Estimation of the systolic pulmonary arterial pressure using contrast-enhanced continuous-wave Doppler in patients with trivial tricuspid regurgitation.

Noninvasive estimation of pulmonary arterial pressure is important for hemodynamic monitoring of patients with heart disease. In patients with tricuspid regurgitation (TR), the peak velocity of TR on continuous-wave (CW) Doppler can be used to estimate the systolic pulmonary arterial pressure (PAPs) using the simplified Bernoulli equation. We evaluated a new technique of contrast-enhanced CW Doppler for calculating PAPs in patients with trivial TR. Forty-one patients without visible TR detected by color Doppler, pulsed Doppler or CW Doppler were evaluated. Age ranged from 19 to 73 (55 +/- 12) years old. Tricuspid flow signals were recorded on CW Doppler after intravenous administration of indocyanin green (ICG) or Albunex. PAPs was calculated as; PAPs = 4 x VTR2 + 10 mmHg, where VTR is the peak velocity of TR. PAPs calculated using contrast-enhanced CW Doppler was compared with PAPs measured by the following cardiac catheterization. 1) TR signals were recorded using the contrast-enhanced CW Doppler technique in 39 of 41 patients (95%) after intravenous administration of contrast agents. 2) The error of estimate of PAPs using the contrast-enhanced CW Doppler technique was -2.4 +/- 7.5 mmHg, and the percent error was -10.7 +/- 32.4% in all patients. In 20 of 39 patients (51%), the error of estimate was within +/- 5 mmHg. 3) PAPs was overestimated by 12.2 +/- 6.1 mmHg in patients with good contrast enhancement of TR signals. The contrast-enhanced CW Doppler technique is useful for estimating PAPs noninvasively in patients with trivial TR. It is better to assume the right atrial pressure as 3-5 mmHg, not 10 mmHg, in patients with good enhancement of trivial TR. Physiological TR may be enhanced by contrast agents in these patients.     

Non-invasive evaluation with continuous Doppler of the systolic pressure of the right ventricle in patients with tricuspid insufficiency

Tricuspid regurgitation (TR) is detected by Doppler echocardiography in a high proportion of patients with right ventricle pressure or volume overload. Continuous wave Doppler (CW) provides a noninvasive estimation of the transtricuspid systolic pressure gradient, applying the modified Bernoulli formula to the maximum velocity of the TR jet. The purpose of this study was to test the accuracy of the CW prediction of systolic right ventricular pressure (RVPs), obtained adding a clinical estimate of the mean right atrial pressure (RAPm) to the Doppler derived pressure gradient. The study population consisted of 22 adult patients with Doppler proved TR, undergoing right heart catheterization (cath) for mitral valve disease (12 pts), atrial septal defect (8 pts), dilated cardiomyopathy (1 pt) or pulmonary hypertension (1 pt). Two studies were duplicated after nifedipine administration. TR was graded by pulsed Doppler flow mapping as mild in 7, moderate in 11, severe in 4 pts. RAPm was estimated clinically from the inspection of neck veins pulsatility (mmHg = pulsatility cm+5/1.3). At CATH RVPs ranged from 27 to 80 (46 +/- 17) mmHg, RAPm from 0 to 13 (6 +/- 3) mmHg. RVPs Doppler prediction showed a close correlation with CATH (r .97, SEE 4.2 mmHg), with a slight mean underestimation (-2 +/- 4 mmHg) (Fig. 3, Tab. I). The discrepancies between CW and CATH ranged from -9 to +10 mmHg, almost entirely due to inaccuracy of the RAPm clinical estimate (r .48, see 3.8 mmHg) (Fig. 4, Tab. I).(ABSTRACT TRUNCATED AT 250 WORDS)     

Paroxysmal Atrial Fibrillation Maintained by Nonpulmonary Vein Sources Can Be Predicted by Dominant Frequency Analysis of Atriopulmonary Electrograms

Introduction: Increasing evidence suggests that high-frequency excitation in the pulmonary vein (PV) plays a dominant role in the maintenance of paroxysmal atrial fibrillation (AF). However, in a certain population of patients, AF remains inducible after PV isolation (PVI). We sought to clarify whether dominant frequency (DF) analysis of atriopulmonary electrograms can predict paroxysmal AF maintained by non-PV sources.
Methods and Results: Sixty-one patients with paroxysmal AF (aged 59 ± 12 years) were studied. Before PVI, bipolar electrograms during AF were recorded simultaneously from three PV ostia, the coronary sinus (CS), and the septum and free wall of the right atrium (RA). DF was obtained by fast Fourier transform (FFT) analysis. AF was rendered noninducible after PVI in 39 of the 61 patients (noninducible group), but was still inducible in the remaining 22 (inducible group). Among the six recording sites, the highest DF was documented in the PV in all of the patients in the noninducible group; the maximum DF among the three PVs (PV-DF_max) was higher than that among the CS and two RA sites (atrial DF_max; 7.2 ± 1.0 Hz vs 5.8 ± 0.7 Hz, P < 0.0001). In contrast, the highest DF was documented in the CS or RA in 45.5% of the patients in the inducible group; PV-DF_max was comparable with atrial DF_max (6.6 ± 0.8 Hz vs 6.6 ± 0.6 Hz). AF inducibility after PVI was predicted by a PV-to-atrial DF_max gradient of <0.5 Hz, with a sensitivity of 90.9% and a specificity of 89.7%.
Conclusion: Paroxysmal AF maintained by non-PV sources can be predicted by the PV-to-atrial DF gradient.     

Noninvasive estimation of systolic pulmonary artery pressure using Doppler echocardiography in patients with chronic obstructive pulmonary disease

In patients with acquired or congenital heart diseases, the systolic pulmonary artery pressure (PAPs) can be predicted using continuous-wave Doppler ultrasound (CWD) measurement of the peak velocity of a tricuspid regurgitation (TR) jet. The aim of this study was to determine whether CWD could be used to accurately estimate PAP in patients with chronic obstructive pulmonary disease (COPD). In 41 patients with stable COPD, we prospectively performed CWD and right heart catheterization. The mean value of PAPs for the entire group was 38.5 +/- 14.9 mm Hg. Pulmonary arterial hypertension (PAPs greater than or equal to 35 mm Hg) occurred in 51 percent (21/41) of patients. Doppler estimation of PAP was impossible in 34 percent (14/41) because of poor signal quality (n = 3), absence of Doppler-detected TR (n = 8), and inadequate TR Doppler signal (n = 3). The PAP could be estimated in 66 percent (27/41) of patients. A statistically significant correlation was found between the Doppler-estimated PAP and the catheter-measured PAPs (r = 0.65; p less than 0.001; SEE = 9 mm Hg). Therefore, CWD appears to be useful for the noninvasive estimation of PAP in patients with COPD. However, this method is associated with two limitations: (1) the high percentage of patients in whom the PAP cannot be estimated by CWD, mainly because of the absence of Doppler-detected TR, and (2) the high value of the standard error of the estimate. The combination of CWD with other Doppler methods should increase the feasibility and accuracy of Doppler echography for the prediction of PAP in patients with COPD.     

Late Results of Pulmonary Balloon Valvuloplasty in Adults Using Double Balloon Technique

Between July 1985 and July 1987, 18 consecutive adult patients with congenital pulmonary stenosis underwent pulmonary balloon valvuloplasty (PBV). There were 11 males and 7 females, aged 15–45 years (mean 25). A double balloon technique was used in 14 patients and a single balloon in four. The size of the balloon used was 0.9 to 1.4 times the size of the pulmonary annulus. Eleven patients were restudied by repeat cardiac catheterization 6 months later. Student's t-test was used for comparison of data. Right ventricular (R V) systolic pressure before dilatation ranged from 84 to 180 (mean 123 ± 28.3) mmHg and the right ventricular to pulmonary artery (PA) peak systolic gradient ranged from 60 to 165 (mean 105 ± 30.2) mmHg. Immediately after dilatation, the RVsystolic pressure dropped to 30–80 (mean 53 ± 14.2) mmHg (P < 0.001). RV to PA peak systolic gradient dropped to 10–57 (mean 32 ± 14.2) mmHg (P < 0.001). A restudy of 11 patients 6 months later showed a further drop of RV systolic pressure to 35–65 (mean 49 ± 11.3) mmHg (P < 0.05). RV to PA peak systolic gradient continued to drop to 10–48 (mean 26 ± 11.3) mmHg (P < 0.01). Cardiac index improved from 2.68 ± 0.73 to 3.03 ± 0.40 L/min/m², P < 0.05. No complication was noted apart from either sinus bradycardia or extrasystole in a few patients. It was noted that balloon to annulus ratios of 1.1 to 1.4 produced sustained relief of the pulmonary valve stenosis. We concluded that PBV is the treatment of choice for congenital pulmonary stenosis. It reduced the hospital stay to 2 days and avoids the ri±k of open heart surgery. (J Interven Cardiol 1988:1:1)     

Percutaneous Mitral Commissurotomy in Acute Pulmonary Edema

From January 1994 to July 1998, percutaneous mitral commissurotomy was performed in 520 patients. Of these patients, 7 (4 men and 3 women aged 31 ± 5.6 years) were dilated in an emergency situation of intractable pulmonary edema caused by severe mitral stenosis. Three patients required mechanical ventilatory support. Percutaneous mitral commissurotomy was performed with the Inoue balloon. The dilatation of the valve was undertaken even though the echocardiographic score of the valve was high. Percutaneous mitral commissurotomy resulted in an increase in the mitral valve area from 0.72 ± 0.18 cm² to 1.95 ± 0.18 cm² (P = 0.011) with a concomitant reduction in pulmonary artery systolic pressure from 82.5 ± 16.4 mmHg to 46.7 ± 11.6 mmHg (P = 0.018). One patient died (he had two cardiac arrests before the dilatation). During follow-up (mean 18 months), one patient presented with a restenosis, one an aggravation of mitral insuflciency grade, and four were in NYHA functional Class II. Thus, percutaneous mitral commissurotomy can be considered as a treatment of choice in patients with intractable pulmonary edema caused by severe mitral stenosis.     

Effect of interferon gamma on intrahepatic haemodynamics of the cirrhotic rat liver

Sublethal injury of the liver with carbon tetrachloride (CCI₄) induces the modulation of hepatic stellate cells to their myofibroblast (MFB) phenotype. Pretreatment or concomitant treatment with interferon gamma (IFNγ) has been shown to inhibit this phenomenon. The aim of this study was to investigate the influence of IFNγ treatment (50 000 IU s.c. each day for 5 days) in rats with an established cirrhosis. Cirrhosis was induced with nine doses of CCI⁴. Comparison of biopsies before and after treatment with IFNγ showed that the number of MFB present, identified by their α-smooth muscle actin immunoreactivity, was markedly reduced. Pressure-flow curves were constructed in isolated perfused liver preparations from IFNγ-treated and saline-treated cirrhotic rats and analysed to obtain the extrapolated zero-flow intercept (P⁰, an index of hepatic vascular distensibility) and the vasodilator-induced change in resistance at a flow rate of 1 mL/min per g (ΔR₁ an indication of the level of intrinsic vascular tone). In IFNγ-treated rats, portal venous pressure measured in vivo was significantly reduced compared with controls (11.9±1.2 vs 16.0 ± 0.5 mmHg, P < 0.05), P₀ was lower (2.03 ± 0.18 vs 2.87 ± 0.32 mmHg, P < 0.05) and ΔR₁ was decreased (0.39 ± 0.15 vs 1.02 ± 0.19 mmHg/mL per min per g, P < 0.05). The findings indicate that treatment with IFNγ is effective in reducing MFB density in established CCI₄-cirrhosis in the rat and results in a marked improvement in intrahepatic haemodynamics.     

A simultaneous study of doppler-echo and catheterization in noninvasive assessment of the left ventricular dp/dt

To confirm the feasibility and accuracy of the method for the noninvasive measurement of the left ventricular dp/dt, 53 patients with mitral regurgitation underwent simultaneous determination of left ventricular dp/dt by continuous-wave Doppler echocardiography and cardiac catheterization. Doppler-determined left ventricular dp/dt is derived from the Doppler mitral regurgitant spectrum by dividing the magnitude of the left ventricular-atrial pressure gradient rise between 1 and 3 m/s of the mitral regurgitant velocity signal by the time taken for this change. Left ventricular dp/dt by Doppler ranged from 629 to 3494 mmHg/s (x? ± SD, 1971 ± 785 mmHg/s), and that by catheterization varied between 716 and 3650 mmHg/s (x? ± SD, 1974 ± 727 mmHg/s). There was a high correlation (r = 0.93, y = 0.862 × + 274.77, SEE = 271 mmHg/s, p < 0.001) of left ventricular dp/dt between the two techniques. It is concluded that left ventricular dp/dt is one of the most commonly used parameters for the evaluation of left ventricular systolic function and that Doppler echocardiography provides a new, accurate and noninvasive method of evaluation.     

Echocardiographic Contrast Enhancement of Poor or Weak Continuous-Wave Doppler Signals

Echocardiography contrast enhancement of poor continuous-wave Doppler signals was demonstrated with peripheral venous dye injections in a patient undergoing balloon pulmonary valvuloplasty. The use of intracardiac dye injections for contrast enhancement of poor or weak continuous-wave Doppler signals also was demonstrated. Simultaneous continuous-wave Doppler echocardiography, with dual-catheter measurement of the outflow tract gradient during the echocardiographic contrast injections (indocy-anine green dye and saline), confirmed the accuracy of the spectral signals obtained with contrast enhancement. These preliminary findings– that peripheral venous echocardiographic enhancement of weak or poor continuous-wave Doppler signals can provide added information for evaluation of stenotic lesions, valvular regurgitation, and ventricular septal defect–are encouraging.     

Relationships between the severity of cirrhosis and haemodynamic values in patients with cirrhosis

Abstract The relationship between the severity of cirrhosis and systemic and hepatic haemodynamic values was evaluated in 193 patients with cirrhosis, most of whom were diagnosed with post-necrotic cirrhosis. It was found that the hepatic venous pressure gradient and cardiac output in Pugh's A patients (13.6 ± 4.8 mmHg and 6.2 ± 1.6 L/min, mean ± s.d.) were significantly lower than in both Pugh's B (16.8 ± 4.3 mmHg and 7.3 ± 2.1 L/min) and Pugh's C (18.8 ± 5.5 mmHg and 7.4 ± 2.3 L/min) patients ( P < 0.01), respectively. In contrast, the systemic vascular resistance in Pugh's A patients (1232 ± 369 dyn/s per cm⁵) was significantly higher than in both Pugh's B (1016 ± 345 dyn/s per cm⁵) and Pugh's C (935 ± 234 dyn/s per cm⁵) patients ( P < 0.01), respectively. Additionally, not only was there a positive correlation found between Pugh's score and cardiac output and hepatic venous pressure gradient, but a negative correlation was found between Pugh's score and systemic vascular resistance. It was also confirmed that the degree of portal hypertension and the hyperdynamic circulation were more severe in patients with ascites than in those without ascites. However, there were no statistically significant differences in hepatic venous pressure gradient among patients with F1, F2 and F3 esophageal varices (15.7 ± 4.0, 17.0 ± 4.8 and 18.0 ± 4.8 mmHg, respectively). It is concluded that in those patients with cirrhosis, the severity of cirrhosis is closely related to the degree of the hyperkinetic circulatory state and portal hypertension.     

Electrocardiographic Changes Following Balloon Dilatation of Valvar Pulmonic Stenosis

The purpose of this paper was to study the electrocardiographic changes following balloon pulmonary valvuloplasty for pulmonic stenosis and to see if such changes reflect improvement in pulmonary valve gradient following balloon valvuloplasty. Forty-one patients, ages 7 days to 20 years, underwent balloon valvuloplasty for severe valvar pulmonic stenosis. In 35 of these patients ECGs were available 3 to 34 months (mean 11) following valvuloplasty and were compared with pre-valvu-loplasty electrocardiograms. In 30 children with excellent relief of pulmonic stenosis (group I), frontal plane mean QRS vector moved toward the left from 127 ±25° to 81 ±47°as did the horizontal plane mean QRS vector, 88 ± 36° to 27 ±51°. The amplitude of R wave in V_1, 19 ± 11.6 mm, and V₂, 19.7 ± 12.2 mm, decreased respectively to 9.5 ± 5.9 mm and 11.3 ±6.1 mm. S wave amplitude in V₅ and V₆ also decreased. The improvement in the electrocardiogram is associated with a decrease in pulmonary valve gradient from 95 ± 50 to 29 ± 23 mm Hg. In five children with significant residual pulmonary valve gradient (group II), the electrocardiograms did not show any significant change. Evaluation of the time course of ECG changes in group I revealed that recognizable electrocardiographic improvement was first observed at 6 months following successful balloon pulmonary valvuloplasty. Normal electrocardiogram suggests minimal residual pulmonary valve gradient while right ventricular hypertrophy suggests significant residual obstruction unless the electrocardiogram was recorded at or before six months following balloon valvuloplasty. These data suggest that electrocardiogram is a good indicator of improvement following balloon pulmonary valvuloplasty. (J. Interven Cardiol 1988:1:3)     

Noninvasive Estimation of Pulmonary Vascular Resistance in Pulmonary Hypertension

Background: Determination of pulmonary vascular resistance (PVR) in patients with suspected or known pulmonary hypertension (PH) requires right heart catheterization. Our purpose was to use Doppler echocardiography to estimate PVR in patients with PH. Methods: Patient population consisted of 52 patients (53 ± 12 years; 35 females) who underwent Doppler echocardiography and right heart catheterization within 24 hours of each other. The ratio of peak tricuspid regurgitation velocity (TRV) and right ventricular outflow time-velocity integral (VTI_RVOT) was measured via transthoracic echocardiography and correlated to invasively determined PVR. A linear regression equation was generated to determine PVR by echocardiography based upon the TRV/VTI_RVOT ratio. PVR by echocardiography was compared to invasive PVR using Bland-Altman analysis. Results: Significant correlation was demonstrated between TRV/VTI_RVOT and PVR by catheterization (r = 0.73; P < 0.001). However, Bland-Altman analysis showed that agreement between PVR determined by echocardiography and invasive PVR was poor (bias = 0; standard deviation = 4.3 Wood units). In a subset of patients with invasive PVR < 8 Wood units (26 patients), correlation between TRV/VTI_RVOT and invasive PVR was strong (r = 0.94; P < 0.001). In these patients, agreement between PVR by echocardiography and invasive PVR was satisfactory (bias = 0; standard deviation = 0.5 Wood units). There was no correlation between TRV/VTI_RVOT and invasive PVR in patients with PVR > 8 Wood units (n = 26; r = 0.17). Conclusion: While TRV/VTI_RVOT correlates significantly with PVR, using it to estimate PVR in a PH patient population cannot be recommended.     

Pulmonary gas exchange in the morbidly obese

The literature on pulmonary gas exchange at rest, during exercise, and with weight loss in the morbidly obese (body mass index or BMI ≥ 40 kg m⁻²) is reviewed. Forty-one studies were found (768 subjects weighted mean = 40 years old, BMI = 48 kg m⁻²). The alveolar-to-arterial oxygen partial pressure difference (AaDO₂) was large at rest in upright subjects at sea level (23, range 5–38 mmHg) while the arterial pressure of oxygen (PaO₂) was low (81, range 50–95 mmHg). Arterial pressure of carbon dioxide (PaCO₂) was normal. At peak exercise (162 W), gas exchange improves. Weight loss of 45 kg (BMI = −13 kg m⁻²) over 18 months is associated with an improvement in PaO₂ (by 10 mmHg, range 1–23 mmHg), a reduction in AaDO₂ (by 8 mmHg, range −3 to −16 mmHg), and PaCO₂ (by −3 mmHg, range 3 to −14 mmHg) at rest. Every 5–6 kg reduction in weight increases PaO₂ by 1 and reduces AaDO₂ by 1 mmHg, respectively. Morbidly obese women have better gas exchange at rest compared with morbidly obese men which is likely due to lower waist-to-hip ratios in women than from differences in weight or BMI.     

Pulmonary artery diastolic pressure: a simultaneous Doppler echocardiography and catheterization study

Pulmonary hypertension is an important determinant of the clinical presentation of and surgical approach to patients with heart disease. To confirm the utility of continuous wave Doppler echocardiography in assessing the pulmonary artery diastolic pressure in patients with pulmonary regurgitation, 51 patients representing the wide hemodynamic spectrum of pulmonary artery pressure underwent simultaneous determination of pulmonary artery diastolic pressure by continuous wave Doppler echocardiography and cardiac catheterization. Pulmonary artery diastolic pressure was estimated from the Doppler recordings by the end-diastolic pressure gradient obtained by the modified Bernoulli equation plus the estimated right atrial pressure. A correlation was observed (r = 0.935, SEE = 7.4 mmHg) between Doppler and catheterization pulmonary artery diastolic pressure. In addition, comparison between the mean diastolic pressure gradient across the pulmonary valve by Doppler and pulmonary artery diastolic pressure at catheterization yielded a high correlation (r = 0.947, SEE = 5.1 mmHg). These data demonstrate that continuous wave Doppler echocardiography is a useful noninvasive technique for evaluating the pulmonary artery diastolic pressure in patients with pulmonary regurgitation.     

Selexipag as Add-on Therapy for Patients with Pulmonary Arterial Hypertension Associated with Congenital Heart Disease: A Single-Center Retrospective Study

Purpose: This study examined the efficacy and safety of selexipag in treating pulmonary arterial hypertension (PAH) associated with congenital heart disease (CHD). Materials and Methods: We conducted a retrospective study of patients with CHD-associated PAH, treated with selexipag since December 2017. Thirteen adult patients (mean age, 45.4 years; women, 77%) were treated with selexipag as add-on therapy. Baseline characteristics, World Health Organization functional class, 6-minute walking distance (6MWD) test results, N-terminal pro-B-type natriuretic peptide levels, echocardiographic data, and incidence of side effects were assessed. Results: The majority of patients (12/13, 92.3%) experienced more than one treatment-associated complication; one patient dropped out of the study due to intolerable myalgia. The results of 6MWD test (from 299.2 ± 56.2 m to 363.8 ± 86.5 m, p = 0.039) and tricuspid regurgitation (TR) pressure gradient (from 84.7 ± 20.5 mmHg to 61.6 ± 24.0 mmHg, p = 0.018) improved and remained improved after selexipag treatment in 12 patients. Based on the results of a non-invasive risk assessment, 8 (66.7%) patients showed improvement, 3 (25.0%) showed no interval change, and the status of one patient (8.3%) deteriorated. Moreover, compared to patients treated with a low dosage, patients treated with a medium-to-high dosage showed a greater increase in 6MWD results (88.3 ± 26.4 m vs. 55.3 ± 27.6 m, p = 0.043) and a greater reduction in the TR pressure gradient (−33.7 ± 10.9 mmHg vs. −12.5 ± 12.0 mmHg, p = 0.015). Conclusion: Selexipag is an efficient pulmonary vasodilator as add-on therapy in treating CHD-associated PAH.     

Non-invasive evaluation of systolic pressure of the pulmonary artery in patients with tricuspid regurgitation, using Doppler echocardiography

STUDY OBJECTIVE: To quantify the systolic pulmonary artery pressure (SPAP) by continuous wave Doppler echocardiography and record the prevalence of tricuspid regurgitation (TR). DESIGN: Prospective analysis of 42 patients (pts), submitted to right heart catheterization (RHC). SETTING: Pts referred to the Echocardiographic Laboratory at Sta. Marta Hospital - H.C.L. PATIENTS: Sequential sample of 42 pts with several cardiac pathologies, subjected to RHC and 2D Doppler Echocardiography. INTERVENTIONS: The right ventricular and SPAP were recorded in the hemodynamic exam. We considered pulmonary hypertension (PH) if SPAP was greater than 35 mmHg or mean pressure greater than 20 mmHg. The pts were divided into two groups: I-pts without PH and II-pts with PH. The 2D Doppler echocardiography was made within 24 H of the hemodynamic one. Peak gradient (pg) of TR and the correlation with catheterization data were analysed. RESULTS: Hemodynamic--The mean SPAP in the sample was 46 +/- 21.5 mmHg (27 +/- 4.6 in group I and 55 +/- 20.2 mmHg in II). In 35 pts with TR the mean SPAP was 50.3 +/- 21.2 mmHg. Doppler--The pressure gradient was 40 +/- 18.7 mmHg. 57% pts of the group I and 96% II had TR p less than 0.001. The correlation between Doppler gradient and SPAP was r = 0.95, and no change was noted when 7 is used as a constant. CONCLUSION: Continuous wave Doppler echocardiography is a non invasive technic useful to the quantitative analysis of SPAP.     

Plasma Renin Activity and Hypertension in Acute Glomerulonephritis*

Summary: The relationship between plasma renin activity (PRA), plasma volume (PV) and mean arterial pressure (MAP) in children with acute glomerulonephritis was assessed in two groups of patients between the ages of three to six years. One group with normal blood pressure (13 children) and a group with significantly elevated blood pressure (20 children) were compared with a control group of ten normal children.
In patients who developed hypertension (MAP: 113 ± 3 mmHg), the mean PRA was 0±45 ± 0±1 ng/ml/hr, and the mean PV measured in ten of these children was 1526 ± 47±9 ml/M². In the group of normotensive patients with acute glomerulonephritis (MAP = 79 ± 1±8 mmHg), the mean PRA was 1±6 ± 0±32 ng/ml/hr, the mean PV in four of these patients was 1285±37±6 ml/M². The children in the control group (MAP = 77± 1±6 mmHg) had a mean PRA of 7±93 ± 0±2 ng/ml/hr and six of these children had a mean PV of 1115 ± 103 ml/M².
The results showed children who developed hypertension had significantly higher PV lower PRA than children with acute glomerulonephritis who were normotensive and the control subjects. A positive correlation was found between MAP and PV and negative correlation between MAP and PRA. There was no significant difference in MAP, PV and PRA between children with acute glomerulonephritis with normal blood pressure and children in the control group.     

Intraoperative Transgastric Echo Assessment During Left Ventricular Outflow Tract Surgery

Standard transesophageal echocardiography (TEE) views of the left ventricular outflow tract (LVOT) are limited by poor Doppler beam alignment with the peak velocity of flow. Transgastric imaging allows well-aligned continuous-wave Doppler interrogation of the LVOT and was attempted during intraoperative TEE in all children undergoing LVOT surgery at Children's Hospital of Wisconsin. Thirty-eight patients, ranging in age from 2 days to 18 years (median, 5.2 years) and in weight from 2.9 to 100 kg (median, 16.7 kg), had TEE during surgery to resect membranous or fibromuscular subaortic obstruction (20 patients), valvuloplasty for aortic stenosis/insufficiency (13 patients), aortoplasty for supravalvar stenosis (one patient), or repair/replacement for aortic insufficiency (four patients). In four patients, transgastric images of the LVOT could not be obtained. Intraoperative Doppler gradients identified severe residual obstruction (mean, 67 ± 13.5 mmHg) after surgery in seven patients; six of these patients underwent immediate repeat operation with subsequent adequate relief, and one patient required later aortoventriculoplasty for persistent annular/valvar obstruction. All other patients had successful LVOT reconstruction with intraoperative Doppler gradients ranging from 0 to 46 mmHg, and none required early repeat operation. Good correlation was found between the intraoperative transgastric gradient (mean, 25.8 ± 17.7 mmHg) and the early postoperative transthoracic echo gradient (mean, 21.8 ± 21.4 mmHg). In addition, there was consistent agreement in the assessment of aortic insufficiency between the transesophageal and transthoracic studies. We conclude that transgastric Doppler assessment of the LVOT is a critical component of intraoperative monitoring during LVOT surgery and is a reliable predictor of residual obstruction.     

Echocardiography during treadmill exercise testing for evaluation of pulmonary artery systolic pressure: advantages of the method

INTRODUCTION: Determination of pulmonary artery systolic pressure by Doppler echocardiography (based on the pressure gradient between the right ventricle and right atrium - DeltaP RV/RA) or by right heart catheterization is useful in evaluating the severity and prognosis of cardiac disease. The aim of the study was to evaluate DeltaP RV/RA non-invasively during treadmill exercise in patients with tricuspid regurgitation and without coronary artery disease. METHODS: Of a total of 149 patients referred to our echo laboratory, we completed the study in 142 (95%), of whom 120 were women, mean age 52+/-13 years (23 to 82). We studied 68 patients with valvular heart disease (of whom 56 had mitral valve stenosis and sinus rhythm on ECG), 42 with systemic sclerosis, 10 with severe pulmonary hypertension, 12 with a history of pulmonary embolism and 10 healthy controls. The DeltaP RV/RA was determined from the tricuspid regurgitation jet using continuous wave Doppler in left lateral decubitus (LLD) before exercise testing (BLLD), in a standing position (SP), at peak workload (PW) before termination of the test, and in the first 60 seconds of the recovery period in LLD (RLLD). RESULTS: The DeltaP RV/RA in BLLD was 36+/-21 mmHg (range 18 to 147); the SP [symbol: see text]P RV/RA was 32+/-24 mmHg (range 12 to 137), p<0.001 vs. BLLD DeltaP RV/RA; the PW DeltaP RV/RA was 58+/-26 mmHg (range 28 to 177), p<0.0001 vs. SP DeltaP RV/RA; and the RLLD DeltaP RV/RA was 47+/-25 mmHg (range 20 to 152), p<0.001 vs. PW DeltaP RV/RA. The differences between PW DeltaP RV/RA and RLLD DeltaP RV/RA changed therapeutic decisions in 10 patients (18%) with mitral stenosis, and modified the management of 13 patients (30%) with systemic sclerosis (who then underwent right heart catheterization). CONCLUSIONS: Echocardiography during treadmill exercise testing was feasible in most patients. The DeltaP RV/RA decreases in response to the standing position. The DeltaP RV/RA rises considerably with exercise in the majority of patients and is significantly higher at peak workload than in the recovery period. The differences between PW DeltaP RV/RA and RLLD DeltaP RV/RA influenced patient management.     

Diastolic blood pressure-estimated left ventricular dp/dt

BACKGROUND: Peak dp/dt is one of the best isovolumic phase indexes of the myocardial contractile state requiring invasive procedures or presence of mitral regurgitation severe enough to measure in clinical practice by Doppler echocardiography. In this study, we sought the correlation between two noninvasive methods of measurements for left ventricular dp/dt-diastolic blood pressure- (DBP) estimated and continuous-wave Doppler-derived dp/dt-min electrocardiographic/echocardiographic study to emphasize the clinical feasibility of the DBP-estimated method. METHOD: Thirty-six randomized patients (27 male, 9 female; 58 +/- 8 years) with mild mitral regurgitation were enrolled in this study. DBP-estimated dp/dt was calculated from DBP minus the left ventricular end-diastolic pressure (LVEDP) over the isovolumetric contraction time (IVCT). LVEDP was assumed to be 10 mmHg for all patients. Doppler-determined left ventricular dp/dt was derived from the continuous-wave Doppler spectrum of mitral regurgitation jet by dividing the magnitude of the left ventricular atrial pressure gradient rise between 1 mm/sec-3 mm/sec of mitral regurgitant velocity signal by the time taken for this change. RESULTS: Left ventricular dp/dt by Doppler was 1122 +/- 303 mmHg/sec and blood pressure-estimated dp/dt was 1063 +/- 294 mmHg/sec. There was a high correlation (r = 0.97, P < 0.001) of dp/dt between the two techniques. CONCLUSIONS: DBP and IVCT can generate left ventricular dp/dt without invasive procedures, even in the absence of mitral regurgitation in clinical practice.