Exploring the predictive value of combined ultrasound parameters for spinal anesthesia-induced hypotension in cesarean section: a prospective observational study.

BACKGROUND: Prophylactic vasopressor infusion can effectively assist with fluid loading to prevent spinal anesthesia-induced hypotension. However, the ideal dose varies widely among individuals. We hypothesized that hypotension-susceptible patients requiring cesarean section (C-section) could be identified using combined ultrasound parameters to enable differentiated prophylactic medical interventions. METHODS: This prospective observational trial was carried out within a regional center hospital for women and children in Sichuan Province, China. Singleton pregnant women undergoing combined spinal-epidural anesthesia for elective C-sections were eligible. Women with contraindications to spinal anesthesia or medical comorbidities were excluded. Velocity time integral (VTI) and left ventricular end-diastolic area (LVEDA) in the supine and left lateral positions were measured on ultrasound before anesthesia. Stroke volume, cardiac output, and the percentage change (%) in each parameter between two positions were calculated. Vital signs and demographic data were recorded. Spinal anesthesia-induced hypotension was defined as a mean arterial pressure decrease of > 20% from baseline. The area under the receiver operating characteristic curve (AUROC) was used to analyze the associations of ultrasound measurements, vital signs, and demographic characteristics with spinal anesthesia-induced hypotension. This exploratory study did not have a predefined outcome; however, various parameter combinations were compared using the AUROC to determine which combined parameters had better predictive values. RESULTS: Patients were divided into the normotension (n = 31) and hypotension groups (n = 57). A combination of heart rate (HR), LVEDAs, and VTI% was significantly better at predicting hypotension than was HR (AUROC 0.827 vs. 0.707, P = 0.020) or LVEDAs (AUROC 0.827 vs. 0.711, P = 0.039) alone, but not significantly better than VTI% alone (AUROC 0.827 vs. 0.766, P = 0.098). CONCLUSION: The combined parameters of HR and LVEDAs with VTI% may predict spinal anesthesia-induced hypotension more precisely than the single parameters. Future research is necessary to determine whether this knowledge improves maternal and neonatal outcomes. TRIAL REGISTRATION: ChiCTR1900025191.

The in vivo study of cardiac mechano-electric and mechano-mechanical coupling during heart development in zebrafish.

In the adult heart, acute adaptation of electrical and mechanical activity to changes in mechanical load occurs via feedback processes known as "mechano-electric coupling" and "mechano-mechanical coupling." Whether this occurs during cardiac development is ill-defined, as acutely altering the heart's mechanical load while measuring functional responses in traditional experimental models is difficult, as embryogenesis occurs in utero, making the heart inaccessible. These limitations can be overcome with zebrafish, as larvae develop in a dish and are nearly transparent, allowing for in vivo manipulation and measurement of cardiac structure and function. Here we present a novel approach for the in vivo study of mechano-electric and mechano-mechanical coupling in the developing zebrafish heart. This innovative methodology involves acute in vivo atrial dilation (i.e., increased atrial preload) in larval zebrafish by injection of a controlled volume into the venous circulation immediately upstream of the heart, combined with optical measurement of the acute electrical (change in heart rate) and mechanical (change in stroke area) response. In proof-of-concept experiments, we applied our new method to 48 h post-fertilisation zebrafish, which revealed differences between the electrical and mechanical response to atrial dilation. In response to an acute increase in atrial preload there is a large increase in atrial stroke area but no change in heart rate, demonstrating that in contrast to the fully developed heart, during early cardiac development mechano-mechanical coupling alone drives the adaptive increase in atrial output. Overall, in this methodological paper we present our new experimental approach for the study of mechano-electric and mechano-mechanical coupling during cardiac development and demonstrate its potential for understanding the essential adaptation of heart function to acute changes in mechanical load.

High-echoic line tracing of transthoracic echocardiography accurately assesses right ventricular enlargement in adult patients with atrial septal defect.

Accurate measurement of right ventricular (RV) size using transthoracic echocardiography (TTE) is important for evaluating the severity of congenital heart diseases. The RV end-diastolic area index (RVEDAi) determined using TTE is used to assess RV dilatation; however, the tracing line of the RVEDAi has not been clearly defined by the guidelines. This study aimed to determine the exact tracing method for RVEDAi using TTE. We retrospectively studied 107 patients with atrial septal defects who underwent cardiac magnetic resonance imaging (CMR) and TTE. We measured the RVEDAi according to isoechoic and high-echoic lines, and compared it with the RVEDAi measured using CMR. The isoechoic line was defined as the isoechoic endocardial border of the RV free wall, whereas the high-echoic line was defined as the high-echoic endocardial border of the RV free wall more outside than the isoechoic line. RVEDAi measured using high-echoic line (high-RVEDAi) was more accurately related to RVEDAi measured using CMR than that measured using isoechoic line (iso-RVEDAi). The difference in the high-RVEDAi was 0.3 cm2/m2, and the limit of agreement (LOA) was - 3.7 to 4.3 cm2/m2. With regard to inter-observer variability, high-RVEDAi was superior to iso-RVEDAi. High-RVEDAi had greater agreement with CMR-RVEDAi than with iso-RVEDAi. High-RVEDAi can become the standard measurement of RV size using two-dimensional TTE.

Characterization of Favorable Right Ventricular Dimensions for Optimal Reverse Remodeling Following Pulmonary Valve Replacement.

We sought to couple current cardiac magnetic resonance (CMR) thresholds of right ventricular (RV) size and function with longitudinal trajectories of RV recovery, after pulmonary valve replacement (PVR). We aimed to identify optimal timing of PVR and couple CMR-based metrics with contemporaneous echocardiographic metrics. From June 2002 to January 2019, 174 patients with severe pulmonary regurgitation and peak RV outflow tract gradient <30 mm Hg underwent PVR at Cleveland Clinic. Mean age was 35 ± 16 years and 60 (34%) had concomitant tricuspid valve surgery. RV end diastolic area index (RVEDAi) and function metrics were measured by offline image review on preoperative and 794 postoperative echocardiograms. Contemporaneous RV end diastolic volume index (RVEDVi) was assessed on CMR and correlated to RVEDAi. Multiphase nonlinear mixed-effects models were used to analyze the longitudinal change in RV size and function after PVR. RVEDAi was correlated with RVEDVi (P < 0.0001, r = 0.59). RVEDAi decreased slowly over 10 years following PVR. An inflection point at 24 cm2/m2 was noted at 1 year post-PVR and was associated with failure of RV reverse remodeling and RVEDVi ≥150 mL/m2. Compared to patients with preoperative RVEDVi ≥150 mL/m2, patients with RVEDVi <150 mL/m2 had accelerated recovery of longitudinal trajectories of RV size and function metrics on echocardiograms. Reverse remodeling of RV following PVR is an ongoing process. Current accepted threshold values for PVR are associated with greatest RV recovery, suggesting that earlier PVR is warranted. Echocardiography can potentially be utilized in lieu of CMR for surveillance and interventional triage.

Combination of Static Echocardiographic Indices for the Prediction of Fluid Responsiveness in Patients Undergoing Coronary Surgery: A Pilot Study.

We investigated the role of echocardiographic indices consisting of left ventricular end-diastolic area (LVEDA) in combination with Doppler-derived surrogates of diastolic compliance and filling (E/E', E'/S', E'/A'; early transmitral flow velocity (E), tissue Doppler-derived early (E') diastolic, late (A') diastolic, or peak systolic (S') velocity of the mitral annulus) in predicting fluid responsiveness in off-pump coronary surgery. Hemodynamic and echocardiographic variables were prospectively assessed under general anesthesia before and after a fluid challenge of 6 mL/kg during apnea at atmospheric pressure in 64 patients with LV ejection fraction ≥40%. Forty patients (63%) were fluid responders (≥15% increase in stroke volume index). E/E' and E'/S' could predict fluid responsiveness with area under the receiver operating characteristic curve (AUROC) of 0.71 (95% confidence interval [CI], 0.56-0.85; p = 0.006) and 0.68 (95% CI, 0.54-0.82; p = 0.017), respectively. The combination of LVEDA and E/E' showed incremental predictive ability for fluid responsiveness compared with LVEDA (AUROC, 0.60; p = 0.170) or pulse pressure variation (AUROC, 0.70; p = 0.002), yielding the highest AUROC of 0.78 (95% CI, 0.66-0.90; p < 0.001). The combined index of echocardiographic variables reflecting LV dimension (LVEDA) and diastolic compliance and filling (E/E') is a potentially useful predictor of fluid responsiveness.

Can a Biohybrid Patch Salvage Ventricular Function at a Late Time Point in the Post-Infarction Remodeling Process?

A biohybrid patch without cellular components was implanted over large infarcted areas in severely dilated hearts. Nonpatched animals were assigned to control or losartan therapy. Patch-implanted animals responded with better morphological and functional echocardiographic endpoints, which were more evident in a subgroup of animals with very low pre-treatment ejection fraction (<35%). Patched animals also had smaller infarcts than both nonpatched groups. This simple approach could hold promise for clinical translation and be applied using minimally invasive procedures over the epicardium in a large set of patients to induce better ventricular remodeling, especially among those who are especially frail.

Left ventricular vortex analysis by high-frame rate blood speckle tracking echocardiography in healthy children and in congenital heart disease.

BACKGROUND: High-frame rate blood speckle tracking (BST) echocardiography is a new technique for the assessment of intracardiac flow. The purpose of this study was to evaluate the characteristics of left ventricular (LV) vortices in healthy children and in those with congenital heart disease (CHD). METHODS: Characteristics of LV vortices were analyses based on 4-chamber BST images from 118 healthy children (median age 6.84 years, range 0.01-17 years) and 43 children with CHD (median age 0.99 years, range 0.01-14 years). Both groups were compared after propensity matching. Multiple linear regression was used to identify factors that independently influence vortex characteristics. RESULTS: Feasibility of vortex imaging was 93.7% for healthy children and 95.6% for CHD. After propensity matching, there were no overall significant differences in vortex distance to apex, distance to interventricular septum (IVS), height, width, sphericity index, or area. However, multiple regression analysis revealed significant associations of LV morphology with vortex characteristics. Furthermore, CHD involving LV volume overload and CHD involving LV pressure overload were both associated with vortices localized closer to the IVS. CONCLUSIONS: LV vortex analysis using high-frame rate BST echocardiography is feasible in healthy children and in those with CHD. As they are associated with LV morphology and are modified in some types of CHD, vortices might yield diagnostic and prognostic value. Future studies are warranted to establish applications of vortex imaging in the clinical setting.

Periscopic technique in Norwood operation is associated with better preservation of early ventricular function.

OBJECTIVE: Although the right ventricle (RV) to pulmonary artery conduit in stage 1 Norwood operation results in improved interstage survival, the long-term effects of the ventriculotomy used in the traditional technique remain a concern. The periscopic technique (PT) of RV to pulmonary artery conduit placement has been described as an alternative technique to minimize RV injury. A retrospective study was performed to compare the effects of traditional technique and PT on ventricular function following Norwood operation. METHODS: A retrospective study of all patients who underwent Norwood operation from 2012 to 2019 was performed. Patients with baseline RV dysfunction and significant tricuspid valve regurgitation were excluded. Prestage 2 echocardiograms were reviewed by a blinded experienced imager for quantification of RV function (sinus and infundibular RV fractional area change) as well as for regional conduit site wall dysfunction (normal or abnormal, including hypokinesia, akinesia, or dyskinesia). Wilcoxon rank-sum tests were used to assess differences in RV infundibular and RV sinus ejection fraction and the Fisher exact test was used to assess differences in regional wall dysfunction. RESULTS: Twenty-two patients met inclusion criteria. Eight underwent traditional technique and 14 underwent PT. Median infundibular RV fractional area change was 49% and 37% (P = .02) and sinus RV fractional area change was 50% and 41% for PT and traditional technique (P = .007) respectively. Similarly qualitative regional RV wall function was better preserved in PT (P = .002). CONCLUSIONS: The PT for RV to pulmonary artery conduit in Norwood operation results in better preservation of early RV global and regional systolic function. Whether or not this benefit translates to improved clinical outcome still needs to be studied.

Right ventricle and outcome in left ventricular non-compaction cardiomyopathy.

BACKGROUND: The risk of adverse events in patients with left ventricular non-compaction cardiomyopathy (LVNC) is substantial. Information on prognostic factors, however, is limited. This study was designed to assess the prognostic value of right ventricular (RV) size and function in LVNC patients. METHODS: Cox regression analyses were used to determine the association of indexed RV end-diastolic area (RV-EDAI), indexed end-diastolic diameter (RV-EDDI), fractional area change (FAC), and tricuspid annular systolic excursion (TAPSE) with the occurrence of death or heart transplantation (composite endpoint). RESULTS: Out of 127 patients (53.2 ±â€¯17.8 years; 61% males, median follow-up time was 7.7 years), 17 patients reached the endpoint. In a univariate analysis, RV-EDAI was the strongest predictor of outcome [HR 1.48 (1.24-1.77) per cm2/m2; p < 0.0001]. FAC was predictive as well [HR 1.44 (1.16-1.83) per 5% decrease; p = 0.0009], while TAPSE was not (p=ns). RV-EDAI remained an independent predictor in a bivariable analysis with indexed left ventricular ED volume [HR 1.41 (1.18-1.70) per cm2/m2; p = 0.0002], while analysis of FAC and left ventricular ejection fraction demonstrated that FAC was not independent [HR 1.20 (0.98-1.52); per 5% decrease; p = 0.0721]. RV-EDAI 11.5 cm2/m2 was the best cut-off value for separating patients in terms of outcome. Patients with RV-EDAI >11.5 cm2/m2 had a survival rate of 18.5% over 12 years as compared to 93.8% in patients with RV-EDAI <11.5 cm2/m2 (p < 0.0001). CONCLUSION: Increased end-diastolic RV size and decreased systolic RV function are predictors of adverse outcome in patients with LVNC. Patients with RV-EDAI >11.5 cm2/m2 exhibit a significantly lower survival than those <11.5 cm2/m2.

Sonographic Evaluation of Internal Jugular Vein Diameter and Cross-sectional Area Measurements in Correlation with Left Ventricular End Diastolic Area as a Tool for Perioperative Assessment of Volume Status in Pediatric Patients Undergoing Cardiac Surgery.

AIM: The aim of this study is to compare the ultrasound estimation of the cross-sectional area (CSA) and diameter of internal jugular vein (IJV) with left ventricular end diastolic area (LVEDA) for the assessment of intravascular volume in pediatric patients during cardiac surgery. PATIENTS AND METHODS: The CSA and diameter of the left IJV were defined, using ultrasound machine, and compared with LVEDA, estimated by transesophageal echo, in four times intervals (immediately after induction [T1], before the start of cardiopulmonary bypass [CPB] [T2], immediately after weaning of CPB [T3], and at the end of surgery before transfer to the Intensive Care Unit [T4]) as a tool for intravascular volume assessment in 16 pediatric patients undergoing cardiac surgery. RESULTS: There was a poor correlation between IJV CSA and diameter with LVEDA. r values were 0.158, 0.265, 0.449, and 0.201 at the four time intervals (T1, T2, T3, and T4), respectively. CONCLUSION: Estimation of the CSA and diameter of the left IJV using ultrasound is not reliable and cannot be used alone to decide further management.

Biodegradable elastic patch plasty ameliorates left ventricular adverse remodeling after ischemia-reperfusion injury: a preclinical study of a porous polyurethane material in a porcine model.

OBJECTIVE: Myocardial infarction (MI) can lead to irreversible adverse left ventricular remodeling resulting in subsequent severe dysfunction. The objective of this study was to investigate the potential for biodegradable, elastomeric patch implantation to positively alter the remodeling process after MI in a porcine model. METHODS: Yorkshire pigs underwent a 60-minute catheter balloon occlusion of the left circumflex artery. Two weeks after MI animals underwent epicardial placement of a biodegradable, porous polyurethane (poly(ester urethane)urea; PEUU) patch (MI+PEUU, n = 7) or sham surgery (MI+sham, n = 8). Echocardiography before surgery and at 4 and 8 weeks after surgery measured the end-diastolic area (EDA) and fractional area change (%FAC). All animals were humanely killed 8 weeks after surgery and hearts were histologically assessed. RESULTS: At 8 weeks, echocardiography revealed greater EDA values in the MI+sham group (23.6 ± 6.6 cm(2), mean ± standard deviaation) than in the MI+PEUU group (15.9 ± 2.5 cm(2)) (P < .05) and a lower %FAC in the MI+sham group (24.8 ± 7.6) than in the MI+PEUU group (35.9 ± 7.8) (P < .05). The infarcted ventricular wall was thicker in the MI+PEUU group (1.56 ± 0.5 cm) than in the MI+sham group (0.91 ± 0.24 cm) (P < .01). CONCLUSIONS: Biodegradable elastomeric PEUU patch implantation onto the porcine heart 2 weeks post-MI attenuated left ventricular adverse remodeling and functional deterioration and was accompanied by increased neovascularization. These findings, although limited to a 2-month follow-up, may suggest an attractive clinical option to moderate post-MI cardiac failure.

Response of right ventricular size to treatment with cardiac resynchronization therapy and the risk of ventricular tachyarrhythmias in MADIT-CRT.

BACKGROUND: Cardiac resynchronization therapy (CRT) is increasingly recognized for its ability to reduce ventricular tachyarrhythmias, possibly associated with left ventricular reverse remodeling, but the role of the right ventricle (RV) in this process has not been examined. OBJECTIVE: The purpose of this study was to investigate the relationship between ventricular tachyarrhythmias and change in RV dimensions in patients receiving CRT with a defibrillator (CRT-D). METHODS: Multivariate Cox proportional hazards regression modeling was used to assess the risk for fast (≥180 bpm) ventricular tachycardia/ventricular fibrillation (VT/VF) or death by baseline and follow-up RV size (defined as right ventricular end-diastolic area [RVEDA]) among 1495 patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT). RESULTS: Multivariate analysis showed that treatment with CRT-D was independently associated with a 27% (P = .003) reduction in the risk of VT/VF or death among patients with larger RVs (>first quartile RVEDA ≥13 mm(2)/m(2)) compared with implantable cardioverter-defibrillator (ICD)-only therapy, whereas in patients with smaller RVs there was no significant difference in the risk of VT/VF between the 2 treatment arms (hazard ratio = 1.00, P = .99). At 1-year follow-up, CRT-D patients displayed significantly greater reductions in RVEDA compared to ICD-only patients (P <.001), associated with a corresponding reduction in the risk of subsequent VT/VF or death (>first quartile reduction in RVEDA with CRT-D vs ICD-only: hazard ratio = 0.55, P <.001) independent of changes in left ventricular dimensions. CONCLUSION: Our findings suggest that the RV may have an important role in determining the antiarrhythmic effect of CRT independent of the effect of the device on the left ventricle.

Should we stop using the determination of central venous pressure as a way to estimate cardiac preload? / Debemos abandonar la determinacion de la presion venosa central como medida de estimacionde la precarga cardiaca?

The determination of the values of central venous pressure has long been used as a guideline for volumetric therapy in the resuscitation of the critical patient, but the performance of such parameter is currently being questioned as an effective measurement of cardiac preload. This has aroused great interest in the search for more accurate parameters to determine cardiac preload and a patient’s blood volume.Goals and Methodology: Based on literature currently available, we aim to discuss the performance of central venous pressure as an effective parameter to determine cardiac preload.Results and Conclusion: Estimating variables such as end-diastolic ventricular area and global end-diastolic volume have a better performance than central venous pressure in determining cardiac preload. Despite the best performance of these devices, central venous pressure is still considered in our setting as the most practical and most commonly available way to assess the patient’s preload.Only dynamic variables such as pulse pressure change are superior in determining an individual’s blood volume