Transesophageal Doppler evaluation of left anterior descending coronary artery angioplasty

Coronary flow reserve is associated with tissue ischemia and is an additive predictor of intensive care unit mortality to traditional risk scores in septic shock

BACKGROUND

Reduced coronary velocity flow reserve (CFR) is associated with poor outcome in patients with cardiovascular disease. We investigated whether CFR is associated with tissue ischemia and acidosis, impaired myocardial deformation and adverse outcome in patients with septic shock.

METHODS

In 70 mechanically-ventilated patients with septic shock, we examined: a) S' and E' mitral annular velocities using tissue Doppler imaging (TDI), b) CFR of the left anterior descending artery after adenosine infusion using transesophageal Doppler echocardiography and c) lactate, pyruvate and glycerol in tissue by means of a microdialysis (MD) catheter inserted into the subcutaneous adipose tissue as markers of tissue ischemia and acidosis. SOFA and APACHE II prognostic scores and mortality in the intensive care unit (ICU) were recorded.

RESULTS

Reduced CFR, S' and E' as well as increased E/E' correlated with increased SOFA, APACHE II and MD lactate to pyruvate ratio (p<0.05 for all correlations). Impaired TDI markers also correlated with increased MD glycerol (p<0.05). Reduced CFR correlated with decreased E' (p<0.05). CFR was 1.8 ± 0.42 in non-survivors (n=34) versus 2.08 ± 0.44 in survivors (p=0.007). A CFR<1.90 predicted mortality with sensitivity of 70% and specificity of 69% (area under the curve 77%; p=0.003). CFR had an additive value to APACHE (chi-square change: 4.358, p=0.03) and SOFA (chi-square change: 3.692, p=0.04) for the prediction of mortality.

CONCLUSION

Tissue ischemia and acidosis is a common pathophysiological link between decreased CFR and impaired LV myocardial deformation in septic shock. CFR is an additive predictor of ICU mortality to traditional risk scores in septic shock.

Womersley number-based estimates of blood flow rate in Doppler analysis: in vivo validation by means of phase-contrast MRI

A common clinical practice during single-point Doppler analysis is to measure the centerline maximum velocity and to recover the time-averaged flow rate by exploiting an assumption on the shape of velocity profile (a priori formula), either a parabolic or a flat one. In a previous study, we proposed a new formula valid for the peak instant linking the maximum velocity and the flow rate by including a well-established dimensionless fluid-dynamics parameter (the Womersley number), in order to account for the hemodynamics conditions (Womersley number-based formula). Several in silico tests confirmed the reliability of the new formula. Nevertheless, an in vivo confirmation is missing limiting the clinical applicability of the formula. An experimental in vivo protocol using cine phase-contrast MRI (2-D PCMRI) technique has been designed and applied to ten healthy young volunteers in three different arterial districts: the abdominal aorta, the common carotid artery, and the brachial artery. Each PCMRI dataset has been used twice: 1) to compute the value of the blood flow rate used as a gold standard and 2) to estimate the flow rate by measuring directly the maximum velocity and the diameter (i.e., emulating the intravascular Doppler data acquisition) and by applying to these data the a priori and the Womersley number-based formulae. All the in vivo results have confirmed that the Womersley number-based formula provides better estimates of the flow rate at the peak instant with respect to the a priori formula. More precisely, mean performances of the Womersley number-based formula are about three times better than the a priori results in the abdominal aorta, five times better in the common carotid artery, and two times better in the brachial artery.

The coronary flow velocity reserve measured by stress transoesophageal echocardiography evaluates the success of coronary interventions – Results of a 5-year follow-up

OBJECTIVES

The aim of the present study was to examine the long-term prognostic value of coronary flow velocity reserve (CFR) evaluated by means of stress transoesophageal echocardiography (STEE) in patients who have undergone percutaneous coronary intervention (PCI).

DESIGN

The study comprised 31 patients with significant LAD stenosis who underwent LAD-PCI. In consequence of their clinical signs, 11 subjects required rePCI or coronary artery bypass graft (CABG) operation within six months. The clinical status of the remaining 20 cases improved during the follow-up. STEE examinations were performed before LAD-PCI and after it.

RESULTS

The CFR of patients in a stable clinical condition improved during the follow-up, while the CFR of those who required rePCI or CABG remained unchanged. From this patient population, two subjects died during the 5-year follow-up.

CONCLUSIONS

Most of the patients who displayed an improved CFR after PCI suffered no major clinical events during the 5-year follow-up; in contrast, in those who a priori had a low CFR and did not show any improvement after PCI, major events did occur during this period.

Fragment reconstruction of coronary arteries using transesophageal echocardiography for coronary diagnostics

AIMS

Ultrasound differs procedurally from the established methods for non-invasive coronary visualization and is therefore an interesting alternative for non-invasive diagnostics. In this study, fragment reconstruction of coronary arteries by transesophageal echocardiography (FRC-TEE) was investigated for the first time in a patient population being evaluated for coronary angiography.

METHODS AND RESULTS

Ultrasonic and angiographic findings were compared visually and using quantitative measurements in 50 patients. One hundred and seventy-one vessels were examined by FRC-TEE. The total lengths visualized were 9.6 +/- 1.7 cm for the right coronary artery, 7.0 +/- 1.1 cm for left circumflex, 3.9 +/- 1.2 cm for left anterior descending (LAD), and 1.5 +/- 0.8 cm for the left main coronary artery. There was high concordance between results of both procedures. Sixty-three stenoses were detected using FRC-TEE. The mean difference in degree of stenosis between techniques was 0.2 +/- 5.1%. Stents could be visualized in 19 segments. FRC-TEE detected distal stenoses of the coronary arteries to only a limited extent: 14 stenoses and 2 stents, predominantly in the LAD artery (n = 13), were not identified.

CONCLUSIONS

FRC-TEE is a potential method for diagnosing coronary artery disease. FRC-TEE and angiography yield comparable findings during the evaluation of coronary lesions. Further investigations are needed to verify the encouraging findings and define FRC-TEE's applications.

Noninvasive evaluation of a cutting balloon entrapped in a left main coronary artery using transesophageal echocardiography

There are reports in the literature describing the utility of transesophageal echocardiography (TEE) in the evaluation of the coronary arteries. Studies have also shown the value of TEE in patients undergoing coronary intervention such as assessing coronary anatomy and flow following angioplasty. We report an interesting case where TEE helped to establish the location of a fractured cutting balloon device lodged in the left main coronary artery and obviated the need for cardiac surgery to remove the fractured balloon catheter. To our knowledge, this is the first case report of this type of complication utilizing a cutting balloon device.

Serial evaluation of coronary flow reserve by transesophageal doppler echocardiography after angioplasty of proximal left anterior descending coronary artery: a 6-month follow-up study

BACKGROUND

Coronary flow reserve can be estimated by transesophageal Doppler echocardiography (TDE).

OBJECTIVE

To evaluate the coronary flow reserve by TDE, serially over 6 months' follow-up, after successful percutaneous transluminal coronary angioplasty (PTCA) of proximal left anterior descending coronary artery (LADA).

METHODS AND RESULTS

We performed TDE examination of 30 patients (mean age 55 +/- 9 years) 72 h, 3 months, and 6 months after PTCA of LADA. Selective angiography of LADA was repeated 72 h and 6 months after PTCA of LADA. Velocity of flow in LADA was measured before and 2 min after cessation of intravenous infusion of dipyridamole (0.56 mg/kg in 4 min). The dipyridamole: rest mean diastolic velocity ratio was considered as an index of coronary flow reserve (CFR). For 20 of 21 patients with CFR > 2 there was no restenosis, whereas coronary angiography revealed restenosis in eight of nine patients with CFR < 2. The sensitivity was 88.9% and the specificity was 95.2%. For the 21 patients without restenosis mean CFR was 2.1 +/- 0.1 72 h after PTCA, had increased to 3.1 +/- 0.3 (P < 0.0001) 3 months after PTCA, and remained stable thereafter (3.0 +/- 0.9).

CONCLUSION

CFR after PTCA of proximal LADA can be evaluated serially by transesophageal Doppler echocardiography. CFR of LADA in patients without restenosis is increased 3 months after PTCA and remains stable thereafter.

Transesophageal echocardiography (TEE) in the evaluation of the coronary arteries

With technical advancements, including high frequency, multiplane transducers, digital acquisition and display, and left-sided contrast agents, TEE is emerging as a promising method for evaluating coronary artery disease. Visualization of proximal coronary artery stenoses and coronary artery anomalies is already possible. Research studies using TEE measurement have contributed to understanding coronary artery physiology and may prove to be a valuable clinical tool in the future.

Coronary flow reserve of normal left anterior descending artery in patients with ischemic heart disease: A transesophageal Doppler study

The aim of this study was to investigate the flow reserve of a normal left anterior descending coronary artery (LAD) in patients with coronary artery disease (CAD) of other epicardial vessels by Doppler transesophageal echocardiography (TEE). Thirty-one consecutive patients (age 59 +/- 8 years; 23 men) referred for TEE were considered. Eighteen patients had CAD and a 70% or greater LAD stenosis (group 1); 13 patients had right and/or circumflex CAD (>/=70% stenosis) and normal or minimally diseased LAD (group 2). Ten patients (age 54 +/- 11 years) with normal coronary arteries constituted group 3. Baseline and adenosine (0.160 microg/kg per minute intravenously over 60 minutes) flow velocities in the LAD were measured by pulsed Doppler examination during TEE. Peak and mean systolic and diastolic flow velocities were calculated. Adenosine/baseline peak and mean velocity ratios were used for evaluating blood flow reserve in the LAD. Heart rate and arterial pressure values were similar in the 3 groups at baseline and during adenosine infusion. Baseline and adenosine-related flow velocities were comparable in the 3 groups. Peak and mean diastolic velocity ratios were lower in groups 1 and 2 compared with group 3 (peak velocity ratio 1.68 +/- 0.81 and 1.93 +/- 0.35 vs 2.62 +/- 0.32, P <. 05; mean velocity ratio 1.71 +/- 0.86 and 2.01 +/- 0.41 vs 2.84 +/- 0.74, P <.05), whereas no differences were found between groups 1 and 2. No significant differences were found in systolic flow velocity ratios among the 3 groups. Patients with ischemic heart disease have a reduced diastolic flow velocity reserve in the LAD independent from the presence of significant LAD stenosis. Thus the adenosine TEE-Doppler study should be considered a screening test for CAD rather than for LAD disease.