Joaquim Miro

Doppler and M-Mode ultrasonography to time fetal atrial and ventricular contractions

Objective To compare ease of recording and reliability of ultrasonographic approaches used to time fetal heart atrial and ventricular contractions. Methods Seventeen consecutive fetuses seen at our fetal cardiology unit for possible fetal cardiac arrhythmia were included in this study. The same ultrasonographer obtained M-mode tracings of atrial and ventricular free walls, atrial wall and opening of the aortic valves, a peak of the mitral valve, and the opening of the aortic valves; and Doppler signals of flow-velocity waveforms in the outflow tract of the left ventricle and simultaneous flow-velocity waveforms in the aorta and superior vena cava. The outcome measures were rate of successful attempts and intra- and interobserver reliability coefficients. Results Valid recordings were made for all patients with one M-mode (atrial and ventricular free walls) and two Doppler (intraventricular, superior vena cava, and ascending aorta) approaches. Atrioventricular intervals were significantly longer with M-mode compared with Doppler ultrasonography. Reliability coefficients were excellent (at least 0.89) for all intraobserver measurements. Comparisons of atrioventricular and ventriculoatrial interval measurements made by two observers gave the following intraclass correlation coefficients (95% confidence interval): atrioventricular = M-mode: 0.87 (0.79, 0.91), left ventricular outflow: 0.93 (0.89, 0.96), superior vena cava–aorta: 0.98 (0.97, 0.99); ventriculoatrial = M-mode: 0.79 (0.67, 0.87), left ventricular outflow: 0.97 (0.95, 0.98); superior vena cava–aorta: 0.99 (0.98, 0.99). Conclusion Fetal atrioventricular intervals measured indirectly from M-mode or Doppler tracings were equally reliable when measured by the same observer; the Doppler approaches had better correlation between measurements made by two different observers.

Correlation between Electrocardiographic and Ultrasonographic Time-Interval Measurements in Fetal Lamb Heart

The objective of this study was to establish the echocardiographic modality that best correlates with electrical events in the fetal heart. No documentation on the relationship between electrical events recorded with a surface ECG and fetal M-mode or Doppler echocardiographic measurements is available. The following ultrasound tracings were recorded simultaneously with a surface ECG on six exteriorized near-term fetal lambs:1) M-mode echocardiography of atrial and ventricular contractions; and 2) Doppler flow velocity waveforms in the right superior vena cava (SVC) either alone or 3) in association with those of the ascending aorta. In the SVC, the onset of the retrograde A wave and the beginning of the forward wave during ventricular systole were used as markers for the start of the P wave and QRS complex, respectively. For the simultaneous SVC and ascending aorta tracings, the beginnings of the A and of the aortic ejection waves were used as markers. On average, the atrioventricular interval was 84 ms longer than the PR interval with the M-mode, corresponding to an increase of 107%. A similar observation was made for the simultaneous Doppler signals from SVC and ascending aorta, but the difference between the atrioventricular and PR intervals was smaller, averaging 35 ms. When the SVC Doppler was taken alone, no significant difference was found between atrioventricular and ventriculoatrial compared with PR and RP intervals, respectively, and a strong correlation was found between the two methods of measurement, both for the atrioventricular (r = 0.91) and ventriculoatrial (r = 0.89) intervals. Doppler interrogation of the SVC alone and, to a lesser degree, of the SVC and ascending aorta are reliable indirect markers for the timing of electrical events of the fetal lamb heart in sinus rhythm.

Congenital atresia and stenosis of the duodenum: The impact of a prenatal diagnosis

This review was undertaken to determine the effects of prenatal diagnosis, on the basis of ultrasonographic evidence, of a duodenal obstruction on the care and morbidity of the newborn infant. The records of 46 cases of either atresia or stenosis of the small bowel in infants treated during the last six years in a tertiary perinatal center were reviewed retrospectively. A prenatal fetal diagnosis of obstruction was made in 13 patients (12 obstructions located in the duodenum and one in the jejunum). The mean gestational age at prenatal diagnosis was 33.7 weeks (range 27 to 37 weeks). The course of those infants with the prenatal diagnosis made by ultrasound was compared with that of those infants in whom the diagnosis was established after the onset of symptoms of obstruction appeared. Such a prenatal diagnosis resulted in earlier surgical intervention (1.8 versus 3.9 days). Metabolic complications secondary to repeated vomiting were found to be less frequent. The expectant mother in whom such a fetal prenatal diagnosis has been made can be transported to a tertiary level perinatal center where neonatal and specialized surgical expertise are available. After birth, the infant can undergo immediate operation without being separated from its mother.

Transcatheter closure of perimembranous ventricular septal defect with the Amplatzer® membranous VSD occluder 2: Initial world experience and one‐year follow‐up

To describe the initial world experience and mid‐term follow‐up of perimembranous ventricular septal defect (pmVSD) closure with a newly designed occluder.

Treatment of Isolated Ventricular Septal Defects in Children: Amplatzer Versus Surgical Closure

BACKGROUND Isolated hemodynamically significant ventricular septal defects (VSD) were previously treated surgically. Since the introduction of percutaneous (PC) devices, the management of isolated VSD has evolved. In our center, Amplatzer devices have been implanted for selected isolated perimembranous VSD since 2002. METHODS The charts of all isolated PC perimembranous VSD closures and all surgical closures performed since 2002 were reviewed retrospectively. Clinical, electrocardiographic, and echocardiographic data were analyzed. The preclosure, immediate postclosure, and 1-month, 6-month, and 12-month postclosure results were assessed. RESULTS Thirty-seven patients underwent PC closure, and 34 had surgical treatment. Mean follow-up was 42.1 ± 26.0 months. The PC group was significantly older (p < 0.01) and larger in size (p < 0.001). Surgical patients had more severe congestive heart failure and a significantly lower VSD gradient (p < 0.004). At follow-up, there were no differences in the incidence of residual shunting between the two groups (p = 0.92). All valvular regurgitations improved over time, except for 3 aortic regurgitations (5.4%) in the PC group that got worse. Two permanent pacemakers were implanted for early complete heart block in the PC group, and one was implanted in the surgical group (p = 0.94). CONCLUSIONS The surgical results in our population were excellent. The selection of patients with perimembranous VSD remains a challenge to avoid post-PC intervention complications such as heart block and aortic insufficiency. For isolated VSD, PC closure, which avoids the morbidity of open heart surgery, should be considered as part of the therapeutic armamentarium.

Rejection of transplanted hearts in patients evaluated by the component analysis of multi-wavelength NAD(P)H fluorescence lifetime spectroscopy

Rejection of transplanted hearts remains one of the principal reasons for death of paediatric patients, but an appropriate diagnostic tool for the mild rejection in early stages is still missing. Tissue autofluorescence (AF) is one of the most versatile non-invasive tools for mapping the metabolic state in living tissues. Increasing interest in the imaging and diagnosis of living cells and tissues based on their intrinsic fluorescence rather than fluorescence labelling is closely connected to the latest developments in high-performance spectroscopy and microscopy techniques. In this contribution, we investigate individual components in spectrally- and time-resolved NAD(P)H fluorescence, revealed by linear unmixing, responsible for increased fluorescence in patients presenting mild rejection of transplanted hearts. Application of such approach has the potential to improve the diagnostics of the cardiac transplant rejection by helping currently used histological analysis.

Rapid pacing rotational angiography with three-dimensional reconstruction: use and benefits in structural heart disease interventions

AIMS High quality three-dimensional imaging is one of the cornerstones in structural heart disease interventions. Current mainstream technology to acquire three-dimensional imaging utilises computed tomography or magnetic resonance imaging. Incorporation of these data with conventional angiographic images may not be sufficient. We describe a new imaging technique consisting of rotational angiography combined with rapid pacing to obtain real-time, high-quality, three-dimensional images in the catheterisation laboratory. METHODS AND RESULTS Rotational angiography is performed with breath holding and rapid pacing on a large format digital flat-panel angiographic system. During a 200 degrees rotation, 150 angiographic images are acquired in five seconds and automatically reconstructed in less than 30 seconds. This imaging technique was used in six patients (mean age 32 +/- 10 years) to guide structural heart disease interventions. No complications were associated with rapid pacing. This imaging technique allowed acquisition of high-quality, three-dimensional images with a low volume of contrast media. Volume renderings helped appreciation of the lesions and optimisation of the working views. Multiplanar visualisation allowed true orthogonal measurements of vascular diameter during the procedures. CONCLUSIONS The advantages of this imaging technique include rapid image acquisition and precise imaging of complex structures using low volume of contrast media.

Recanalization of systemic venous baffles by radiofrequency perforation and stent implantation

Complete transposition of the great arteries has been historically managed by the Mustard (atrial switch) operation. This procedure is associated with longterm complications such as baffle occlusion, which also precludes the insertion of a permanent transvenous pacemaker. Transcatheter techniques have allowed the successful angioplasty and stenting of stenotic baffles but complete occlusions continue to pose a therapeutic challenge. We report the use of a novel technique, a radiofrequency perforation wire for the management of complete occlusion of systemic venous baffles post‐Mustard operation.

Transcatheter closure of perimembranous ventricular septal defects: initial human experience with the Amplatzer® membranous VSD occluder 2.

Although effective, transcatheter closure of perimembranous ventricular septal defects (pmVSD) with the Amplatzer Membranous VSD Occluder (AGA Medical Corporation, MN) carries a substantial risk of complete heart block, prompting many to abandon this intervention. A newly designed Amplatzer device for pmVSD was modified, in part, to minimize this risk. After rigorous preclinical testing, we report the first human experience with the Amplatzer Membranous VSD Occluder 2 (AGA Medical Corporation) in two patients (a 5‐year old with a 12‐mm pmVSD and a 26‐year‐old male with a 8‐mm defect). Both procedures were successful, with no adverse events at 7 and 4 weeks of follow‐up, respectively. Herein, we discuss characteristics of the new device, potential advantages compared to the prior version, and main technical aspects related to the procedure.

Therapeutic Strategies in Children with an Isolated Unilaterally Absent Proximal Pulmonary Artery

Therapeutic strategies for isolated unilateral absence of a proximal pulmonary artery remain unclear. The natural history of the disease, or thrombosis of primary surgical anastomosis, leads to exclusion of the affected lung with increased risk of intrapulmonary bleeding, impaired quality of life, and shortened life expectancy. We herein describe our two-stage approach in a small series of patients starting with interventional catheterization followed by surgical anastomosis. Other medical interventions, such as anticoagulation and pulmonary vasodilatation, are key factors to successfully restore pulmonary circulation in this rare defect.