MRI for patients with cardiac implantable electronic devices: simplifying complexity with a 'one-stop' service model.

BACKGROUND: Patients with cardiac pacemakers and defibrillators are disadvantaged because of poor access to MRI scans, leading to late and misdiagnosis particularly for cancer and neurological disease. New technology allied to tested protocols now allows safe MRI scanning of such patients; however, logistical barriers persist. AIM: To deliver a streamlined sustainable service that provides timely MRI scans to patients with cardiac implantable electronic devices (CIEDs). METHODS: Patients requested a 'one-stop' service for MRI, whereby devices could be reprogrammed and scans acquired at a single location and visit. To provide this 'one-stop' service, we trained a team including administrators, physicians, cardiac physiologists and radiographers. A standard protocol was used to prevent unnecessary request refusals and delays to scheduling. Service volume, waiting time and safety were analysed 6 months before and 2 years after service redesign. Waiting times for internal and external inpatient referrals plus time to treatment for patients on a cancer pathway were analysed. RESULTS: 215 MRI scans were performed over 2 years. After service redesign, MRI provision increased six-fold to 20 times the national average with reduced waiting time from 60 to 15 days and no adverse events. Departmental throughput was maintained. 85 (40%) referrals were external. 41 (19%) inpatients were scanned, reducing bed-stay by 3 days for internal referrals. 24 (11%) scans were for suspected cancer, 83% allowed treatment within the national standard of 62 days. There was no preintervention service for either inpatients or suspected cancer investigation. CONCLUSION: Implementation of a 'one-stop' service model to provide MRI for patients with CIEDs is safe, streamlined, scalable and has reduced delays making economic and clinical sense. Protocols and checklists are available at mrimypacemaker.com.

Clinical impact of cardiovascular magnetic resonance with optimized myocardial scar detection in patients with cardiac implantable devices.

BACKGROUND: Myocardial scar assessment using late gadolinium enhancement Cardiovascular Magnetic Resonance (LGE CMR) is commonly indicated for patients with cardiac implantable electronic devices (CIEDs), however metal artifact can degrade images. We evaluated the clinical impact of LGE CMR incorporating a device-dependent metal artifact reduction strategy in patients with CIEDs. METHODS: 136 CMR studies were performed in 133 consecutive patients (age 56 ±â€¯19 years, 69% male) with CIEDs (22% implantable loop recorders [ILRs], 40% permanent pacemakers [PPMs], 38% implantable cardioverter defibrillators [ICDs]; 42% non-MRI conditional) over 2 years, without complication. LGE imaging was tailored to the CIED, using a wideband sequence for left-sided PPMs and ICDs and conventional sequences for ILRs and right-sided PPMs, scoring segmental artifact. Diagnostic utility and impact on clinical management were scored by consensus of experts. RESULTS: CMR provided unexpected diagnoses in 22 (16%) and changed management in 113 (83%) patients. Myocardial scar was present in 92 (68%), with other abnormalities detected in another 13%. Using conventional LGE, 43 (32%) studies were non-diagnostic (79% of defibrillators) compared to 0% using wideband LGE imaging. Wideband LGE results changed clinical management in an additional 39 (75%) defibrillator patients and 10 (19%) pacemaker patients when compared to imaging with conventional LGE sequences. CONCLUSION: The clinical yield from CMR using optimized LGE sequences in patients with CIEDs is high with no demonstrated clinical risk. A device-dependent LGE imaging strategy using wideband LGE is needed to achieve clinical utility especially in ICD recipients.

Plasma-Lyte 148 vs. Hartmann's solution for cardiopulmonary bypass pump prime: a prospective double-blind randomized trial.

BACKGROUND: The mechanisms of acid-base changes during cardiopulmonary bypass (CPB) remain unclear. We tested the hypothesis that, when used as CPB pump prime solutions, Plasma-Lyte 148 (PL) and Hartmann's solution (HS) have differential mechanisms of action in their contribution to acid-base changes. METHODS: We performed a prospective, double-blind, randomized trial in adult patients undergoing elective cardiac surgery with CPB. Participants received a CPB prime solution of 2000 mL, with either PL or HS. The primary endpoint was the standard base excess (SBE) value measured at 60 minutes after full CPB flows (SBE60min). Secondary outcomes included changes in SBE, pH, chloride, sodium, lactate, gluconate, acetate, strong ion difference and strong ion gap at two (T2min), five (T5min), ten (T10min), thirty (T30min) and sixty (T60min) minutes on CPB. The primary outcome was measured using a two-tailed Welch's t-test. Repeated measures ANOVA was used to test for differences between time points. RESULTS: Twenty-five participants were randomized to PL and 25 to HS. Baseline characteristics, EURO and APACHE scores, biochemistry, hematology and volumes of cardioplegia were similar. Mean (SD) SBE at T60min was -1.3 (1.4) in the PL group and -0.1 (2.7) in the HS group; p=0.55. No significant differences in SBE between the groups was observed during the first 60 minutes (p=0.48). During CPB, there was hyperacetatemia and hypergluconatemia in the PL group and hyperlactatemia and hyperchloremia in the HS group. No significant difference between the groups in plasma bicarbonate levels and total weak acid levels were found. Complications and intensive care unit and hospital length of stays were similar. CONCLUSIONS: During CPB, PL and HS did not cause a significant metabolic acidosis. There was hyperacetatemia and hypergluconatemia with PL and hyperchloremia and hyperlactatemia with HS. These physiochemical effects appear clinically innocuous.

Transcriptome Signatures of Selection, Drift, Introgression, and Gene Duplication in the Evolution of an Extremophile Endemic Plant.

Plants on serpentine soils provide extreme examples of adaptation to environment, and thus offer excellent models for the study of evolution at the molecular and genomic level. Serpentine outcrops are derived from ultramafic rock and have extremely low levels of essential plant nutrients (e.g., N, P, K, and Ca), as well as toxic levels of heavy metals (e.g., Ni, Cr, and Co) and low moisture availability. These outcrops provide habitat to a number of endemic plant species, including the annual mustard Caulanthus amplexicaulis var. barbarae (Cab) (Brassicaceae). Its sister taxon, C. amplexicaulis var. amplexicaulis (Caa), is intolerant to serpentine soils. Here, we assembled and annotated comprehensive reference transcriptomes of both Caa and Cab for use in protein coding sequence comparisons. A set of 29,443 reciprocal best Blast hit (RBH) orthologs between Caa and Cab was compared with identify coding sequence variants, revealing a high genome-wide dN/dS ratio between the two taxa (mean = 0.346). We show that elevated dN/dS likely results from the composite effects of genetic drift, positive selection, and the relaxation of negative selection. Further, analysis of paralogs within each taxon revealed the signature of a period of elevated gene duplication (∼10 Ma) that is shared with other species of the tribe Thelypodieae, and may have played a role in the striking morphological and ecological diversity of this tribe. In addition, distribution of the synonymous substitution rate, dS, is strongly bimodal, indicating a history of reticulate evolution that may have contributed to serpentine adaptation.

Groin complications in endovascular mechanical thrombectomy for acute ischemic stroke: a 10-year single center experience.

BACKGROUND: The increasing utilization of balloon guide catheters (BGCs) in thrombectomy therapy for ischemic stroke has led to concerns about large-bore sheaths causing vascular groin complications.Objective To retrospectively assess the impact of large large-bore sheaths and vascular closure devices on groin complication rates at a comprehensive stroke center over a 10-year period. METHODS: Radiological and clinical records of patients with acute ischemic stroke who underwent mechanical endovascular therapy with an 8Fr or larger sheaths were reviewed. A groin complication was defined as the formation of a groin hematoma, retroperitoneal hematoma, femoral artery pseudoaneurysm, or the need for surgical repair. Information collected included size of sheath, type of hemostatic device, and anticoagulation status of the patient. Blood bank records were also analyzed to identify patients who may have had an undocumented blood transfusion for a groin hematoma. RESULTS: A total of 472 patients with acute ischemic stroke who underwent mechanical thrombectomy with a sheath and BGC sized 8Fr or larger were identified. 260 patients (55.1%) had tissue Plasminogen Activator (tPA) administered as part of stroke treatment. Vascular closure devices were used in 97.9% of cases (n=462). Two patients were identified who had definite groin complications and a further two were included as having possible complications. There was a very low rate of clinically significant groin complications (0.4-0.8%) associated with the use of large-bore sheaths. CONCLUSIONS: These findings suggest that concerns for groin complications should not preclude the use of BGCs and large-bore sheaths in mechanical thrombectomy for acute ischemic stroke.

Something fishy: an unusual Erysipelothrix rhusiopathiae infection in an immunocompromised individual.

A 39-year-old man with a history of Crohn's disease presented to the emergency department with a 12-h history of worsening febrile illness. He deteriorated rapidly with progression to sepsis and was admitted to the intensive care unit. Initial treatment comprised broad spectrum antibiotics and inotropic support resulting in rapid improvement. With the immunocompromised state of the patient, and multiple blood cultures revealing Erysipelothrix rhusiopathiae, a detailed history disclosed a recent injury sustained from a fishing wire as the probable source of an infection. Treatment was narrowed to target the identified pathogen, the patient made a full recovery, and was counselled to be more cautious in future fishing activities.

Genetic analyses of nickel tolerance in a North American serpentine endemic plant, Caulanthus amplexicaulis var. barbarae (Brassicaceae).

PREMISE OF THE STUDY: The evolution of metal tolerance in plants is an important model for studies of adaptation to environment, population genetics, and speciation. Here, we investigated nickel tolerance in the North American serpentine endemic Caulanthus amplexicaulis var. barbarae in comparison with its nonserpentine sister taxon C. amplexicaulis var. amplexicaulis. We hypothesized that the serpentine endemic would have a heritable growth advantage on nickel-containing substrates. METHODS: We employed an artificial growth assay to quantify biomass accumulation. Study plants were crossed to create an F(2:3) population that was used to determine the heritability of nickel tolerance and to map quantitative trait loci (QTL). Nickel accumulation in both laboratory populations and native specimens was examined using energy-dispersive x-ray fluorescence (EDXRF). KEY RESULTS: The serpentine endemic had a dramatic growth advantage at concentrations of nickel >30 µmol/L. Caulanthus amplexicaulis var. barbarae and its nonserpentine sister taxon both accumulated nickel to substantial levels. Nickel tolerance was highly heritable (h(2) = 0.59) and not associated with accumulation. The QTL analyses identified two major loci for nickel tolerance, on linkage group 2 (LG2) and linkage group 9 (LG9). CONCLUSIONS: In our study, nickel tolerance was determined by two major loci with large effects. At both loci, alleles from the serpentine parent conferred positive effects on nickel tolerance, suggesting that they are adaptive in the natural serpentine environment. The mechanism of nickel tolerance in the serpentine plant was not exclusion of nickel. Nickel tolerance may have an inducible component in C. amplexicaulis var. barbarae.

Pneumococcal meningitis during pregnancy: a case report and review of literature.

BACKGROUND: Bacterial meningitis is a medical emergency for which prompt diagnosis and treatment are imperative to reducing the rate of death and long-term neurologic compromise. Few cases of meningitis have been reported during pregnancy, many of which had devastating outcomes for mother, neonate, or both. CASE: A 38-year-old multigravida at 35 weeks of gestation presented with mental status changes, fever, and preterm contractions. Lumbar puncture revealed gram positive cocci consistent with S. pneumoniae. Patient was intubated and admitted to ICU where she was given antibiotics and adjunctive therapy with dexamethasone. Continuous fetal monitoring was utilized throughout her course of her hospitalization. Patient was discharged home after ten days in the hospital and had an uncomplicated vaginal birth after caesarean section (VBAC) at 38 weeks. Both she and the infant are doing well with no permanent neurologic sequelae. CONCLUSION: A review of literature indicates only isolated cases of pneumococcal meningitis being described during pregnancy. An extended period of time between onset of maternal illness and delivery appears to reduce the risk of neonatal transmission and improve both maternal and fetal outcomes.