Transesophageal echocardiographic assessment of pulmonary veins and left atrium in patients undergoing atrial fibrillation ablation

Background: Pulmonary vein (PV) antrum isolation with ganglionated plexi (GP) ablation is a novel atrial fibrillation (AF) ablation technique. The aim of this study was to evaluate acute changes in left atrial and PV flow velocities following PV antrum isolation with GP ablation using transesophageal echocardiography (TEE). Methods: TEE was performed before and after PV antrum isolation with GP ablation in 88 consecutive patients. All four PVs, when possible, were analyzed with regard to peak systolic and diastolic pulsed‐wave Doppler flow velocities. Left atrial appendage emptying velocities were also obtained. PV stenosis was defined as a peak PV Doppler flow velocity of ≥110 cm/sec with spectral broadening (turbulence). Results: All but four right inferior and four left inferior PVs were visualized. Compared to preablation values, both PV systolic and diastolic velocities increased after ablation (P < 0.05 for each of the four PVs). However, the systolic to diastolic ratio decreased significantly after ablation in all PVs (1.3 ± 0.6 to 0.9 ± 0.4, P < 0.0001, 1.2 ± 0.7 to 0.9 ± 0.4, P < 0.0001, 1.2 ± 0.6 to 1.0 ± 0.6, P = 0.035 and 1.1 ± 0.5 to 0.9 ± 0.5, P = 0.0001, for left superior, left inferior, right superior and right inferior PV, respectively). Left atrial appendage emptying velocities showed a trend towards higher values following ablation (62.7 ± 26.1 cm/sec vs. 67.5 ± 23.2 cm/sec, P = 0.07). Asymptomatic PV stenosis occurred in seven patients (seven PVs). Conclusions: PV antrum isolation with GP ablation acutely increased PV flow velocities and altered the pattern of PV Doppler flow signal, likely correlating with increased left atrial pressures, but did not appear to adversely impact on left atrial appendage physiology. (Echocardiography 2011;28:775‐781)     

Hemodynamic Determinants of Doppler Pulmonary Venous Flow Velocity Components: New Insights From Studies in Lightly Sedated Normal Dogs

Objectives. We sought to define the hemodynamic determinants of pulmonary venous (PV) flow velocities to assess how these are affected by respiration, heart rate and loading conditions.Background. Pulmonary venous flow velocity (PVFV) recorded with pulsed wave Doppler technique is currently used in the noninvasive evaluation of left ventricular (LV) diastolic function and filling pressures. Although previous studies in both animals and humans have shown that PV flow is pulsatile, the hemodynamic determinants of the individual components of this flow remain controversial. Understanding the physiologic mechanisms should help to better define the clinical utility of these Doppler techniques.Methods. PV flow velocities obtained with transesophageal pulsed wave Doppler imaging were recorded together with PV, left atrial (LA) and LV pressures in 10 sedated, spontaneously breathing normal dogs. PVFV and hemodynamic data were analyzed during apnea, inspiration and expiration, at atrial paced heart rates of 60, 80, 100 and 120 beats/min and mean LA pressures of 6, 12, 18 and 24 mm Hg.Results. The data showed that 1) PV pressure varied depending on recording site, resembling pulmonary artery pressure closer to the pulmonary capillary bed and LA pressure closer to the venoatrial junction; 2) PVFV qualitatively followed changes in the PV–LA pressure gradient; 3) four PVFV components exist under normal conditions—three of which follow phasic changes in LA pressure and one of which (the late systolic component) is more influenced by RV stroke volume and the compliance of the pulmonary veins and left atrium; 4) normal respiration and changes in heart rate significantly alter PVFV variables—in particular, reverse flow velocity at atrial contraction; and 5) increasing LA pressure results in larger PV A wave and PV early systolic flow velocities, as well as an earlier peak in PV late systolic flow velocity and a more prominent velocity minimum before PV diastolic flow.Conclusions. Using transesophageal pulsed wave Doppler technique, four PVFV components are identifiable and determined by PV–LA hemodynamic pressure gradients. These gradients appear to be influenced by a combination of physiologic events that include RV stroke volume, the compliance of the pulmonary vasculature and left atrium and phasic changes in LA pressure. PV flow velocity components are significantly influenced by heart rate, respiration and LA pressure. These findings have implications for the interpretation of LV diastolic function and filling pressures by current Doppler echocardiographic techniques but require further clinical investigation.     

Assessment of pulmonary blood flow after total cavopulmonary shunt operation and the modified Fontan procedure for univentricular heart

Pulsed Doppler echocardiography was utilized to elucidate the characteristics of pulmonary arterial (PA) blood flow in five patients without apparent pumping chambers in their right heart circulation after right heart bypass surgery for univentricular heart. Two of these patients underwent total cavopulmonary shunt operation, in which the total systemic venous return drained directly into the PA, bypassing the right atrium and ventricle. Three underwent the modified Fontan procedure with atrial partition, in which the right-sided atrium was reconstructed merely as a pathway from the vena cava to the PA, and atrial contraction was nearly entirely excluded. The flow pattern in the PA was biphasic and forward in all five patients. Pulmonary regurgitation was not observed in any of the patients. The first phase of PA flow had its peak during atrial systole; the second, during ventricular systole. Simultaneous observation of PA flow and pressures demonstrated an inverse relation between PA flow and pressure. Pulmonary venous (PV) blood flow pattern was also biphasic and similar to the PA blood flow pattern with time lags. In conclusion, in cases without pumping right heart chambers, PA flow reflects PV flow resulting from contraction and relaxation of the left atrium and ventricle.     

Phased-Array intracardiac echocardiography to guide radiofrequency ablation in the left atrium and at the pulmonary vein ostium

INTRODUCTION: We sought to evaluate the utility of a phased-array intracardiac echocardiography (ICE) device to identify left atrial (LA) and pulmonary vein (PV) anatomy; accurately guide radiofrequency ablation (RFA) to the right or left PV ostium and LA appendage (LAA); and evaluate PV blood flow before and after RFA using Doppler parameters. METHODS AND RESULTS: Twelve adult sheep were anesthetized and an Acuson 10-French, 7-MHz ICE transducer introduced via the internal jugular vein into the right atrium. The LA was imaged and PV anatomy and blood flow documented using two-dimensional and pulsed-wave Doppler. Mean LA dimensions were 4.6 +/- 0.4 x 3.5 +/- 0.5 cm; mean single right and left main PV ostium diameters were 1.5 +/- 0.2 and 1.3 +/- 0.3 cm; and mean right and left PV first-order branch diameters were 0.8 +/-0.2 and 0.6 +/- 0.1 cm. Mean PV maximum inflow velocity for the right PV were 0.30 +/- 0.05 m/sec and for the left PV were 0.35 +/- 0.04 m/sec. The PV ostia and LAA could be targeted accurately for RFA using ICE guidance. At pathologic evaluation, the mean distance of the lesion center to the right or left PV-LA junction was 3.0 +/- 2.0 mm. The mean distance of the lesion center to the posterior margin of the LAA was <4 mm in all cases. There was no significant increase in PV maximum inflow velocity or decrease in PV diameter following RFA at the PV ostium. Absence of PV obstruction was confirmed at pathology. CONCLUSION: Phased-array ICE allows detailed assessment of LA and PV anatomy when imaged from the right atrium; accurate guidance of RFA to the PV ostium and LAA; and immediate evaluation of PV patency after RFA.     

The influence of atrioventricular asynchronous contraction on left and right ventricular performance]

To investigate the influence of atrioventricular asynchronous contraction on left and right ventricular performance, pulsed Doppler echocardiographic studies were performed in 10 patients who received permanent pacemaker (VVI mode), but without significant heart disease except for complete heart block. After setting the pacing rate at 40 per min, the performance was analyzed during the patient's own slow ventricular rate. Flow velocity patterns at the left (LVOT) and right ventricular outflow tracts (RVOT) were recorded by pulsed Doppler echocardiography, and ejection time (EjT), acceleration time (AcT), peak velocity (PV) and flow velocity integral (FVI), which is proportional to stroke volume, were measured for each outflow tract. When the patient's own atrial contraction occurred during ventricular systole, EjT, AcT, PV and FVI of flow at the LVOT and EjT, AcT and FVI of flow at the RVOT were decreased. Percent change of the FVI of flow at the RVOT (-34.6%) was significantly greater than that of flow at the LVOT (-16.2%, p < 0.01). These results indicate that the loss of right ventricular performance might play a prominent role in the genesis of the hemodynamic deterioration with atrioventricular asynchronous contraction.     

Assessment of left atrial input impedance in normal subjects and in hypertensive patients

BACKGROUND: To assess left atrial (LA) input impedance in patients with signs and/or symptoms of heart failure and normal left ventricular ejection fraction, transesophageal Doppler pulmonary venous (PV) flow velocity and pulmonary capillary wedge pressure (PCWP) were studied in 20 patients and compared to 20 matched normal controls. METHODS: LA impedance was calculated as the ratio of harmonic terms of the PCWP (measured by right heart catheterization) to the corresponding harmonic terms of PV flow (measured by transesophageal Doppler echocardiography). Eight harmonics were analyzed. RESULTS: Left ventricular mass index (LVMI, p<0.001), heart rate (p<0.05), systolic and diastolic blood pressure (p<0.001), isovolumic relaxation time (IVRT, p<0.001), peak A transmitral flow velocity (p<0.001), peak reversal atrial PV flow velocity (p<0.001) and LA diameter (p<0.001) were increased in patients compared to controls. Spectra of impedance moduli were displaced upwards and to the right. The increase in the impedance moduli was observed at all frequencies of the first to seventh harmonic components (p<0.001). In multivariate tests LVMI (p=0.003), IVRT (p=0.001), and LA diameter (p=0.007) had a significant effect on all harmonic components of the impedance moduli (adjusted R2=0.970 to 0.999, p<0.001). CONCLUSIONS: LA input impedance derived from data obtained invasively and semi-invasively represents left ventricular diastolic function. Resistance to left ventricular filling is increased in hypertensive patients.     

Uses and limitations of transthoracic echocardiography in the assessment of atrial septal defect in the adult

Two-dimensional and color Doppler echocardiography accurately detected the presence of an atrial septal defect (ASD) in 47 of 50 adults (mean age 40 years) confirmed by surgery or cardiac catheterization, or both. It correctly categorized all patients with ostium secundum and ostium primum ASD but misdiagnosed 3 of 5 patients with surgically proven sinus venosus ASD. The shunt flow volume across the ASD was calculated with the standard Doppler equation, and assuming the ASD to be circular correlated with shunt flow volume obtained by cardiac catheterization (r = 0.74). The maximum width of the color flow signals moving across the ASD was taken as its diameter. Mean flow velocity was determined either by placing a pulsed Doppler sample volume parallel to the flow across the ASD as visualized by color Doppler or by color M-mode examination, which allowed determination of flow velocities using a previously validated method that incorporates a computer analysis of pixel color intensity. The pulmonary to systemic blood flow ratio obtained by color-guided conventional Doppler interrogation of the left and right ventricular outflow tracts correlated poorly with cardiac catheterization results (r = 0.38). In patients with associated tricuspid regurgitation, the peak systolic pulmonary artery pressure obtained by color Doppler-guided continuous-wave Doppler correlated well with that obtained at cardiac catheterization (r = 0.89). The maximum color Doppler jet width of the flow across the ASD poorly correlated with ASD size estimated at surgery (r = 0.50).     

Left ventricular filling characteristics in pulmonary hypertension: a new mode of ventricular interaction.

OBJECTIVE--To examine the effects of pulmonary hypertension on left ventricular diastolic function and to relate the findings to possible mechanisms of interdependence between the right and left sides of the heart in ventricular disease. DESIGN--A retrospective and prospective analysis of echocardiographic and Doppler studies. SETTING--A tertiary referral centre for both cardiac and pulmonary disease. PATIENTS--29 patients with pulmonary hypertension (12 primary pulmonary hypertension, 10 pulmonary fibrosis, five atrial septal defect (ASD), and two scleroderma) were compared with a control group of 10 patients with an enlarged right ventricle but normal pulmonary artery pressure (six ASD, one after ASD closure, one ASD and pulmonary valvotomy, one tricuspid valve endocarditis and repair, and one pulmonary fibrosis). None had clinical or echocardiographic evidence of intrinsic left ventricular disease. MAIN OUTCOME MEASURES--M mode echocardiographic measurements were made of septal thickness, and left and right ventricular internal cavity dimensions. Doppler derived right ventricular to right atrial pressure drop, and time intervals were measured, as were isovolumic relaxation time, and Doppler left ventricular filling characteristics. RESULTS--The peak right ventricular to right atrial pressure gradient was (mean (SD)) 60 (16) mm Hg in pulmonary hypertensive patients, and 18 (5) mm Hg in controls. The time intervals P2 to the end of the tricuspid regurgitation, and P2 to the start of tricuspid flow were both prolonged in patients with pulmonary hypertension compared with controls (115 (60) and 120 (40) v 40 (15) and 45 (10) ms, p values less than 0.001). Pulmonary hypertensive patients commonly had a dominant A wave on the transmitral Doppler (23/29); however, all the controls had a dominant E wave. Isovolumic relaxation time of the left ventricle was prolonged in pulmonary hypertensive patients compared with controls, measured as both A2 to mitral valve opening (80 (25) v 50 (15) ms) and as A2 to the start of mitral flow (105 (30) v 60 (15) ms, p values less than 0.001). The delay from mitral valve opening to the start of transmitral flow was longer in patients with pulmonary hypertension (30 (15) ms) compared with controls (10 (10) ms, p less than 0.001). At the time of mitral opening there was a right ventricular to right atrial gradient of 12 (10) mm Hg in pulmonary hypertensive patients, but this was negligible in controls (0.4 (0.3) mm Hg, p less than 0.001). CONCLUSIONS--Prolonged decline of right ventricular tension, the direct result of severe pulmonary hypertension, may appear as prolonged tricuspid regurgitation. It persists until after mitral valve opening on the left side of the heart, where events during isovolumic relaxation are disorganised, and subsequent filling is impaired. These effects are likely to be mediated through the interventricular septum, and this right-left ventricular asynchrony may represent a hitherto unrecognised mode of ventricular interaction.     

Echocardiographic Diagnosis and Transcatheter Occlusion of Pulmonary Arteriovenous Fistula in Cyanotic Newborn

Pulmonary arteriovenous malformation (PAVM) is a rare cause of cyanosis in newborn. A 12‐day‐old male newborn (2.8 kg) was referred to our hospital with the complaints of cyanosis and respiratory distress. On two‐dimensional echocardiography, the right pulmonary artery (PA) appeared larger than left PA and the left atrium, left ventricle were dilated. The right heart chambers were in normal limits. A color flow Doppler echocardiogram revealed a turbulent flow due to a PAVM originating from medium branch of right PA, and continuous wave Doppler showed continuous flow pattern. Agitated saline injection resulted in the delayed appearance of the contrast in the left‐side chambers three to four heart cycles after appearance in the right‐side chambers; the study was considered positive and indicative of an intrapulmonary shunt. Selective angiography of the right PA confirmed the diagnosis of a large solitary PAVM in the right middle lobe with a feeding artery. Amplatzer vascular plug I, which is designed to close abnormal vascular structures, was chosen to close the PAVM. The deployment of device performed safely and the oxygen saturation of baby increased to 95% immediately after deployment. Heart failure and respiratory distress also resolved after the procedure.     

Two cases of atrial septal defect diagnosed by two-dimensional Doppler echocardiography: comparison with other methods for detecting atrial septal defect]

We describe two cases of atrial septal defect(ASD) diagnosed by chance with two-dimensional Doppler echocardiography(2DD) which was carried out for another purpose. There were no findings characteristic of ASD such as systolic murmurs in the pulmonary area, incomplete right bundle branch block pattern on electrocardiograms, increased hilar shadow on chest films or increased right ventricular chamber diameter in two-dimensional echocardiography. However, the 2DD showed blood flow crossing through the atrial septum. Cardiac catheterization confirmed the presence of a small ASD. ASD diagnosed by 2DD alone without other classical characteristic signs of ASD indicates that the ASD is small and clinically insignificant as it is with Doppler valvular heart disease.     

Diagnosis of constrictive pericarditis and restrictive cardiomyopathy by pulsed Doppler echocardiography

Characteristics of flow through atrioventricular valves were analyzed by pulsed Doppler echocardiography (PDE) in 7 patients with either constrictive pericarditis or restrictive cardiomyopathy and 10 controls to determine the value of this technique in their differentiation. All patients were admitted with systemic venous congestion and underwent right and left heart catheterization. PDE variables considered included peak flow velocity (PV), acceleration time, peak velocity of the atrial component (PVA), PVA/PV quotient, duration of early diastolic fillings, deceleration of early diastolic filling, duration of diastolic flow and mean temporal velocity. Ventricular filling differed between patients and controls in that the former group was characterized by higher PV's, lower PVA's, higher deceleration and lower PVA/PV quotient. When we compared both patient groups we found a significant tendency toward higher PV's, faster deceleration and lower PVA/PV quotient in constrictive pericarditis.     

Aortopulmonary Artery Fistula: Ruptured Aneurysm of the Distal Aortic Arch into the Pulmonary Artery

Aortopulmonary artery fistula is uncommon, but the clinical outcome is often lethal. A 76‐year‐old man with a history of acute thoracic aortic dissection 6 years previously was admitted with dyspnea. A chest x‐ray showed pleural effusion and pulmonary congestion. Transthoracic echocardiography revealed preserved systolic function, but continuous and abnormal flow from the distal aortic arch into the pulmonary artery (PA). Transesophageal echocardiography (TEE) in the Doppler color‐flow mode demonstrated a left‐to‐right shunt between a large distal aortic arch aneurysm and the left PA via an aortopulmonary fistula and a pressure gradient across the shunt of 56 mmHg. Contrast‐enhanced computed tomography showed that the aneurysm compressed the PA. Aortography also revealed a large distal aortic arch aneurysm and almost simultaneous contrast enhancement of the aorta and the PA. Right‐heart catheterization showed a significant increase in oxygen saturation between the right ventricle and the PA. A left‐to‐right shunt due to a distal aortic arch aneurysm rupturing into the left PA was diagnosed based on these findings. TEE was very helpful in confirming the presence and precise location of the fistula.     

Incidence and Predictors of Atrial Septal Defect after Percutaneous Transvenous Mitral Commissurotomy – A Transesophageal Echocardiographic Study of 209 Cases

Background: The incidence of atrial septal defect (ASD) after percutaneous transvenous mitral commissurotomy (PTMC) ranges from 15.2% to 92% in small studies. Aim: To estimate the incidence of atrial septal defect (ASD) following PTMC and to determine the factors contributing to its development. Methods: We studied 209 patients with mitral stenosis (MS) undergoing PTMC. Transesophageal echocardiography (TEE) with color Doppler examination was performed to detect ASD. Results: TEE demonstrated ASD in 139 (66.5%) of 209 patients. The mean diameter of the interatrial septal defect detected by TEE was 4.47 ± 1.7 mm. The most common site of septal puncture was the inferior vena caval side of the interatrial septum followed by fossa ovalis. Color flow imaging across the defect showed left to right shunting in all the patients (100%). We examined the relationship of age, Wilkins score, left atrial volumes, the mitral valve orifice area, mitral valve gradient, and the degree of mitral and tricuspid regurgitation between the group that developed ASD and the group without ASD and found that none of these factors predicted the development of ASD. A residual ASD was seen in 11 patients (8.7%) at 6‐month follow‐up. Conclusion: Incidence of residual atrial septal defect immediately following PTMC by TEE color flow Doppler imaging is 66.5%. Surrogate markers of elevated left atrial pressures do not determine the development of atrial septal defect after PTMC. The majority of the defects close spontaneously and a residual defect is observed in 8.7% patients at 6 months.     

Left atrial thrombus causing pulmonary embolism by passing through an atrial septal defect.

A 66-year-old woman admitted with dyspnea on exertion had atrial fibrillation and left ventricular dysfunction. Echocardiography revealed an atrial septal defect (ASD) and a soft, easily deformable thrombus in the dilated left atrium. The atrial mass suddenly disappeared on the 10th day after admission, and contrast-enhanced chest computed tomography and pulmonary blood flow scintigraphy showed that the thrombus had detached from the left atrium, floated into the right atrium through the ASD and caused pulmonary embolism. This is the first documented case of a left atrial thrombus causing pulmonary embolism by passing through an ASD. When an ASD is present, it is important to consider not only paradoxical thromboembolism (from the right to the left atrium), but also pulmonary embolism caused by thromboembolism from the left to the right atrium.     

Contrast Doppler echocardiography

First clinical experiences with contrast Doppler echocardiography -- a new technique of cardiac ultrasound examination are described. The presence of contrast material within the right heart cavities following the peripheral vein injection is easily recognized by characteristic Doppler signal changes. This knowledge was used to detect a small amount of contrast passing through atrial (ASD) or ventricular septal defect (VSD) towards the left heart cavities despite the dominant left-to-right shunting. The high sensitivity of this technique in those conditions was attested to by correct diagnosis of 10 ASD and 3 VSD. Besides that, this technique is indicated also in selected cases of tricuspid regurgitation. The combination of both pulsed Doppler and contrast echo-investigation seems to be advantageous in the diagnosis of the mentioned diseases. However, further study of this very specialized method is required.     

Left and right atrial myocardial deformation properties in patients with an atrial septal defect

Background: Atrial septal defect (ASD) is a common form of congenital heart defect in adults, which affects all cardiac chambers. Atrial myocardial function in patients with ASD has not yet been clearly elucidated. The aim of this study was to investigate atrial myocardial deformation properties in patients with ASDs. Methods: The study involved 24 patients with a secundum type ASD, and 22 healthy subjects. Color Doppler myocardial imaging was used to measure left and right atrial myocardial systolic strain and strain rate values, together with peak systolic velocity, early velocity, and late diastolic velocity. Results: There was no significant difference between the two groups with regard to age, gender, body mass index, heart rate, blood pressure, left atrial diameter, and ventricular function. The peak systolic atrial myocardial strain and strain rate values in each of the atrial walls studied were lower in the ASD group compared to those of the control group, but the difference reached statistical significance only in the case of the right atrial wall (right atrial strain: 48.0 ± 32.7% vs 100.2 ± 46.6%, P = 0.006; right atrial strain rate: 2.6 ± 1.2/sec vs 3.8 ± 1.2/sec, P = 0.024). Conclusion: The left to right cardiac shunt that results from ASD leads to a reduction in the right atrial myocardial longitudinal lengthening that occurs during ventricular ejection. These findings demonstrate that the reservoir function of the atrium is impaired and atrial stiffness increases in patients with ASDs.     

Acquired pulmonary vein stenosis after radiofrequency catheter ablation of paroxysmal atrial fibrillation

INTRODUCTION: Elimination of the initiating focus within the pulmonary vein (PV) using radiofrequency (RF) catheter ablation is a new treatment modality for treatment of drug-refractory atrial fibrillation. However, information on the long-term safety of RF ablation within the PV is limited. METHODS AND RESULTS: In 102 patients with drug-refractory atrial fibrillation and at least one initiating focus from the PV, series transesophageal echocardiography was performed to monitor the effect of RF ablation on the PV. There were 66 foci in the right upper PV and 65 foci in the left upper PV. Within 3 days of ablation, 26 of the ablated right upper PVs (39%) had increased peak Doppler flow velocity (mean 130+/-28 cm/sec, range 106 to 220), and 15 of the ablated left upper PVs (23%) had increased peak Doppler flow velocity (mean 140+/-39 cm/sec, range 105 to 219). Seven patients had increased peak Doppler flow velocity in both upper PVs. No factor (including age, sex, site of ablation, number of RF pulses, pulse duration, and temperature) could predict PV stenosis after RF ablation. Three patients with stenosis of both upper PVs experienced mild dyspnea on exertion, but only one had mild increase of pulmonary pressure. There was no significant change of peak and mean flow velocity and of PV diameter in sequential follow-up studies up to 16 (209+/-94 days) months. CONCLUSION: Focal PV stenosis is observed frequently after RF catheter ablation applied within the vein, but usually is without clinical significance. However, ablation within multiple PVs might cause pulmonary hypertension and should be considered a limiting factor in this procedure.     

Association of plasma B-type natriuretic peptide levels with shunt size in young adults with atrial septal defect

Objective: This study was designed to investigate the validity of brain natriuretic peptide (BNP) levels for the estimation of the shunt size in young adults with atrial septal defect (ASD), and to determine the relationship between BNP levels and echocardiographic parameters of right heart chambers. Methods: Fifty‐six patients with ASD (mean age 22.9 ± 2.0 years) were studied. The control group consisted of 31 age‐gender matched healthy volunteers (mean age 22.7 ± 1.9 years). Coventional echocardiography, tissue Doppler imaging (TDI) and plasma BNP level measurement was performed in all participants. The ratio of pulmonary to systemic blood flow (Qp/Qs) was measured noninvasively using transthoracic echocardiography. Results: Plasma BNP levels were significantly higher in ASD patients than in controls (42.9 ± 29.4 vs. 8.3 ± 2.6 pg/mL, P < 0.05). Pulmonary artery pressure (PAP) (P = 0.0001), right atrium (RA) volume (P = 0.0001), and right ventricular end‐diastolic volume (RVEDV) (P = 0.0001) values were higher in ASD patients. There was a powerful correlation between plasma BNP levels and Qp/Qs ratio (r = 0.71, P < 0.0001). The plasma BNP levels significantly correlated with PAP (r = 0.61, P < 0.0001), RA volume (r = 0.54, P < 0.0001), RVEDV (r = 0.55, P < 0.0001), and right ventricular myocardial performance index (r = 0.50, P < 0.0001). Conclusion: This study shows that there is a significant correlation between right heart echocardiographic parameters and concentrations of BNP in the plasma of young adults with ASD. BNP levels may provide a supplemental data to predict of shunt size in these patients. (Echocardiography 2011;28:243‐247)     

Detection of intracardiac shunt flow in atrial septal defect using a real-time two-dimensional color-coded Doppler flow imaging system and comparison with contrast two-dimensional echocardiography

To evaluate the noninvasive detection of shunt flow using a newly developed real-time 2-dimensional color-coded Doppler flow imaging system (D-2DE), 20 patients were examined, including 10 with secundum atrial septal defect (ASD) and 10 control subjects. These results were compared with contrast 2-dimensional echocardiography (C-2DE). Doppler 2DE displayed the blood flow toward the transducer as red and the blood flow away from the transducer as blue in 8 shades, each shade adding green according to the degree of variance in Doppler frequency. In the patients with ASD, D-2DE clearly visualized left-to-right shunt flow in 7 of 10 patients. In 5 of these 7 patients, C-2DE showed a negative contrast effect in the same area of the right atrium. Thus, D-2DE increased the sensitivity over C-2DE for detecting left-to-right shunt flow (from 50% to 70%). However, the specificity was slightly less in D-2DE (90%) than C-2DE (100%). Doppler 2DE could not visualize right-to-left shunt flow in all patients with ASD, though C-2DE showed a positive contrast effect in the left-sided heart in 9 of 10 patients with ASD. Thus, D-2DE is clinically useful for detecting left-to-right shunt flow in patients with ASD.