Doppler Flow Velocity Research Articles

Quantifying coronary microvascular disease: assessing absolute microvascular resistance reserve (MRR) by continuous coronary thermodilution

Abstract Background and aim Hyperemic absolute coronary blood flow (in mL/min) can be safely and reproducibly measured with intracoronary continuous thermodilution of saline at room temperature at an infusion rate of 20 mL/min. This study aims at assessing whether continuous thermodilution can also measure resting flow and microvascular resistance. Methods and results In 87 coronary arteries (58 patients) with angiographic non-significant stenoses absolute flow was assessed by continuous thermodilution of saline at infusion rates of 10 mL/min and 20 mL/min using a pressure/temperature sensored guide wire, a dedicated infusion catheter and a dedicated software. In addition, in 26 arteries, average peak velocity (APV) was measured simultaneously using an intracoronary Doppler-wire. There was no significant difference between Pd/Pa at baseline and during saline infusion at 10 mL/min, (0.95±0.053 vs 0.94±0.054, respectively (p=0.53) and there was no significant difference in APV at baseline and during the infusion of saline at 10 mL/min (22.2±8.40 vs 23.2±8.39 cm/s, respectively, p=0.63), thus indicating presence of resting coronary blood flow during the infusion of 10 mL/min of saline. In contrast, at an infusion rate of 20 mL/min, a significant decrease in Pd/Pa was observed compared to baseline: (0.85±0.089 vs 0.95±0.053, respectively, p<0.001) and a significant increase in APV was observed (22.2±8.4 cm/s to 57.8±25.5 cm/s, respectively, p<0.001). The coronary flow reserve (CFR) calculated by thermodilution and by Doppler flow velocity were similar (2.73±0.85 vs 2.72±1.07, respectively) and their individual values correlated closely (r=0.87, 95% CI 0.72–0.94, p<0,001). Microvascular resistance (Rμ), defined as the distal coronary pressure divided by the absolute flow was calculated both at rest (Rμ-rest) and during hyperemia (Rμ-hyper). Microvascular Resistance Reserve (MRR), is calculated as the ratio of Rμ-rest and Rμ-hyper and showed a good correlation with the analogous Doppler-derived parameter (using the APV instead of absolute flow). Mean doppler and thermodilution derived MRR were similar (3.32±1.50 vs 3.23±1.16) and values correlated closely (r=0.91, 95% CI 0.81 - 0.96, p<0.001; Bland-Altman analysis: mean bias = 0.071, limit of agreement −1.195 to 1.338). Conclusion Absolute coronary blood flow (in mL/min) can be measured by continuous thermodilution both at rest and during hyperemia. This allows accurate, reproducible, and operator-independent direct volumetric calculation of CFR and MRR. The latter is a quantitative metric which is specific for microvascular function and independent from myocardial mass. Doppler and Thermodilution derived MRR Funding Acknowledgement Type of funding source: None

Extent and characteristics of carotid plaques and brain parenchymal loss in asymptomatic patients with no indication for revascularization.

Extent of subclinical atherosclerosis has been associated with brain parenchymal loss in community-dwelling aged subjects. Identification of patient-related and plaque-related markers could identify subjects at higher risk of brain atrophy, independent of cerebrovascular accidents. Aim of the study was to investigate the relation between extent and characteristics of carotid plaques and brain atrophy in asymptomatic patients with no indication for revascularization. Sixty-four patients (aged 69±8years, 45% females) with carotid stenosis <70% based on Doppler flow velocity were enrolled in the study. Potential causes of cerebral damage other than atherosclerosis, including history of atrial fibrillation, heart failure, previous cardiac or neurosurgery and neurological disorders were excluded. All subjects underwent carotid computed tomography angiography, contrast enhanced ultrasound for assessment of plaque neovascularization and brain magnetic resonance imaging for measuring brain volumes. On multivariate regression analysis, age and fibrocalcific plaques were independently associated with lower total brain volumes (β=-3.13 and β=-30.7, both p<0.05). Fibrocalcific plaques were also independently associated with lower gray matter (GM) volumes (β=-28.6, p=0.003). On the other hand, age and extent of carotid atherosclerosis were independent predictors of lower white matter (WM) volumes. WM and GM have different susceptibility to processes involved in parenchymal loss. Contrary to common belief, our results show that presence of fibrocalcific plaques is associated with brain atrophy.

Effect of Hydration on Doppler Velocity of Renal Arteries.

Doppler sonography is a noninvasive method to evaluate the hemodynamic status of the kidney, and its parameters are used as direct and indirect predictors of certain parenchyma and renovascular diseases. However, the effect of hydration on kidney hemodynamics has not been explored via Doppler sonography. To examine differences in arterial Doppler velocities of normal adult kidney before and after hydration. A total of 60 native kidneys in 30 normal adult participants (mean age, 26 years) were assessed using Doppler sonography. Quantitative ultrasound Doppler parameters of peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index (RI) of the main renal artery and the intrarenal (interlobar) arteries were measured immediately before and 1 hour after ingestion of 500 mL of water. We tested differences in Doppler parameters before and after hydration using a paired t test, analyzed the correlation of the increase in PSV to the increase in EDV after hydration using Pearson correlation coefficient (PCC), and examined intraobserver reliability using intraclass correlation coefficient (ICC). Statistical analyses revealed that the differences in PSV and EDV values before and after hydration at the main renal artery and interlobar arteries of the kidney were significant (P<.001), whereas the RI at the main renal artery and interlobar arteries were not (P>.05). PCC for the correlation of the increase in PSV to the increase in EDV was greater than 0.80. ICC for intraobserver repeatability in performing kidney Doppler sonography was 0.92. Our results suggest that Doppler sonography is able to demonstrate changes in kidney hemodynamics within 1 hour after hydration. The normal kidney reflects proportional increases in PSV and EDV at the main renal artery and interlobar arteries, while maintaining vascular resistance. Doppler flow velocities of renal arteries can be considered as noninvasive quantitative markers for evaluating the response of kidney hemodynamics to hydration.

Coronary Flow Capacity to Identify Stenosis Associated With Coronary Flow Improvement After Revascularization: A Combined Analysis From DEFINE FLOW and IDEAL.

BackgroundCoronary flow capacity (CFC), which is a categorical assessment based on the combination of hyperemic coronary flow and coronary flow reserve (CFR), has been introduced as a comprehensive assessment of the coronary circulation to overcome the limitations of CFR alone. The aim of this study was to quantify coronary flow changes after percutaneous coronary intervention in relation to the classification of CFC and the current physiological cutoff values of fractional flow reserve, instantaneous wave‐free ratio, and CFR.Methods and ResultsUsing the combined data set from DEFINE FLOW (Distal Evaluation of Functional Performance With Intravascular Sensors to Assess the Narrowing Effect ‐Combined Pressure and Doppler FLOW Velocity Measurements) and IDEAL (Iberian‐Dutch‐English), a total of 133 vessels that underwent intracoronary Doppler flow measurement before and after percutaneous coronary intervention were analyzed. CFC classified prerevascularization lesions as normal (14), mildly reduced (40), moderately reduced (31), and severely reduced (48). Lesions with larger impairment of CFC showed greater increase in coronary flow and vice versa (median percent increase in coronary flow by revascularization: 4.2%, 25.9%, 50.1%, and 145.5%, respectively; P<0.001). Compared with the conventional cutoff values of fractional flow reserve, instantaneous wave‐free ratio, and CFR, an ischemic CFC defined as moderately to severely reduced CFC showed higher diagnostic accuracy with higher specificity to predict a >50% increase in coronary flow after percutaneous coronary intervention. Receiver operating characteristic curve analysis demonstrated that only CFC has a superior predictive efficacy to CFR (P<0.05). Multivariate analysis revealed lesions with ischemic CFC to be the independent predictor of a significant coronary flow increase after percutaneous coronary intervention (odds ratio, 10.7; 95% CI, 4.6–24.8; P<0.001).ConclusionsCFC showed significant improvement of identification of lesions that benefit from revascularization compared with CFR with respect to coronary flow increase.RegistrationURL: https://www.clinicaltrials.gov; Unique identifier: NCT02328820.

Venous blood flow alterations in glaucoma patients.

To evaluate the correlation between retinal venous blood flow parameters and glaucomatous visual field damage in a retrospective analysis. Fifty-five (24 male, 31 female) glaucoma patients, under intraocular pressure (IOP) reducing treatment, aged (mean ± SD) 69 ± 10years, 29 with primary open-angle and 26 with normal-tension glaucoma, were evaluated with regard to the correlation between IOP, color Doppler retinal venous blood flow velocity and glaucomatous damage. Univariate regression analysis disclosed statistically significant correlations of the visual field index MD with age, IOP and venous blood flow (p ≤ 0.026 for each parameter). A mixed linear effects model disclosed a significant correlation of MD with age, IOP and venous blood flow (p ≤ 0.002 for each parameter), but not with sex, side (right eye versus left eye) and diagnosis (primary open-angle glaucoma versus normal-tension glaucoma). Finally, interocular difference (right eye vs. left eye of the same patient) in MD correlated with interocular differences in venous blood flow velocities (p < 0.001), but not with interocular differences in IOP. Glaucomatous damage correlated negatively with retinal venous blood flow velocity, be it between subjects or between eyes within individuals. This study is limited by its cross-sectional design, and it is not possible to draw any conclusion with regard to the origin of the correlations.

Right Ventricular Outflow Tract Doppler Envelope Notching Predicts Pulmonary Hypertension and Outcomes in Lung Transplant Candidates

Hemodynamic variables have prognostic implications in lung transplant (LT) candidates, but it is unclear which echocardiographic (TTE) parameters predict outcomes in this population. We retrospectively studied 149 LT candidates who underwent TTE and right heart catheterization (RHC) 2007-2014, with follow-up to 2018. TTE parameters included the pulmonary artery systolic pressure (PASP), pulmonary vascular resistance (ePVR), and notching of the right ventricular outflow tract Doppler flow velocity envelope (FVERVOT), which has been shown to correlate with invasive PVR. We used Kaplan-Meier survival analysis and multivariate Cox proportional-hazards regression to analyze the relationship between TTE parameters and pre- and post-LT outcomes. Most patients were from Lung Allocation Groups A (25%) and D (66%). Mean age was 55±12 years, 60% were men. The PASP was identifiable in 135 patients. FVERVOT was interpretable in all patients, and notching was present in 46 patients. Mid-systolic notching of the FVERVOT had perfect specificity for prediction of pulmonary hypertension (13% sensitivity). Of 149 patients, 127 underwent LT; there were 9 deaths prior to LT and 36 deaths after LT. Median post-transplant follow-up was 5.5 (IQR 3.7-7.0) years. Pre-LT, patients with FVERVOT notching had shorter transplant-free survival (Figure 1a) and increased likelihood of undergoing transplantation (HR 1.87, 95%CI 1.25-2.80). Neither the PASP nor ePVR were predictive of transplantation. Post-LT, none of the TTE parameters predicted mortality, although patients with notching trended towards worse survival (Figure 1b) and increased mortality (HR 1.88, 95%CI 0.91-3.91, p=0.09). Unlike the PASP or ePVR, FVERVOT notching identified a group of LT candidates who had PH and were likely to undergo transplantation. Assessment of FVERVOT notching may help clinicians determine when repeat RHC is indicated to optimize the lung allocation score.

Does uncontrolled diabetes mellitus affect cerebral hemodynamics in heart surgery?

In this study, we aimed to investigate the effects of poor blood glucose control on the intraoperative cerebral system in patients undergoing coronary artery bypass grafting using various neuromonitors. Between January 2011 and December 2011, a total of 40 adult patients (31 males, 9 females; mean age 58.8±9.2 years; range, 38 to 78 years) who were scheduled for elective coronary artery bypass grafting were included in the study. The patients were divided into four groups according to hemoglobin A1c levels as follows: Group 1 including non-diabetic controls (n=11); Group 2 including those with a hemoglobin A1c value of <7% (n=10); Group 3 including those with a hemoglobin A1c value of 7 to 10% (n=11); and Group 4 including those with a hemoglobin A1c value of ≥10% (n=8). Cerebral monitoring was performed with near-infrared spectroscopy and transcranial Doppler. Measurement periods were defined as follows: Before anesthesia induction (period 1), 10 min after anesthesia induction (period 2), during cannulation (period 3), 10 min after cardiopulmonary bypass (period 4), at 32°C temperature during cardiopulmonary bypass (period 5), at 36°C temperature during cardiopulmonary bypass (period 6), and at the end of the operation (period 7). There was a significant difference in the near-infrared spectroscopy values in the cannulation period for both right (p<0.001) and left (p=0.002) sides and the mean transcranial Doppler flow velocity (p=0.002) in Group 4, compared to Group 1. The heart rate was found to be significantly lower in Group 4 in the cannulation period. The near-infrared spectroscopy values and transcranial Doppler blood flow velocity decreased in Group 4 in all measurement periods. The results of our study show that, in patients with severe diabetes undergoing open heart surgery, heart rate decreases in the cannulation period due to possible autonomic neuropathy, and cerebral blood flow and oxygenation decrease. For these patients, particularly in the cannulation period, perfusion of both cerebral and other organs should be closely monitored and necessary interventions should be performed.

P189 Use of transabdominal ultrasonography for the evaluation of Crohn’s disease activity

Abstract Background Ileocolonoscopy is accepted as the gold standard method for the diagnosis of Crohn’s disease (CD). However, there are cases where it is inadequate due to being invasive, failure to allow endoscopic exploration of the small intestine, and failure to show the extraintestinal pathologies. In the present study, it is aimed to compare clinical, endoscopic scores and computerised tomography enterography (CTE) findings with transabdominal ultrasonography (TAUS) findings in order to evaluate the activity of CD. Methods The study included 79 patients diagnosed with CD. Crohn’s Disease Activity Index (CDAI) and Harvey Bradshaw Index (HBI) were used for the evaluation of the clinical activities of the patients. The patients with CDAI equal to 150 and more and HBI equal to 5 points and more were assessed as clinically active. Colonoscopic disease activity was assessed by The Simple Endoscopic Score for Crohn’ disease (SES-CD), SES-CD score of 3 and higher was defined as endoscopically active. In the evaluation of CTE and TAUS, the measurement of the thickness of the intestinal wall above 3 mm was accepted as pathological. Abscess, mass, fistula and ileus were evaluated as complications. Superior mesenteric artery (SMA) flow velocity was assessed by Color Doppler US. Limberg score was graded from Grades 0 to 4 for Doppler TAUS. Results Of the patients, 57 (72.1%) were male and 22 (27.8%) were female. Age average of the patients was 37.5 years (17–64) and the mean duration of disease was 48.6 months (0–240 months). Increase in the wall thickness in CTE and TAUS, detection of inflammation and complication in mesenteric fatty planes were found to be highly significant (p ˂ 0.0001). Wall thickness increase sensitivity level of TAUS according to CTE was 82%, specificity level was 97%, sensitivity level of the inflammation finding in mesenteric fatty planes was measured as 80%, and specificity level as 95%. A significant correlation was found between the wall thickness increase in CTE and TAUS and inflammation in mesenteric fatty planes via CDAI, HBI and SES-CD scoring (p ˂ 0.05). In addition, there was a significant relationship between the presence of lymphadenopathy in CTE in active patients according to HBI (p ˂ 0.05). According to the CDAI and SES-CD scores, Doppler flow velocity of SMA was significantly higher in the active group than the inactive group (p ˂ 0.05). CDAI, HBI and SES-CD results were found highly significant via the Limberg Scoring results (p &amp;lt; 0.0001). Conclusion In the current study, it is shown that TAUS is a diagnostic tool as effective as CTE in the evaluation of CD activity. In addition, it is an important finding that the flow velocity of SMA increases as correlated with inflammation via the Doppler feature of TAUS.

P768 Potential utility of fully automated Doppler flow velocity tracing software in patients with atrial fibrillation

Abstract Background Stroke volume (SV) using Doppler echocardiography is a significant prognosticator in patients with atrial fibrillation (AF). However, tracing multiple left ventricular outflow tract (LVOT) Doppler flow velocity envelope is tedious. Although ASE recommends to average 5 -10 beats of SV in AF, this has not been validated. Recently developed fully automated Doppler flow velocity analytical software can analyze Doppler parameters in multiple consecutive beats on the screen within a few seconds. Purpose We aimed to determine the usefulness of the software, and to validate the minimum number of beats required to approximate SV in patients with AF. Methods We selected 21 AF patients who had undergone 2D echocardiography using GE ultrasound machine (E95, GE healthcare). LVOT area was calculated by 3.14×(LVOT diameter/2)². LVOT pulse-wave Doppler velocity was recorded from an apical approach with a quiet breathing. To maximize the number of flow envelope on the screen, sweep speed was set at 12.5 mm/s. LVOT velocity time integral was measured by both manual tracing method and fully automated method (Cardiac Auto Doppler, GE healthcare). The grand truth of mean SV (reference SV) in each patient was defined as the averaged values of SV from all consecutive beats. We also calculated the mean SV value with the successive addition of sequential beats started from the 1st beat. Each value was compared with the reference SV and % variability was calculated. We determined the minimum number of beats showing %variability becoming &amp;lt;5%. Results Mean age was 77 years. Mean heart rate and reference SV index (SVI) were 80 ± 12 bpm and 35 ± 10 mL/m2. A total number of beats for recording was ranged from 16 to 25 in each patient. The fully automated software could analyze Doppler envelope in 395 out of 412 beats (Feasibility: 96%). Although there was a good correlation of SV in individual beats between the manual and automatic method (r = 0.92), the automatic method significantly overestimated SV (mean bias: 2.6 mL, p &amp;lt; 0.001) compared with the manual method. The median values of minimum number of beats showing % variability &amp;lt; 5% were 4 (interquartile range: 2 -7) for manual tracing method. The corresponding values were 5 (2 -6) for automatic method. If we used mean values of SV during consecutive 10 beats, 92% of patients using manual method and 96% of patients using automatic method showed % variability &amp;lt; 5%. There were excellent correlation between reference SV and averaged SV from the 1st beat to 10th beat (manual: r = 0.98, automatic: r = 0.99). If we defined low flow status as &amp;lt; 35 mL/m2, averaged SVI during consecutive 10 beats using the automatic method had a correct diagnosis in 20 out of 21 patients. Conclusions We concluded that minimum number of required beats for averaging was 10 in most AF patients. Rapid and reliable SV analysis with a novel fully automated Doppler software has a potential for its adoption in busy echocardiography laboratories.

Assessment of the carotid artery Doppler flow time in patients with acute upper gastrointestinal bleeding.

INTRODUCTION:Because of the subjectivity and ambiguity of the noninvasive measurements and limited use of invasive ones, there is an impending need for a real-time, fast, inexpensive, and reproducible noninvasive measurement method in acute upper gastrointestinal (GI) bleeding with active bleeding in emergency services.AIMS:In this study, we aimed to evaluate the effect of bedside carotid artery flow time (CFT) measurement before and after the passive leg raising (PLR) maneuver on the determination of active bleeding in patients admitted to the emergency department (ED) with upper GI bleeding.MATERIALS AND METHODS:This prospective case–control study was conducted in the ED of a training and research hospital with upper GI bleeding. Patients were placed in the supine position to perform bedside carotid Doppler ultrasonography before starting treatment. CFT, corrected CFT (CFTc), and carotid artery Doppler flow velocity were measured. After then performed PLR, the same parameters were measured again.RESULTS:A total of 94 patients, including 50 patients with GI bleeding and 44 healthy volunteers as control group were included in the study. CFT and CFTc were shorter in the patient group than the control group (P < 0.001, P = 0.004, respectively). After PLR, there were statistically significant differences in change in the CFT (ΔCFT) and change in the corrected CFT (ΔCFTc) between the groups (P = 0.001, P < 0.001). There were also statistically significant differences in ΔCFT and ΔCFT between the patients with active bleeding and the nonbleeding ones (P = 0.01, P = 0.005, respectively). Area under curve to detect active bleeding for ΔCFT and ΔCFTc were calculated as 0.801 (95% confidence interval [CI]: 0.65–0.95) and 0.778 (95% CI: 0.63–0.91), respectively.CONCLUSION:The corrected carotid Doppler flow time measurements in patients with GI bleeding at the time of presenting to the emergency department can be helpful to interpret the active bleeding.

Cerebral blood flow is reduced in ME/CFS during head-up tilt testing even in the absence of hypotension or tachycardia: A quantitative, controlled study using Doppler echography

ObjectiveThe underlying hypothesis in orthostatic intolerance (OI) syndromes is that symptoms are associated with cerebral blood flow (CBF) reduction. Indirect CBF measurements (transcranial Doppler flow velocities), provide inconsistent support of this hypothesis. The aim of the study was to measure CBF during a 30 min head-up tilt test (HUT), using Doppler flow imaging of carotid and vertebral arteries, in individuals with chronic fatigue syndrome/myalgic encephalomyelitis (ME/CFS), a condition with a high prevalence of OI. Methods429 ME/CFS patients were studied: 247 had a normal heart rate (HR) and blood pressure (BP) response to HUT, 62 had delayed orthostatic hypotension (dOH), and 120 had postural orthostatic tachycardia syndrome (POTS). We also studied 44 healthy controls (HC). CBF measurements were made at mid-tilt and end-tilt. Before mid-tilt, we administered a verbal questionnaire to ascertain for 15 OI symptoms. ResultsEnd-tilt CBF reduction was 7% in HC versus 26% in the overall ME/CFS group, 24% in patients with a normal HR/BP response, 28% in those with dOH, and 29% in POTS patients (all P < .0005). Using a lower limit of normal of 2SD of CBF reduction in HC (13% reduction), 82% of patients with normal HR/BP response, 98% with dOH and 100% with POTS showed an abnormal CBF reduction. There was a linear correlation of summed OI symptoms with the degree of CBF reduction at mid-tilt (P < .0005). ConclusionsDuring HUT, extracranial Doppler measurements demonstrate that CBF is reduced in ME/CFS patients with POTS, dOH, and even in those without HR/BP abnormalities. SignificanceThis study shows that orthostatic intolerance symptoms are related to CBF reduction, and that the majority of ME/CFS patients (90%) show an abnormal cerebral flow reduction during orthostatic stress testing. This may have implications for the diagnosis and treatment of ME/CFS patients.

Coronary wave intensity patterns in stable coronary artery disease: influence of stenosis severity and collateral circulation

ObjectiveWave intensity analysis is a method that allows separating pulse waves into components generated proximally and in the periphery of arterial trees, as well as characterising them as accelerating or...

Distal Evaluation of Functional performance with Intravascular sensors to assess the Narrowing Effect—combined pressure and Doppler FLOW velocity measurements (DEFINE-FLOW) trial: Rationale and trial design

It remains uncertain if invasive coronary physiology beyond fractional flow reserve (FFR) can refine lesion selection for revascularization or provide additional prognostic value. Coronary flow reserve (CFR) equals the ratio of hyperemic to baseline flow velocity and has a wealth of invasive and noninvasive data supporting its validity. Because of fundamental physiologic relationships, binary classification of FFR and CFR disagrees in approximately 30%-40% of cases. Optimal management of these discordant cases requires further study. The aim of the study was to determine the prognostic value of combined FFR and CFR measurements to predict the 24-month rate of major adverse cardiac events. Secondary end points include repeatability of FFR and CFR, angina burden, and the percentage of successful FFR/CFR measurements which will not be excluded by the core laboratory. This prospective, nonblinded, nonrandomized, and multicenter study enrolled 455 subjects from 12 sites in Europe and Japan. Patients underwent physiologic lesion assessment using the 0.014" Philips Volcano ComboWire XT that provides simultaneous pressure and Doppler velocity sensors. Intermediate coronary lesions received only medical treatment unless both FFR (≤0.8) and CFR (<2.0) were below thresholds. The primary outcome is a 24-month composite of death from any cause, myocardial infarction, and revascularization. The DEFINE-FLOW study will determine the prognostic value of invasive CFR assessment when measured simultaneously with FFR, with a special emphasis on discordant classifications. Our hypothesis is that lesions with an intact CFR ≥ 2.0 but reduced FFR ≤ 0.8 will have a 2-year outcome with medical treatment similar to lesions with FFR> 0.80 and CFR ≥ 2.0. Enrollment has been completed, and final follow-up will occur in November 2019.

Application of transesophageal echocardiography in anesthesia management in modified morrow operation

Objective To evaluate the application of transesophageal echocardiography (TEE) in anesthesia management of obstructive hypertrophic cardiomyopathy (HOCM) during modified morrow operation and to evaluate the effect of TEE on surgical decision-making. Methods Twenty-one HOCM patients who were admitted into our hospital from March 2015 to March 2019 for TEE were selected. All patients underwent transesophageal ultrasound. The diameter of the narrowest left ventricular outflow tract, and subaortic interventricular septal thickness and length were recorded before and after operation. Continuous Doppler flow velocity was measured at the left ventricular outflow tract and the difference of transvalvular pressure was calculated. At point of mitral valve apex, peak velocity and atrial filling (A) and early filling (E) of mitral valve were recorded on four-chamber level of middle esophagus, E/A(mitral valve E peak velocity divided by A peak velocity ratio). Early diastolic (e′) phase of ventricular lateral wall of mitral annulus with tissue doppler, E/e′ (mitral valve E peak velocity divided by mitral annulus e′) were recorded. Results Intro-operative aerodynamics was stable and no malignant adverse events such as ventricular fibrillation occurred. There were 18 cases of auto-cardiac resuscitation (85%), 3 cases of temporary pacemaker use (15%), while 17 patients (81%) did not need to use positive inotropic drugs after rebound, but could successfully depart from cardiopulmonary bypass at low doses of deoxyepinephrine. The remaining four patients (19%) required low doses of milrinone or combined with deoxyepinephrine or norepinephrine. The cardiopulmonary bypass (CPB) time was (124±45) min and the aortic occlusion time was (85±21) min. The trans-valvular pressure of left ventricular outflow tract decreased to (68±8) mmHg (1 mmHg=0.133 kPa) to (16±6) mmHg by TEE after operation (P 14, and the lateral wall of ventricular septum e′ was<10 cm/s. Conclusions TEE plays an important role in anesthesia management, surgical decision-making and evaluation of operation. For patients with normal systolic function, TEE monitoring of transvalvular pressure through deep transgastric lax is consistent with intraoperative monitoring of transvalvular pressure through catheter. Key words: Transesophageal echocardiography; Modified morrow operation; Obstructive hypertrophic cardiomyopathy; Anesthesia management

General anesthesia and positive pressure ventilation suppress left and right ventricular myocardial shortening in patients without myocardial disease \u2013 a strain echocardiography study

BackgroundMyocardial deformation imaging using speckle-tracking echocardiography to assess global longitudinal strain (GLS) is today considered a more sensitive measure of left ventricular (LV) systolic function than ejection fraction. General anesthesia and positive pressure ventilation (PPV) are known to change the right ventricular (RV) and LV loading conditions. However, little is known about the effects of anesthesia and PPV on RV free wall and LV GLS. We studied the influence of general anesthesia and PPV on RV and LV longitudinal strain in patients without myocardial disease.MethodsTwenty-one patients scheduled for non-cardiac surgery were included. The baseline examination was performed on the un-premedicated patients within 60 min of anesthesia. The second examination was performed 10–15 min after induction of anesthesia (propofol, remifentanil), intubation and start of PPV. The examinations included apical four-, two- and three-chamber projections, mitral and aortic Doppler flow velocities and tissue Doppler velocities of tricuspid and mitral annulus. LV end-systolic elastance (Ees) and aortic elastance were determined (Ea).ResultsGeneral anesthesia and PPV reduced the mean arterial blood pressure (− 29%, p < 0.0019), stroke volume index (− 13%, p < 0.001) and cardiac index (− 23%, p < 0.001). RV end-diastolic area index and LV end-diastolic volume index decreased significantly, while systemic vascular resistance was not significantly affected. Ees decreased significantly with the induction of anaesthesia (− 23%, p = 0.002), while there was a trend for a decrease in Ea (p = 0.053). The ventriculo-arterial coupling, Ea/Ees, was not significantly affected by the anesthetics and PPV. The LV GLS decreased from − 19.1 ± 2.3% to − 17.3 ± 2.9% (p < 0.001) and RV free wall strain decreased from − 26.5 ± 3.9% to − 24.1 ± 4.2% (p = 0.001). One patient (5%) had at baseline a LV GLS > − 16% compared with 6 patients (28%) during general anesthesia and PPV. Three patients (14%) had a RV free wall strain > − 24% compared to 8 patients (38%) during general anesthesia and PPV.ConclusionsGeneral anesthesia and PPV reduces systolic LV and RV function to levels considered indicating dysfunction in a substantial proportion of patients without myocardial disease.

Progression of brain white matter hyperintensities in asymptomatic patients with carotid atherosclerotic plaques and no indication for revascularization

Background and aimsBrain white matter hyperintensities (WMHs) have been associated with an increased risk of ischemic stroke and considered as markers of brain ischemia. Progression of WMHs in asymptomatic patients with non-hemodynamically significant carotid plaque could represent a putative marker of plaque vulnerability. We prospectively evaluate progression and determinants of WMHs in this population. MethodsThis prospective study included 51 asymptomatic patients with carotid stenosis <70% that underwent brain magnetic resonance imaging scans at baseline and after a median follow up of 595 days (interquartile range 553–641 days). Patients (mean age of 69 years and 45% females) underwent baseline carotid computed tomography angiography, contrast-enhanced ultrasound for carotid plaque characterization and analysis of subsets of circulating lymphocytes and monocytes by flow cytometry. ResultsSeventeen subjects (33.3%) had carotid stenoses of 50–70% (Doppler flow velocity) while the rest had stenoses of <50%. In 25 (49.0%) patients, new WMHs, with 5 new lesions on average and a median volume of 134 mm3, were detected at follow-up. None of the plaque characteristics or of the circulating cellular biomarkers investigated were associated with the global and ipsilateral occurrence of new WMHs whereas, at multivariate analysis, female sex, hypercholesterolemia, and lower glomerular filtration rate (GFR) emerged as independent variables associated with new WMHs. ConclusionsHalf of the patients with carotid plaques of intermediate severity had evidence of WMH progression at follow up. Female gender and systemic factors such as hypercholesterolemia, and lower GFR, but not plaque characteristics or circulating cellular biomarkers, are associated with WMH progression.

Structural and Functional Characterization of the Adult Giant Danio Heart

Cardiovascular diseases remain that number one cause of death in the northern hemisphere and are increasing globally in developing economies. In spite of evolutionary separation between fishes and mammalian, the use of non‐mammalian model species has significantly increased our understanding of cardiac diseases. We have recently described the growth and cardiovascular development of the Devario malabaricus, a giant danio (GD) species closely related to the zebrafish. We hypothesize that the adult GD heart can serve as a robust non‐mammalian model for in vivo studies of cardiac biology. Using immunostaining, transmission electron microscopy, scanning block‐face electron microscopy, and Doppler, we have characterized the anatomical and functional characteristics of the adult GD heart. First, we found that the adult giant danio possesses a thick and highly vascularized compact heart. Second, the GD heart possesses a junctional region populated with a fibroblasts network similar to that observed in zebrafish. Third, multiple large coronary vessels investing the compact myocardium are connected to and continuous with atrioventricular (AV) canal lumen. In addition, the AV canal and bulbus are highly innervated, suggesting complex regulation in heart function. Moreover, we demonstrate that their cardiac function can be measured using Doppler flow velocity. These studies along with previous findings support the GD as a robust model for the study of cardiac biology.Support or Funding Information1R15HD084262‐01, Buehler Family FoundationThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Increased Pulmonary Vascular Impedance in Patients with Severe Pulmonary Arterial Hypertension

IntroductionPulmonary arterial hypertension (PAH) is characterized by increased pulmonary artery (PA) pressure and resistance due to pulmonary vascular remodeling. The functional effect of this vascular remodeling on the pulsatile pulmonary hemodynamics has not been well studied. Pulmonary vascular impedance (PVZ) represents the relationship between pulsatile pressure and flow in the pulmonary artery (PA) and provides a more comprehensive view of pulmonary arterial function. We hypothesized that decreased pulmonary vascular compliance and increased pulmonary vascular resistance (PVR) would significantly alter the pulsatile pulmonary hemodynamics in severe PAH.MethodsGroup 1 PAH patients (mean pulmonary arterial pressure (mPAP) ≥ 25 mmHg, pulmonary capillary wedge pressure ≤ 15 mmHg) and control patients (without pulmonary hypertension (PH), mPAP &lt; 25 mmHg) with both an echocardiogram including right ventricular outflow tract (RVOT) images and a right heart catheterization (RHC) within three months were identified from the University of Arizona PH registry. The PAH patients were divided into those with mild PH (PVR &lt; 7 mmHg*min/L) and severe PH (PVR ≥ 7 mmHg*min/L). RVOT Doppler flow velocity profiles were first traced using a custom MATLAB program. Flow velocity profiles were multiplied by the average PA diameter (ratio of thermodilution cardiac output and mean RVOT flow velocity) to determine PA flow profiles. PVZ was calculated in the frequency domain using RHC measured PA pressure and PA flow profiles. Characteristic Impedance (ZC) was calculated as the mean of Z2–4. Data is presented as mean ± standard error or median [interquartile range].ResultsFourteen subjects were identified (Control: n = 2, 2 female, 70 ± 3 yrs; Mild PAH: n = 6, 2 female, 63 ± 11 yrs; and Severe PAH: n = 6, 4 female, 45 ± 13 yrs, p = 0.05). The median time between the RHC and echo was 8 [1 − 15] days. Severe PAH patients have increased mPAP (60 ± 19 vs 38 ± 17 mmHg, p = 0.04) and end‐diastolic elastance (1.05 ± 0.43 vs 0.39 ± 0.3 mmHg/mL, p = 0.2), decreased stroke volume (61 ± 7 vs 91 ± 20 mL, p = 0.01) and no change in cardiac output (5.16 ± 0.81 vs 6.23 ± 1.3 L/min) compared to controls. Severe PAH showed increased 0 Hz impedance (Z0, 966 ± 138 dynes/sec/cm−5) compared to controls (288 ± 34 dynes/sec/cm−5, p = 0.02) and mild PAH (538 ± 64 dynes/sec/cm−5, p = 0.03, Figure 1). ZC in severe PAH had a non‐significant increase compared to controls (139 ± 23 vs 69 ± 19 dynes/sec/cm−5, respectively). Z1 was significantly increased in severe PAH compared to controls (52 ± 91 vs 5 ± 43 dynes/sec/cm−5, p = 0.02) but not compared to mild PAH (52 ± 91 vs 64 ± 54 dynes/sec/cm−5, p = 0.09).ConclusionPulmonary vascular impedance analysis in a small PAH cohort demonstrated that vascular resistance (Z0) and global vascular stiffness (Z1) are increased in severe PAH patients and that there is a non‐significant increase in proximal vascular stiffness (ZC).Support or Funding InformationThis work was supported in part by grants from the Arizona Biomedical Research Commission (ABRC NIA ADHS18‐198871 (RRV))This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Diastolic-systolic velocity ratio to detect coronary stenoses under physiological resting conditions: a mechanistic study

ObjectiveDiastolic-systolic velocity ratio (DSVR) is a resting index to assess stenoses in the left anterior descending artery (LAD). DSVR can be measured by echocardiographic or intracoronary Doppler flow velocity. The...

Comprehensive physiological evaluation of epicardial and microvascular coronary domains using vascular conductance and zero flow pressure.

Assessment of the coronary circulation has been based largely on pressure ratios (epicardial) and resistance (micro-vessels). Simultaneous assessment of epicardial (CEPI) and microvascular conductance (CMICRO) provides an intuitive approach using the same units for both coronary domains and expressing the actual deliverability of blood. The aim of this study was to develop a novel integral method for assessing the functional severity of epicardial and microvascular disease. We performed intracoronary pressure and Doppler flow velocity measurements in 403 vessels in 261 patients with stable coronary artery disease. Hyperaemic mid-to-late diastolic pressure and flow velocity (PV) relationships were calculated. The slope of the aortic PV indicates the overall conductance and the slope of the distal PV relationship represents CMICRO. The intercept with the x-axis represents zero-flow pressure (Pzf). CEPI was derived from microvascular and overall conductance. Median CEPI was higher compared to CMICRO (4.2 [2.1-8.0] versus 1.3 [1.0-1.7] cm/s/mmHg, p<0.001). CMICRO was independent of stenosis severity (1.3 [1.0-1.7] in FFR ≤0.80 versus 1.4 [1.0-1.8] in FFR >0.8, p=0.797). ROC curves (using FFR and HSR concordant vessels as standard) demonstrated an excellent ability of CEPI to characterise significant stenoses (AUC 0.93). When CEPI<CMICRO, a decrease in flow velocity and coronary pressure (optimal cut-off value 0.97, AUC 0.90) was demonstrated. A comprehensive assessment of separate CEPI and CMICRO was feasible. CEPI has a remarkable diagnostic efficiency to detect a clinically relevant stenosis. When CEPI<CMICRO, distal flow and pressure decrease steeply, indicating myocardial ischaemia. CMICRO can be used to explore the severity of microvascular disease.