A Targeted Swallow Screen for the Detection of Postoperative Dysphagia

Postoperative dysphagia leads to aspiration pneumonia, prolonged hospital stay, and is associated with increased mortality. A simple and sensitive screening test to identify patients requiring objective dysphagia evaluation is presently lacking. In this study, we evaluated the efficacy of a novel targeted swallow screen evaluation. This was a prospective trial involving all adult patients who underwent elective cardiac surgery with cardiopulmonary bypass at our institution over an 8-week period. Within 24 hours of extubation and before the initiation of oral intake, all postsurgical patients were evaluated using the targeted swallow screen. A fiberoptic endoscopic evaluation of swallowing was requested for failed screenings. During the study, 50 postcardiac surgery patients were screened. Fifteen (30%) failed the targeted swallow screen, and ten of the fifteen (66%) failed the subsequent fiberoptic endoscopic evaluation of swallowing exam and were confirmed to have dysphagia. The screening test had 100 per cent sensitivity for detecting dysphagia in our patient population, and a specificity of 87.5 per cent. The overall incidence of dysphagia was 20 per cent. We have shown that a targeted swallow evaluation can efficiently screen patients during the postcardiac surgery period. Furthermore, we have shown that the true incidence of dysphagia after cardiac surgery is significantly higher than previously recognized in literature.

Quantitative analysis of localized sources identified by focal impulse and rotor modulation mapping in atrial fibrillation

BACKGROUND

New approaches to ablation of atrial fibrillation (AF) include focal impulse and rotor modulation (FIRM) mapping, and initial results reported with this technique have been favorable. We sought to independently evaluate the approach by analyzing quantitative characteristics of atrial electrograms used to identify rotors and describe acute procedural outcomes of FIRM-guided ablation.

METHODS AND RESULTS

All FIRM-guided ablation procedures (n=24; 50% paroxysmal) at University of California, Los Angeles Medical Center were included for analysis. During AF, unipolar atrial electrograms collected from a 64-pole basket catheter were used to construct phase maps and identify putative AF sources. These sites were targeted for ablation, in conjunction with pulmonary vein isolation in most patients (n=19; 79%). All patients had rotors identified (mean, 2.3±0.9 per patient; 72% in left atrium). Prespecified acute procedural end point was achieved in 12 of 24 (50%) patients: AF termination (n=1), organization (n=3), or >10% slowing of AF cycle length (n=8). Basket electrodes were within 1 cm of 54% of left atrial surface area, and a mean of 31 electrodes per patient showed interpretable atrial electrograms. Offline analysis revealed no differences between rotor and distant sites in dominant frequency or Shannon entropy. Electroanatomic mapping showed no rotational activation at FIRM-identified rotor sites in 23 of 24 patients (96%).

CONCLUSIONS

FIRM-identified rotor sites did not exhibit quantitative atrial electrogram characteristics expected from rotors and did not differ quantitatively from surrounding tissue. Catheter ablation at these sites, in conjunction with pulmonary vein isolation, resulted in AF termination or organization in a minority of patients (4/24; 17%). Further validation of this approach is necessary.

Acute Effects of Pacing at Different Ventricular Sites on Left Ventricular Rotational Mechanics in a Porcine Model

OBJECTIVE

The purpose of this study was to examine the acute effects of pacing at different ventricular sites on hemodynamics and left ventricular (LV) rotational mechanics using speckle-tracking echocardiography (STE) in a porcine model.

DESIGN

A prospective laboratory investigation.

SETTING

University research laboratory.

PARTICIPANTS

Yorkshire pigs.

INTERVENTIONS

In 9 pigs, after midline sternotomy, epicardial pacing was performed from the right ventricular outflow tract (RVOT), right ventricular apex (RVA), and LV free wall.

MEASUREMENTS AND MAIN RESULTS

Two-dimensional STE and conductance catheter-derived LV pressure-volume measurements were made to determine the impact of pacing from various sites on LV rotational parameters (twist/untwist) and hemodynamics. RVOT pacing caused the least decrease in end-systolic pressure from baseline (-9.5%), when compared with RVA (-19.1%) and LV (-23.4%). Systolic and diastolic parameters (Emax, Tau) also were different among RVOT (4.7±0.8 mmHg/mL, 32±4 ms), RVA (3.9±0.7 mmHg/mL, 37±6 ms), and LV sites (3.6±0.8 mmHg/mL, 42±7 ms). Similar to the effects of pacing on hemodynamics, RVOT pacing better preserved LV twist (11.1±1.8 v 8.6±1.7, 5.9±0.7 °) and untwisting rate (64.6±8.5 v 56.2±5.3, 48.2±8.5 °/s) when compared with RV apical pacing and LV pacing. Furthermore, prolongation of conduction from LV lateral to anteroseptal at LV base (26.5±3.8 v 13.8±3.3 ms, p<0.05) and LV midpapillary muscle level (35.6±5.6 v 14.1±2.4 ms, p<0.05) was observed with LV pacing compared with RVOT pacing.

CONCLUSIONS

The present data showed that the LV twist/untwist and cardiac systolic and diastolic function were least affected by RVOT pacing. This finding may be explained by the proximity of this location to the native ventricular conduction system.

The cost of preventing readmissions: why surgeons should lead the effort

In accordance with the Affordable Care Act, Medicare has instituted financial penalties for hospitals with 30-day readmission rates that exceed a predetermined value. Currently, this value only considers "excess" readmissions for myocardial infarction, heart failure, and pneumonia with a maximum fine being one per cent of total Medicare reimbursements. In 2015, this penalty will increase to three per cent and encompass more surgical diagnoses. We retrospectively reviewed a database of adult patients undergoing cardiac surgery treated at our institution in 2012 to establish whether patients with readmissions within 30 days of the index operation could have been managed more cost-effectively without readmission. A calculation of cost efficiency was performed to compare the net hospital profit for two scenarios: admitting patients versus hypothetical preventative measures. Of the 576 patients during the study period, a total of 68 (11.8%) patients with unplanned 30-day readmissions were identified. Outpatient management was determined to have been feasible for 18 (26.5%) patients. Whereas the calculated net profit for readmission was $144,000, inclusion of Medicare's penalty resulted in a loss of $11,950. A readmission reduction program with an annual cost exceeding $11,950 would lead to financial loss. The financial implications of Medicare's readmission penalty alone necessitate the development of cost-effective strategies to reduce rehospitalization.

Do Preoperative β-blockers Improve Postoperative Outcomes in Patients Undergoing Cardiac Surgery? Challenging Societal Guidelines

Preoperative β-blockers (BBs) are widely administered to reduce morbidity and mortality among surgical patients. In fact, the Society of Thoracic Surgeons uses the administration of preoperative BBs as a quality metric. Recent reports, however, have questioned the benefit and safety of pre-operative BB administration. The aim of our study was to investigate whether preoperative BBs lead to improved surgical outcomes in patients undergoing cardiac surgery. A review of our prospectively maintained institutional database was done to identify adults undergoing cardiac operations at our institution from 2008 to 2013. Survival to discharge was the primary outcome with several additional secondary measures of morbidity included. A total of 2120 patients were included in the analysis and a multivariate logistic regression model was developed to adjust for differences between patient groups. After adjustment, BB administration was associated with lower odds of both prolonged ventilation (odds ratio [OR], 0.73; P = 0.032) and prolonged length of stay (OR, 0.79; P = 0.044). BB use was not associated with significant differences in other outcomes such as mortality or postoperative atrial fibrillation. Our study found that preoperative BBs may not be associated with sufficiently improved outcomes to justify their use as a quality metric in this population. Thus, prospective studies are warranted.

Do preoperative β-blockers improve postoperative outcomes in patients undergoing cardiac surgery? Challenging societal guidelines

Preoperative β-blockers (BBs) are widely administered to reduce morbidity and mortality among surgical patients. In fact, the Society of Thoracic Surgeons uses the administration of preoperative BBs as a quality metric. Recent reports, however, have questioned the benefit and safety of preoperative BB administration. The aim of our study was to investigate whether preoperative BBs lead to improved surgical outcomes in patients undergoing cardiac surgery. A review of our prospectively maintained institutional database was done to identify adults undergoing cardiac operations at our institution from 2008 to 2013. Survival to discharge was the primary outcome with several additional secondary measures of morbidity included. A total of 2120 patients were included in the analysis and a multivariate logistic regression model was developed to adjust for differences between patient groups. After adjustment, BB administration was associated with lower odds of both prolonged ventilation (odds ratio [OR], 0.73; P = 0.032) and prolonged length of stay (OR, 0.79; P = 0.044). BB use was not associated with significant differences in other outcomes such as mortality or postoperative atrial fibrillation. Our study found that preoperative BBs may not be associated with sufficiently improved outcomes to justify their use as a quality metric in this population. Thus, prospective studies are warranted.

The Cost of Preventing Readmissions: Why Surgeons Should Lead the Effort

In accordance with the Affordable Care Act, Medicare has instituted financial penalties for hospitals with 30-day readmission rates that exceed a predetermined value. Currently, this value only considers “excess” readmissions for myocardial infarction, heart failure, and pneumonia with a maximum fine being one per cent of total Medicare reimbursements. In 2015, this penalty will increase to three per cent and encompass more surgical diagnoses. We retrospectively reviewed a database of adult patients undergoing cardiac surgery treated at our institution in 2012 to establish whether patients with readmissions within 30 days of the index operation could have been managed more cost-effectively without readmission. A calculation of cost efficiency was performed to compare the net hospital profit for two scenarios: admitting patients versus hypothetical preventative measures. Of the 576 patients during the study period, a total of 68 (11.8%) patients with unplanned 30-day readmissions were identified. Outpatient management was determined to have been feasible for 18 (26.5%) patients. Whereas the calculated net profit for readmission was $144,000, inclusion of Medicare's penalty resulted in a loss of $11,950. A readmission reduction program with an annual cost exceeding $11,950 would lead to financial loss. The financial implications of Medicare's readmission penalty alone necessitate the development of cost-effective strategies to reduce rehospitalization.

Significance of "Deqi" response in acupuncture treatment: myth or reality

Acupuncture has been practiced in China for over 2000 years to treat a variety of diseases based on the "meridian theory," as described in the "Yellow Emperor's Classics of Internal Medicine." Deqi refers to the excitation of qi or vital energy inside meridians by acupuncture needle stimulation. Patients often experience multidimensional and intense needling sensations such as numbness, soreness, distention, heaviness, dull pain, and sharp pain during acupuncture stimulation. Deqi is considered as an important parameter in the process of achieving therapeutic effectiveness in acupuncture treatment. Understanding this phenomenon from neurophysiological aspects is important for clinical practice and enables practitioners to perform quantitative acupuncture evaluation to obtain a reliable prognosis of acupuncture treatment. This review paper describes our current knowledge and understanding of Deqi from a physiological aspect.

A framework for modeling and visualizing cardiovascular deformation under normal and altered circulatory conditions

The aim of this paper is to model and visualize cardiovascular deformations in order to better understand vascular movements inside the lung and heart caused by abnormal cardiac conditions. The modeling was performed in two steps: first step involved modeling the cardiac output taking into account of the heart rate and preload blood volume, contractility and systematic vascular resistance. The second step involved deforming a 3D cine cardiac gated Magnetic Resonance Volume to the corresponding cardiac output. Cardiac-gated MR imaging of 4 healthy volunteers were acquired. For each volunteer, a total of 24 short-axis and 18 radial planar views were acquired on a 1.5 T MR scanner during a series of 12-15 second breath-hold maneuvers. A 3D multi-resolution optical flow deformable image registration algorithm was used to quantify the volumetric cardiovascular displacements for known cardiac outputs. Results show that a real-time visualization of the vascular deformations inside both the lung as well as the heart can be seen for different cardiac outputs representing normal and abnormal cardiac conditions.

Cardiovascular blood flow analysis under normal and open injury conditions

The aim of this paper is to enable a simulation tool for cardiovascular blood flow in order to better understand normal and hemorrhage conditions. A second order partial differential model for cardiovascular blood flow is employed. The individual components of the model is represented as an RLC circuit representation. Injury behavior is simulated by varying the circuit system parameters for the section representing different arterial levels. Our results show that significant changes in the blood flow inside the cardiovascular system can be observed when different injury conditions are modeled.

Left ventricular twist and untwist rate provide reliable measures of ventricular function in myocardial ischemia and a wide range of hemodynamic states

Although rotational parameters by speckle tracking echocardiography (STE) have been previously compared to sonomicrometry and cardiac magnetic resonance imaging, few have examined the relationship between left ventricular (LV) rotational mechanics and intraventricular measures of load-independent contractility, LV stiffness, or ventriculoarterial coupling. The aim of this study was to compare the changes in LV rotational indices to intraventricular pressure–volume (PV) relationships under a range of inotropic states induced by pharmacological interventions, acute ischemia, and changes in preload. In nine pigs, simultaneous echocardiographic imaging and LVPV measurements were performed during pharmacologically induced high or low inotropy and during acute ischemia by ligation of the left anterior descending coronary artery (LAD). Maximal ventricular elastance (E_max), arterial elastance (E_a), ventricular–arterial coupling (E_max/E_a), dP/dt, tau, and other hemodynamic parameters were determined. Dobutamine and esmolol infusions led to inversely correlated changes in hemodynamic measurements of LV function. Apical but not basal rotation and diastolic rotation rate were decreased by esmolol and increased by dobutamine. The LV twist correlates well with E_max (r = 0.83) and E_max/E_a (r = 0.80). Apical diastolic rotation rate also correlates with dP/dt_min (r = −0.63), τ (r = −0.81), and LV stiffness (r = −0.52). LAD ligation decreased systolic and diastolic LV rotation in apical (P < 0.05), but not basal myocardium. Occlusion of the inferior vena cava, to reduce preload, increased apical rotation in systole and diastole. LV rotational parameters measured by STE provide quantitative and reproducible indices of global LV systolic and diastolic function during acute changes in hemodynamics.