Cardiac Magnetic Resonance to Detect the Underlying Substrate in Patients with Frequent Idiopathic Ventricular Arrhythmias

Background: A routine diagnostic work-up does not identify structural abnormalities in a substantial proportion of patients with idiopathic ventricular arrhythmias (VAs). We investigated the added value of cardiac magnetic resonance (CMR) imaging in this group of patients. Methods: A single-centre prospective study was undertaken of 72 patients (mean age 46 ± 16 years; 53% females) with frequent premature ventricular contractions (PVCs ≥ 500/24 h) and/or non-sustained ventricular tachycardia (NSVT), an otherwise normal electrocardiogram, normal echocardiography and no coronary artery disease. Results: CMR provided an additional diagnostic yield in 54.2% of patients. The most prevalent diagnosis was previous myocarditis (23.6%) followed by possible PVC-related cardiomyopathy (20.8%), non-ischaemic cardiomyopathy (8.3%) and ischaemic heart disease (1.4%). The predictors of abnormal CMR findings were male gender, age and PVCs/NSVT non-outflow tract-related or with multiple morphologies. Patients with VAs had an impaired peak left ventricular (LV) global radial strain (GRS) compared with the controls (28.88% (IQR: 25.87% to 33.97%) vs. 36.65% (IQR: 33.19% to 40.2%), p < 0.001) and a global circumferential strain (GCS) (−17.66% (IQR: −19.62% to −16.23%) vs. −20.66% (IQR: −21.72% to −19.6%), p < 0.001). Conclusion: CMR reveals abnormalities in a significant proportion of patients with frequent idiopathic VAs. Male gender, age and non-outflow tract PVC origin can be clinical indicators for CMR referral

Contrast-enhanced ultrasonography of the carotids

Contrast-enhanced ultrasonography of the carotids has recently emerged as a complementary examination to conventional carotid Doppler ultrasonography. It is an examination providing improved visualization of the vascular lumen, more accurate and detailed delineation of the vascular wall, and identification of atherosclerotic plaques. Moreover, contrast-enhanced ultrasonography has specific advantages over conventional ultrasonography and plays an important role in the diagnosis of the vulnerable carotid plaque, as it can identify intraplaque neovascularization and carotid plaque ulceration. Given the specific advantages and improved imaging of the carotids provided by this method, radiologists should be familiar with it. This pictorial essay illustrates the advantages of this technique and discusses its value in the imaging of carotid arteries

Microanatomic Morphometric Characteristics of the Third Ventricle Floor

Background: Endoscopic third ventriculostomy (ETV) is an effective treatment for hydrocephalus. The in-depth understanding of microanatomy is essential for accurate diagnosis, treatment and complications prevention. The aim of this study is to supplement the knowledge gap regarding the microanatomical metrics and correlations for which the literature includes only scarce mentions at best. Methods: This is a descriptive microanatomical study including 25 cadaver brains. Specimens from donors with neurological, psychiatric disorders or alcohol abuse were excluded. Surgical loops were used for harvesting. High-precision tools were employed to dissect and measure the anatomical landmarks under a surgical microscope. Each measurement was performed in three consecutive attempts and outliers were rejected. RStudio was used for statistical analysis. Distribution was evaluated employing the Shapiro–Wilk test. Normally distributed values were presented as mean and standard deviation, and others as median and interquartile range. Results: The age of the donors was 61.72 (±10.08) years. The distance from the anterior aspect of the foramen of Monro to the anterior margin of the mamillary body was 16.83 (±1.04) mm, and to the posterior margin was 16.76 (±1.9) mm. The distance from the anterior mamillary body margin to the infundibulum was 6.39 (±1.9) mm, to the optic recess was 8.25 (±1.84) mm, and to the apex of the vertebral artery was 5.05 (±1.62) mm. The distance from the anterior commissure to the brain aqueduct was 22.46 (±2.29) mm, and to the infundibulum was 13.93 (±2.54) mm. The mamillary body diameter was 4.91 (±0.34) mm in the anteroposterior and 4.21 (±0.48) mm in the cranio-caudal plane. The intraventricular segment was protruding by 1.63 (±0.46) mm. The diameter of the hypothalamus on the anterior margin of mamillary bodies was 1.37 (±0.75) mm, of the Liliequist membrane was 0.19 (±0.07) mm and of the lamina terminalis was 0.35 (±0.32) mm. Conclusion: The presented microanatomical measurements and correlations are expected to contribute to the improvement of ETV safety

Electric Field Distribution Induced by TMS: Differences Due to Anatomical Variation

Transcranial magnetic stimulation (TMS) is a well-established technique for the diagnosis and treatment of neuropsychiatric diseases. The numerical calculation of the induced electric field (EF) distribution in the brain increases the efficacy of stimulation and improves clinical outcomes. However, unique anatomical features, which distinguish each subject, suggest that personalized models should be preferentially used. The objective of the present study was to assess how anatomy affects the EF distribution and to determine to what extent personalized models are useful for clinical studies. The head models of nineteen healthy volunteers were automatically segmented. Two versions of each head model, a homogeneous and a five-tissue anatomical, were stimulated by the model of a Hesed coil (H-coil), employing magnetic quasi-static simulations. The H-coil was placed at two standard stimulating positions per model, over the frontal and central areas. The results show small, but indisputable, variations in the EFs for the homogeneous and anatomical models. The interquartile ranges in the anatomical versions were higher compared to the homogeneous ones, indicating that individual anatomical features may affect the prediction of stimulation volumes. It is concluded that personalized models provide complementary information and should be preferably employed in the context of diagnostic and therapeutic TMS studies

Bolus Intravenous Procainamide in Patients with Frequent Ventricular Ectopics during Cardiac Magnetic Resonance Scanning: A Way to Ensure High Quality Imaging

Acquiring high-quality cardiac magnetic resonance (CMR) images in patients with frequent ventricular arrhythmias remains a challenge. We examined the safety and efficacy of procainamide when administered on the scanner table prior to CMR scanning to suppress ventricular ectopy and acquire high-quality images. Fifty consecutive patients (age 53.0 [42.0–58.0]; 52% female, left ventricular ejection fraction 55 ± 9%) were scanned in a 1.5 T scanner using a standard cardiac protocol. Procainamide was administered at intermittent intravenous bolus doses of 50 mg every minute until suppression of the ectopics or a maximum dose of 10 mg/kg. The average dose of procainamide was 567 ± 197 mg. Procainamide successfully suppressed premature ventricular contractions (PVCs) in 82% of patients, resulting in high-quality images. The baseline blood pressure (BP) was mildly reduced (mean change systolic BP −12 ± 9 mmHg; diastolic BP −4 ± 9 mmHg), while the baseline heart rate (HR) remained relatively unchanged (mean HR change −1 ± 6 bpm). None of the patients developed proarrhythmic changes. Bolus intravenous administration of procainamide prior to CMR scanning is a safe and effective alternative approach for suppressing PVCs and acquiring high-quality images in patients with frequent PVCs and normal or only mildly reduced systolic function

Off-label intravenous thrombolysis for early recurrent brain embolism associated with aortic arch thrombus.

Safety data of intravenous thrombolysis (IVT) in presence of aortic arch thrombus is scant. Furthermore, IVT is debatable in patients with prior recent stroke. We present a 51-year-old woman with recurrent major infarction 5 days after a minor left MCA territory stroke. She had a floating aortic arch thrombus and she was treated safely and effectively with off-label IVT. Patients with small infarct volumes and mild/no residual neurological deficits after an initial stroke might be considered for IVT in case of early recurrence. IVT may be reasonable in a context of acute severely disabling stroke associated with aortic arch thrombus

The impact of carotid stenting on the hemodynamic parameters and cerebrovascular reactivity of the ipsilateral middle cerebral artery

ObjectiveThe study was conducted to determine the effect of carotid angioplasty and stenting (CAS) on the hemodynamic parameters and cerebrovascular reactivity (CVR) of the ipsilateral middle cerebral artery (MCA) and examine the relation between preprocedural exhausted CVR and perioperative neurologic events.MethodsThe study included 29 patients with severe extracranial carotid stenosis undergoing CAS. Transcranial Doppler imaging was performed before the procedure, 2 days, and 2 to 4 months postoperatively. Peak systolic velocity, end-diastolic velocity, mean flow velocity, and pulsatility index of the ipsilateral MCA were recorded at rest. CVR was assessed with the breath holding test: the increase of mean flow velocity and the breath holding index were calculated.ResultsPeak systolic and mean flow velocities increased significantly in both postoperative studies compared to the preoperative values, end-diastolic velocity was significantly elevated only in the first study, and pulsatility index did not change significantly. When stimulated by breath holding, preoperative mean flow velocity did not increase significantly compared with the resting values; however, it did increase significantly during breath holding in both studies after CAS. The breath holding index improved significantly from −0.35 (−0.71 to 0.55) to 0.38 (0.12 to 0.61) at 2 days (P = .049) and 0.44 (0.31 to 0.92) at 2 to 4 months (P = .020). Exhausted CVR of the MCA preoperatively was associated with increased risk of neurological complications during or after the procedure (P = .006).ConclusionsCAS may improve the hemodynamic parameters and the vasomotor reactivity in the ipsilateral MCA. Exhausted CVR is associated with an increased risk of periprocedural neurologic complications