs.

Introduction: The Apple Watch valuably records event-based electrocardiograms (iECG) in children, as shown in recent studies by Paech et al. In contrast to adults, though, the automatic heart rhythm classification of the Apple Watch did not provide satisfactory results in children. Therefore, ECG analysis is limited to interpretation by a pediatric cardiologist. To surmount this difficulty, an artificial intelligence (AI) based algorithm for the automatic interpretation of pediatric Apple Watch iECGs was developed in this study. Methods: A first AI-based algorithm was designed and trained based on prerecorded and manually classified i.e., labeled iECGs. Afterward the algorithm was evaluated in a prospectively recruited cohort of children at the Leipzig Heart Center. iECG evaluation by the algorithm was compared to the 12-lead-ECG evaluation by a pediatric cardiologist (gold standard). The outcomes were then used to calculate the sensitivity and specificity of the Apple Software and the self-developed AI. Results: The main features of the newly developed AI algorithm and the rapid development cycle are presented. Forty-eight pediatric patients were enrolled in this study. The AI reached a specificity of 96.7% and a sensitivity of 66.7% for classifying a normal sinus rhythm. Conclusion: The current study presents a first AI-based algorithm for the automatic heart rhythm classification of pediatric iECGs, and therefore provides the basis for further development of the AI-based iECG analysis in children as soon as more training data are available. More training in the AI algorithm is inevitable to enable the AI-based iECG analysis to work as a medical tool in complex patients.

Implantation of a Melody valve in tricuspid position.

A transcatheter pulmonary valve (Melody) was implanted within a stenotic biological valve prosthesis in tricuspid position, as an alternative to the fourth major cardiac surgery in a 12-year-old girl. There were no complications. The postinterventional result was very good.

[Preoperative and postoperative imaging in patients with transposition of the great arteries]. / Prä- und Postoperative Bildgebung bei Patienten mit Transposition der großen Gefäße.

Transposition of the great arteries (TGA) is a rare disease representing not more than 3-5% of all congenital heart diseases. TGA is a cardiac anomaly in which the aorta arises entirely or largely from the morphological right ventricle and the pulmonary artery from the morphological left ventricle. This is called a ventriculo-arterial discordant connection and when accompanied by an atrio-ventricular concordant connection it is called a complete or D-transposition (D-TGA). The terms congenitally corrected TGA (ccTGA) or L-TGA describe an atrio-ventricular discordant connection. In D-TGA survival can only be achieved if additional shunting is simultaneously present, which possibly has to be created post-natal by the so-called Rashkind maneuver.Nowadays, an early anatomic correction using the arterial switch operation is the treatment of choice. Up to the 1980s, an atrial switch operation according to Senning/Mustard was performed. Apart from echocardiography the imaging modality of choice is usually MRI to assess the complex postoperative anatomy, viability of the myocardium and to perform a volumetric and functional assessment, including MR flow measurements. Multidetector computed tomography (MDCT) is used if there are contraindications to MRI or if an assessment of cardiac and especially coronary anatomy is the main interest.

Rupture of the papillary muscle of the tricuspid valve - echocardiographic diagnosis of a rare anomaly leading to critical tricuspid valve regurgitation in the newborn.

We present the case of a male full-term neonate who presented at 4 h of age with severe cyanosis unresponsive to mechanical ventilation and oxygen supplementation. The diagnosis of rupture of the papillary muscle of the tricuspid valve was made by echocardiography. Preoperative stabilization was achieved by adding nitric oxide and extracorporeal membrane oxygenation therapy could be avoided. Corrective surgery was successfully performed on the 7th day of life. Follow-up examination at 2 months of age revealed an excellent postoperative result. Perinatal rupture of the papillary muscle and/or chordae tendineae of the tricuspid valve is exceedingly rare and usually lethal when untreated or diagnosed late. Therefore, timely diagnosis is mandatory for adequate preoperative management and subsequent surgical treatment.

Pacemaker-associated thrombotic occlusion of the inferior vena cava causing liver failure.

Pacemaker implantation using endocardial leads can give rise to thrombotic venous occlusion. We report the case of a 23-year-old male with transposition of the great arteries, who had previously undergone a Senning repair at the age of one year. A sick sinus syndrome required pacemaker implantation with subsequent multiple lead revisions. Following the implantation of the last lead, the patient developed complete occlusion of the inferior vena cava (IVC) with stenosis of the superior vena cava (SVC) with pacemaker leads in both lesions. Liver failure, ascites and esophageal varices developed. Thrombolytic treatment was ineffective; finally the patient was listed for liver transplantation. We explanted the lead embedding the thrombosis, together with some lead remnants. The stenosis of the SVC and the occlusion of the IVC were dilatated and stabilized with four stents. Over a follow-up period of 4 months, NYHA class improved from NYHA III to NYHA I-II, the hepatic function showed complete remission, and a liver transplantation was not necessary.

Transcatheter aortic valve closure to treat severe aortic regurgitation in a patient failing stage I palliation for hypoplastic left heart syndrome.

We present a patient with borderline left ventricle, in whom significant aortic regurgitation after failed attempt of biventricular repair with balloon valvuloplasty and consecutive Norwood stage 1 procedure substantially contributed to persisting hemodynamic instability. Transcatheter closure of the aortic valve using an Amplatzer(R) septal occluder was performed and led to clinical stabilization. At medium-term follow-up, there was neither residual aortic regurgitation nor obstruction of the coronary artery origins.

Lung protection in cardio-pulmonary bypass.

Since the invention of the heart-lung machine paediatric cardiac surgery developed rapidly. For correction of complex cardiac malformations the application of a cardio-pulmonary bypass (CPB) has become indispensable but possible negative effects of this technique should not be neglected. Especially, both bypassed organs i.e. heart and lung are not perfused during the procedure and therefore are threatened by ischemia and reperfusion injury. Additionally, CPB was developed with a non-pulsatile flow but there are clinical observations that pulsatile flow might be superior with improved patient outcomes. Thus, the aim of our study was to evaluate the effect of CPB on lung structure and to assess whether different flow modalities (pulsatile vs. non-pulsatile flow) or application of the antibiotic minocycline might be advantageous. Thirty five piglets of four weeks age were examined and divided into five experimental groups: control (no CPB) without or with minocycline, CPB (non-pulsatile flow) without or with minocycline and CPB with pulsatile flow. CPB was performed for 90 min followed by a 120 min reperfusion and recovery phase. Thereafter, adenosine triphosphate-content of lung biopsies and histology was carried out. We found that CPB was associated with a significant thickening of alveolar wall accompanied by an infiltration of neutrophil leucocytes. Moreover, markers for hypoxia, apoptosis, nitrosative stress, inflammation and DNA damage were significantly elevated after CPB. These cellular damages could be partially inhibited by minocycline or pulsatile flow. Both, minocycline and pulsatile flow attenuate lung damage after CPB.

Heterotaxia syndrome and autosomal dominant inheritance.

Previous familial cases of recurrent heterotaxia have suggested an autosomal recessive or exceptionally X-linked or dominant inheritance. Here, we report six families including 18 affected members, consistent with autosomal dominant inheritance. Among these, four families have more than one case of heterotaxia. The other two families have one member with heterotaxia and at least one other affected member with an "isolated" heart malformation, which could be considered as a mild form of heterotaxia. In five families, the disorder is transmitted through two or three generations. In one family, the patients are of the same generation but are linked to each other by obligate carriers. We suggest a rule to classify these families with heart malformations, according to the etiologic factor involved (rule of precocity). This rule might be useful to other disruptions of morphogenetic processes.

Capillary leak syndrome in children who undergo cardiopulmonary bypass: clinical outcome in comparison with complement activation and C1 inhibitor.

OBJECTIVES: Capillary leak syndrome (CLS) is associated with significantly increased morbidity and occurs after cardiopulmonary bypass in children with congenital heart disease. We investigated the early clinical parameters that predict the development of CLS and examined the relationship between the presence of CLS and complement and contact activation and C1 esterase inhibitor (C1-INH) during and after bypass. DESIGN: In this prospective study we took serial serological measurements of the complement and contact system and C1-INH in a cohort of 27 infants before, during, and up to 96 h after open-heart surgery. RESULTS: Complement and contact activation and a decrease in C1-INH were measured in all infants during and after CPB. Ten infants developed CLS postoperatively. Younger age and longer bypass time were strongly correlated to the development of CLS. No relationship was found between the degree of hypothermia, weight, gender, or cross-clamp time. C1-INH concentration and activity were lower peri- and postoperatively in the CLS group. Infants with CLS had a more pronounced postoperative increase in the C5a and C3a levels, higher postoperative level of factor XIIa, and lower prekallikrein activity than those without CLS. CONCLUSION: Contact and complement activation occurs during cardiopulmonary bypass and contributes to CLS more frequently in infants of a younger age and with a prolonged bypass time. This activation and decrease in C1-INH was strongly expressed in the CLS group, and therefore early substitution of C1-INH may prevent CLS after open-heart surgery in high-risk infants.

Randomised trial on the influence of continuous magnesium infusion on arrhythmias following cardiopulmonary bypass surgery for congenital heart disease.

OBJECTIVES: To check the hypothesis that continuous magnesium infusion protects the heart from arrhythmias following cardiopulmonary bypass surgery for congenital heart disease. DESIGN: A prospective randomised placebo-controlled study, with patients stratified in three weight groups. PATIENTS AND PARTICIPANTS: The study group ( n=65) postoperatively received a magnesium infusion (1 mmol/kg), the control group ( n=66) received placebo. In both groups serum and ionised magnesium values were followed, and all postoperative arrhythmias were documented for 24 h. MEASUREMENTS AND RESULTS: Serum and ionised magnesium in the blood was elevated after the end of bypass (0.54+/-0.15 mmol l(-1) pre-operatively, 0.88+/-0.24 mmol l(-1) postoperatively), where a cardioplegia solution containing magnesium was used. Magnesium values remained at this elevated level in the magnesium therapy group, and decreased to normal pre-operative values within 24 h in controls ( P<0.001). The incidence of postoperative arrhythmias was lower in the study group: 8/65 in the study group and 17/66 in the control group, respectively (chi-squared test, P=0.05). Lower patient weight (32.7 kg versus 22.6 kg), longer cardiopulmonary bypass time (128.7 min versus 87.9 min) and deeper body temperature during extracorporeal circulation (29.2 degrees C versus 32.6 degrees C) were identified as risk factors for postoperative arrhythmias ( P<0.05). CONCLUSIONS: Continuous magnesium infusion effectively reduces the rate of arrhythmias following cardiopulmonary bypass surgery for congenital heart disease and should, therefore, be routinely used.

Acute hemodynamic effects of post cardiotomy peritoneal dialysis in neonates and infants.

OBJECTIVE: Evaluation of the acute hemodynamic changes during peritoneal dialysis in patients with low cardiac output syndrome and acute renal failure after open heart surgery. PATIENTS: Three newborns and three infants after corrective surgery of congenital heart disease with post cardiotomy dialysis. Five of these had an open thorax during dialysis. METHODS: Cardiac output measurements using the thermodilution technique on two consecutive days at four different times during the peritoneal dialysis cycle. RESULTS: We did not find a deterioration of the cardiac index or systemic vascular resistance measured over two cycles in each of the six patients. Pulmonary artery pressure rose slightly after instillation of the dialysate solution in all patients. Changes in central venous pressure and left atrial pressure were not clinically meaningful. In all patients fluid removal by peritoneal dialysis was effective. All five surviving patients recovered renal function. CONCLUSIONS: Peritoneal dialysis can be performed in newborns and infants following cardiac surgery without causing acute hemodynamic imbalances. An open chest may have a significant impact on hemodynamic stability during peritoneal dialysis by blunting any possible negative alterations of increased intraabdominal pressure.

Critical subaortic stenosis in a newborn caused by accessory mitral valve tissue.

A 2-week-old newborn girl underwent successful surgery in our clinic for critical subaortic stenosis caused by accessory mitral valve tissue, which, because of excessive growth, protruded into the left ventricular outflow tract. The preoperative pressure gradient below the aortic valve was 80 mm Hg. The operation consisted of resection of the accessory tissue through a combined aortotomy and atriotomy approach without residual pressure gradient and mitral valve incompetence. This approach is recommended to ensure that accessory tissue is removed without damaging the mitral valve.

Complement and contact activation during cardiovascular operations in infants.

BACKGROUND: By comparing the results of cardiac operations with or without cardiopulmonary bypass (CPB) in infants in a prospective study, we sought to determine which part of the postoperative systemic inflammatory response was caused by CPB. METHODS: Thirty-five patients were divided into two groups: 11 infants operated on without CPB and 24 infants operated on with CPB. Blood samples were drawn before, during, and after the operation. We assessed complement function and the concentrations or activities of C1q, C3, C4, C1 inhibitor, factor B, the activated split product C3a, and prekallikrein and factor XIIa of the contact system. RESULTS: All of the patients exhibited a decrease of complement proteins. This was greater in infants who underwent CPB. A increase in C3a and factor XIIa and changes in prekallikrein activity occurred only in infants during CPB. CONCLUSIONS: Complement activation occurs in all infants, but is significantly higher in the group with CPB. Contact activation only occurs in patients who undergo CPB. Thus, the inflammatory response is caused by the use of a CPB circuit and to a lesser degree by surgical procedures and anesthesia.