Jochen Weil

Utility of Cardiac Magnetic Resonance Imaging in the Diagnosis of Hypertrophic Cardiomyopathy

Background—Two-dimensional echocardiography is currently the standard test for the clinical diagnosis of hypertrophic cardiomyopathy (HCM). The present study was undertaken to determine whether cardiac MRI (CMR) affords greater accuracy than echocardiography in establishing the diagnosis and assessing the magnitude of left ventricular (LV) hypertrophy in HCM. Methods and Results—Forty-eight patients (age 34±16 years) suspected of having HCM (or with a confirmed diagnosis) were imaged by both echocardiography and CMR to assess LV wall thickness in 8 anatomic segments (total n=384 segments) and compared in a blinded fashion. Maximum LV thickness was similar by echocardiography (21.7±9.1 mm) and CMR (22.5±9.6 mm; P=0.21). However, in 3 (6%) of the 48 patients, echocardiography did not demonstrate LV hypertrophy, and CMR identified otherwise undetected areas of wall thickening in the anterolateral LV free wall (17 to 20 mm), which resulted in a new diagnosis of HCM. In the overall study group, compared with CMR, echocardiography also underestimated the magnitude of hypertrophy in the basal anterolateral free wall (by 20±6%; P=0.001), as well as the presence of extreme LV wall thickness (≥30 mm) in 10% of patients (P<0.05). Conclusions—CMR is capable of identifying regions of LV hypertrophy not readily recognized by echocardiography and was solely responsible for diagnosis of the HCM phenotype in an important minority of patients. CMR enhances the assessment of LV hypertrophy, particularly in the anterolateral LV free wall, and represents a powerful supplemental imaging test with distinct diagnostic advantages for selected HCM patients.

Magnetic Resonance Image-Guided Transcatheter Closure of Atrial Septal Defects

Background—Recent developments in cardiac MRI have extended the potential spectrum of diagnostic and interventional applications. The purpose of this study was to test the ability of MRI to perform transcatheter closures of secundum type atrial septal defects (ASD) and to assess ASD size and changes in right cardiac chamber volumes in the same investigation. Methods and Results—In 7 domestic swine (body weight, 38±13 kg), an ASD (Qp:Qs=1.7±0.2) was created percutaneously by balloon dilation of the fossa ovalis. The ASD was imaged and sized by both conventional radiography and MRI. High-resolution MRI of the ASD diameters correlated well with postmortem examination (r =0.97). Under real-time MR fluoroscopy, the introducer sheath was tracked toward the left atrium with the use of novel miniature MR guide wires. The defect was then closed with an Amplatzer Septal Occluder. In all animals, it was possible to track and interactively control the position of the guide wire within the vessels and the heart, including the successful deployment of the Amplatzer Septal Occluder. Right atrial and ventricular volumes were calculated before and after the intervention by using cine-MRI. Both volumes were found to be significantly reduced after ASD closure (P <0.005). Conclusions—These in vivo studies demonstrate that catheter tracking and ASD device closure can be performed under real-time MRI guidance with the use of intravascular antenna guide wires. High-resolution imaging allows accurate determination of ASD size before the intervention, and immediate treatment effects such as changes in right cardiac volumes can also be measured.

Impedance cardiography (electrical velocimetry) and transthoracic echocardiography for non-invasive cardiac output monitoring in pediatric intensive care patients: a prospective single-center observational study

IntroductionElectrical velocimetry (EV) is a type of impedance cardiography, and is a non-invasive and continuously applicable method of cardiac output monitoring. Transthoracic echocardiography (TTE) is non-invasive but discontinuous.MethodsWe compared EV with TTE in pediatric intensive care patients in a prospective single-center observational study. Simultaneous, coupled, left ventricular stroke volume measurements were performed by EV using an Aesculon® monitor and TTE (either via trans-aortic valve flow velocity time integral [EVVTI], or via M-mode [EVMM]). H0: bias was less than 10% and the mean percentage error (MPE) was less than 30% in Bland–Altman analysis between EV and TTE. If appropriate, data were logarithmically transformed prior to Bland–Altman analysis.ResultsA total of 72 patients (age: 2 days to 17 years; weight: 0.8 to 86 kg) were analyzed. Patients were divided into subgroups: organ transplantation (OTX, n =28), sepsis or organ failure (SEPSIS, n =16), neurological patients (NEURO, n =9), and preterm infants (PREM, n =26); Bias/MPE for EVVTI was 7.81%/26.16%. In the EVVTI subgroup analysis for OTX, NEURO, and SEPSIS, bias and MPE were within the limits of H0, whereas the PREM subgroup had a bias/MPE of 39.00%/46.27%. Bias/MPE for EVMM was 8.07%/37.26% where the OTX and NEURO subgroups were within the range of H0, but the PREM and SEPSIS subgroups were outside the range. Mechanical ventilation, non-invasive continuous positive airway pressure ventilation, body weight, and secondary abdominal closure were factors that significantly affected comparison of the methods.ConclusionsThis study shows that EV is comparable with aortic flow-based TTE for pediatric patients.

Left Coronary Artery Occlusion After Percutaneous Pulmonary Valve Implantation

Percutaneous pulmonary valve implantation (PPVI) is an attractive option for patients with pulmonary valve insufficiency or stenotic right ventricular outflow tracts. We present the case of a 26-year-old patient in which PPVI was used to treat d-transposition of the great arteries, uncommon coronary artery anatomy, and conduit stenosis that resulted from multiple operations on the right outflow. Days after discharge to home, she experienced acute chest discomfort correlating with ischemia noted on an electrocardiogram and elevated troponin levels. Coronary angiography confirmed mechanical compression of the left anterior descending coronary artery. The valve was removed in an emergency operation and replaced with a biological conduit.

Mechanisms underlying air aspiration in patients undergoing left atrial catheterization

Background: Air embolism in patients undergoing percutaneous interventions requiring access to the left atrium (LA) represents a potentially fatal complication. Here we tested if a decline in LA pressures following sedation represents an important mechanistic link underlying air intrusion into the LA. Methods and Results: Left atrial pressures were measured in 26 consecutive patients (49 ± 14 years; 27% male), who underwent percutaneous atrial septal occlusion for persistent foramen ovale or secundum atrial septal defects. Patients either received sedation by propofol allowing for guidance by transesophageal echocardiography (n = 13) or underwent occluder implantation without sedation and under fluoroscopic control only (n = 13). Whereas mean exspiratory LA pressures remained unchanged in either group, sedation provoked a marked decline in the mean inspiratory LA pressure as compared to non‐sedated patients (Δp 6.9 ± 8.6 mm Hg vs. 0.1 ± 1.2 mm Hg in nonsedated patients, P < 0.001). Ex vivo experiments evaluating the air‐tightness of different sheaths in response to negative pressures revealed air aspiration at –13.4 ± 1.2 mm Hg of suction in all cases, once a guide wire was inserted. Conclusions: Negative LA pressures in conjunction with air‐leaking sheaths are identified as potentially important factors for air intrusion into the LA with the patients sedation being a primary risk factor to lower LA pressure levels. The results advocate close monitoring of LA pressures during intervention, prevention of airway collapse and protection of LA sheaths from communication with the atmosphere, during procedures under sedation.

Ross-Konno procedure in neonates: report of three patients

The Ross-Konno procedure, applied to neonates with severe left ventricular outflow tract (LVOT) obstruction, offers a satisfactory solution in fully releasing the LVOT gradient, and in replacing the aortic valve with a pulmonary autograft with an excellent growth potential. We reported on three recent neonatal cases.

The Kid-Short Marfan Score (Kid-SMS) - an easy executable risk score for suspected paediatric patients with Marfan syndrome

Due to age‐dependent manifestations, diagnosis of Marfan syndrome (MFS) in children and adolescents is sophisticated. Although revised Ghent criteria is a major step forward, its utility in children is still restricted due to expensive and technically advanced diagnostics. As early diagnosis submits long‐term benefits concerning prognosis, the need of an appropriate diagnostic tool for risk stratification of suspected paediatric patients with Marfan is justified.

Aortic arch repair: let it beat!

Objective aortic arch repair (AAR) on the beating heart may reduce cross-clamping times and offer improved postoperative cardiac function.Methods A single-center review of all patients (n = 24) who underwent surgical AAR during biventricular repair between 01/2006 and 01/2008 was done. All patients were operated on under cardiopulmonary bypass (CPB) with antegrade cerebral perfusion (ACP). During AAR, 13 patients (group 1) received cardioplegic arrest, and were compared to 11 patients (group 2) who underwent a beating-heart modification with selective myocardial perfusion. Seventeen patients had additional intracardiac lesions and underwent simultaneous correction during the procedure.Results Durations of CPB, AAR and ACP did not differ statistically between groups. Cardioplegic arrest time was significantly lower in group 1 (34 ± 13 vs. 76 ± 11 min, p = 0.02) and resulted in a subsequent reduction of myocardial ischemic damage as borne out by lower postoperative levels of troponin T and CK-MB (2.5 ± 0.7 vs. 7.1 ± 1.4 ng/mL, p = 0.02; 68.7 ± 11.5 vs. 149.1 ± 27.2 U/l, p = 0.03). We observed an enhanced patient recovery with shorter inotropic and ventilatory support times (p < 0.05).Conclusion Pediatric aortic arch correction on a CPB beating heart with selective myocardial perfusion is technically feasible and safe. The reduction of the myocardial ischemic time is effective and results in less myocardial damage.

Cardiovascular computed tomography angiography in newborns and infants with suspected congenital heart disease: retrospective evaluation of low-dose scan protocols

Twelve infants (body weight, 3.59±1.36 kg) with congenital heart disease underwent a clinically indicated cardiovascular computed tomography angiography (CTA) study. Retrospectively, we investigated the feasibility and diagnostic capability of different non-electrocardiogram-triggered CTA protocols and assessed radiation doses. Scans were performed on a 256-multislice CT (MSCT) scanner with the vendor-preset helical protocol at 120 kV for babies, with axial single-shoot scans at 120 kV and 80 kV. The 80-kV protocol led to significantly reduced mean effective doses of 0.29±0.08 mSv (P=.017) and renders diagnostic image quality. All major cardiovascular defects were detected on MSCT, and all images were of diagnostic quality.

Complete Ectopia Cordis

Complete ectopia cordis is a very rare condition. With few exceptions, it is uniformly considered fatal. Death usually occurs within the first days of life as a result of infection, cardiac failure, or hypoxemia. We report the case of a male infant with Cantrell’s syndrome. There was complete thoracic exteriorization of the heart, with cephalic orientation of the cardiac apex (Figure 1). The cardiac surface was covered by …