Cardiac wall motions reflect systolic and diastolic function. We have previously demonstrated the ability of a miniaturized three-axis (3D) accelerometer to monitor left ventricular function in experimental models and in patients. The main aim of this study was to investigate the clinical utility of the method for monitoring the left and right ventricular function during changes in global and regional cardiac function in a postoperative closed-chest situation. In 13 closed-chest pigs, miniaturized 3D accelerometers were placed on the left ventricle in the apical and basal regions and in the basal region of the right ventricle. An epicardial 3D motion vector was calculated from the acceleration signals in each heart region. Peak systolic velocity along this 3D vector (3D Vsys) was compared with the positive time derivative of the left and right ventricular pressure and with cardiac index during changes in global LV function (unloading, fluid loading, esmolol, dobutamine) and with ultrasound during regional left ventricular dysfunction (3-min occlusion of the left anterior descending coronary artery). Significant and typical changes in accelerometer 3D Vsys were seen in all heart regions during changes in global cardiac function. 3D Vsys reflected the left and right ventricular contractility via significant correlations with the positive time derivative of the left and right ventricular pressure, r = 0.86 and r = 0.72, and with cardiac index r = 0.82 and r = 0.73 (all P < 0.001), respectively. The miniaturized accelerometers also detected regional dysfunction, but showed reduced ability to localize ischaemia as the 3D Vsys in all heart regions showed similar reductions during coronary artery occlusion. Miniaturized 3D accelerometers placed on the heart can assess global and regional function in a closed-chest model. The technique may be used for continuous postoperative monitoring after cardiac surgery.
BackgroundFrom 2013 a midwife-led continuity model of care was implemented in the Nablus region in occupied Palestine, involving a governmental hospital and ten rural villages. This study analysed the relation between the midwife-led model and maternal and neonatal health outcomes.MethodA register-based, retrospective cohort design was used, involving 2201 singleton births between January 2016 and June 2017 at Nablus governmental hospital. Data from rural women, with singleton pregnancies and mixed risk status, who either lived in villages that offered the midwife-led continuity model and had registered at the governmental clinic, or who lived in villages without the midwife-led model and received regular care, were compared. Primary outcome was unplanned caesarean section. Secondary outcomes were other modes of birth, postpartum anaemia, preterm birth, birth weight, and admission to neonatal intensive care unit.FindingsStatistically significant less women receiving the midwife-led model had unplanned caesarean sections, 12·8% vs 15·9%, adjusted risk ratio (aRR) 0·80 (95% CI 0·64–0·99) and postpartum anaemia,19·8% vs 28·6%, aRR 0·72 (0·60–0·85). There was also a statistically significant lower rate of preterm births within the exposed group, 13·1% vs 16·8, aRR 0·79 (0·63–0·98), admission to neonatal intensive care unit, 7·0% vs 9·9%, aRR 0·71 (0·52–0·98) and newborn with birth weight 1500 g and less, 0·1% vs 1·1%, aRR 0·13 (0·02–0·97).InterpretationReceiving the midwife-led continuity model of care in Palestine was associated with several improved maternal and neonatal health outcomes. The findings support further implementation of the model. Implementation research, including randomised studies, would be useful to further investigate the effect and feasibility of the model in a low resource setting.FundingThis study was partly funded by the Research Council of Norway through the Global Health and Vaccination Program (GLOBVAC), project number 243706. The implementation received public funding through Norwegian Aid Committee (NORWAC).
Purpose The purpose of this paper is to review the design and fabrication of a micro‐accelerometer to be used to measure the heart wall motion of patients who have just undergone coronary artery bypass graft (CABG) surgery. The sensor will provide a means of early warning for the medical staff of associated complications with this surgery occurring. Design/methodology/approach A feasibility paper is carried out with the use of commercially available MEMS three‐axis accelerometers. The sensors are used in animal studies during which the sensor is stitched directly to the surface of a pig's heart. A need for smaller sensors is required and these are designed in‐house and fabricated using a MEMS process. The final dimensions of the sensors are 2.5×3.5×1.4 mm in width, length and height, respectively. Findings The results of the feasibility studies demonstrate the viability of this type of sensor for heart wall motion measurement. It is possible to detect abnormalities, which can indicate complications associated with CABG. The sensors presented here are fabricated within the tight overall size specifications deemed necessary for this application. Research limitations/implications This paper demonstrates an application of MEMS for implantable medical sensors. Practical implications In the UK, approximately 300,000 people have a heart attack each year. One of the most common surgeries that is used to treat this is CABG. This sensor is to be used by the medical staff in post‐surgery to provide “real‐time” monitoring of the heart and give early warning of regional cardiac ischemia which can save lives and reduce hospital waiting times and costs. Originality/value This paper demonstrates an original way of measuring heart wall motion. Results from the feasibility studies have proven that this can provide an invaluable way of providing early warning of complications after heart surgery.
Background: Cardiac fibrosis is an important complication of intestinal carcinoid disease (CD). Evaluation of myocardial function in patients with CD has focused on the right ventricle (RV) function. It has recently been suggested that the left ventricle (LV) function is also affected. Impaired myocardial function increases mortality, and we hypothesized that function by LV and RV strain could predict death in patients with intestinal CD. Methods: 89 patients (age 61±12 years) with verified intestinal CD were examined with 2-dimensional speckle tracking echocardiography (2D-STE) at baseline. LV global longitudinal strain was calculated from a 16 segments model, and RV longitudinal strain was calculated in a 3 segments model (free wall). The patients were followed up for a period of 1252 ± 374 days. Mortality data was obtained from hospital records. Survival was calculated by the Kaplan-Meier method, and log-rank test was used to compare the survival curves. Follow up 2D-STE was done among survivors. Results: Twenty-one patients (24%) died during follow up. LV function by global strain at baseline was significantly reduced (-17.6 ± 2.0% vs. -19.3 ± 2.6%, p=0.001) in those who died during follow up. RV function was also significantly reduced (-23.9 ± 4.6% vs. -26.6 ± 4.0%, p=0.02). By Cox regression analysis, LV and RV baseline strain were independent predictors of mortality (LV: Hazard ratio (HR) 1.17 (95% CI 1.04-1.32) (p=0.011), RV: HR 1.26 (95% CI 1.04-1.53) (p=0.018)). At follow up of survivors, myocardial strain was significantly reduced from baseline in both LV (19.6 ± 2.6% to 17.9 ± 2.5%, p Conclusion: LV and RV myocardial strain predicted mortality in patients with intestinal CD during 3.5 years of follow up. Our findings indicate a biventricular progressive deterioration in patients with intestinal CD.
