Improving stress echocardiography accuracy for detecting left circumflex artery stenosis: a new echocardiographic sign?

BACKGROUND

The accuracy and reproducibility of stress echocardiography (SE) for the detection of coronary artery lesions requires improvement, particularly in the left circumflex artery (LCx).

AIMS

To evaluate the feasibility and diagnostic value of a new sign: Rise of the Apical lateral wall and/or Horizontal displacement of the Apex toward the septum ("RA-HA") in apical echocardiographic views.

METHODS

Consecutive patients with normal left ventricular function at rest, positive SE and an indication for coronary angiography were included. SEs were analysed blindly by three independent cardiologists: two seniors (S1 and S2) and one junior (J).

RESULTS

Of 81 patients, 58 had an exercise SE and 23 had a dobutamine SE. Significant coronary stenosis was found in 59 of 77 patients who underwent coronary angiography (76.6%). Interobserver reproducibility for the presence of RA-HA was very good between S1 and S2 (κ = 0.86), and good between S1 and J (0.67) and S2 and J (0.70). The sensitivity, specificity and positive and negative predictive values of RA-HA for the detection of significant coronary artery stenosis were, respectively, 39-41%, 83-89%, 88-92% and 29-31% for S1/S2; and 29%, 83%, 85% and 26% for J. To predict LCx stenosis (single or multivessel): 67-70%, 89%, 80-81% and 80-82% for S1/S2, respectively, and 50%, 89%, 75% and 74% for J.

CONCLUSION

With a short learning curve, RA-HA is easily diagnosed with a very good interobserver reproducibility. It has high specificity and PPV for the detection of a coronary artery stenosis, particularly in the LCx artery, during exercise or dobutamine SE.

Influence of Preoperative Left Ventricular Contractile Reserve on Postoperative Ejection Fraction in Low-Gradient Aortic Stenosis

Background— Dobutamine stress hemodynamics (DSH) has the potential to stratify operative risk in low-gradient aortic stenosis (AS), but little is known about the relation between left ventricle contractile reserve and postoperative left ventricular ejection fraction (LVEF). We sought to assess the value of DSH to predict postoperative improvement in LVEF.

Methods and Results— Sixty-six consecutive patients with symptomatic severe AS (aortic valve area ≤1 cm 2 ), LVEF ≤40%, and mean pressure gradient ≤40 mm Hg prospectively enrolled in the French multicenter study on low-gradient AS and who survived to aortic valvular replacement (AVR) were included. Preoperative contractile reserve was present in 46 patients (group I; 70%) and absent in 20 patients (group II; 30%). In the overall sample, 58% of patients improved by 2 New York Heart Association (NYHA) classes after AVR. Mean LVEF improved from 29±6% to 47±11% ( P <0.0001). LVEF improved by ≥10 EF units in 38 patients (83%) in group I and in 13 patients (65%) in group II. Mean LVEF improvement was similar in the 2 groups (19±10% versus 17±11%; P =0.54). On multivariable analysis, multivessel coronary artery disease ( P =0.05) and baseline mean transaortic pressure gradient ( P =0.01) were related to LVEF improvement, whereas contractile reserve was not.

Conclusions— LVEF increases in the majority of patients with low-gradient AS who survive after AVR. Although the absence of contractile reserve on DSH is related to high operative mortality, it does not predict the absence of LVEF recovery in patients surviving to AVR. These data further support the concept that surgery should not be contraindicated on the basis of absence of contractile reserve alone.

Functional Assessment of Mitral Regurgitation by Transthoracic Echocardiography Using Standardized Imaging Planes

OBJECTIVES

We sought to assess the value of transthoracic echocardiography (TTE) using standardized imaging planes for the functional analysis of mitral regurgitation (MR) as well as for postoperative outcome implications.

BACKGROUND

The feasibility of mitral valve repair is based on functional assessment of MR, mainly by transesophageal echocardiography (TEE). Considering the recent advances in TTE imaging, the incremental value of TEE in this setting needs to be re-examined.

METHODS

Consecutive patients (n = 279; 181 men; median age 68 years [quartiles, 61 to 74]) who underwent surgery for MR were enrolled prospectively in two tertiary care centers. The accuracy of TTE (harmonic imaging) versus TEE for functional assessment of MR was evaluated against surgical findings.

RESULTS

Valve repair (n = 237 patients, 85%) or replacement (n = 42) was predicted accurately by TTE in 97% of cases; TEE added significant information for only two patients. In the subgroup of degenerative MR (n = 190), agreement with surgical findings for the localization of prolapsed segments was 91% for TTE (kappa, 0.81) and 93% for TEE (kappa, 0.85) without incremental value of TEE (p = 0.40). Patients with single prolapse of the middle posterior scallop (P2) had a better postoperative outcome as compared with patients who had non-P2 lesions (p = 0.008). Furthermore, mitral replacement predicted by TTE was an independent predictor for postoperative long-term mortality (odds ratio 5.7, 95% confidence interval 1.97 to 16.4, p = 0.001).

CONCLUSIONS

In experienced hands, functional assessment of MR by TTE can predict accurately valve repairability and has a strong influence on postoperative outcome. Thus, in most cases preoperative TEE is not mandatory, provided intraoperative TEE is performed.

[Impact of advances in transthoracic imaging on the indications for transesophageal echocardiography]

Technical advances have considerably improved the quality of imaging by transthoracic echocardiography in recent years. This has allowed access to information formerly reserved for transoesophageal investigation. As a result, certain changes in the indications of transoesophageal echocardiography have come about in clinical practice. The best example is probably in the evaluation of mitral regurgitation. The possibilities of accurate description of mitral valve anatomy and of reliable quantification of the lesion have reduced the indications of transoesophageal echocardiography in this pathology. In other indications, such as suspected endocarditis, the investigation of systemic embolism or dissection of the aorta, transoesophageal echocardiography is irreplaceable but the additional information obtained compared with transthoracic echocardiography is less.

Low-gradient aortic stenosis: operative risk stratification and predictors for long-term outcome: a multicenter study using dobutamine stress hemodynamics

BACKGROUND

The prognostic value of dobutamine stress hemodynamic data in the setting of low-gradient aortic stenosis has been addressed in small, single-center studies. Larger studies are needed to define the criteria for selecting the patients who will benefit from valve replacement.

METHODS AND RESULTS

Six centers prospectively enrolled 136 patients with aortic stenosis (96 men; median age, 72 years [range, 65 to 77 years]; median aortic valve area, 0.7 cm2 [range, 0.6 to 0.8]; mean transaortic gradient, 29 mm Hg [range, 23 to 34 mm Hg]; cardiac index, 2.11 L x min(-1) x m(-2) [range, 1.75 to 2.55 L x min(-1) x m(-2)]). Left ventricular contractile reserve on the dobutamine stress Doppler study was present in 92 patients (group I) and absent in 44 patients (group II). Operative mortality was 5% (3 of 64 patients) in group I compared with 32% (10 of 31 patients) in group II (P=0.0002). Predictors for operative mortality were the lack of contractile reserve (odds ratio, 10.9; 95% confidence interval [CI], 2.6 to 43.4; P=0.001) and a mean transaortic gradient < or =20 mm Hg (odds ratio, 4.7; 95% CI, 1.1 to 21.0; P=0.04). Predictors for long-term survival were valve replacement (hazard ratio, 0.30; 95% CI, 0.17 to 0.53; P=0.001) and left ventricular contractile reserve (hazard ratio, 0.40; 95% CI, 0.23 to 0.69; P=0.001).

CONCLUSIONS

In the setting of low-gradient aortic stenosis, surgery seems beneficial for most of the patients with left ventricular contractile reserve. In contrast, the postoperative outcome of patients without reserve is compromised by a high operative mortality. Thus, dobutamine stress Doppler hemodynamics may be factored into the risk-benefit analysis for each patient.

[Role of echocardiography prior to to conservative treatment of mitral valvulopathy]

Echography is a key investigation in the diagnosis and follow up of patients with mitral valvulopathy. Recent advances in transthoracic imaging allow precise evaluation of the entire mitral apparatus in the majority of patients, which avoids recourse to the esophageal route especially for mitral insufficiency. On the other hand, TEE remains systematic in cases of stenosis when percutaneous commissurotomy is envisaged to look for intra-cavitary thrombosis. Echographic analysis has the objectives of defining the anatomical mechanism of the leak or stenosis, addressing aetiological arguments, quantifying the valvular dysfunction, and finally appreciating its repercussions (size of the left atrium, left ventricular function, pulmonary pressures). These elements, as well as evaluation of the symptoms, influence the therapeutic indications. The feasibility of conservative action, for which the significance compared to valvular replacement is known, depends directly upon the anatomical lesion and influences the therapeutic indications, especially in asymptomatic subjects for whom recent recommendations have been published. The experience of the ultrasonographer in the evaluation of mitral valvulopathies and his knowledge of conservative techniques allows improvement of the therapeutic discussion with the patient, the surgeon and the catheteriser. Performing TEE in the operative suite prior to conservative mitral surgery is practiced in many centres, as well as checking at the end of the procedure, especially for complex plasties. Three dimensional echography can currently be performed routinely by the transesophageal route, and probably in the near future by the transthoracic route, thanks to the recent arrival of real time 3D. Exercise echography also promises an important development thanks to the commercialization of new effort tables, and will allow refinement of the therapeutic indications in patients with few symptoms or for whom there is a discordance between the objective data and the functional status, but the therapeutic implications of this investigation remain to be defined.

[Usefulness of intraoperative echocardiography for the management of mitral regurgitation]

Intraoperative transesophageal echocardiography is crucial in the management of patients with mitral regurgitation. In fact, a vast majority mitral insufficiencies may actually be repaired. This kind of surgery require an excellent definition of anatomic lesions and mechanisms of mitral regurgitation in order to optimize the result of the repair. In this field, intraoperative echocardiographic findings are complementary with anatomical findings for the surgeon. Before surgery, intraoperative echography help to describe all valvular lesions and mechanisms of the regurgitation. Three-dimensional echocardiography may be obtained using intraoperative echography and may be useful in mitral valve prolapse to better define the location and size of prolapse and to communicate informations to the surgeon. After repair, echographyallow the control of the result and also of right and left ventricular function. In case of major abnormality such as residual significant mitral regurgitation or important intra-ventricular obstruction, a second procedure may be required. The collaboration between the echographist and the surgeon is crucial to obtain the best results in mitral valve repair. Indications for intraoperative echocardiography are dependent on the experience of the surgeon and the complexity of mitral lesions to repair.

Usefulness of three-dimensional echocardiography for the evaluation of mitral valve prolapse: an intraoperative study

BACKGROUND AND AIM OF THE STUDY

The study aim was to evaluate the feasibility of intraoperative three-dimensional (3D) transesophageal echocardiography (TEE) in patients referred for mitral valve prolapse (MVP) repair and to compare two-dimensional (2D) TEE and 3D TEE and surgical findings.

METHODS

Forty-six patients (mean age 67 +/- 11 years) underwent 3D TEE intraoperatively. Measurements were made of the posterior part of mitral annulus circumference (PMAC), and the width of mitral valve surgical resection on the mitral annulus (WMVR). Using 3D TEE, MVP topography was described, and PMAC in diastole and the width of implantation of MVP on the mitral annulus (WMVP) in systole were measured.

RESULTS

3D TEE was successful in 42 patients (91%). 2D and 3DTEE correctly predicted MVP localization in 38 (90%) and 36 (86%) patients, respectively (p = NS). 3D TEE and surgical PMAC were 89 +/- 13 and 93 +/- 21 mm, respectively (p = 0.01, R = 0.42). WMVR and WMVP were 28 +/- 11 mm and 26 +/- 11 mm, respectively (p <0.0001, R = 0.82). WMVR/anatomic PMAC (0.29 +/- 0.11) and WMVP/3D echo PMAC (0.32 +/- 0.11) were correlated (p <0.0001, R= 0.69).

CONCLUSION

Intraoperative 3D TEE evaluation of MVP is feasible. MVP width and its ratio to the mitral annulus were assessed, and found to correlate with surgical findings. These 3D data may be of value to the surgeon when performing mitral valve repair.

Usefulness of isometric exercise during dobutamine administration for stress echocardiography

An isometric exercise was performed by 170 consecutive patients at peak dose dobutamine, before atropine administration. The test was well tolerated, heart rate increased significantly during exercise, and atropine administration was avoided in 29% of patients.

[Recommendations of the French Society of Cardiology for the training of echocardiographers and performing echocardiograms]

The considerable advances achieved in the field of echocardiography have made this investigation an essential diagnostic tool. Under the auspices of the French Society of Cardiology, the Working group on Echocardiography publishes its practical recommendations for optimising the training of echocardiographers (theoretical instruction and practical courses) and for performing echocardiography (understanding the clinical problem, referral to previous examinations, necessary recordings and measurements, and appropriate equipment). In the future, these recommendations should be updated to take into account continuing technical improvements and changes in methods of studying cardiac disease by echocardiography.

[Guidelines of the French Society of Cardiology on the training of echocardiographers and the performing of echocardiography]

The considerable advances achieved in the field of echocardiography have made this investigation an essential diagnostic tool. Under the auspices of the French Society of Cardiology, the Working group on Echocardiography publishes its practical recommendations for optimising the training of echocardiographers (theoretical instruction and practical courses) and for performing echocardiography (understanding the clinical problem, referral to previous examinations, necessary recordings and measurements, and appropriate equipment). In the future, these recommendations should be updated to take into account continuing technical improvements and changes in methods of studying cardiac disease by echocardiography.

[Doppler echocardiographic evaluation of right heart pressure in children with ventricular septal defect]

Thirty seven children with ventricular septal defects (VSD) alone or associated with other malformations were examined by Doppler echocardiography to evaluate systolic right ventricular pressure (SRVP) non-invasively. All patients underwent cardiac catheterisation within 48 hours of the Doppler estimation. The maximum interventricular pressure gradient could be assessed in 32 patients (86%) from the recording of the maximum velocity of the VSD jet using the simplified Bernoulli formula. The SRVP was calculated by subtracting the maximum interventricular pressure gradient from the systolic blood pressure measured by sphygmomanometry. The SRVP estimated by continuous wave Doppler ranged from 24 to 108 mmHg (mean: 60 mmHg) compared with 20 to 109 mmHg (mean: 64 mmHg) at catheterisation. Two types of correlation were sought: 1) between the maximum interventricular pressure gradient measured by Doppler echo and the peak-to-peak LV-RV pressure gradient (r = 0.95; SD = 6 mmHg; Y = 1.03 x X + 1.3); 2) and between the SRVP measured by Doppler and by catheterisation (r = 0.94; SD = 6 mmHg; Y = 1.06 x X + 7.7). These results show that the maximum velocity of the interventricular jet and thereby the SRVP may be accurately measured by Doppler echocardiography in the majority of patients with VSD.

[Calculation of the pulmonary to systemic flow ratio using echo-Doppler in septal defects--correlation with oximetry]

OBJECTIVE

1. local validation of a protocol of measurement of pulmonary to systemic flow ratio (QP/QS) by echo-Doppler in children with septal defects; 2. to assess continuous wave Doppler efficacy mainly in those patients where peak pulmonary flow velocity was beyond the Nyquist limit of pulsed Doppler.

DESIGN

To correlate QP/QS ratio determined by echo-Doppler with that obtained by cardiac catheterization (oximetric method) performed within 48 hours, in children with isolated septal defects.

MATERIAL AND METHODS

The QP/QS ratio was evaluated by pulsed and or continuous wave echo-Doppler in 50 children who were submitted within 48 hours to cardiac catheterization. All children had an intracardiac shunt (12 atrial septal defects--ASD; 26 ventricular septal defects--VSD and 12 atrio ventricular septal defects--AVDS). Identical measurements were performed in a group of 20 children without cardiac malformation--control group. To test inter-observer variability, all the measurement in 31 patients were repeated by a second observer. Pulmonary and aortic flow was calculated as: Q = A x V x ET x CF where, A is the valvular orifice area (cm2), V the mean flow velocity (cm/sec), ET the ejection time (sec) and CF the cardiac frequency (cycles/min). The Doppler beam-flow direction angle in the pulmonary (P) artery and ascending aorta (Ao) was less than 20 degrees. Results were correlated with those obtained by catheterization (oximetric method).

RESULTS

We obtained a fairly good correlation with both pulsed wave Doppler (n = 43; r = 0.88; p less than 0.001; y = 0.84x + 0.40) and continuous wave Doppler (n = 50; r = 0.91; p less than 0.001; y = 0.86x + 0.35) or with pulsed wave Doppler in the P artery and continuous wave Doppler in the Ao (n = 43; r = 0.92; p less than 0.001; y = 0.86x + 0.27). In the control group, QP/QS ratio was evaluated by echo-Doppler: pulsed wave Doppler at 1.05 +/- 0.15 (mean +/- DS); continuous wave Doppler at 1.05 +/- 0.12 and, pulsed wave Doppler in the P artery and continuous wave Doppler in the Ao at 1.03 +/- 0.12. There was no significant difference in all three groups to the normal range of 1.00 (p less than 0.01). Inter-observer variability was less than 5.5% (p less than 0.001).

CONCLUSION

Pulsed and/or continuous wave echo-Doppler measurements are a reliable noninvasive method in evaluating QP/QS ratio in children with isolated septal defects.

[Acute aortic insufficiency. Diagnostic and prognostic value of cardiac ultrasonic Doppler]

Although infrequent, acute aortic insufficiency must be identified at an early stage. The clinical picture is often deceptive. Ultrasonic cardiography and cardiac Doppler represent, today, a diagnostic technique of choice which specify the mechanism of the acute valve leakage, the condition of the ascending aorta and the repercussions on the left ventricle.

[Aneurysms of the atrial septum. From diagnosis to treatment. Apropos of 33 consecutive cases]

Although rare, aneurysms of the atrial septum are the object of a renewed interest, for they are found with an ever increasing frequency due to technical advances in echocardiography and they have been blamed for a number of disorders, including arrhythmias and embolic accidents. We report here a series of 33 consecutive cases of atrial septal aneurysm discovered by two-dimensional echocardiography over a 5-year period. There were 21 children and 12 adults. In children, the aneurysm was usually associated with a congenital heart disease (17/21 cases). Spontaneous closure was observed in 3 cases where that disease was an isolated septal defect. In adults the aneurysm was usually isolated, but it was complicated by repeated transient ischaemic accidents in 3 patients. No arrhythmia ascribable to the aneurysm was observed.