Prognostic utility of the assessment of diastolic function in patients undergoing cardiac resynchronization therapy.

Conflicting data exist about the relationship between cardiac resynchronization therapy (CRT) and diastolic function. Aims of the study are to assess diastolic patterns in patients undergoing CRT according to the 2016 recommendations of the American Society of Echocardiography/European Association of Cardiovascular Imaging and to evaluate the prognostic value of diastolic dysfunction (DD) in CRT candidates. METHODS AND RESULTS: One-hundred ninety-three patients (age: 67 ± 11 years, QRS width: 167 ± 21 ms) were included in this multicentre prospective study. Mitral filling pattern, mitral tissue Doppler velocity, tricuspid regurgitation velocity, and indexed left atrial volume were used to classify DD from grade I to III. CRT-response, defined as a reduction of left ventricular (LV) end-systolic volume > 15% at 6-month follow-up (FU), occurred in 132 (68%) patients. The primary endpoint was a composite of heart transplantation, LV assisted device implantation, or all-cause death during FU and occurred in 29 (15%) patients. CRT was associated with a degradation of DD in non-responders. At multivariable analysis corrected for clinical variables, QRS duration, mitral regurgitation, CRT-response and LV dyssynchrony, grade I DD was associated with a better outcome (HR 0.37, 95% CI: 0.14-0.96). Non-responders with grade II-III DD had the worse prognosis (HR 4.36, 95%CI: 2.10-9.06). CONCLUSIONS: The evaluation of DD in CRT candidates allows the prognostic stratification of patients, independently from CRT-response.

[Echocardiographic assessment of myocardial function during His bundle and right ventricular pacing]. / Echokardiographische Beurteilung der myokardialen Funktion unter His-Bündel- und rechtsventrikulärer Schrittmacherstimulation.

INTRODUCTION: In patients with pacemaker (PM) therapy, His bundle stimulation (HBS) may lead to a more synchronous activation of the left ventricle (LV) than conventional right ventricular stimulation (RVS). In this study, we investigated to which extent this effect can be objectified by means of contemporary echocardiographic functional imaging. METHODS: In all, 15 RVS patients (6 women, mean age 76.6 ± 4.1 years) and 15 HBS patients (6 women, mean age 74.6 ± 3.7 years) underwent echocardiography with and without cardiac pacing. Besides LV end-diastolic volume (EDV), ejection fraction (EF), and global strain (GLS), we measured global and regional myocardial work and LV efficiency based on noninvasive pressure-strain loops. RESULTS: In all HBS patients, optimization of PM settings resulted in immediate changes in myocardial function parameters. With pacing, RVS patients showed a higher decrease in EF and GLS than HBS patients. Global LV work and LV work efficiency decreased significantly only in RVS patients. CONCLUSION: Changes in regional and global myocardial function can by proven and quantified by functional echocardiography. In patients under PM therapy, HBS shows functional advantages in comparison to conventional RVS.

Analysis of partial volume correction on quantification and regional heterogeneity in cardiac PET.

BACKGROUND: The partial volume correction (PVC) of cardiac PET datasets using anatomical side information during reconstruction is appealing but not straightforward. Other techniques, which do not make use of additional anatomical information, could be equally effective in improving the reconstructed myocardial activity. METHODS: Resolution modeling in combination with different noise suppressing priors was evaluated as a means to perform PVC. Anatomical priors based on a high-resolution CT are compared to non-anatomical, edge-preserving priors (relative difference and total variation prior). The study is conducted on ex vivo datasets from ovine hearts. A simulation study additionally clarifies the relationship between prior effectiveness and myocardial wall thickness. RESULTS: Simple resolution modeling during data reconstruction resulted in over- and underestimation of activity, which hampers the absolute left ventricular quantification when compared to the ground truth. Both the edge-preserving and the anatomy-based PVC techniques improve the absolute quantification, with comparable results (Student t-test, P = .17). The relative tracer distribution was preserved with any reconstruction technique (repeated ANOVA, P = .98). CONCLUSIONS: The use of edge-preserving priors emerged as optimal choice for quantification of tracer uptake in the left ventricular wall of the available datasets. Anatomical priors visually outperformed edge-preserving priors when the thinnest structures were of interest.

Partial volume and motion correction in cardiac PET: First results from an in vs ex vivo comparison using animal datasets.

BACKGROUND: In a previous study on ex vivo, static cardiac datasets, we investigated the benefits of performing partial volume correction (PVC) in cardiac 18F-Fluorodeoxyglucose(FDG) PET datasets. In the present study, we extend the analysis to in vivo cardiac datasets, with the aim of defining which reconstruction technique maximizes quantitative accuracy and, ultimately, makes PET a better diagnostic tool for cardiac pathologies. METHODS: In vivo sheep datasets were acquired and reconstructed with/without motion correction and using several reconstruction algorithms (with/without resolution modeling, with/without non-anatomical priors). Corresponding ex vivo scans of the excised sheep hearts were performed on a small-animal PET scanner (Siemens Focus 220, microPET) to provide high-resolution reference data unaffected by respiratory and cardiac motion. A comparison between the in vivo cardiac reconstructions and the corresponding ex vivo ground truth was performed. RESULTS: The use of an edge-preserving prior (Total Variation (TV) prior in this work) in combination with motion correction reduces the bias in absolute quantification when compared to the standard clinical reconstructions (- 0.83 vs - 3.74 SUV units), when the end-systolic gate is considered. At end-diastole, motion correction improves absolute quantification but the PVC with priors does not improve the similarity to the ground truth more than a regular iterative reconstruction with motion correction and without priors. Relative quantification was not influenced much by the chosen reconstruction algorithm. CONCLUSIONS: The relative ranking of the algorithms suggests superiority of the PVC reconstructions with dual gating in terms of overall absolute quantification and noise properties. A well-tuned edge-preserving prior, such as TV, enhances the noise properties of the resulting images of the heart. The end-systolic gate yields the most accurate quantification of cardiac datasets.

Left atrial myxoma. Evaluation with transoesophageal echocardiographic and real time three-dimensional imaging.

Myxoma is the most common benign cardiac neoplasm. A 66-year-old woman presented with a large left atrial myxoma, which was detected by a real-time three-dimensional echocardiography (RT3DE) and a real-time three-dimensional transoesophageal echocardiography (RT3D-TEE) approach. RT3DE and RT3D-TEE proved to be techniques that can provide additional contributions to the diagnostic investigation of structural heart diseases.

Sequential changes in myocardial function after valve replacement for aortic stenosis by speckle tracking echocardiography.

AIMS: Regional myocardial function may change differently in different pathology. Speckle tracking echocardiography (STE) was applied to evaluate longitudinal, radial, and circumferential function in patients with aortic stenosis (AS) before, within 1 week, and 6 months after aortic valve replacement (AVR). METHODS AND RESULTS: In 40 consecutive patients with severe AS, we acquired apical four-, three-, and two-chamber views and standard short-axis view pre- and post-AVR and after 6 months. Longitudinal, radial, and circumferential (LS, RS, and CS) were calculated by commercial STE software. Further, we analysed diastolic myocardial function by measuring E/e' ratio. With AVR, valve area increased and remained stable at 6 months follow-up. Left ventricular mass was unchanged 1 week after AVR (270 +/- 58 g vs. 267 +/- 58 g, n.s.) but decreased significantly during the next 6 months (219 +/- 50 g, P < 0.05). Left ventricular ejection fraction remained unchanged. Strain values did not change significantly within 1 week after AVR but increased significantly after 6 months (LS by 16%, RS by 21%, and CS by 28% of baseline values). E/e' ratio was highly augmented before AVR (26.1 +/- 12.5) and decreased significantly 6 months after AVR (15.9 +/- 5.9). CONCLUSION: Myocardial function significantly recovers after replacing the stenosed aortic valve. However, there is a considerable difference between the response of longitudinal, radial, and circumferential function. Our data suggest that echocardiographic assessment of regional function is feasible and of potential clinical importance.

Deformation imaging describes right ventricular function better than longitudinal displacement of the tricuspid ring.

AIMS: To quantify right ventricular (RV) function in patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and after pulmonary endarterectomy (PEA). METHODS: Out of 33 patients, 16 were evaluated clinically and with echocardiography (conventional and myocardial deformation parameters) before PEA (preop) and at 1 week, 1 month, 3 months and 6 months after PEA. RV fractional area change (RVFAC), tricuspid annular plane systolic excursion (TAPSE) as well as mid-apical and basal peak ejection strain (S) and strain rate (SR) of the RV free wall were measured. Left ventricular (LV) apical lateral wall motion was regarded as indicating changes in overall heart rocking motion (RM). Heart catheterisation was performed before, within 1 week and at 6 months after PEA. RESULTS: Clinical and haemodynamic parameters improved significantly after PEA. This correlated with the improvement in RVFAC, S and SR. TAPSE, on the other hand, showed a biphasic response (14.5 (4) mm preop, 8.5 (2.7) mm at 1 week and 11 (1.5) mm at 6 months). Changes in LV apical motion explain this finding. At baseline, TAPSE was enhanced by rocking motion of the heart as a result of the failing RV. Unloading the RV by PEA normalised the rocking motion and TAPSE decreased. CONCLUSIONS: RV function of CTEPH patients improves steadily after PEA. Unlike S, SR and RVFAC, this is not reflected by TAPSE because of postoperative changes in overall heart motion. Motion independent deformation parameters (S, SR) appear superior in the accurate description of regional RV function.

The interventricular septum is functionally bilayered: a fresh look at a well known structure.

Increasingly sophisticated echocardiographic procedures are revealing previously unknown details of well known structures such as the interventricular septum.

Dose-dependent disintegration of human endothelial monolayers by contrast echocardiography.

Biological effects on endothelium induced by contrast ultrasound (US) may be relevant for transferring drugs into the tissue. An in vitro tissue-mimicking phantom was developed to simulate clinical precordial echocardiography of three modalities (two-dimensional (2DE), pulsed wave (PW), and Power Doppler echocardiography) with gradual increases of acoustic output (mechanical index (MI) 0.0-1.6 and thermal index soft tissue (TIS) 0.0-1.3, respectively; transmit-frequency 1.8 MHz in second harmonic mode (SHI) by 2DE, 1.8 MHz for PW-Doppler, and 3.2 MHz for Power Doppler) as well as contrast agent (CA) concentrations (0.002-4 mg/mL Levovist). Disintegration of the endothelial monolayer was quantitatively analyzed by counting intercellular gaps in light microscopy. No gaps were observed in CA application without sonication. Only few gaps appeared at sonication without CA application in 2DE at MI=1.6 and in PW- and Power Doppler at TIS > or =0.4 and MI > or =0.4. The number of gaps increased significantly with the gradual increase of US output and to a comparably lesser but also significant extent with CA concentrations. Diagnostic contrast echocardiography may induce endothelial disintegrations dependent on US output as well as on CA concentrations. This aspect might be helpful in further in vivo series on local drug delivery.

[Tissue doppler for the assessment of LV function--what makes sense?]. / Gewebe-Doppler zur Beurteilung der LV-Funktion--Was ist sinnvoll?

Tissue Doppler based velocity and deformation measurements allow the quantitative and thus objective assessment of myocardial function. So far, many techniques and parameters have been developed, most of which require an explanation for the clinical user. This article reviews relevant tissue Doppler parameters and gives examples of the current clinical usage of this technique.

Strain and strain rate. New and clinically relevant echo parameters of regional myocardial function.

Strain (deformation) and strain rate (velocity of deformation) are parameters of regional myocardial function which can be calculated at the bedside from tissue Doppler echocardiographic data. These parameters are less image quality dependent and less subjective than visual assessment of endocardial border motion, and they track myocardial deformation with a considerably higher time resolution than magnetic resonance imaging. Thus, the technique can document short-lived subtle changes in deformation patterns, such as post-systolic shortening/thickening. The ability to detect regional myocardial ischemia and viability has been confirmed in animal experiments and clinical studies. The technique has also been used to detect early cardiomyopathy and to differentiate physiologic and pathologic myocardial hypertrophy, as well as to identify regional dyssynchrony in candidates for resynchronization therapy. Applications in heart transplantation, right ventricular disease and valvular heart disease are under evaluation. Thus, strain and strain rate data offer a new window on regional myocardial function and may, in the future, become an integral part of echocardiographic evaluation.

Changes in ocular blood flow velocities during external counterpulsation in healthy volunteers and patients with atherosclerosis.

BACKGROUND: External counterpulsation (ECP) is a new noninvasive means of augmenting organ perfusion by applying ECG-triggered diastolic pressure to the vascular bed of the lower limbs. In this study, effects of ECP on changes of ocular blood flow velocities were studied. METHOD: Mean, systolic and diastolic flow velocities of the ophthalmic artery were measured by Doppler sonography before and during ECP. Twelve healthy volunteers (age 31.3+/-4.3 years) and 12 patients with severe atherosclerosis (inclusion criteria: two atherosclerotic risk factors, at least one severe coronary stenosis, age 62.1+/-5.3 years) were included in the study. RESULTS: In healthy subjects, ECP changed diastolic flow velocity of the ophthalmic artery nonsignificantly from 21.6+/-7.7 to 23.7+/-10.5 cm/s. Systolic flow velocity decreased significantly from 36.1+/-13.6 to 28.9+/-10.2 cm/s (P<0.01). Mean flow velocity changed nonsignificantly from 28.1+/-9.4 to 26.5+/-9.9 cm/s. In atherosclerotic patients, mean flow velocity increased significantly from 26.3+/-11.4 to 29.3+/-11.2 cm/s (P<0.001), which was caused by significant diastolic flow augmentation from 19.7+/-9.1 to 23.9+/-9.7 cm/s (P<0.001). Systolic flow velocity was not changed significantly (from 34.2+/-12.8 to 32.6+/-11.8 cm/s). CONCLUSION: No significant change of mean blood flow velocity in the ophthalmic artery was found in young healthy subjects. In elderly patients with atherosclerosis, ECP significantly increased blood flow velocity in the ophthalmic artery by 11.4%. This may indicate an ocular perfusion benefit in these patients as a result of ECP and could also explain the increase of perfusion found in patients with retinal ischemia after ECP.

Does atrioventricular ring motion always distinguish constriction from restriction? A Doppler myocardial imaging study.

Constrictive pericarditis and restrictive cardiomyopathy can be difficult to differentiate on clinical examination. Cardiac ultrasonography is increasingly being used as the noninvasive method of choice for confirming the specific morphologic and hemodynamic abnormalities associated with either condition. Interrogation of atrioventricular valve plane motion by Doppler myocardial imaging (DMI) has been suggested as a valuable new approach that can help differentiate one from the other. We report the color DMI, pulsed DMI, and strain rate findings in 2 cases of constrictive pericarditis in which consideration of the annular motion pattern alone would not have allowed such differentiation.

Doppler myocardial imaging in the assessment of regional myocardial function in longitudinal direction pre- and post-PTCA.

AIMS: Doppler myocardial imaging is potentially a sensitive tool to assess regional myocardial velocities pre- and post-percutaneous transluminal coronary angioplasty (PTCA) as a marker of contractility to evaluate short- to medium-term information on functional myocardial recovery following the release of ischaemia. METHODS: Thirty patients with single vessel disease were studied to assess regional myocardial peak systolic velocity, systolic velocity time integral and mitral valve plane excursion in longitudinal direction one day pre-, one day post- and 3 months post-PTCA. The patients were assigned to group A with coronary stenoses >70% and group B with stenoses < 70%. RESULTS: In group A pre-PTCA the ischaemic segments showed a significantly lower peak systolic velocity and velocity time integral compared with the values one day after PTCA (5.8 +/- 1.4 vs 7.7 +/- 1.4cm.s(-1); 1.06 +/- 0.22 vs 1.23 +/-0.28cm;P< 0.03). In contrast, mitral valve plane excursion in this group remained unchanged after PTCA for both the ischaemic and non-ischaemic left ventricular wall. In group B no changes of these parameters and no differences in mitral valve plane excursion of the ischaemic and the non-ischaemic left ventricular wall could be seen. CONCLUSION: With Doppler myocardial imaging it was possible to quantify a number of indices which changed due to the successful release of ischaemia.

A comparison of regional myocardial velocity information derived by pulsed and color Doppler techniques: an in vitro and in vivo study.

The objective was to compare velocity information derived from either a tissue mimicking phantom or normal contracting myocardium by both pulsed wave and color Doppler myocardial imaging (PWDMI and CDMI). Both CDMI and PWDMI allow quantitative assessment of regional myocardial contraction and relaxation velocities, but their potential clinical applications have not yet been investigated. Moreover, no information is available as to whether they can be used interchangeably for regional velocity assessment. For the in vitro study, a rotating, circular-shaped, tissue-mimicking sponge driven by a motor at speeds of 15, 30, 60, 90 rpm was used to derive velocity data from the same eight points of interest by using PWDMI or CDMI techniques. For the in vivo study, 25 normal subjects were examined at rest using parasternal and apical approaches. Velocity profiles were derived from the same 26 areas of interest (18 left ventricular segments, 3 right ventricular segments, and 5 measurement points for the tricuspid and mitral annuli) for each technique. Peak maximal velocities were detected by PWDMI and peak mean velocities were measured using CDMI. The results of the in vitro study phantom showed excellent correlation (r = 0.99, P < 0. 001) and satisfactory agreement (0.04 cm/sec; 3.3 cm/sec) between both Doppler techniques. PWDMI velocities were higher than CDMI velocities by up to 20% and overestimated the real velocity value (0. 37 +/- 0.29 cm/sec) while CDMI underestimated predicted velocity by 1.35 +/- 0.36 cm/sec. Good correlation (r = 0.87, P < 0.001), but poor agreement (-2.1 cm/sec; 5.4 cm/sec) was shown in vivo for all segments with regard to peak systolic and diastolic velocities. Both Doppler techniques cannot be used interchangeably for comparing peak velocities in the clinical situation. However, with adequate temporal resolution, they can be used interchangeably for velocity profile recording and for timing of events.

[Contrast echocardiography]. / Kontrastechokardiographie.

The intravenous application of an ultrasound contrast agent induces enhanced display of blood in all its pathways. Within cardiology, this principle is mainly utilized for signal enhancement of color Doppler and spectral Doppler in order to improve quantification of congenital and acquired valvular lesions and also for improved endocardial delineation during stress tests and in the evaluation of LV function. The new domaine of myocardial perfusion imaging by contrast echocardiography, however, needed profound technical developments before realization of the clinical potential could even be conceived. These are based on the complex reactions of microbubbbles in the acoustic field in order to allow the sensitive and bubble specific display of intramyocardial contrast effects. The presently available acquisition techniques, second harmonic imaging and harmonic power Doppler, demonstrate significant improvements if compared to traditional fundamental 2-d echocardiography; however, they are still subjected to important limitations. There are many anatomical, physiological, and technical reasons for insufficient display of intramyocardial microbubbles, the most important one being attenuation. It is hoped that the most recently developed imaging modality, pulse inversion technique, allows the necessary diagnostic accuracy and reproducibility in myocardial perfusion imaging.