The gold standard to obtain pressure-volume relations (PVR) of the heart, the conductance technology (PVRCond), is rarely used in children. PVR can also be obtained by 3D-echocardiography volume data ...combined with simultaneously measured pressure data by a mini pressure-wire (PVR3DE). We sought to investigate the feasibility of both methods in patients with univentricular hearts and to compare them, including hemodynamic changes.
We studied 19 patients (age 2-29 years). PVR3DE and PVRCond were assessed under baseline conditions and stimulation with dobutamine.
Obtaining PVR3DE was successful in all patients. Obtaining PVRCond was possible in 15 patients during baseline (79%) and in 12 patients under dobutamine (63%). Both methods showed that end-systolic elastance (Ees) and arterial elastance (Ea) increased under dobutamine and that Tau showed a statistically significant decrease. Intraclass correlation (95% confidence interval) showed moderate to good agreement between methods: Ees: 0.873 (0.711-0.945), Ea: 0.709 (0.336-0.873), Tau: 0.867 (0.697-0.942). Bland-Altman analyses showed an acceptable bias with wider limits of agreement: Ees: 1.63 mmHg/ml (-3.83-7.08 mmHg/ml), Ea: 0.53 mmHg/ml (-5.23-6.28 mmHg/ml), Tau: -0,76 ms (-10.73-9.21 ms).
Changes of PVR-specific parameters under dobutamine stimulation were reflected in the same way by both methods. However, the absolute values for these parameters could vary between methods and, therefore, methods are not interchangeable. Obtaining PVR3DE in a single ventricle was easier, faster and more successful than PVRCond. PVR3DE provides a promising and needed alternative to the conductance technology for the assessment of cardiac function in univentricular hearts.
Fetal tachyarrhythmia can lead to fetal hydrops due to heart failure. Flecainide is often considered as second-line therapy when digoxin monotherapy fails, which is more likely in hydropic fetuses. ...Time to conversion to sinus rhythm (SR) is critical in cases presenting with hydrops.
The aim of this study was to evaluate the efficacy and time to conversion to SR of transplacental treatment, especially flecainide.
This is a retrospective observational study of 46 fetuses with fetal tachyarrhythmia. Treatment was either flecainide (n = 28, 60.9%), digoxin+flecainide combination (n = 4, 8.7%), or digoxin (n = 10, 21.7%). In 4 fetuses (8.7%), no treatment was necessary.
In our study population, 26 of the 32 fetuses (81.2%) that were treated with flecainide as a first-line therapy (flecainide or digoxin+flecainide) converted to SR. The median time to conversion to SR was 3 days (range 1-7 days) with flecainide monotherapy and 11.5 days (range 3-14 days) with a combination therapy. Seventy-two percent (13/18) of hydropic fetuses and 90% (9/10) of nonhydropic fetuses converted to SR when treated with flecainide monotherapy. There was no statistical difference in rates of conversion to SR in hydropic and nonhydropic fetuses (P = .37) or time to conversion to SR in the 2 groups (P = .9). In the majority of the remaining fetuses, there was a partial response with decreased ventricular heart rates that were well tolerated.
Flecainide is highly effective in achieving SR in hydropic and nonhydropic fetuses with supraventricular tachycardia in a median time of 3 days. In our opinion, flecainide should be considered as first-line therapy in fetal supraventricular tachycardia with and without hydrops.
Unilateral phrenic nerve damage is a dreaded complication in congenital heart surgery. It has deleterious effects in neonates and children with uni-ventricular circulation. Diaphragmatic palsy, ...caused by phrenic nerve damage, impairs respiratory function, especially in new-borns, because their respiration depends on diaphragmatic contractions. Furthermore, Fontan patients with passive pulmonary perfusion are seriously affected by phrenic nerve injury, because diaphragmatic contraction augments pulmonary blood flow. Diaphragmatic plication is currently employed to ameliorate the negative effects of diaphragmatic palsy on pulmonary perfusion and respiratory mechanics. This procedure attenuates pulmonary compression by the abdominal contents. However, there is no contraction of the plicated diaphragm and consequently no contribution to the pulmonary blood flow. Hence, we developed a porcine model of unilateral diaphragmatic palsy in order to evaluate a diaphragmatic pacemaker. Our illustrated step-by-step description of the model generation enables others to replicate and use our model for future studies. Thereby, it might contribute to investigation and advancement of potential improvements for these patients.
Exercise capacity is impaired in Fontan palliated patients. The change in daily activity behaviour with an increase in sedentary lifestyle results in low physical activity levels. This might have a ...greater impact on patients with chronic heart disease in contrast to healthy controls. For a better understanding, we compared data from cardiopulmonary exercise testing (CPET) with heart rates and physical activity in daily life.
21 Fontan patients and 20 age, sex and BMI matched controls underwent CPET and 5 days of daily life activity tracking with a triaxial accelerometer (wGT3x-BT, Actigraph) including heart rate monitoring with an optical heart rate sensor.
27% of our Fontan teenagers and 71% of the Fontan adults reached the specific WHO recommendations for moderate to vigorous physical activity (MVPA) during everyday life (EDL), without differences to controls. There was a strong correlation between MVPA and Formula: see text for all Fontan patients (p = 0.0035, Pearson r = 0.788). Daily MVPA correlated to peak oxygen uptake and lactate production. Up to workloads of 2 W/kg and in daily life heart rates in Fontan patients were similar to controls.
Daily MVPA is alarmingly low without any differences between Fontan patients and controls. Heart rate behaviour was similar and does not seem to be a limiting factor for physical activity in daily life. Higher intensity activities should be implemented regularly in EDL for Fontan patients. Proof is needed as to whether sports in moderate or possibly even in vigorous activity (e.g. high-intensity interval training) improve exercise capacity the most.
Unilateral diaphragmatic paralysis in patients with univentricular heart is a known complication after pediatric cardiac surgery. Because diaphragmatic excursion has a significant influence on ...perfusion of the pulmonary arteries and hemodynamics in these patients, unilateral loss of function leads to multiple complications. The current treatment of choice, diaphragmatic plication, does not lead to a full return of function. A unilateral diaphragmatic pacemaker has shown potential as a new treatment option. In this study, we investigated an accelerometer as a trigger for a unilateral diaphragm pacemaker (closed-loop system).
Seven pigs (mean weight 20.7 ± 2.25 kg) each were implanted with a customized accelerometer on the right diaphragmatic dome. Accelerometer recordings (mV) of the diaphragmatic excursion of the right diaphragm were compared with findings using established methods (fluoroscopy mm; ultrasound, M-mode cm). For detection of the amplitude of diaphragmatic excursions, the diaphragm was stimulated with increasing amperage by a cuff electrode implanted around the right phrenic nerve.
Results with the different techniques for measuring diaphragmatic excursions showed correlations between accelerometer and fluoroscopy values (correlation coefficient 0.800, P < 0.001), accelerometer and ultrasound values (0.883, P < 0.001), and fluoroscopy and ultrasound values (0.816, P < 0.001).
The accelerometer is a valid method for detecting diaphragmatic excursion and can be used as a trigger for a unilateral diaphragmatic pacemaker.
Objectives
We aimed to evaluate the effect of technical aspects of fetal aortic valvuloplasty (FAV) on procedural risks and pregnancy outcomes.
Background
FAV is performed in cases of severe ...mid‐gestation aortic stenosis with the goal of preventing hypoplastic left heart syndrome (HLHS).
Methods
The International Fetal Cardiac Intervention Registry was queried for fetuses who underwent FAV from 2002 to 2018, excluding one high‐volume center.
Results
The 108 fetuses had an attempted cardiac puncture (mean gestational age GA 26.1 ± 3.3 weeks). 83.3% of attempted interventions were technically successful (increased forward flow/new aortic insufficiency). The interventional cannula was larger than 19 g in 70.4%. More than one cardiac puncture was performed in 25.0%. Intraprocedural complications occurred in 48.1%, including bradycardia (34.1%), pericardial (22.2%) or pleural effusion (2.7%) requiring drainage, and balloon rupture (5.6%). Death within 48 hr occurred in 16.7% of fetuses. Of the 81 patients born alive, 59 were discharged home, 34 of whom had biventricular circulation. More than one cardiac puncture was associated with higher complication rates (p < .001). Larger cannula size was associated with higher pericardial effusion rates (p = .044). On multivariate analysis, technical success (odds ratio OR = 10.9, 95% confidence interval CI = 2.2–53.5, p = .003) and later GA at intervention (OR = 1.5, 95% CI = 1.2–1.9, p = .002) were associated with increased odds of live birth.
Conclusions
FAV is an often successful but high‐risk procedure. Multiple cardiac punctures are associated with increased complication and fetal mortality rates. Later GA at intervention and technical success were independently associated with increased odds of live birth. However, performing the procedure later in gestation may miss the window to prevent progression to HLHS.
Mitochondrial acyl-CoA dehydrogenase family member 9 (ACAD9) is essential for the assembly of mitochondrial respiratory chain complex I. Disease causing biallelic variants in ACAD9 have been reported ...in individuals presenting with lactic acidosis and cardiomyopathy.
We describe the genetic, clinical and biochemical findings in a cohort of 70 patients, of whom 29 previously unpublished. We found 34 known and 18 previously unreported variants in ACAD9. No patients harbored biallelic loss of function mutations, indicating that this combination is unlikely to be compatible with life. Causal pathogenic variants were distributed throughout the entire gene, and there was no obvious genotype-phenotype correlation. Most of the patients presented in the first year of life. For this subgroup the survival was poor (50% not surviving the first 2 years) comparing to patients with a later presentation (more than 90% surviving 10 years). The most common clinical findings were cardiomyopathy (85%), muscular weakness (75%) and exercise intolerance (72%). Interestingly, severe intellectual deficits were only reported in one patient and severe developmental delays in four patients. More than 70% of the patients were able to perform the same activities of daily living when compared to peers.
Our data show that riboflavin treatment improves complex I activity in the majority of patient-derived fibroblasts tested. This effect was also reported for most of the treated patients and is mirrored in the survival data. In the patient group with disease-onset below 1 year of age, we observed a statistically-significant better survival for patients treated with riboflavin.
A frequent complication of Fontan operations is unilateral diaphragmatic paresis, which leads to hemodynamic deterioration of the Fontan circulation. A potential new therapeutic option is the ...unilateral diaphragmatic pacemaker. In this study, we investigated the most effective stimulation location for a potential fully implantable system in a porcine model.
Five pigs (20.8 ± 0.95 kg) underwent implantation of a customized cuff electrode placed around the right phrenic nerve. A bipolar myocardial pacing electrode was sutured adjacent to the motor point and peripherally at the costophrenic angle (peripheral diaphragmatic muscle). The electrodes were stimulated 30 times per minute with a pulse duration of 200 µs and a stimulation time of 300 ms. Current intensity was the only variable changed during the experiment.
Effective stimulation occurred at 0.26 ± 0.024 mA at the phrenic nerve and 7 ± 1.22 mA at the motor point, a significant difference in amperage (p = 0.005). Even with a maximum stimulation of 10 mA at the peripheral diaphragm muscle, however, no effective stimulation was observed.
The phrenic nerve seems to be the best location for direct stimulation by a unilateral thoracic diaphragm pacemaker in terms of the required amperage level in a porcine model.
Postoperative junctional ectopic tachycardia (JET) is a frequent complication after pediatric cardiac surgery. Current recommendations on how and when to treat JET are inconsistent. We evaluated the ...management strategies of postoperative JET in German-speaking countries. We sent an online survey to 30 centers of pediatric cardiology that perform surgery for congenital heart defects in Germany (24), Austria (4), and Switzerland (2). The survey asked 18 questions about how and in what treatment sequence postoperative JET was managed. All 30 centers completed the survey (100% return rate). There was general agreement that the management of JET is based on administration of antiarrhythmic drugs, body surface cooling, and temporary pacing. Many centers presented treatment algorithms based on published literature, all centers named amiodarone as the first drug of choice. Significant disagreement was found concerning the timing and sequential order of additional therapeutic measures and particularly about the dosing of amiodarone and the role of R-wave synchronized atrial pacing.
Conclusion
: This survey reveals that from center to center, the treatment of postoperative JET may vary substantially. Future work should focus on those treatment modalities where a high rate of variation is found. Such studies may be of value to achieve commonly adopted treatment recommendations.
What is known:
•
Treatment of postoperative junctional ectopic tachycardia is predominantly based on administration of antiarrhythmic drugs, therapeutic cooling, and temporary pacing.
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Amiodarone is the antiarrhythmic drug of choice in this context.
What is new:
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Dosing and duration of administration of amiodarone differ relevantly from center to center.
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The sequential order of drug administration, therapeutic cooling, and pacing is not consistent.
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