Diagnosis of pulmonary embolism by transoesophageal echocardiography.

A 68-year-old woman was admitted for major dyspnoea. A transoesophageal echocardiogram was performed after the occurrence of acute circulatory shock. During the examination, the patient was under mechanical ventilation. We found a thrombus that had almost occluded the right pulmonary artery and which was later confirmed by selective angiography. Despite treatment, the patient died 2 days later; autopsy confirmed the thrombus in the right pulmonary artery.     

Pulmonary venous flow in hypertrophic cardiomyopathy as assessed by the transoesophageal approach. The additive value of pulmonary venous flow and left atrial size variables in estimating the mitral inflow pattern in hypertrophic cardiomyopathy.

AIMS: This study was conducted to assess the characteristics of the pattern of pulmonary venous flow and to document the interaction of this flow and left atrial function with the pattern of mitral inflow in hypertrophic cardiomyopathy. METHODS AND RESULTS: Pulmonary venous and mitral flows were evaluated by the transoesophageal approach in 80 patients with hypertrophic cardiomyopathy. Left atrial size and function were measured by the transthoracic approach. Their values were compared with those obtained from 35 normal controls. Twelve patients showed significant (> 2+) mitral regurgitation. As a group, hypertrophic cardiomyopathy patients showed increased atrial reversal flow and longer deceleration time of the diastolic wave, but a wide variability of pulmonary venous flow patterns were observed. Thirty patients (37.5%) had pseudonormal mitral flow patterns. Stepwise multilinear regression analysis identified the ratio of systolic to diastolic pulmonary venous flow velocity, the ratio of velocity-time integrals of both flow waves at atrial contraction, the left atrial minimal volume and the systolic fraction as independent predictive variables of the mitral E/A wave velocity ratio (r = 0.82). By logistic regression, the former three variables were selected as independent predictive covariates of a pseudonormal mitral flow pattern (sensitivity: 83%, specificity: 90%). The ratio of velocity-time integrals of both atrial waves was the most important predictive variable in both analyses. CONCLUSIONS: The observed variability in the configuration of pulmonary venous flow velocity waveform is related to what occurs in transmitral flow in patients with hypertrophic cardiomyopathy. Significant mitral regurgitation is not an independent correlate of pseudonormal mitral inflow patterns in these patients. Our results further emphasize the complementary, additive value of the pulmonary venous flow velocity pattern and left atrial size in the interpretation of the mitral flow velocity pattern, and indirectly suggest the underlying increased left ventricular filling pressures of patients with hypertrophic cardiomyopathy and pseudonormal mitral flow patterns.     

Effect of atrial fibrillation on pulmonary venous flow patterns: transoesophageal pulsed Doppler echocardiographic study

The effect of atrial fibrillation on pulmonary venous flow patternsis still not well known. Twenty-four patients in atrial fibrillationand 21 patients in sinus rhythm were studied by transoesophagealechocardiography. In ninety-five percent (20/21) of sinus rhythmpatients, the early systolic wave due to atrial relaxation orreverse wave due to atrial contraction could be distinguishedon pulsed Doppler tracings by transoesophageal echocardiography.However, there was no early systolic wave and/or reverse atthe end of diastole in any atrial fibrillation patients. Inatrial fibrillation patients without mitral regurgitation (n= 14), the onset of systolic flow was delayed (165±38vs 50±46 ms, P < 0.05), and systolic peak velocities,time-velocity integrals and systolic fractions were reduced(31 ± 13 vs 54±17 cm.s^–1, P < 0.05; 5± 2 vs 13 ± 6 cm, P < 0.05 and 36 ±8 vs 61±15%, P < 0.05, respectively) as compared tothose in sinus rhythm. Significant mitral regurgitation (n =10) reduced systolic velocity parameters considerably in atrialfibrillation patients but the diastolic flow parameters werenot significantly different between sinus rhythm and atrialfibrillation patients. Stepwise multiple regression analysis identified atrial fibrillationas an important independent predictor for changes in systolicflow parameters. The R-R interval is also an important factorfor diastolic flow parameters. Thus, the present study demonstratesthat atrial fibrillation significantly modifies pulmonary venousflow pattern and is an important factor for systolic flow parameters.Significant mitral regurgitation can further modify systolicflow pattern in atrial fibrillation patients.     

Pulmonary vein flow analysis by transoesophageal echocardiogr phy in patients with chronic atrial fibrillation; 1 year follow-up after cardioversion.

AIMS: Left and right upper pulmonary vein flow can be adequately recorded by transoesophageal Doppler echocardiography. The aim of this study was to investigate whether analysis of the pulmonary venous flow velocity pattern can predict the long-term maintenance of sinus rhythm after successful cardioversion of chronic atrial fibrillation. METHODS AND RESULTS: Thirty-six consecutive patients, aged 53+/-9 years, with chronic atrial fibrillation of 5.33+/-2 months duration, were subjected to transoesophageal Doppler echocardiography to record left and right upper pulmonary venous flow, 24 h and 3 months following successful cardioversion. One year following cardioversion, 12 patients (33.3%) were in sinus rhythm (sinus rhythm group) while the remaining 24 patients were in atrial fibrillation (atrial fibrillation group). At 24 h following cardioversion, biphasic systolic forward flow in the left and/or right upper pulmonary venous flow velocity was detected in 10 patients of the sinus rhythm group and in four patients of the atrial fibrillation group (P<0001). The systolic fraction was significantly higher in the sinus rhythm group, 0.48+/-0.04 and 0.39+/-0.06, P<0.001 for the left upper pulmonary venous flow, and 0.52+/-0.05 and 0.41+/-0.04, P<0.001 for the right upper pulmonary venous flow, respectively. In patients who displayed a biphasic systolic forward flow and in whom the right upper pulmonary venous flow systolic fraction was higher than 0.50 at 24 h post-cardioversion, the probability of maintenance of sinus rhythm at 1 year exceeded 95%. CONCLUSION: The detection of a biphasic systolic forward flow in the pulmonary venous flow velocity, and of a right upper pulmonary vein systolic fraction higher than 0.50 as early as 24 h following cardioversion of chronic atrial fibrillation, identifies patients who will remain in sinus rhythm 1 year after cardioversion.     

Systolic left atrial failure in elderly women with severe aortic stenosis: mitral and pulmonary vein Doppler analysis by transesophageal echocardiography

We studied prospectively 35 elder women aged 65-82 years, with isolated severe symptomatic aortic stenosis, referred for aortic valve surgery. We assessed diastolic function by TEE before and after cardiac surgery, although follow-up data were collected in 26 patients. The examination was performed prior to surgery and 6 months after. The control group consisted of 32 patients referred for TEE. In the preoperative study, the velocities and integrals of the waves in the pulmonary vein flow were similar to the people of their same age, except the A-wave of atrial contraction and the integral of the systolic wave, which were significantly smaller (Control A-wave 26.1 +/- 5.1 vs preoperative A-wave 22.6 +/- 5.6, P = 0.009 and control double product A vel xA dur 2,748 +/- 835 vs preoperative 2,273 +/- 968, P = 0.03; systolic integral 14.6 +/- 3.8 vs 11.3 +/- 4, P = 0.0009). Six months after surgery, the PV flow was similar to the control group except for the wave of atrial contraction, which was significantly smaller but tended to normalization (postoperative A-wave 23.3 +/- 5, P = 0.04 vs control, and postoperative double product A vel x A dur 2460 +/- 893, P = 0.21 vs control). Mitral flow parameters did not change in the preoperative and postoperative period. Left ventricular mass index changed from 166 +/- 54 g/m(2) to 105 +/- 39 g/m(2) (P< 0.0001). The results of this study show that in elderly women with symptomatic severe AS, diastolic function does not change, left ventricular mass reduces, with improvement in symptoms, and the left atrium function, considered by pulmonary vein flow, is preoperative depressed and tends to mild recovery in the postoperative period, suggesting systolic LA failure.     

Paradoxical cerebrovascular embolism associated with pulmonary arteriovenous fistula: contrast transoesophageal echocardiographic diagnosis.

We report two cases of paradoxical cerebrovascular embolism associated with intrapulmonary arteriovenous fistulas. In both cases the diagnosis was made by the use of contrast transoesophageal echocardiography, which not only detected the fistulas but also localized the arteriovenous fistula to specific pulmonary vascular beds.     

Transthoracic Doppler echocardiographic measurement of left atrial appendage blood flow velocity: comparison with transoesophageal measurement.

AIM: We validated transthoracic echocardiographic measurements of left atrial appendage flow velocity by comparing them with transoesophageal echocardiographic measurements. METHODS AND RESULTS: Eighty-four consecutive patients (mean age, 64.6 years) with various cardiac diseases, who underwent both transthoracic echocardiography and transoesophageal echocardiography were studied. Thirty-two patients were in sinus rhythm, and the remaining 52 patients were in atrial fibrillation. On transthoracic echocardiography, the transducer was placed somewhat superior and outside from the position viewing the conventional parasternal short-axis image of the aortic valve, so that the angle between left atrial appendage midline and Doppler beam could be narrowed. The left atrial appendage flow velocity pattern was recorded by pulsed Doppler mode with a sampling volume placed at the left atrial appendage orifice on both transthoracic echocardiography and transoesophageal echocardiography. In both approaches, the peak emptying velocity (LAA-E) and the peak filling velocity (LAA-F) of the left atrial appendage were measured. In sinus rhythm, the LAA-E was detectable in 25 of the 32 patients (78.1%) and the LAA-F in 20 of the 32 patients (62.5%). Both LAA-E and LAA-F were detectable in 46 of the 52 patients (88.5%) in atrial fibrillation. Good correlations of LAA-E and LAA-F were observed between transthoracic echocardiography and transoesophageal echocardiography measurements in sinus rhythm (r=0.94, r=0.95, respectively; both, P<0.0001) and in atrial fibrillation (r=0.89, r=0.95, respectively; both, P<0.0001). CONCLUSIONS: The left atrial appendage flow velocities could be sufficiently recorded and assessed by transthoracic echocardiography in 84 Japanese unselected consecutive patients with sinus rhythm or atrial fibrillation.     

Prominent pulmonary venous flow mimicking mitral regurgitation

The present case highlights a potential pitfall in assessing mitral regurgitation severity due to the presence of similar colored prominent pulmonary vein signals in the left atrium during color Doppler examination.     

Intraoperative assessment of pulmonary vein flow

This study was undertaken to assess the suitability for intraoperative pulmonary vein flow measurements in 15 patients undergoing coronary artery bypass grafting. Using two-dimensional color Doppler transesophageal echocardiography, all four pulmonary veins--right upper and lower and left upper and lower pulmonary veins were easily visualized. Pulmonary vein flow was pulsatile. J wave occurred in the ventricular systole with relaxation of the left atrium and K wave in the ventricular diastole with relaxation of the left ventricle. There were differences in suitability for flow measurements among four pulmonary veins: (1) consistent visualization; (2) stable visualization throughout measurement; (3) minimal angle between ultrasonic beam and pulmonary vein course; and (4) minimal shift of sampling volume during measurement. The left pulmonary veins were suitable for flow velocity measurement by transesophageal echocardiography. The left lower pulmonary vein was stable for visualization once it was visualized although the angle was occasionally large. The left upper pulmonary vein was consistently visualized although the angle was occasionally large. On the other hand, the right pulmonary veins were unsuitable for flow measurement. Since sampling volume shifted in the direction of the long axis by the average of 5 to 6 mm during cardiac cycle, it should be positioned inside of the pulmonary vein at about 5 mm from the orifice of the left atrium.     

Pulmonary artery origin of the left coronary artery: diagnosis by transoesophageal echocardiography in infancy

In two infants the anomalous origin of the left coronary arteryfrom the pulmonary artery (ALCAPA) was detected prospectivelyby transoesophageal echocardiography (TEE). Colour flow mappingand pulsed Doppler ultrasound revealed a predominant right-to-leftshunt from the pulmonary artery to the left coronary artery.These findings were confirmed by angiography. Transihoracic echocardiography (TTE)failed to show the anomalousorigin of the left coronary artery or any abnormal pulmonaryflow pattern. TEE may be useful in the diagnosis of ALCAPA in selected cases,when TTE is inconclusive.     

Culture-negative suppurative endocarditis causing severe mitral valve obstruction: complementary use of transesophageal and transthoracic echocardiography

Infective endocarditis causes a myriad number of serious complications. Mitral valve obstruction is a rare complication. We report a 48-year-old Asian female who presented with two-week duration of fever and rapidly developed acute pulmonary edema and cardiogenic shock. Sequential transthoracic and transesophageal echocardiography revealed a rapidly growing vegetation on the anterior mitral leaflet with severe stenosis of the valve. All the blood cultures were negative. The patient underwent a successful mitral valve replacement. A review of 21 previously reported cases of mitral valve obstruction from endocarditis demonstrates the poor prognosis of this entity and supports early surgery.     

Extension of bronchogenic carcinoma through pulmonary vein into the left atrium detected by echocardiography

This is the case of a 46-year-old female recently diagnosed with a squamous cell bronchogenic carcinoma that spread through the pulmonary veins into the left atrium. This mass was initially seen on surface echocardiography as emanating from the pulmonary vein and subsequently confirmed to be arising from the right superior pulmonary vein by transesophageal echocardiography.     

Use of intracardiac echocardiography for prediction of chronic pulmonary vein stenosis after ablation of atrial fibrillation

INTRODUCTION: Measurements of pulmonary vein (PV) flow with intracardiac echocardiography (ICE) immediately before and after PV isolation may be a useful method for predicting which patients will develop chronic PV stenosis. METHODS AND RESULTS: We assessed preablation and postablation flows in each of the four PVs using a phase-array ICE catheter in 95 patients (mean age 52 +/- 13) undergoing atrial fibrillation ablation. The ostium of each of the PVs was defined using angiography, electrical mapping, and ICE imaging. Ostial electrical isolation of all PVs was achieved using a 4-mm cooled-tip radiofrequency ablation catheter. Change in PV flow, when present, was examined as both an absolute value and as a percentage of the baseline flow. All patients underwent spiral computed tomography (CT) scans of the PVs 3 months after the procedure for detection of stenosis. The average preablation diastolic flows for the left superior, left inferior, right superior, and right inferior veins were 0.56, 0.54, 0.47, and 0.45 m/sec, respectively. These values increased to 0.74, 0.67, 0.58, and 0.59 m/sec postablation (P < 0.001). Of 380 PVs ablated, the CT scans revealed 2 (1%) with severe (>70%) stenosis, 13 (3%) with moderate (51%-70%) stenosis, and 62 (16%) with mild (< or = 50%) stenosis. The r value between flow and stenosis was only 0.09 (P = NS). CONCLUSION: Acute changes in PV flow immediately after ostial PV isolation do not appear to be a strong predictor of chronic PV stenosis.     

Intracardiac Doppler echocardiographic quantification of pulmonary vein flow velocity: an effective technique for monitoring pulmonary vein ostia narrowing during focal atrial fibrillation ablation

INTRODUCTION: Ablation at the pulmonary vein (PV) ostium to isolate triggers for atrial fibrillation (AF) may induce PV narrowing. The AcuNav ultrasound catheter can image PV flow and quantify peak velocity and may be useful in assessing the degree of narrowing of PV ostia. METHODS AND RESULTS: In 93 patients with AF undergoing PV ostial ablation (up to 40 W, 52 degrees C, 90 sec), the ultrasound catheter was placed in the right atrium and PV peak flow velocities were measured during systole and diastole before and after ablation. Ostial PV electrical isolation was achieved in 216 of the 219 targeted PVs. The ultrasound catheter provided flow imaging of all PVs. The ostial peak flow velocities measured 56 +/- 12 cm/sec before ablation and increased to 101 +/- 22 cm/sec after ablation (P < 0.001). Peak velocity >100 cm/sec was detected in 103 (47%) of 219 and > or = 158 cm/sec (estimated pressure gradient 10 mmHg) with turbulent flow features, in 7 (3.2%) of 219 PVs. The highest velocity detected in one PV was 211 cm/sec (17.7 mmHg). Follow-up ultrasound catheter measurements were obtained in 13 patients (30 previously ablated PVs) during repeat ablations. The ostial peak velocity had decreased by 22 +/- 14 cm/sec and in 25 (83%) of 30 PVs was within the baseline range (<100 cm/sec) at a mean follow-up of 4.9 +/- 2.2 months. Follow-up magnetic resonance imaging (MRI) or contrast-enhanced CT was obtained at 7.0 +/- 3.8 months in seven patients with PV velocity > 158 cm/sec after initial ablation. No significant stenosis (<30%) was identified, and no patient suffered clinical symptoms (follow-up 6-18 months) related to the described acute changes in PV flow after an initial ablation procedure. Of 13 patients with repeat ablation, two had PV velocities >100 cm/sec before repeat ablation, and three PVs in two patients had flow velocity >158 cm/sec after repeat ablation. One of these patients developed symptoms of exertional dyspnea; MRI at 4 months showed 50% to 60% ostial narrowing. CONCLUSION: Ostial ablation for PV isolation may induce a mild-to-moderate increase in PV flow velocity, which can be identified using an ultrasound catheter with Doppler color flow imaging. Increases in PV flow velocity (<158 cm/sec) after a primary ablation procedure appear to be well tolerated, and a return toward baseline flow characteristics should be anticipated by 3 months. A more cautious approach may be required for patients undergoing repeat PV isolation.     

Pulmonary venous flow pattern studied by transoesophageal pulsed Doppler echocardiography in mitral stenosis in sinus rhythm: effect of atrial systole

In 13 patients with isolated mitral stenosis in sinus rhythmthe pulmonary venous flow was evaluated by transoesophagealpulsed Doppler echocardiography. The patients were divided intotwo groups according to their mitral valve area (MVA); GroupI (MVA<1.5 cm², n=7 patients); and Group II (MVA> 1.5cm², n=6). The patients in group I with haemodynamically significantmitral stenosis had lower velocities of systolic (S), diastolic(D) and atrial retrograde (A) waves of pulmonary venous flow(PVF) compared to milder stenosis (P<0.05). The peak velocityof pulmonary retrograde venous flow at atrial contraction (A)primarily depends on the relative amplitude of the atrial transmitralwave (RA), which is measured from the onset of atrial systoleto its peak velocity. We found a highly positive correlationbetween RA of mitral valve flow (MVF) and A wave of PVF (r=0.87,P<0.001). There was also a highly negative correlation (r=0.80,P<0.001) between A of PVF and ratio of early (PE) to late(PA) velocities of MVF. Therefore, the retrograde A wave ofPVF is related to the pressure generated in the left atriumduring atrial systole. Use of pulmonary vein velocities in conjunction with mitralflow velocities can increase our understanding of the haemodynamicsof mitral stenosis and provide a new insight into left atrialperformance.     

Identification of pulmonary vein potentials by differential site atrial pacing in patients with paroxysmal atrial fibrillation: enhanced detection by pulmonary vein pacing

INTRODUCTION: Pulmonary vein (PV) isolation may cure paroxysmal atrial fibrillation (PAF); however, identification of PV potentials may be difficult in sinus rhythm. Studies have suggested that atrial pacing may improve the identification of PV potentials. METHODS AND RESULTS: In 25 consecutive patients who underwent PV isolation for PAF, the results of pacing from the distal PV, distal and proximal coronary sinus, and high right atrium compared to sinus rhythm were analyzed to determine the most effective pacing site for identification of PV potentials. The percentage of confirmed PV potentials and the longest interval between atrial and PV potentials in each PV were compared during differential site pacing and sinus rhythm. PV potentials were confirmed in 63 (82%) of 77 PVs that could be mapped during the complete pacing protocol and during sinus rhythm. Distal PV pacing identified significantly more PV potentials (left upper pulmonary vein [LUPV] 100%, left lower pulmonary vein [LLPV] 84%, right upper pulmonary vein [RUPV] 80%, right lower pulmonary vein [RLPV] 53%) compared to other pacing sites and sinus rhythm. Among atrial pacing sites, those ipsilateral to the PV being mapped were the most effective for identifying PV potentials. The intervals between atrial and PV potentials were significantly longer during distal PV pacing than pacing at other sites (LUPV 81.6 +/- 26.2 ms, LLPV 61.4 +/- 26.1 ms, RUPV 59.7 +/- 33.2 ms, RLPV 39.7 +/- 26.7 ms). CONCLUSION: (1) Distal PV pacing was most effective for identifying PV potentials. (2) The interval between atrial and PV potentials was longest during distal PV pacing.     

Location, size and morphological characteristics of left atrial thrombi as assessed by echocardiography in patients with rheumatic mitral valve disease.

AIMS: This study aimed to assess the use of transthoracic and transoesophageal echocardiography in diagnosing the thrombi located in the left atrium and/or left atrial appendage in patients with rheumatic mitral valve disease, and to investigate the characteristics of thrombi in comparison to intraoperative findings. METHODS AND RESULTS: The study group was comprised of 474 patients who underwent transthoracic and transoesophageal echocardiography prior to mitral valve surgery. Location, thickness and morphological characteristics of thrombi were determined by transoesophageal echocardiography. Intraoperative assessment disclosed left atrial thrombi in 105 patients. Thickness of thrombi < or = 1cm, and thrombi confined to left atrial appendage were associated with false-negative results by transthoracic echocardiography. However, diameter and morphological characteristics of thrombi, left atrial and left atrial appendage size, and the presence of the spontaneous echo contrast were not associated with the diagnosis of thrombi by transthoracic echocardiography. For overall left atrial thrombi, sensitivity and specificity of transthoracic echocardiography were 32%, and 94%, respectively. Sensitivity and specificity of transoesophageal echocardiography for thrombi in the left atrial appendage were 98%, and 98%, for thrombi in the main left atrial cavity were 81%, and 99%, and for thrombi located in both left atrium and appendage cavities were 100%, and 100%, respectively. CONCLUSION: In patients with rheumatic mitral valve disease, detection of left atrial thrombi by transthoracic echocardiography seems to be determined by thickness and location of thrombi. The multilobed structure of the left atrial appendage and artifacts over posterior wall of the left atrium may still prevent precise diagnosis even with transoesophageal echocardiography.