Right Ventricular Outflow Tract Doppler Research Articles

Right ventricular outflow tract Doppler flow analysis and pulmonary arterial coupling by transthoracic echocardiography in sepsis: a retrospective exploratory study

IntroductionRight ventricular (RV) and pulmonary vascular dysfunction appear to be common in sepsis. RV performance is frequently assessed in isolation, yet its close relationship to afterload means combined analysis with right ventricular outflow tract (RVOT) Doppler and RV–pulmonary arterial (RV–PA) coupling may be more informative than standard assessment techniques. Data on feasibility and utility of these parameters in sepsis are lacking and were explored in this study.MethodsThis is a retrospective study over a 3-year period of one-hundred and thirty-one patients admitted to ICU with sepsis who underwent transthoracic echocardiography (TTE) with RVOT pulsed wave Doppler. RVOT Doppler flow and RV–PA coupling was evaluated alongside standard measurements of RV systolic function and pulmonary pressures. RVOT Doppler analysis included assessment of pulmonary artery acceleration time (PAAT), velocity time integral and presence of notching. RV–PA coupling was assessed using tricuspid annular planar systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) ratio.ResultsPAAT was measurable in 106 (81%) patients, and TAPSE/PASP was measurable in 77 (73%). Seventy-three (69%) patients had a PAAT of ≤ 100 ms suggesting raised pulmonary vascular resistance (PVR) is common. RVOT flow notching occurred in 15 (14%) of patients. TRV was unable to be assessed in 24 (23%) patients where measurement of PAAT was possible. RV dysfunction (RVD) was present in 28 (26%), 26 (25%) and 36 (34%) patients if subjective assessment, TAPSE < 17 mm and RV dilatation definitions were used, respectively. There was a trend towards shorter PAAT with increasing severity of RVD. RV–PA uncoupling defined as a TAPSE/PASP < 0.31 mm/mmHg was present in 15 (19%) patients. As RV dilatation increased the RV–PA coupling ratio decreased independent of LV systolic function, whereas TAPSE appeared to be more susceptible to changes in LV systolic function.ConclusionRaised PVR and RV–PA uncoupling is seen in a significant proportion of patients with sepsis. Non-invasive assessment with TTE is feasible. The role of these parameters in assisting improved definitions of RVD, as well as their therapeutic and prognostic utility against standard parameters, deserves further investigation.

Right Ventricular Outflow Tract Doppler Notching Predicts Survival in Patients with Pulmonary Hypertension and Heart Failure with Preserved Ejection Fraction

Background Pulmonary hypertension (PH) in the setting of left heart disease (PH-LHD) is the most common cause of PH in the general population, with a prevalence of up to 80% and is associated with high morbidity and mortality. We have previously demonstrated the utility of right ventricular outflow tract (RVOT) Doppler notching as a composite marker of pulmonary vascular disease (PVD) in patients with PH-associated with heart failure with preserved ejection fraction (HFpEF). Our study examines the ability of RVOT Doppler notching to predict survival in patients with PH-HFpEF. Methods We retrospectively evaluated consecutive patients referred to the Penn PH program between January 2007 and March 2013 diagnosed with PH-HFpEF. Patients were included who had right heart catheterization with mean pulmonary artery pressure ≥ 25mmHg and pulmonary artery wedge pressure > 15 mmHg. All patients underwent echocardiographic and hemodynamic assessment as indicated clinically. Statistical analysis included student's t-test and chi-squared to assess continuous and categorical variables, respectively, along with use of Cox regression and the Kaplan-Meier estimator to evaluate survival. Results Of 86 patients, 53 had notching and 33 did not. Baseline characteristics were similar across both groups. Patients with notching had higher diastolic pulmonary gradient (8.2±6.4 vs 1.4±4.3, p Conclusions In PH-HFpEF, RVOT Doppler notching is a composite marker of PVD and is a strong predictor of long-term survival. Further work is needed to validate this marker in larger cohorts.

A Doppler Echocardiographic Pulmonary Flow Marker of Massive or Submassive Acute Pulmonary Embolus

To date, echocardiography has not gained acceptance as an alternative imaging modality for the detection of massive pulmonary embolism (MPE) or submassive pulmonary embolism (SMPE). The objective of this study was to explore the clinical utility of early systolic notching (ESN) of the right ventricular outflow tract (RVOT) pulsed-wave Doppler envelope in the detection of MPE or SMPE. Two hundred seventy-seven patients (mean age, 56±16years; 52% women), without known pulmonary hypertension, who underwent contrast computed tomographic angiography for suspected pulmonary embolism (PE) and underwent echocardiography were retrospectively studied. Extent of PE was categorized using standard criteria. ESN identified from pulsed-wave spectral Doppler interrogation of the RVOT was analyzed, as were other echocardiography parameters such as McConnell's sign, the "60/60" sign, and acceleration and deceleration times of the RVOT Doppler signal. Analysis was conducted using probability statistics and receiver operating characteristic curve analysis. Of the 277 patients studied, 100 (44%) had MPE or SMPE, 87 (38%) had subsegmental PE, and 90 (39%) did not have PE. ESN was observed in 92% of patients with MPE or SMPE, 2% with subsegmental PE, and in no patients without PE. Interobserver assessment of early systolic notching demonstrated 97% agreement (κ=0.93, P<.001). Compared with more widely recognized echocardiographic parameters, the area under the receiver operating characteristic curve (AUC) of 0.96 (95% CI, 0.92-0.98) for ESN was superior to that for McConnell's sign (AUC, 0.75; 95% CI, 0.68-0.80), the 60/60 sign (AUC, 0.74; 95% CI, 0.68-0.79), and RVOT acceleration time≤87 msec (AUC, 0.84; 95% CI, 0.79-0.88), as well as other study Doppler variables, in patients with computed tomography-confirmed MPE or SMPE. The pulmonary Doppler flow pattern of ESN appears to be a promising noninvasive sign observed frequently in patients with MPE or SMPE. Future prospective study to ascertain diagnostic utility in a broader population is warranted.

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.

Analysis of Biphasic Right Ventricular Outflow Doppler Waveform in Patients with Pulmonary Hypertension.

Pulmonary hypertension (PH) with pulmonary vascular disease (PVD) is a progressive and debilitating disease associated with increased pulmonary vascular resistance (PVR). Biphasic right ventricular outflow tract (RVOT) Doppler flow is frequently seen in severe PH patients with PVD. In association with hemodynamics, the precise analysis of biphasic RVOT Doppler flow (RVDF) has not been fully elucidated. Therefore, the purpose of the present study is to analyze the relation between the hemodynamics and indices of biphasic RVDF in PH patients with PVD.Seventy PH patients with biphasic RVDF were analyzed. All patients underwent transthoracic echocardiography and right heart catheterization. For the analysis of biphasic RVDF, the early waveform was determined as P1 while the late waveform was determined as P2. For each P1 and P2, the duration (D, seconds) and peak flow velocity (PFV, in m/second) were measured.P1D and P2PFV were significantly correlated with PVR (P1D: r = -0.542, P < 0.0001, P2PFV: r = -0.513, P < 0.0001). Therefore, we propose a novel RVDF formula for estimation of PVR, as follows. PVR = 26 - 77 × P1D - 14 × P2PFV. The PVR could be estimated by this proposed formula (r = 0.649, P < 0.0001), which is derived from one Doppler image only unlike previously used PVR prediction formula.P1D and P2PFV were associated with PVR. Moreover, this simple RVDF formula proposed herein can estimate PVR in PH patients with PVD.

Unraveling the RV Ejection Doppler Envelope: Insight Into Pulmonary Artery Hemodynamics and Disease Severity

ObjectivesThe purpose of this study was to characterize the profiles of right ventricular outflow tract (RVOT) Doppler flow velocity envelopes in patients with pulmonary arterial hypertension (PAH) and to establish whether changes in the RVOT flow profile related to patient outcome. BackgroundThe RVOT systolic flow profile is frequently abnormal, with findings of a mid-systolic flow deceleration and notching, previously proposed as an indicator of elevated pulmonary vascular resistance (PVR). MethodsWe reviewed RVOT systolic flow profiles recorded by pulsed-wave Doppler from 159 consecutive patients with PAH and measured deceleration time (DT) of mid-systolic deceleration slope (mid-systolic DT) and the peak velocity of pre- and post-notching flow. Concurrent right-heart catheterization was available in all (41 of 41) incident patients and in 39 of 118 established patients. Outcomes, defined as time to all-cause mortality or need for lung transplantation, were assessed during 3 years of follow-up. ResultsNotched envelopes were identified in 150 of 159 patients. The presence of a notched pattern and a decrease in the mid-systolic DT were associated with higher PA pressures; higher PVR; and, at a threshold of a mid-systolic DT of <120 ms, worse outcome. Those patients with a shorter DT were further subdivided based on the post-notch systolic flow velocity. In these patients, a decline in the post-notch flow velocity to <62% of the pre-notch flow velocity defined a cohort with a marked reduction in systolic function and the worst outcome. ConclusionsIn PAH, the notched profile of RVOT Doppler flow velocity envelope appears to integrate indicators of pulmonary vascular load and RV function and serves as a marker for adverse outcomes.

Progressive intermediate-term improvement in ventricular and atrioventricular interaction after transcatheter pulmonary valve replacement in patients with right ventricular outflow tract obstruction

Relief of postoperative right ventricular outflow tract (RVOT) obstruction with transcatheter pulmonary valve replacement (TPVR) results in functional improvement in the short term which we investigated at baseline (BL), early follow-up (FU), and midterm FU after TPVR. Echocardiography and cardiopulmonary exercise testing were performed at BL and at early (median 6 months) and midterm FU (median 2.5years) after TPVR. Patients with RVOT obstruction (n=22, median age 17years) were studied. The max RVOT Doppler gradient fell from BL to early FU (60±24 to 26±8mm Hg, P<.001). Left ventricular (LV) end-diastolic and stroke volume increased at early FU (both P<.001) without further change, whereas LV ejection fraction improved throughout FU (P<.001). LV end-systolic and diastolic eccentricity (leftward septal displacement) improved early (both P≤.003), and end-diastolic eccentricity improved further at midterm FU (P=.02). Furthermore, whereas mitral inflow A wave velocity increased (P=.003), the LV A' velocity declined early (P=.007) without further change at midterm. RV systolic and early diastolic function was impaired at BL. Whereas RV strain improved partially at early and midterm FU (P≤.02), RV E' velocity did not improve throughout FU. Mildly impaired LV strain at BL fully recovered by midterm FU (P≤.002). Peak oxygen uptake improved at early and midterm FU (all P≤.003). Patients with RVOT obstruction had biventricular systolic and diastolic dysfunction at BL. Relieving RVOT obstruction with TPVR reduced adverse ventricular and compensatory atrioventricular interaction, resulting in progressive biventricular functional improvement and remodeling at early and midterm FU.

Doppler and Volumetric Echocardiographic Methods for Cardiac Output Measurement in Standing Adult Horses

Cardiac output (CO) is not routinely measured in critically ill adult horses because of invasiveness of currently validated methods. Noninvasive CO monitoring would complement clinical assessment of hemodynamic status in adult horses. Volumetric methods for measuring CO will have better agreement with lithium dilution than Doppler-based methods. Eight healthy adult horses. Prospective study. CO was manipulated with continuous rate infusions of dobutamine and romifidine to achieve high and low CO states, respectively. At each level, CO was measured by lithium dilution and various echocardiographic methods. Images stored as video loops were reviewed by an individual blinded to the lithium dilution results. Lithium dilution determinations of CO ranged between 16.6 and 63.0L/min. There was a significant effect of method of CO measurement (P<.001), but no significant effect of CO level (P=.089) or interaction between level and method (P=.607) on the absolute value of the bias. The absolute values of the bias of the right ventricular outflow tract (RVOT) Doppler, Simpson, 4-chamber area-length, and bullet methods [5.5, 6.1, 6.5, 8.8L/min, respectively] were significantly lower than that of the left ventricular outflow tract (LVOT) Doppler or cubic methods [14.8, 24.3L/min, respectively]. The 4-chamber area-length, Simpson, bullet, and RVOT Doppler provided better agreement with lithium dilution than the other methods evaluated. These methods warrant further investigation for use in critically ill adult horses.

Shape of the right ventricular outflow Doppler envelope and severity of pulmonary hypertension

It is now well known that timing of right ventricular outflow tract (RVOT) spectral Doppler signals change with increasing pulmonary hypertension severity. We devised a study to determine whether visual assessment of these RVOT Doppler signals can be useful identifying the severity of pulmonary hypertension. Visual inspection of pulsed RVOT Doppler signals from 120 consecutive patients (mean age of 55 ± 12, range 29-89 years; 45 males); with a mean pulmonary artery systolic pressure (PASP) of 59 ± 29, (ranging from 18 to 150 mmHg), of whom 78 patients had PASP >40 mmHg, was performed and correlated with standard echo Doppler variables of right ventricular performance. Visual inspection of RVOT spectral Doppler signals from the 120 patients showed four dynamic patterns and on a stepwise multiple regression analysis, PASP was the only echocardiographic variable that correlated with these different types of RVOT spectral Doppler signals. Furthermore, receiver operator curve analysis of these RVOT spectral Doppler signals correlated well with different ranges of PASP. Visual assessment of RVOT spectral signals demonstrates the presence of four dynamic patterns, independent of the aetiology of the pulmonary hypertension, that not only correlate with the severity of pulmonary hypertension, but also are useful in identifying a range of PASP with great accuracy that minimizes subjective interpretation. These simple visual assessments of RVOT Doppler signals can be done routinely when evaluating patients with pulmonary hypertension without the need of additional sophisticated equipment.

Different patterns of notching on doppler graph and hemodynamics in patients with pulmonary hypertension

Objective To investigate whether simple visual assessment of FVERVOT(the right ventricular outflow tract Doppler flow velocity envelop) graphs aids in hemodynamic differentiation. Method The hemodynamics, echocardiography, and clinical data of 88 patients with pulmonary hypertension (PH) were reviewed. The FVERVOTgraphs were categorized into normal pattern (no notch; NN), late systolic notch pattern (LSN) or mid-systolic notch pattern (MSN). Results The pulmonary vascular resistance (PVR) was highest in the MSN pattern (9.2±3.5 WU; P＜0. 001), in comparison with LSN (5,7 ±3. 1 WU) and NN (3.3±2.4 WU) patterns. The ratio of stroke volume to pulse pressure (compliance) also varied with different patterns of FVERVOr graph (MSN = 1.2 ± 0. 5; LSN = 1.7 ± 0.8; NN = 2.6 ± 1. 7, P = 0.001 and 0.04 respectively compared with NN). The specificity and sensitivity of MSN were 96% and 71%, respectively in case of a PVR ＞ 5 WU (PPV 98%). In the patients with PH, any notching pattern of FVERVOT graph was highly associated with PVR ＞ 3 WU (OR = 22.3, 95 % CI: 5.2 ～ 96.4), whereas the NN pattern predicted a PVR ≤3 WU and pulmonary artery wedge pressure (PAWP) ＞ 15 mmHg (OR =30.2, 95%CI: 6.3 ～ 144.9). Conclusions Visual inspection of the shape of the FVERVOT graphs provides insight into the hemodynamic status of patients with PH. Key words: Pulmonary hypertension; Hemodynamic; The right ventricular outflow tract Doppler flow velocity envelope (FVERVOT)