Heterogeneity in the Structure of the Left Ventricular Outflow Tract: A 3-Dimensional Transesophageal Echocardiographic Study.

BACKGROUND: The left ventricular outflow tract (LVOT) is a composite of adjoining structures; therefore, a circular or elliptical shape at one point may not represent its entire structure. The purpose of this study was to evaluate the presence of heterogeneity in the LVOT. METHODS: Patients with normal valvular and ventricular function undergoing elective coronary revascularization surgery were included in the study. Intraoperative R-wave gated 3-dimensional (3D) transesophageal echocardiographic imaging of the LVOT was performed at end-systole, with the midesophageal long axis as the reference view. Acquired data were analyzed with the Philips Q-Lab software with multiplanar reformatting in the sagittal (minor axis), transverse (major axis), and coronal (cross-sectional area by planimetry) views of the LVOT. These measurements were made on the left ventricular side or proximal LVOT, aortic side, or distal LVOT and mid-LVOT. RESULTS: Fifty patients were included in the study. The LVOT minor (sagittal) axis dimension did not differ across the mid-LVOT, proximal LVOT, and distal LVOT (P = .11). The major axis diameter of LVOT differed among the 3 regions of the LVOT (P < .001). A difference in major axis diameter was observed between the proximal and the distal LVOT (median difference of 0.39 cm; Bonferroni-adjusted 95% confidence interval [CI] of the difference = 0.31-0.48 cm; Bonferroni-adjusted P < .001). Planimetry of the LVOT area differed significantly (P < .001) between the regions analyzed, and we found a difference between the distal and the proximal LVOT (median difference = 0.65 cm, Bonferroni-adjusted 95% CI of the difference = 0.44-0.88 cm, Bonferroni-adjusted P < .001). The LVOT area calculated from minor axis diameter differed significantly from the area obtained by planimetry (P < .001). CONCLUSIONS: There was heterogeneity in the major axis diameter and cross-sectional area for the different regions of the LVOT. The distal LVOT (aortic side) was more circular, whereas the proximal LVOT (left ventricular side) was more elliptical in shape. This change in shape from circular to elliptical was accounted for by a difference in the major axis diameter from proximal to distal LVOT and a relatively similar minor axis diameter. Although the clinical significance of this finding is unknown, the assumption of a uniform structure of LVOT is incorrect. Three-dimensional imaging may be useful for assessing the LVOT shape and size at a specific region of interest.

Cardiac output calculation and three-dimensional echocardiography.

OBJECTIVE: To compare the determination of stroke volume (SV) and cardiac output (CO) using 2-dimensional (2D) versus 3-dimensional (3D) transesophageal echocardiography (TEE). DESIGN: Prospective observational study. SETTING: Tertiary care university hospital. PARTICIPANTS: 35 patients without structural valve abnormalities undergoing isolated coronary artery bypass grafting. INTERVENTIONS: Left ventricular outflow tract (LVOT) diameter determined with 2D TEE was used to estimate LVOT cross-sectional area (CSALVOT). LVOT area was measured directly with 3D TEE by planimetry on an en face view. SV and CO were calculated for both methods using the continuity equation. MEASUREMENTS AND MAIN RESULTS: The area of the LVOT differed significantly between methods, being significantly larger in the 3D method (3.57±0.70 cm(2)v 3.98±0.93 cm(2)) . This resulted in a 10% lower CO with the 2D method of LVOT area estimation. CONCLUSIONS: LVOT area is underestimated with the single- axis 2D method when compared with 3D planimetered area. This results in a CO that is approximately 10% lower with the 2D method.

Dynamism of the mitral annulus: a spatial and temporal analysis.

OBJECTIVE: In this study, the authors sought to investigate the extent and timing of changes in mitral annular area during the cardiac cycle. Particularly, the authors assessed whether these changes were limited to the posterior part of the annulus or were more global in nature. DESIGN: Prospective, observational study SETTING: Tertiary care university hospital PARTICIPANTS: Twenty three patients undergoing non-valvular cardiac surgery and 3 patients undergoing vascular procedures. INTERVENTIONS: Intraoperative 3-dimensional transesophageal echocardiographic data obtained from patients with normal mitral valves undergoing non-valvular cardiac surgery were analyzed geometrically. Annular areas and diameters were measured during various stages of the cardiac cycle. Intertrigonal distance also was measured using 3D data. MEASUREMENTS AND MAIN RESULTS: Both anterior and posterior portions of the mitral annulus demonstrated dynamism throughout the cardiac cycle. The expansion phase ranged from mid-systole to early-diastole, whereas mid-diastole to early-systole was characterized by an annular contraction phase. Area changes were contributed equally by anterior and posterior parts of the annulus. Annular dimensions increased in accordance with mitral annular area (p<0.05). Echocardiographically-identified intertrigonal distance showed the least delta change. CONCLUSIONS: Both the anterior and posterior parts of the annulus contribute to changes in mitral annular area, which undergoes discrete expansion and contraction phases that extend into both systole and diastole. Compared to other annular dimensions, the echocardiographically-identified intertrigonal distance does not change significantly during the cardiac cycle.

Obesity Trends Amongst Hospitalized Patients with Spinal Cord Stimulator Implants.

INTRODUCTION: Chronic pain remains an important public health problem as it continues to increase healthcare-related cost. Comorbidities like obesity have been associated with efficacy of spinal cord stimulator (SCS) therapy and worse outcomes. The goal of this study is to investigate the trends of obesity amongst hospitalized patients with SCS therapy as well as healthcare utilization outcomes. METHODS: Using the International Classification of Diseases (ICD) ninth and tenth procedure and diagnosis code, we investigated the National Inpatient Sample (NIS) for patients with SCS implants between 2011 and 2015. Patients received a diagnosis of obesity based on the following categories: class I, II and III obesity. Age, gender, and comorbid conditions of patients with obesity were matched 1:1 on propensity score to those without obesity diagnosis. Our primary outcome was defined as trend of obesity diagnosis. Our secondary outcome, healthcare utilization, included in-hospital cost, length of stay, and discharge location. RESULTS: Between 2011 and 2015, a total of 3893 patients with SCS implants were identified (average age 56 ± 15 years, 58% female, 0.70 ± 1.1 Charlson Comorbidity Index, CCI). Of this cohort, 640 patients were identified as obese. The proportion of patients with obesity diagnosis increased significantly from 13.75% in 2011 to 19.36% in 2015 (p < 0.001). After 1:1 matching on propensity score, 597 patients with obesity were successfully matched to 597 patients without obesity. The total hospital cost for SCS patients with obesity (median $104,845, IQR $74,648-144,292) was not significantly different from patients without obesity diagnosis (median $111,092, IQR $68,990-145,459) (p = 0.161). CONCLUSIONS: The data from our study suggests that there is an increasing rate of obesity diagnosis amongst patients with SCS therapy. However, there was no difference in healthcare utilization between patients with and without obesity. Additional studies may provide more insight into our findings.

Trends of Co-Morbid Depression in Hospitalized Patients with Failed Back Surgery Syndrome: An Analysis of the Nationwide Inpatient Sample.

INTRODUCTION: Co-morbid depression has been associated with poor outcomes following spine surgery and worsening of low back pain symptoms leading to failed back surgery syndrome (FBSS). Given the increasing focus of healthcare utilization and value-based care, it is essential to understand the demographic and economic data surrounding co-morbid depression amongst patients with FBSS. METHODS: Our study investigated the NIS database for FBSS patients who had co-morbid depression (ICD-9 CM codes 300.4, 301.12, 309.0, 309.1, 311; ICD-10 M96.1) between 2011 and 2015 across 44 states. We obtained demographic and economic data such as age, sex, ethnicity, location, number of in-patient procedures, hospital length of stay, cost of hospital stay, and frequency of routine discharge dispositions. The NIS database represents approximately a 20% sample of discharges from hospitals in the United States. These data are weighted to provide national estimates for the total United States population. National administrative databases (NADs) like National Inpatient Sample (NIS) are a common source of data for spine procedures. This database is appealing to investigators because of ease of data access and large patient sample. The NIS database is a de-identified database that consists of a collection of billing and diagnostic codes used by participating hospitals with the goal of quality control, population monitoring, and tracking procedures. The NIS does not require institutional review board (IRB) approval or exempt determination. RESULTS: Between 2011 and 2015, a total number of 115,976 patients with FBSS were identified. Of these patients, about 23,425 had co-morbid depression. The rate of co-morbid depression in 2015 was 23% with the lowest reported rate being 20% in 2011. Females and Caucasians had consistently higher rates of co-morbid depression compared to males and other ethnic groups respectively. The average length of stay for patients with co-morbid depression fluctuated between 2011 and 2015, with the highest reported at 4.81 days in 2015. The number of procedures increased steadily from 2011 to 2015 with a dip in 2013. The highest number of procedures was reported as 3.94 in 2015. The mean total hospital charges remained stable over time with the largest change being the decrease from 2011 (mean $93,939; 95% CI $80,064-$107,815) to 2012 (mean 82,603; 95% CI $75,127-$90,079). Additionally, patients with FBSS and co-morbid depression were more often discharged home than home with healthcare or to another healthcare facility. CONCLUSIONS: The occurrence of co-morbid depression in hospitalized patients with FBSS increased from 20% in 2011 to 23% in 2015. While direct hospital costs and length of stay remained relatively stable, the number of inpatient procedures performed trended upwards. The exact etiology for this increase in depression prevalence is unknown; additional studies are needed to shed further insight.

Dynamic changes in the ischemic mitral annulus: Implications for ring sizing.

OBJECTIVES: Contrary to the rest of the mitral annulus, inter-trigonal distance is known to be relatively less dynamic during the cardiac cycle. Therefore, intertrigonal distance is considered a suitable benchmark for annuloplasty ring sizing during mitral valve (MV) surgery. The entire mitral annulus dilates and flattens in patients with ischemic mitral regurgitation (IMR). It is assumed that the fibrous trigone of the heart and the intertrigonal distance does not dilate. In this study, we sought to demonstrate the changes in mitral annular geometry in patients with IMR and specifically analyze the changes in intertrigonal distance during the cardiac cycle. METHODS: Intraoperative three-dimensional transesophageal echocardiographic data obtained from 26 patients with normal MVs undergoing nonvalvular cardiac surgery and 36 patients with IMR undergoing valve repair were dynamically analyzed using Philips Qlab ® software. RESULTS: Overall, regurgitant valves were larger in area and less dynamic than normal valves. Both normal and regurgitant groups displayed a significant change in annular area (AA) during the cardiac cycle (P < 0.01 and P < 0.05, respectively). Anteroposterior and anterolateral-posteromedial diameters and inter-trigonal distance increased through systole (P < 0.05 for all) in accordance with the AAs in both groups. However, inter-trigonal distance showed the least percentage change across the cardiac cycle and its reduced dynamism was validated in both cohorts (P > 0.05). CONCLUSIONS: Annular dimensions in regurgitant valves are dynamic and can be measured feasibly and accurately using echocardiography. The echocardiographically identified inter-trigonal distance does not change significantly during the cardiac cycle.

Early Cellular Changes in the Ascending Aorta and Myocardium in a Swine Model of Metabolic Syndrome.

BACKGROUND: Metabolic syndrome is associated with pathological remodeling of the heart and adjacent vessels. The early biochemical and cellular changes underlying the vascular damage are not fully understood. In this study, we sought to establish the nature, extent, and initial timeline of cytochemical derangements underlying reduced ventriculo-arterial compliance in a swine model of metabolic syndrome. METHODS: Yorkshire swine (n = 8 per group) were fed a normal diet (ND) or a high-cholesterol (HCD) for 12 weeks. Myocardial function and blood flow was assessed before harvesting the heart. Immuno-blotting and immuno-histochemical staining were used to assess the cellular changes in the myocardium, ascending aorta and left anterior descending artery (LAD). RESULTS: There was significant increase in body mass index, blood glucose and mean arterial pressures (p = 0.002, p = 0.001 and p = 0.024 respectively) in HCD group. At the cellular level there was significant increase in anti-apoptotic factors p-Akt (p = 0.007 and p = 0.002) and Bcl-xL (p = 0.05 and p = 0.01) in the HCD aorta and myocardium, respectively. Pro-fibrotic markers TGF-ß (p = 0.01), pSmad1/5 (p = 0.03) and MMP-9 (p = 0.005) were significantly increased in the HCD aorta. The levels of pro-apoptotic p38MAPK, Apaf-1 and cleaved Caspase3 were significantly increased in aorta of HCD (p = 0.03, p = 0.04 and p = 0.007 respectively). Similar changes in coronary arteries were not observed in either group. Functionally, the high cholesterol diet resulted in significant increase in ventricular end systolic pressure and-dp/dt (p = 0.05 and p = 0.007 respectively) in the HCD group. CONCLUSION: Preclinical metabolic syndrome initiates pro-apoptosis and pro-fibrosis pathways in the heart and ascending aorta, while sparing coronary arteries at this early stage of dietary modification.