Pedal Acceleration Time An Alternative Tool To Ankle-Brachial Index In Peripheral Arterial Disease.

INTRODUCTION: Ankle-Brachial Index (ABI) is a well-established diagnostic tool for evaluating peripheral arterial disease (PAD). Limitations in its application led to the development of alternative diagnostic methods, including Toe-Brachial Index (TBI) and Transcutaneous Pressure of Oxygen (TcPO2), yet these are not as widely available as ABI. Recently, Pedal Acceleration Time (PAT), has gained popularity as a new tool to assess PAD, requiring only an ultrasound. This study seeks to further establish the correlation between ABI and PAT, determining whether PAT can be a reliable alternative for diagnosing and assessing the severity of PAD. METHODS: ABI and PAT were measured in patients attending our consult with no history of vascular or endovascular surgery. Limbs with unmeasurable ABI were excluded. Patients were categorized into groups based on their PAD stage according to the Fontaine classification. Patient demographics, comorbidities and respective ABI and PAT were analysed. RESULTS: Sixty-nine patients (114 limbs) were included in the study. Mean age 68 ± 11.7 years, 78.3% male and 33.3% diabetic patients. Fifty-three claudicant limbs (46.5%) and 26 limbs (22.8%) with chronic limb threatening ischemia. Pearson correlation coefficient between ABI and PAT, showed a strong negative correlation (r= -0.78; p<0.01). Mean ABI and PAT for limbs in Fontaine stage I were 0.94 ± 0.17 and 82.0 ± 27.4 ms; Fontaine stage IIa 0.69 ± 0.21 and 141.3 ± 57.8 ms; Fontaine stage IIb 0.54 ± 0.14 and 173.4 ± 65.1 ms; Fontaine stage III 0.43 ± 0.15 and 216 ± 33.2 ms; Fontaine stage IV 0.49 ± 0.17 and 206.7 ± 78.1 ms, respectively. CONCLUSION: Our study suggests an inverse correlation between ABI and PAT, in accordance with the findings published in the literature, thus supporting the use of PAT as an easily reproducible and efficient alternative to ABI for evaluating the severity of PAD.

Usefulness of "AcT ratio" in diagnosis of internal carotid artery stenosis: a multicenter, retrospective, observational study.

PURPOSE: The ratio of the internal carotid artery (ICA) to the common carotid artery (CCA), especially the "AcT ratio," which is a modified measurement method of acceleration time, is useful for diagnosing ICA-origin stenosis. However, previous studies were single-center studies. Therefore, this multicenter, retrospective, cross-sectional study aimed to determine whether a method using the AcT ratio is useful for estimating stenosis rates. METHODS: This study included 461 vessels subjected to carotid artery ultrasonography and evaluation for ICA-origin stenosis via NASCET at four hospitals. The duration from the steep rise point to the inflection point or the first peak was defined as AcT on pulsed wave Doppler. The AcT ratio was calculated as AcT of ICA/AcT of ipsilateral CCA. The AcT ratio and rate of ICA-origin stenosis were analyzed using Pearson's correlation coefficient, simple regression analysis, and ROC curve. RESULTS: A significant positive correlation was observed between the AcT ratio and NASCET stenosis. NASCET stenosis of ≥ 50% had a sensitivity, specificity, and negative predictive value (NPV) of 70.2%, 71.6%, and 91.5%, respectively, when the cut-off value of the AcT ratio was 1.17. NASCET stenosis of ≥ 70% had a sensitivity, specificity, and NPV of 70.5%, 72.1%, and 95.9%, respectively, when the cut-off value of the AcT ratio was 1.22. CONCLUSIONS: The findings of this multicenter, retrospective, cross-sectional study suggest that the AcT ratio is useful for diagnosing ICA-origin stenosis, especially for diagnosis by exclusion. NASCET stenosis of ≥ 50% was considered unlikely if the Act ratio was ≤ 1.17, whereas NASCET stenosis of ≥ 70% was considered unlikely if it was ≤ 1.22.

Accuracy of maximal acceleration time of pedal arteries to diagnose critical limb-threatening ischemia.

INTRODUCTION: Maximal acceleration time of distal arteries of the foot (ATmax) is correlated to ankle-brachial index (ABI) and toe-brachial index (TBI), and seems very promising in diagnosing severe peripheral artery disease (PAD) and especially critical limb-threatening ischemia (CLTI). Our goal was to confirm the cut-off value of 215 ms to predict a toe pressure (TP) ⩽ 30 mmHg. METHODS: A 4-month retrospective study was conducted on patients addressed for suspicion of PAD. Demographic data, ABI, TBI, and Doppler ultrasound scanning parameters of the dorsal pedis and lateral plantar arteries (DPA and LPA) were recorded. RESULTS: A total of 137 patients with 258 lower limbs were included. ATmax was highly correlated to TBI (r = -0.89, p < 0.001). With the cut-off value of 215 ms, ATmax was effective to diagnose TP ⩽ 30 mmHg with a sensitivity of 93% [95% CI 77-99], a specificity of 96% [95% CI 92-98], a positive predictive value of 73% [95% CI 56-86], a negative predictive value of 99% [95% CI 97-100], and an area under the receiver operating characteristics curve of 0.99 [95% CI 0.98-1.00]. ATmax also showed promising results to rule out PAD in healthy patients. CONCLUSION: ATmax is a reliable diagnostic tool to diagnose low TP and could be a new easily performed hemodynamic criterion for diagnosis of CLTI.

Renal ultrasonography predicts worsening renal function in patients with heart failure under tolvaptan administration.

AIMS: Renal dysfunction in patients with chronic heart failure predicts a poor prognosis. Tolvaptan has a diuretic effect in patients with chronic kidney disease and heart failure without adverse effects on renal function. We aimed to determine the effects of tolvaptan and predictors of worsening renal function in patients with heart failure. METHODS AND RESULTS: This post hoc analysis was a sub-analysis of a single-centre prospectively randomized trial on the early and short-term tolvaptan administration. We enrolled 201 participants with decompensated heart failure between January 2014 and March 2019 (early group, n = 104; age: 79.0 ± 12.8 years; late group, n = 97; age: 80.3 ± 10.8 years). Renal ultrasonography was performed before and after the administration of tolvaptan. Urine output and oral water intake significantly increased during tolvaptan administration. The difference between water intake and urine volume increased during tolvaptan administration. Changes in body weight, blood pressure, heart rate, and estimated glomerular filtration rate (eGFR) in both groups were comparable. The changes in peak-systolic velocity (PSV), acceleration time (AT) of the renal arteries, and resistance index were comparable. The changes in PSV and end-diastolic velocity (EDV) of the interlobar arteries increased following tolvaptan administration (Δmax PSV: 0.0 ± 14.8 cm/s before tolvaptan vs. 5.6 ± 15.7 cm/s after tolvaptan, P = 0.002; Δmean PSV: 0.4 ± 12.3 vs. 4.9 ± 12.7 cm/s, P = 0.002; Δmax EDV: -0.2 ± 3.5 vs. 1.4 ± 4.0 cm/s, P = 0.001; Δmean EDV: -0.0 ± 3.1 vs. 1.1 ± 3.4 cm/s, P = 0.003). The renal artery AT was negatively correlated with the eGFR (Δmax AT: beta = -0.2354, P = 0.044; Δmean AT: beta = -0.2477, P = 0.035). CONCLUSIONS: Tolvaptan increased the PSV and EDV of the interlobar artery, which may mean tolvaptan increased renal blood flow. The renal artery AT may be a surrogate for worsening renal function.

Is the Corrected Carotid Flow Time a Clinically Acceptable Surrogate Hemodynamic Parameter for the Left Ventricular Ejection Time?

OBJECTIVE: The corrected left ventricular ejection time (cLVET) comprises the phase from aortic valve opening to aortic valve closure corrected for heart rate. As a surrogate measure for cLVET, the corrected carotid flow time (ccFT) has been proposed in previous research. The aim of this study was to assess the clinical agreement between cLVET and ccFT in a dynamic clinical setting. METHODS: Twenty-five patients with severe aortic valve stenosis (AS) were selected for transcatheter aortic valve replacement (TAVR). The cLVET and ccFT were derived from the left ventricular outflow tract (LVOT) and the common carotid artery (CCA), respectively, using pulsed wave Doppler ultrasound. Bazett's (B) and Wodey's (W) equations were used to calculate cLVET and ccFT. Measurements were performed directly before (T1) and after (T2) TAVR. Correlation, Bland-Altman and concordance analyses were performed. RESULTS: Corrected LVET decreased from T1 to T2 (p < 0.001), with relative reductions of 11% (B) and 9% (W). Corrected carotid flow time decreased (p < 0.001), with relative reductions of 12% (B) and 10% (W). The correlation between cLVET and ccFT was strong for B (ρ = 0.74, p < 0.001) and W (ρ = 0.81, p < 0.001). The bias was -39 ms (B) and -37 ms (W), and the upper and lower levels of agreement were 19 and -98 ms (B) and 5 and -78 ms (W), respectively. Trending ability between cLVET and ccFT was good (concordance 96%) for both B and W. CONCLUSION: In TAVR patients, the clinical agreement between cLVET and ccFT was acceptable, indicating that ccFT could serve as a surrogate measure for cLVET.

Novel Echocardiographic Measurements of Right Ventricular-Pulmonary Artery Coupling in Predicting the Prognosis of Precapillary Pulmonary Hypertension.

BACKGROUND: Currently, there are many parameters with proven prognostic significance in pulmonary hypertension (PH). Recently, the parameters defining right ventricular-pulmonary artery coupling (RVPAC) have gained clinical importance. In our study, we investigated the prognostic potential of previously known single echocardiographic parameters and new parameters reflecting RVPAC in patients with precapillary PH. OBJECTIVE: Our study aimed to evaluate the prognostic value of selected echocardiographic parameters and the neutrophil-lymphocyte ratio (NLR) in adults with precapillary PH. METHODS: This study included 39 patients (74% women; average age, 63 years) with precapillary PH: pulmonary arterial hypertension (PAH) and chronic thromboembolic PH (CTEPH). The mean follow-up period was 16.6 ± 13.3 months. Twelve patients (31%) died during the observation time. We measured several echocardiographic parameters, which reflect right ventricular function, pulmonary hemodynamics, and RVPAC. To assess disease progression and the patient's functional capacity, the World Health Organization functional class (WHO FC) was determined. The patient's physical capacity was also evaluated using the 6 min walk test (6MWT). The analysis included values of the N-terminal prohormone brain natriuretic peptide (NT-proBNP) and NLR. RESULTS: TAPSE × AcT and TAPSE/sPAP were shown to statistically and significantly correlate with PH predictors, including WHO-FC, 6MWT, and NT-proBNP. Univariate Cox proportional hazards regression analysis revealed that AcT, TAPSE, mPAP, TAPSE/sPAP, RAP, TRPG/AcT, TAPSE × AcT, and NLRs are good predictors of mortality in patients with PH. In addition, the ROC curve analysis showed that TAPSE × AcT is a better predictor of PH-related deaths than TAPSE/sPAP and TAPSE alone. In our study, patients with TAPSE × AcT values < 126.36 had shorter survival times (sensitivity = 72.7%; specificity = 80.0%). CONCLUSIONS: TAPSE × AcT is a novel, promising, and practicable echocardiographic parameter reflecting RVPAC, which is comparable to TAPSE/sPAP. Moreover, TAPSE × AcT can be a useful parameter in assessing the severity and prognosis of patients with precapillary PH.

Multiscale Entropy Algorithms to Analyze Complexity and Variability of Trunk Accelerations Time Series in Subjects with Parkinson's Disease.

The aim of this study was to assess the ability of multiscale sample entropy (MSE), refined composite multiscale entropy (RCMSE), and complexity index (CI) to characterize gait complexity through trunk acceleration patterns in subjects with Parkinson's disease (swPD) and healthy subjects, regardless of age or gait speed. The trunk acceleration patterns of 51 swPD and 50 healthy subjects (HS) were acquired using a lumbar-mounted magneto-inertial measurement unit during their walking. MSE, RCMSE, and CI were calculated on 2000 data points, using scale factors (τ) 1-6. Differences between swPD and HS were calculated at each τ, and the area under the receiver operating characteristics, optimal cutoff points, post-test probabilities, and diagnostic odds ratios were calculated. MSE, RCMSE, and CIs showed to differentiate swPD from HS. MSE in the anteroposterior direction at τ4 and τ5, and MSE in the ML direction at τ4 showed to characterize the gait disorders of swPD with the best trade-off between positive and negative posttest probabilities and correlated with the motor disability, pelvic kinematics, and stance phase. Using a time series of 2000 data points, a scale factor of 4 or 5 in the MSE procedure can yield the best trade-off in terms of post-test probabilities when compared to other scale factors for detecting gait variability and complexity in swPD.

What echocardiographic findings differentiate acute pulmonary embolism and chronic pulmonary hypertension?

BACKGROUND: Pulmonary embolism (PE) and pulmonary hypertension (PH) are potentially fatal disease states. Early diagnosis and goal-directed management improve outcomes and survival. Both conditions share several echocardiographic findings of right ventricular dysfunction. This can inadvertently lead to incorrect diagnosis, inappropriate and potentially harmful management, and delay in time-sensitive therapies. Fortunately, bedside echocardiography imparts a few critical distinctions. OBJECTIVE: This narrative review describes eight physiologically interdependent echocardiographic parameters that help distinguish acute PE and chronic PH. The manuscript details each finding along with associated pathophysiology and summarization of the literature evaluating diagnostic utility. This guide then provides pearls and pitfalls with high-quality media for the bedside evaluation. DISCUSSION: The echocardiographic parameters suggesting acute or chronic right ventricular dysfunction (best used in combination) are: 1. Right heart thrombus (acute PE) 2. Right ventricular free wall thickness (acute ≤ 5 mm, chronic > 5 mm) 3. Tricuspid regurgitation pressure gradient (acute ≤ 46 mmHg, chronic > 46 mmHg, corresponding to tricuspid regurgitation maximal velocity ≤ 3.4 m/sec and > 3.4 m/sec, respectively) 4. Pulmonary artery acceleration time (acute ≤ 60-80 msec, chronic < 105 msec) 5. 60/60 sign (acute) 6. Pulmonary artery early-systolic notching (proximally-located, higher-risk PE) 7. McConnell's sign (acute) 8. Right atrial enlargement (equal to left atrial size suggests acute, greater than left atrial size suggests chronic). CONCLUSIONS: Emergency physicians must appreciate the echocardiographic findings and associated pathophysiology that help distinguish acute and chronic right ventricular dysfunction. In the proper clinical context, these findings can point towards PE or PH, thereby leading to earlier goal-directed management.

Feasibility and Clinical Value of Intraprocedural Doppler Ultrasonography Blood Flow Parameters During Peripheral Endovascular Procedures for Limb Salvage: A Pilot Study.

PURPOSE: To investigate whether Doppler ultrasound (DUS) blood flow parameters could serve as quantifiable functional endpoints of peripheral endovascular arterial procedures for chronic limb-threatening ischemia (CLTI), influencing wound healing. METHODS: This is a prospective single-center study investigating intraprocedural DUS parameters (pulsatility index [PI] and pedal acceleration time [PAT]) in quantifying immediate hemodynamic alterations in consecutive CLTI patients with wound, ischemia, and foot infection wound class ≥1 undergoing endovascular interventions. Primary endpoints were feasibility of preendovascular and postendovascular treatment measurements of PI/PAT, quantification of immediate PI/PAT modifications of the posterior and anterior foot circulation following revascularization, the correlation between PI and PAT, and 6-month complete wound healing. Secondary endpoints included the 6-month limb salvage (no major amputation) and complete and partial wound healing rates. RESULTS: A total of 28 patients (75.0% male) were enrolled, and 68 vessels were treated. The overall mean PAT values significantly decreased from 154.15±70.35 ms preprocedural to 107.21±49.6 ms postprocedural (p<0.01), and the mean PI values significantly increased from 0.93±0.99 to 1.92±1.96 (p<0.01). Postprocedural PAT at the anterior tibial (r2=0.804; p=0.346) and the posterior tibial arteries (r2=0.784; p=0.322) had a strong correlation and postprocedural PI at the anterior tibial (r2=0.704; p=0.301) and the posterior tibial arteries (r2=0.707; p=0.369) had a good correlation with 6-month complete wound healing. The 6-month complete and partial wound healing rates were 38.1% and 47.6%, respectively. Limb salvage was 96.4% and 92.4% at 6 and 12 months of follow-up, respectively. CONCLUSIONS: Pedal acceleration time and PI accurately detected immediate hemodynamic changes of foot perfusion following revascularization and could serve as prognostic factors of wound healing in patients with CLTI. CLINICAL IMPACT: Intraprocedural measurement of simple Doppler ultrasound blood flow parameters, Pulsatility Index (PI) and Pedal Acceleration Time (PAT), accurately detected immediate hemodynamic changes of foot perfusion following endovascular revascularization and could therefore serve as intraprocedural prognostic factors of wound healing in patients with chronic limb-threatening ischemia. This is the first time that PI has been proposed as a hemodynamic index of successful angioplasty outcome. The optimization of intraprocedural PAT and PI could be used to guide angioplasty and predict clinical success.

Effect of Adding Kinesio Taping to Exercise Therapy in the Treatment of Patellofemoral Pain Syndrome.

Background and objectives: Patellar taping has been widely used for the primary or adjunctive treatment of patellofemoral pain syndrome (PFPS); however, there are limited data in terms of functional outcomes. This study aimed to investigate whether there is any beneficial effect of adding Kinesio Taping® (KT) to exercise therapy in the treatment of PFPS. Materials and Methods: Twenty patients (27.5 ± 5.4 years) with PFPS who applied KT and 19 patients (27.3 ± 7.4 years) who did not were included in this study. Quadriceps muscle strength and acceleration time (AT) were assessed using an isokinetic device. Patient-reported outcomes were evaluated using the Kujala anterior knee pain scale (AKPS). Both groups underwent one-month exercise therapy. Results: There was no significant difference in quadriceps strength, AT, and AKPS at baseline and at 1 month between the taping and non-taping groups (p > 0.05). However, for quadriceps muscle strength, the effect of time*group interaction was statistically significant (F(1.37) = 4.543, p < 0.05, partial eta squared 0.109), showing that improvement in the quadriceps strength was higher in the non-taping group than that in the taping group. Conclusions: Adding KT to exercise therapy did not elicit extra benefits in quadriceps muscle strength and AT, and AKPS among PFPS with abnormal patellar tracking at one month.

Mean pulmonary artery pressure estimated by echocardiogram rapidly exceeds 20 mmHg from the normal range in patients with connective tissue disease.

Earlier intervention for pulmonary hypertension (PH) has been reported to improve the prognosis of patients with connective tissue disease (CTD). However, it is not fully elucidated how rapidly PH develops in patients showing normal mean pulmonary arterial pressure (mPAP) at the index investigation. We evaluated 191 CTD patients with normal mPAP retrospectively. The mPAP was estimated by the formerly defined method employing echocardiography (mPAPecho). We investigated predictive factors that predict increasing mPAPecho at follow-up transthoracic echocardiography (TTE) using uni- and multi variable analysis. The mean age was 61.5 years old, and 160 patients were female. The percentage of patients in whom mPAPecho exceeded 20 mmHg at follow-up TTE was 38%. Multivariable analysis revealed that acceleration time/ejection time (AcT/ET) measured at the right ventricular outflow tract at initial TTE was independently associated with the consequent increase of mPAPecho at the follow-up TTE. When using 0.43 of best cutoff value in AcT/ET calculated by receiver operating characteristic analysis, the change in mPAPecho in patients with low AcT/ET was significantly higher than in those with high AcT/ET (3.05 mmHg in patients with AcT/ET < 0.43 and 1.00 mmHg in patients with AcT/ET ≥ 0.43, p < 0.001). Thirty-eight percent of CTD patients who show the normal estimated mPAP by TTE develop gradual elevation of mPAP to the level to consider early intervention within 2 years. AcT/ET at initial TTE can predict increasing mPAP at follow-up TTE.

Accuracy of the pedal acceleration time to diagnose limb ischemia in patients with and without diabetes using the WIfI classification.

INTRODUCTION: Evaluation of limb hemodynamics using the ankle-brachial index (ABI) may be difficult due to skin lesions, extensive necrosis, and obesity, such as commonly present in patients with diabetes with chronic limb-threatening ischemia (CLTI). We hypothesized that the pedal acceleration time (PAT) correlates with ABI and Wound, Ischemia, and foot Infection (WIfI) scores in patients with diabetes to serve as a new modality to accurately stage CLTI. METHODS: A single-center, cross-sectional study included patients with and without diabetes > 18 years with CLTI. Limbs were categorized in three grades of ischemia based on the ABI (ABI < 0.8, < 0.6, and < 0.4) and in two classes based on WIfI stages of amputation risk. Receiver operator characteristic (ROC) curves were used to determine PAT sensitivity, specificity, and accuracy to predict lower-limb ischemia. RESULTS: A total of 141 patients (67 nondiabetic and 74 diabetic) and 198 lower limbs (94 nondiabetic and 104 diabetic) met the inclusion criteria. In patients without diabetes, the accuracy of PAT for detecting an ABI < 0.8 was 85%; for detecting an ABI < 0.6 was 85%; and for detecting an ABI < 0.4 was 87%. In patients with diabetes, the accuracy of PAT in detecting an ABI < 0.8 was 91%; for detecting an ABI < 0.6 was 79%; and for detecting an ABI < 0.4 was 88%. In patients without diabetes, the accuracy for detecting WIfI stages of moderate and high amputation risk was 77% and for patients with diabetes was also 77%. CONCLUSIONS: PAT shows high correlation with the ABI as well as with the WIfI stages of amputation risk and the grades of ischemia, with high accuracy.

Arterial Blood-Flow Acceleration Time on Doppler Ultrasound Waveforms: What Are We Talking About?

In recent years, the assessment of systolic acceleration in lower-extremity peripheral artery disease (PAD) has been brought back into the spotlight, whatever measure is used: time (in s) or acceleration (in cm.s-2). Acceleration time (also called systolic rise time) and maximal acceleration are two different but very useful measurements of growing interest in PAD. A background of the historical development, physics rationale, semantics, and methods of measurement, as well as their strengths and weaknesses, are discussed herein. Acceleration time is a powerful tool for predicting significant arterial stenosis or for estimating the overall impact of PAD as it is highly correlated to the ankle or toe pressure indexes. It could even become a new diagnostic criterion for critical limb ischemia. Similarly, maximal systolic acceleration ratios are highly predictive of carotid or renal stenosis. However, the literature lacks reference standards or guidelines for the assessment of such variables, and their measurement techniques seem to differ between authors. We propose herein a semantic and measurement statement order to clarify and help standardize future research.

Prognostic impact and diagnostic value of invasively derived hemodynamic measures in patients with severe aortic stenosis undergoing TAVI.

BACKGROUND: Ejection time (ET), acceleration time (AT) and time between left ventricular and aortic systolic pressure peaks (T-LVAo) might be of diagnostic and prognostic use in patients with aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). AIM: We aimed to assess the diagnostic value and prognostic impact of invasively measured ET, AT, and T-LVAo in patients undergoing TAVI. METHODS: A total of 1274 patients received invasive measurement of ET, AT and T-LVAo prior to TAVI. Anatomic AS severity was assessed by CT-derived aortic valve calcification density (AVCd). Impact on all-cause mortality was retrospectively analyzed. RESULTS: In multivariable linear regression, T-LVAo showed the strongest correlation with AVCd. No prognostic impact of T-LVAo was found according to uni- and multivariable analyses. In contrast, using an individual C-statistic derived cutoff (CD), patients with ET or AT ≥ CD showed lower mortality rates compared to patients with ET or AT < CD (1-year mortality: ET ≥ vs. < CD: 15.01vs. 33.1%, AT ≥ vs < CD 16.3 vs. 26.5%, p < 0.001). Moreover, multivariable analysis identified ET ≥ CD (HR 0.61 [95% CI 0.43-0.87; p < 0.007]) to be associated with beneficial outcome after TAVI, independent from clinical risk factors and echocardiography-derived parameters. CONCLUSION: Among the studied hemodynamic parameters T-LVAo provides the highest diagnostic value, whereas ET is an outcome predictor beyond clinical risk factors and echocardiographic parameters in AS patients following TAVI. These parameters could be of considerable use in diagnostic evaluation and risk assessment of patients scheduled for TAVI. T-LVAo (yellow): defined as time between left ventricular and aortic systolic pressure peaks. ET (green): Ejection Time defined as time from the start to flow end. AT (orange): Acceleration time defined as time from the start to the peak flow. AOP: aortic pressure, AVC: aortic valve calcification, CI: confidence interval, HGAS: high-gradient aortic stenosis, LGAS: low-gradient aortic stenosis, LVP: left ventricular pressure, SD: standard deviation.

The value of pulmonary artery acceleration time in evaluating pulmonary vascular disease in preterm infants with bronchopulmonary dysplasia.

OBJECTIVES: Early screening and dynamic monitoring of pulmonary vascular disease (PVD) in bronchopulmonary dysplasia (BPD) high-risk infants is of great clinical significance. Pulmonary artery acceleration time (PAAT) is a reliable and non-invasive method for assessing PVD in children over 1 year, but to date, few studies have used PAAT to assess pulmonary hemodynamics of preterm infants, especially those with BPD. Through dynamic monitoring the main hemodynamic indicators reflected PVD after birth, this study aimed to assess the value of PAAT in evaluating early PVD in BPD infants. METHODS: All 81 preterm infants at risk of BPD were divided into BPD and non-BPD groups according to whether BPD occurred. Clinical characteristics, PAAT, right ventricular ejection time (RVET) and other main hemodynamic indicators at four different time points after birth were studied and compared. RESULTS: PAAT and PAAT/RVET increased gradually within 72 h after birth in the BPD group (p < .05), but the curve tended to be flat over time after 72 h (p > .05). At PMA32 and 36 weeks, the PAAT (49.7 ± 4.8 vs. 54.8 ± 5.7, p = .001; 50.0 ± 5.3 vs. 57.0 ± 5.3, p = .001) and PAAT/RVET (.33 ± .04 vs. .35 ± .03, p = .001; .34 ± .03 vs. .37 ± .04, p = .001) in BPD group were significantly lower than those in the non-BPD group. CONCLUSIONS: PAAT and PAAT/RVET in the BPD group infants showed different change patterns compared to non-BPD group infants. PAAT can be used as a noninvasive and reliable screening method for screening and dynamic monitoring of PVD in BPD high-risk infants.

Mode-specific effects of concentric and eccentric isokinetic training of the hamstring muscle at slow angular velocity on the functional hamstrings-to-quadriceps ratio-a randomized trial.

Background: Previous studies have examined the mode specificity of eccentric and concentric isokinetic training, but have reported conflicting results. Few studies have reported that eccentric and concentric isokinetic training are mode-specific, i.e., they will increase only the eccentric or concentric strength, respectively. Other studies have reported that mode specificity does not exist. Therefore, this study aimed to assess the mode-specific effects of eccentric and concentric isokinetic training of the hamstring muscle at slow angular velocity on eccentric peak torque of the hamstring (PTecc), concentric peak torque of the quadriceps (PTcon), acceleration time of the hamstring (AThams) and quadriceps (ATquad), deceleration time of the hamstring (DThams) and quadriceps (DTquad), time to peak torque of the hamstring (TPThams) and quadriceps (TPTquad), and functional Hamstring-to-Quadriceps ratio (PTecc/PTcon). Subjects: A total of 30 participants were randomly divided into eccentric and concentric groups. Methods: Two groups pre-test-post-test experimental design was used. In the eccentric and concentric groups, eccentric and concentric isokinetic training of hamstring muscle was performed respectively, at an angular velocity of 60°/s for 6 weeks duration. PTecc, PTcon, AThams, ATquad, DThams, DTquad, TPThams, TPTquad, and PTecc/PTcon were measured before and after the completion of training. Results: In the eccentric group, a significant difference (p < 0.05) was observed in PTecc (increased by 21.55%), AThams (decreased by 42.33%), ATquad (decreased by 28.74%), and PTecc/PTcon (increased by 17.59%). No significant difference (p > 0.05) was observed in PTcon, TPThams, TPTquad, DThams, and DTquad. In the concentric group, a significant difference (p < 0.05) was observed in PTecc (increased by 12.95%), AThams (decreased by 27.38%) ATquad (decreased by 22.08%), DTquad (decreased by 26.86%), and PTecc/PTcon (increased by 8.35%). No significant difference (p > 0.05) was observed in PTquad, TPThams, TPTquad, and DThams. Between-group analysis revealed a significant difference (p < 0.05) only in TPTquad; otherwise, in the rest of the parameters, no significant difference (p > 0.05) was observed. Conclusions: Both eccentric and concentric isokinetic training of the hamstring for 6 weeks increased PTecc, PTecc/PTcon, and decreased AThams and ATquad. The effects of eccentric and concentric isokinetic training of the hamstring on PTecc, PTecc/PTcon, AThams, and ATquad were not mode specific.

Utility of the tricuspid annular tissue doppler systolic velocity and pulmonary artery systolic pressure relationship in right ventricular systolic function assessment: A pilot study.

BACKGROUND: Tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP) ratio has been validated as a valuable noninvasive measure of right ventricular (RV) elastance and systolic function. However, the more reliable TA systolic (s') velocity measure of RV systolic function compared to TAPSE has not been previously studied. METHODS: We conducted a pilot study using several variables of RV function in 50 patients with the main aim to determine which numerical expression between TA TDI s'/PASP and TAPSE/PASP ratio was most useful. RESULTS: In a stepwise multiple regression analysis, TA TDI s'/PASP ratio (p < .0002); LVOT VTI/RVOT VTI ratio (p < .0002); RVOT VTI (p < .0047); TAPSE/PASP ratio (p < .0259) and TA TDI e' (p < .0292) were best in discriminating normal versus abnormal RV systolic function. Using receiver operator curve analysis, cut-off values for both TA TDI s'/PASP (>3.9 mm/c/mmHg) had 82.1% sensitivity and 77.3% specificity while the TAPSE/PASP (>.61 mm/mmHg) had 89.3% sensitivity and 68.2% specificity in identifying normal RV function in our studied population. CONCLUSION: Our results indicate that TA TDI s'/PASP is a better mathematical expression when examining the relationship between RV contractility and RV resistance relationship. Furthermore, we also found that inclusion of RVOT VTI, RV diastolic properties, and left ventricular systolic function are important determinants of RV systolic function assessments and should be routinely included. Additional prospective studies are now needed to confirm these results using hemodynamic data.

Pulmonary artery acceleration time accuracy for systolic pulmonary artery pressure estimation in critically ill patients.

BACKGROUND: Estimation of pulmonary pressures is of key importance in acute cardiovascular and respiratory failure. Pulmonary artery acceleration time (PAAT) has emerged as reliable parameter for the estimation of systolic pulmonary artery pressure (sPAP) in cardiological population with preserved right ventricular function. We sought to find whether PAAT correlates with sPAP in critically ill patients with and without right ventricular (RV) systolic dysfunction. METHODS: Observational study. We measured sPAP using continuous-wave Doppler analysis of tricuspid regurgitation velocity peak method and we assessed the validity of PAAT in estimating sPAP in patients admitted to adult intensive care unit (ICU) for acute cardiovascular and respiratory failure. RESULTS: We enrolled 236 patients admitted to cardiothoracic ICU for cardiovascular and respiratory failure (respectively: 129, 54.7% and 107, 45.3%). 114 (48.3%) had preserved RV systolic function (defined as TAPSE ≥ 17 mm), whilst 122 (51.7%) had RV systolic impairment (defined as TAPSE < 17 mm). A weak inverse correlation between PAAT and sPAP (ρ-0.189, p 0.0035) was observed in overall population, which was confirmed in those with preserved RV systolic PAAT and sPAP (ρ-0.361, p 0.0001). In patients with impaired RV systolic function no statistically significant correlation between PAAT and sPAP was demonstrated (p 0.2737). Adjusting PAAT values for log10, heart rate and RV ejection time did not modify the abovementioned correlations. CONCLUSIONS: PAAT measurement to derive sPAP is not reliable in cardiothoracic critically ill patients, particularly in the coexistence of RV systolic impairment.

Echocardiographic Assessment of Pulmonary Hypertension in Neonates with Congenital Diaphragmatic Hernia Using Pulmonary Artery Flow Characteristics.

Background: Assessment of pulmonary hypertension (PH) is essential in neonates with congenital diaphragmatic hernia (CDH). Echocardiography is widely established to quantify PH severity, but currently used parameters have inherent limitations. The aim of our study was to investigate the prognostic utility of the index of the pulmonary artery acceleration time to the right ventricular ejection time (PAAT:ET) in CDH neonates assessed using echocardiography. Methods: PAAT:ET values were prospectively measured in CDH neonates on admission, on day of life (DOL) 2 and DOL 5−7. Optimal cut-off values to predict mortality and need for ECMO were calculated and PAAT:ET values were compared between non-ECMO survivors, ECMO-survivors, and ECMO-non-survivors. Results: 87 CDH neonates were enrolled and 39 patients required ECMO therapy. At baseline, PAAT:ET values were significantly lower in ECMO patients compared to non-ECMO patients (p < 0.001). ECMO survivors and ECMO non-survivors had similar values at baseline (p = 0.967) and DOL 2 (p = 0.124) but significantly higher values at DOL 5−7 (p = 0.003). Optimal PAAT:ET cut-off for predicting ECMO was 0.290 at baseline and 0.310 for predicting non-survival in patients on ECMO at DOL 5−7. Conclusion: PAAT:ET is a feasible parameter for early risk assessment in CDH neonates.