Serial semi-invasive hemodynamic assessment following pericardiectomy for chronic constrictive pericarditis.

OBJECTIVES: This study was designed to prospectively investigate the effects of pericardiectomy via median sternotomy on intra- and postoperative hemodynamics by a new semi-invasive device (Flotrac/VigileoTM monitor) using arterial pressure waveform analysis. PATIENTS AND METHODS: Thirty consecutive patients aged 15 to 55 years (mean+SD, 31.73 + 13.53 years), who had undergone total pericardiectomy via median sternotomy underwent serial hemodynamic evaluation. FlotracTM Sensor - derived stroke volume, stroke volume variation, systemic vascular resistance index (SVRI), cardiac index and right atrial pressure were measured just before and after pericardiectomy, at 12 hours, 24 hours, 48 hours, 72 hours and at discharge postoperatively. RESULTS: Majority of patients (73.33%) exhibited statistically significant reduction of right atrial pressure and SVRI along with improvement in cardiac index and oxygen delivery in the immediate and late postoperative period. However, the stroke volume and stroke volume variation did not increase proportionately on completion of surgery. Patients with low cardiac output syndrome exhibited persistently high central venous pressure with reduced cardiac index and echocardiographically abnormal diastolic filling characteristics. CONCLUSIONS: We conclude that there is early normalization of hemodynamics following pericardiectomy via median sternotomy and the adequacy of pericardiectomy can be accurately assessed by the new semi-invasive arterial pressure waveform analysis device. Stroke volume variation is a non-predictor of fluid requirement during and after pericardiectomy.

Echocardiography in the Assessment of Left Atrial Pressure After Pediatric Heart Surgery: A Comparison Study With Measurements Obtained From Left Atrial Catheter.

BACKGROUND: Correlation between ventricular end-diastolic pressure and pulsed Doppler and tissue Doppler-derived E/e' ratio has been widely reported in adults but scarcely studied in children with congenital heart diseases. This ratio is defined as the relationship between diastolic transmitral flow velocity (cm/s; E) and myocardial diastolic relaxation velocity (cm/s; e') in the lateral aspect of the mitral annulus. Our main objective was to ascertain whether a correlation existed between direct measurement of left atrial pressure and echocardiographic E/e' ratio in children after heart surgery. METHODS: Prospective study including 27 consecutive children after pediatric heart surgery. Data were analyzed according to whether they were obtained within the first 72 hours following surgery or later on. Sensitivity, specificity, positive and negative predictive values, and areas under the receiver-operating characteristics curve of E/e' ratio in detection of left atrial pressure values ≥13 mm Hg were evaluated. RESULTS: Forty-eight studies were conducted in 27 patients. Thirty-two studies were performed during the first 72 hours after heart surgery and 16 beyond the third day. Median patient age was 0.82 years (5 days-16 years). Median left atrial pressure values and E/e' measurements of the whole cohort (N = 48) were 12.0 and 10.2, respectively. Intraclass correlation index between left atrial pressure values and echocardiographic E/e' ratio was 0.35, 0.25 for studies performed within 72 hours, but 0.78 (P < .01) for those performed later. There was also a high positive predictive value, since in 13 (87%) of 15 studies with an E/e' ratio ≥13, the left atrial pressure was ≥13 mm Hg. CONCLUSION: While echocardiographic E/e' ratio did not show a good correlation with left atrial pressure in the immediate postoperative period, the positive predictive value may suffice to aid clinicians in predicting elevated pressures.

Assessment of left sided filling dynamics in diastolic dysfunction using cardiac computed tomography.

BACKGROUND: Left ventricular (LV) diastolic dysfunction (DD) often accompanies coronary artery disease but is difficult to assess since it involves a complex interaction between LV filling and left atrial (LA) emptying. OBJECTIVE: To characterize simultaneous changes in LA and LV volumes using cardiac computed tomography (CT) in a group of patients with various grades of DD based on echocardiography. METHODS: We identified 35 patients with DD by echocardiography, who had also undergone cardiac CT, and 35 age-matched normal controls. LV and LA volumes were measured every 10% of the RR interval, using semi-automatic software. From these, - systolic, early-diastolic and late-diastolic volume changes were calculated, and additional parameters of diastolic filling derived. Conduit volume was defined as the difference between the LV and LA early-diastolic volume change. RESULTS: Patients with DD had significantly larger LV mass, and LA volumes, reduced early emptying volumes and increased conduit volume as percent of early LV filling (All p<0.001). LA function, manifesting as total emptying fraction (LATEF), decreased proportionately with worsening grades of DD (p<0.001). LA contractile function was maintained until advanced grade-3 DD. By receiver operating characteristic analysis, LATEF had an AUC of 0.88 to separate between normals and DD. At a threshold of <42.5%, LATEF has 97% sensitivity and 69% specificity to detect DD. CONCLUSIONS: DD is characterized by reduced LA function and an alteration in the relative contributions of the atrial emptying and conduit volume components of early LV filling. In patients undergoing cardiac CT, it is possible to identify the presence and severity of DD.

Echocardiographic assessment of estimated right atrial pressure and size predicts mortality in pulmonary arterial hypertension.

BACKGROUND: Elevated mean right atrial pressure (RAP) measured by cardiac catheterization is an independent risk factor for mortality. Prior studies have demonstrated a modest correlation with invasive and noninvasive echocardiographic RAP, but the prognostic impact of estimated right atrial pressure (eRAP) has not been previously evaluated in patients with pulmonary arterial hypertension (PAH). METHODS: A retrospective analysis of 121 consecutive patients with PAH based on right-sided heart catheterization and echocardiography was performed. The eRAP was calculated by inferior vena cava diameter and collapse using 2005 and 2010 American Society of Echocardiography (ASE) definitions. Accuracy and correlation of eRAP to RAP was assessed. Kaplan-Meier survival analysis by eRAP, right atrial area, and Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL Registry) risk criteria as well as univariate and multivariate analysis of echocardiographic findings was performed. RESULTS: Elevation of eRAP was associated with decreased survival time compared with lower eRAP (P < .001, relative risk = 7.94 for eRAP > 15 mm Hg vs eRAP ≤ 5 mm Hg). Univariate analysis of echocardiographic parameters including eRAP > 15 mm Hg, right atrial area > 18 cm², presence of pericardial effusion, right ventricular fractional area change < 35%, and at least moderate tricuspid regurgitation was predictive of poor survival. However, multivariate analysis revealed that eRAP > 15 mm Hg was the only echocardiographic risk factor that was predictive of mortality (hazard ratio = 2.28, P = .037). CONCLUSIONS: Elevation of eRAP by echocardiography at baseline assessment was strongly associated with increased risk of death or transplant in patients with PAH. This measurement may represent an important prognostic component in the comprehensive echocardiographic evaluation of PAH.

Bedside assessment of right atrial pressure in critically ill septic patients using tissue Doppler ultrasonography.

PURPOSE: Right atrial pressure (RAP) is considered a surrogate for right ventricular filling pressure or cardiac preload. It is an important parameter for fluid management in patients with septic shock. It is commonly approximated by the central venous pressure (CVP) either invasively using a catheter placed in the superior vena cava or by bedside ultrasound, in which the size and respiratory variations of the inferior vena cava (IVC) are measured from the subcostal view. Doppler imaging of the tricuspid valve from the apical 4-chamber view has been proposed as an alternative approach for the estimation of RAP. The tricuspid E/Ea ratio is measured, where E is the peak velocity of the early diastolic tricuspid inflow and Ea is the peak velocity of the early diastolic relaxation of the lateral tricuspid annulus. We hypothesized that the tricuspid E/Ea ratio may represent an alternative to IVC metrics, using invasive CVP as the criterion standard, for the assessment of RAP in critically ill septic patients. MATERIALS AND METHODS: A convenience sample of 30 septic patients, both mechanically ventilated and non-mechanically ventilated, was enrolled. Using a portable ultrasound system, maximum velocity of tricuspid E and Ea was measured from the apical 4-chamber view; and IVC diameter and degree of collapse were measured from the subcostal view. Decision tree induction was used to determine the performance of each model compared with invasive CVP. RESULTS: Our results suggest that a tricuspid E/Ea ratio of greater than 4.7 can predict a CVP greater than 10 mm Hg in septic patients with sensitivity greater than 85% and specificity greater than 90%. CONCLUSIONS: In this pilot study, Doppler imaging of the tricuspid valve provided a valuable alternative for noninvasive bedside estimation of RAP in septic patients.