Normal Values of Pulmonary Artery Acceleration Time (PAAT) and Right Ventricular Ejection Time (RVET) in Children and Adolescents, and the Impact of PAAT/RVET Index in Assessment of Pulmonary Hypertension

Serial echocardiograms were performed in the first three days of life on 38 normal full-term infants. Right ventricular systolic time intervals were measured from the pulmonic valve echogram and left ventricular systolic time intervals were determined from the aortic valve echogram. The heart rate, left ventricular pre-ejection period (LPEP), left ventricular ejection time (LVET), and LPEP/LVET ratio showed insignificant variation with increasing postnatal age. The right ventricular pre-ejection period (RPEP) shortened, the right ventricular ejection time (RVET) lengthened, and the RPEP/RVET ratio decreased with increasing age. The findings suggested that alterations in the RPEP/RVET ratio reflected the decreasing pulmonary artery diastolic pressure and pulmonary vascular resistance of the early neonatal period and may be valuable in the noninvasive evaluation of the newborn's pulmonary vascular bed.

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Pulmonary artery pressure and cardiac function in children and adolescents after rapid ascent to 3,450 m

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00053.2012 ◽

2012 ◽

Vol 302 (12) ◽

pp. H2646-H2653 ◽

Cited By ~ 21

Author(s):

Yves Allemann ◽

Thomas Stuber ◽

Stefano F. de Marchi ◽

Emrush Rexhaj ◽

Claudio Sartori ◽

...

Keyword(s):

Pulmonary Hypertension ◽

Pulmonary Artery ◽

Right Ventricular ◽

High Altitude ◽

Children And Adolescents ◽

Pulmonary Artery Pressure ◽

Young Population ◽

Artery Pressure ◽

Rapid Ascent ◽

Low Altitude

High-altitude destinations are visited by increasing numbers of children and adolescents. High-altitude hypoxia triggers pulmonary hypertension that in turn may have adverse effects on cardiac function and may induce life-threatening high-altitude pulmonary edema (HAPE), but there are limited data in this young population. We, therefore, assessed in 118 nonacclimatized healthy children and adolescents (mean ± SD; age: 11 ± 2 yr) the effects of rapid ascent to high altitude on pulmonary artery pressure and right and left ventricular function by echocardiography. Pulmonary artery pressure was estimated by measuring the systolic right ventricular to right atrial pressure gradient. The echocardiography was performed at low altitude and 40 h after rapid ascent to 3,450 m. Pulmonary artery pressure was more than twofold higher at high than at low altitude (35 ± 11 vs. 16 ± 3 mmHg; P < 0.0001), and there existed a wide variability of pulmonary artery pressure at high altitude with an estimated upper 95% limit of 52 mmHg. Moreover, pulmonary artery pressure and its altitude-induced increase were inversely related to age, resulting in an almost twofold larger increase in the 6- to 9- than in the 14- to 16-yr-old participants (24 ± 12 vs. 13 ± 8 mmHg; P = 0.004). Even in children with the most severe altitude-induced pulmonary hypertension, right ventricular systolic function did not decrease, but increased, and none of the children developed HAPE. HAPE appears to be a rare event in this young population after rapid ascent to this altitude at which major tourist destinations are located.

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VALIDATING THE USE OF PULMONARY ARTERY ACCELERATION TIME IN ESTIMATING PULMONARY PRESSURE IN NEONATES

Paediatrics & Child Health ◽

10.1093/pch/pxy054.064 ◽

2018 ◽

Vol 23 (suppl_1) ◽

pp. e25-e26

Author(s):

Soume Bhattacharya ◽

Patrick McNamara ◽

Amish Jain ◽

Philip Ye ◽

Karl McNamara

Keyword(s):

Pulmonary Artery ◽

Right Ventricular ◽

Pulmonary Vascular Resistance ◽

Vascular Resistance ◽

Resistance Index ◽

Acceleration Time ◽

Pulmonary Pressure ◽

Doppler Waveform ◽

Pulmonary Vascular Resistance Index ◽

Ventricular Ejection Time

Abstract BACKGROUND Estimation of right ventricular peak systolic pressure (RVSP) or pulmonary pressure using echocardiography is crucial in neonates with acute or chronic pulmonary hypertension. Conventionally in echocardiography, the maximal velocity of the Tricuspid Regurgitant jet (TR Vmax) is used to estimate the RVSP. However, TR jet can often be absent or unmeasurable in neonates, resulting in a need to search for alternative echocardiographic measures of pulmonary pressure in neonates. Pulmonary Artery Doppler Waveform Parameter known as Pulmonary Artery Acceleration Time (PAAT) has been investigated in adults and older children and found to be reliable in estimating pulmonary pressure. To date, no such validation study exists for neonates.Hence we designed this study to explore the role of Pulmonary Artery Acceleration Time in estimating pulmonary pressures in neonates. OBJECTIVES To identify the pulmonary artery doppler waveform parameter that most closely reflects pulmonary pressure and analyse the impact of baseline variables and measurement techniques on this relationship. DESIGN/METHODS This was a retrospective cohort analysis conducted at two tertiary neonatal intensive care units. All neonates who underwent Targeted Neonatal Echocardiographic(TnECHO) assessments over May 2014-May 2017 were assessed for eligibility. Neonates whose echocardiography revealed a complete, measurableTR jet were included. Baseline characteristics such as gestational age, chronological age at echo, weight, blood pressure, ventilation and diagnosis were collected. Echocardiographic parameters such as TR Vmax, Pulmonary artery doppler waveform parameters such as Right Ventricular Ejection Time (RVET) and Pulmonary Artery Acceleration Time (PAAT) were measured by a single expert operator. Pulmonary Vascular Resistance Index (PVRI) was calculated as a ratio between RVET and PAAT. Correlation between pulmonary artery waveforms and RVSP estimated from the TR jet was examined using Pearson or Spearman analysis as appropriate. Univariate and multivariate regression analysis was used to further explore the influence of relevant factors on this relationship. Ethical approval was obtained from the institutional ethic board. RESULTS 678 neonates with 1767 echocardiographic studies were screened for eligibility of which 201 scans were included. Mean gestational age of this cohort was 30.5+/-5.7 weeks with mean birthweight of 1635 +/-1115 grams. Pulmonary Vascular Resistance Index (ratio of RVET to PAAT) also known as indexed PAAT, measured by Pulsed Wave Doppler at the level of the main pulmonary artery was found to have the strongest correlation with RVSP estimated from TRVmax. [r=0.45,P<0.05]. Using regression analysis, we could generate an equation to estimate systolic pulmonary artery pressures(ESPAP) directly from PVRI. [ESPAP= 25.53 + 3.97xPVRI, p<0.0001]. At the multivariate level, factors such as the Systolic Blood Pressure at time of echocardiogram and the presence or absence of PDA were found to have a statistically significance influence on this relationship. Pulmonary Vascular Resistance Index could be measured on all eligible scans. Inter-observer and intra-observer reliability assessment completed on a random subset of 30 showed excellent reliability for PVRI. [ICC =0.88, P<0.000] CONCLUSION This important validation study shows that PAAT indexed to right ventricular ejection time(PVRI) has statistically significant correlation with pulmonary pressures as measured by TR jet in neonates. However the strength of correlation in neonates is moderate at best. The measurement is feasible with good interobserver agreement and potentially can play an important role in serial monitoring of pulmonary pressures in neonates without any demonstrable TR jet on echocardiography.

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Clinical Pathophysiological Studies on the Measurement of Right Ventricular Ejection Time and Mechanical Effect

Japanese Circulation Journal ◽

10.1253/jcj.29.525 ◽

1965 ◽

Vol 29 (6) ◽

pp. 525-530

Author(s):

HIDEO YOSHINAKA

Keyword(s):

Right Ventricular ◽

Mechanical Effect ◽

Ventricular Ejection ◽

Ejection Time ◽

Ventricular Ejection Time

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Derivation and Validation of Formula relating Pulmonary Acceleration Time and Mean Pulmonary Artery Pressure in Indian Population

Journal of Perioperative Echocardiography ◽

10.5005/jp-journals-10034-1061 ◽

2017 ◽

Vol 5 (1) ◽

pp. 3-11

Author(s):

Rajarajan Ganesan

Keyword(s):

Pulmonary Artery ◽

Pulmonary Artery Pressure ◽

Indian Population ◽

Artery Bypass ◽

Resistance Index ◽

Ejection Time ◽

Acceleration Time ◽

Artery Pressure ◽

Mean Pulmonary Artery Pressure ◽

Ventricular Ejection Time

ABSTRACT Background Pulmonary acceleration time (PAT) forms a valuable echocardiographic parameter in deriving the mean pulmonary artery pressure (MPAP). The present study aims to derive and validate a formula relating MPAP and PAT in an Indian population. Materials and methods Preoperative echocardiography was performed in 22 adult cardiac surgery patients undergoing coronary artery bypass grafting (CABG) and/or mitral valve replacement. The PAT, PAT/right ventricular ejection time (RVET), PAT corrected for heart rate [(HR) HRcPAT], and tricuspid regurgitation (TR) peak velocity were correlated with MPAP measured from pulmonary artery (PA) catheter, and a new formula relating MPAP and PAT was derived and subsequently validated in another cohort of 21 patients. Results The PAT, HRcPAT, and PAT/RVET correlated well (r2 = 0.69, 0.68 and 0.47 respectively, p < 0.0001), while TR velocity correlated poorly with MPAP (r2 = 0.20, p = 0.046). The cutoff values of PAT and HRcPAT for diagnosing pulmonary artery hypertension (PAH) (MPAP = 25 mm Hg) were 74 and 99 respectively, with 92% sensitivity and 100% specificity. The derived formula (MPAP = 62.4 - 0.3 PAT) correlated well with the standard formula (79-0.45 PAT) on applying in the validation cohort (Bland—Altman plot, bias <10%). In subgroup analysis, patients with severe PAH (MPAP = 50 mm Hg) showed better correlation than patients with less than severe PAH (r2 = 0.633, p =0.038 a nd r2 = 0.46, p = 0.108 respectively). Similarly, the formula for deriving pulmonary vascular resistance index (PVRI) from PAT [(PVRI = 14.9-0.09 pulmonary artery acceleration time (PAAT)] correlated well with the existing formula (PVRI = 9 - 0.07 PAAT). The inter- and intraobserver variabilities were not significant. Conclusion The indexed formula is better in predicting MPAP from PAT in Indian population, particularly in patients with severe PAH (MPAP = 50 mm Hg) and the cutoffs of PAT and HRcPAT in predicting PAH (MPAP = 25 mm Hg) in an Indian population are 74 and 99 msec respectively. How to cite this article Munirathinam GK, Kumar A, Ganesan R, Puri GD. Derivation and Validation of Formula relating Pulmonary Acceleration Time and Mean Pulmonary Artery Pressure in Indian Population. J Perioper Echocardiogr 2017;5(1):3-11.

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Amrinone versus Dobutamine in Cardiac Surgical Patients with Severe Pulmonary Hypertension after Cardiopulmonary Bypass: A Prospective, Randomized Double-Blinded Trial

Anaesthesia and Intensive Care ◽

10.1177/0310057x9702500306 ◽

1997 ◽

Vol 25 (3) ◽

pp. 245-249 ◽

Cited By ~ 20

Author(s):

I. R. Jenkins ◽

J. Dolman ◽

J. P. O'Connor ◽

D. M. Ansley

Keyword(s):

Pulmonary Hypertension ◽

Cardiopulmonary Bypass ◽

Cardiac Index ◽

Ejection Fraction ◽

Pulmonary Artery ◽

Right Ventricular ◽

Right Ventricular Ejection Fraction ◽

Ventricular Ejection ◽

Ventricular Ejection Fraction ◽

Pulmonary Arterial

We compared the relative effects of dobutamine (5 μg/kg/min) and amrinone (1.0 mg/kg bolus followed by 10 μg/kg/min) on right and left ventricular function and pulmonary arterial pressures during weaning from cardiopulmonary bypass in patients with a mean preoperative pulmonary pressure >30 mmHg. Twenty patients scheduled for mitral valve replacement were studied in a prospective, randomized, double-blind trial. Patients receiving amrinone had a greater increase in cardiac index (CI) of 1.38 (±0.95) litre/min/m2 at separation vs 0.69 (±0.63) litre/min/m2 in the dobutamine group (P<0.05). The amrinone group also had a greater increase in right ventricular ejection fraction (0.15±0.08 at separation from cardiopulmonary bypass versus an increase of 0.04 ±0.11 in those receiving dobutamine; P<0.005). Amrinone produced a larger decrease in pulmonary artery wedge pressure 8.0 (±4.4) mmHg vs 0.75 (±6.6) mmHg at separation; pulmonary artery systolic and diastolic pressures also were reduced more in the amrinone group. There were no differences in heart rate, mean arterial pressure, central venous pressure and right ventricular stroke work index between patient groups. In the doses chosen, the use of amrinone compared to dobutamine was associated with a reduction in pulmonary arterial pressures and an increase in cardiac index and right ventricular ejection fraction after separation from bypass in patients with severe preoperative pulmonary hypertension.

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