Color Tissue Doppler Imaging Research Articles

Influence of detomidine on atrial fibrillation cycle length measured by intracardiac electrogram recording and by colour tissue Doppler imaging in horses

Shortening of atrial fibrillation cycle length (AFCL) is a marker of atrial electrical remodelling due to atrial fibrillation (AF). To investigate the effect of administration of detomidine on AFCL measured invasively from an intra-atrial electrogram (AFCLEGM) and noninvasively by tissue Doppler imaging (AFCLTDI). We hypothesised that detomidine would have no effect on AFCL but would improve the ease of TDI measurements and facilitate noninvasive AFCL determination. Prospective clinical study. Measurements were performed before and after i.v. administration of 7.5 μg/kg bwt detomidine in 33 episodes of AF in 32 horses (582 ± 64 kg bwt, 10 ± 3 years old) referred for electrical cardioversion. The AFCLEGM was measured from a right atrial intracardiac electrogram. The AFCLTDI was measured from atrial colour tissue velocity curves in 5 atrial wall regions. Mean AFCLEGM and AFCLTDI without and with sedation were compared using a repeated-measures linear mixed model with Bonferroni correction for multiple comparisons and calculation of the Bland-Altman mean bias and limits of agreement between AFCLEGM and AFCLTDI. The mean AFCL was significantly increased after sedation, but this increase was very small (mean difference +4 ms). For AFCLTDI measurements, sedation significantly improved the quality of the atrial myocardial velocity curves and the number of AF cycles that could be measured per cardiac cycle. The Bland-Altman bias between AFCLEGM without sedation and AFCLTDI with sedation ranged from -18 to +15 ms depending on wall region. Bland-Altman limits of agreement were similar between AFCLEGM without sedation and AFCLTDI without and with sedation. Therefore, noninvasive AFCLTDI measurements with sedation can be used to estimate the atrial fibrillatory rate. Sedation facilitates noninvasive AFCL measurements but causes a slight increase in AFCL. Noninvasive AFCL measurements can be used as an indicator of atrial electrical remodelling, to study AF pathophysiology and to investigate the effect of anti-arrhythmic drugs.

Features of remodeling of right heart chambers according to tissue Doppler and its correlation with cardiac rhythm disturbance in patients with COPD 2-3 severity

The article presents the study of early sings of dysfunction of right and left chambers of heart in patients with COPD 2 - 3 severity, correlation between structural and electrical remodeling of heart according to the stages of pulmonary hypertension. Standard tissue Doppler echocardiographic parameters and modes were used for the diagnosing. We examined 35 patients with COPD 2 - 3 severity; the control group consisted of 15 patients. The ECG Holter monitoring was made for all patients to identify cardiac rhythm disturbance and correlation with the COPD severity. Standard method of the ECG with modes of tissue Doppler (pulsed wave Tissue Doppler Imaging - PW TDI, color tissue Doppler imaging -TDI, tissue myocardial Doppler - TMD, tissue Tracking - TT, Doppler for evaluation of myocardial strain and myocardial strain rate) were made to identify the stage of dysfunction. The results of the study concluded that according to the TDI the dysfunction of right ventricle was more apparent in patients with COPD 3 severity. Pathological arrhythmias were significantly detected in group of patients with COPD 3 severity. In compliance with our observations, the reduce of rapid myocardial strain rates and its inverse proportion with the severity in accordance to the evaluation of longitudinal strain and rate of movement of fibrous ring in tricuspid valve were observed in patients with COPD. Thus the application of the TDI modes for evaluating of early signs of cardiac remodeling in patients with COPD and potential adequate jugulation for preventing chronic cor pulmonale is expedient.

OP05.05: Assessment of fetal arrhythmias by fetal colour tissue Doppler imaging (cTDI)

<scp>OP</scp>05.05: Assessment of fetal arrhythmias by fetal colour tissue Doppler imaging (<scp>cTDI</scp>)

Left ventricular myocardial response to exercise in children after heart transplant

Data on myocardial response to exercise after pediatric heart transplant (HTx) are limited. In this study we used semi-supine bicycle ergometry (SSCE) stress echocardiography to evaluate left ventricular (LV) systolic and diastolic reserve in pediatric HTx recipients. Forty-three HTx patients and 23 controls underwent stepwise SSCE stress echocardiography. Color tissue Doppler imaging (TDI) peak systolic (s') and early diastolic (e') velocities in the LV lateral wall and basal septum, and LV peak global longitudinal and circumferential strain were measured at rest and during different stages of exercise. LV myocardial acceleration during isovolumic contraction (IVA) was measured at incremental heart rates (HRs) to determine the force-frequency relationship (FFR). At rest, compared with controls, HTx patients showed lower TDI velocities in the basal septum (s': 4.7 ± 1.1 vs 5.8 ± 0.8 cm/s, p = 0.002; e': 8.5 ± 2.1 vs 11.3 ± 1.7 cm/s, p < 0.001), whereas in the LV lateral wall only e' was lower (11.2 ± 2.6 vs 13.8 ± 2.3 cm/s, p < 0.001). LV IVA was not different between the groups (p = 0.10). LV peak global longitudinal strain was lower in HTx patients (18 ± 1.9% vs 20 ± 2.2%, p = 0.001), but peak circumferential strain was not different (p = 0.50). At peak, HR was lower in the HTx group (141 ± 12 vs 165 ± 15, p < 0.001), and all systolic and diastolic parameters, except circumferential strain, were lower in HTx recipients. When assessing the increase in TDI and strain values in relation to HR, the slopes were not significantly different between patients and controls. Despite resting differences in myocardial functional parameters, pediatric HTx recipients have preserved LV diastolic and systolic myocardial reserve in response to exercise.

Evaluation of Right Ventricular Myocardial Function in Healthy Horses With Recurrent Airway Obstruction Using Tissue Doppler Imaging

It has been described in humans that chronic obstructive bronchitis leads to pathologic changes, especially in the right ventricular myocardium due to hypoxia, which can be assessed by tissue Doppler imaging (TDI). In our study, different TDI techniques, that is, pulsed-wave TDI and color TDI, were evaluated for applicability in different scan planes (apical long-axis view and short-axis view) for the analysis of right ventricular myocardial function in six healthy horses (control) and six horses affected with recurrent airway obstruction (RAO) (RAO group). Tissue Doppler imaging was applicable to all scan planes described. Myocardial movement directions in general and the absolute values of TDI parameters were assessable. Significantly reduced early diastolic filling velocities (E), elevated late diastolic filling velocities (A), thereby decreased E/A quotient, prolonged electromechanical coupling periods between electrocardiograph Q-wave and maximal velocities, and compensatory elevated systolic strain as well as diminished displacement could be observed in horses with RAO compared with the control group. To conclude, equine right ventricular myocardial function is assessable by TDI. Significant changes of right ventricular myocardial function could be demonstrated by TDI in horses with RAO compared with matched healthy controls. The hypothesis that RAO potentially leads to right ventricular dysfunction detectable by TDI before conventional echocardiography changes are evident is supported by this explorative study.

Cardiovascular effects of dietary salt intake in aged healthy cats: a 2-year prospective randomized, blinded, and controlled study.

High salt dry expanded diets are commercially available for cats to increase water intake and urine volume, as part of the prevention or treatment of naturally occurring urinary stone formation (calcium oxalates and struvites). However, chronic high salt intake may have potential cardiovascular adverse effects in both humans, especially in aging individuals, and several animal models. The objective of this prospective, randomized, blinded, and controlled study was to assess the long-term cardiovascular effects of high salt intake in healthy aged cats. Twenty healthy neutered cats (10.1±2.4 years) were randomly allocated into 2 matched groups. One group was fed a high salt diet (3.1 g/Mcal sodium, 5.5 g/Mcal chloride) and the other group a control diet of same composition except for salt content (1.0 g/Mcal sodium, 2.2 g/Mcal chloride). Clinical examination, systolic and diastolic arterial blood pressure measurements, standard transthoracic echocardiography and conventional Doppler examinations were repeatedly performed on non-sedated cats by trained observers before and over 24 months after diet implementation. Radial and longitudinal velocities of the left ventricular free wall and the interventricular septum were also assessed in systole and diastole using 2-dimensional color tissue Doppler imaging. Statistics were performed using a general linear model. No significant effect of dietary salt intake was observed on systolic and diastolic arterial blood pressure values. Out of the 33 tested imaging variables, the only one affected by dietary salt intake was the radial early on late diastolic velocity ratio assessed in the endocardium of the left ventricular free wall, statistically lower in the high salt diet group at 12 months only (P = 0.044). In conclusion, in this study involving healthy aged cats, chronic high dietary salt intake was not associated with an increased risk of systemic arterial hypertension and myocardial dysfunction, as observed in some elderly people, salt-sensitive patients and animal models.

Avaliação da função diastólica por meio de Doppler tecidual pulsado e colorido em gatos da raça Maine Coon geneticamente testados para a mutação no gene MyBPC-A31P

A cardiomiopatia hipertrófica (CMH) é a principal cardiopatia dos felinos e é caracterizada por hipertrofia miocárdica concêntrica, sem dilatação ventricular. Disfunções miocárdicas ocorrem em gatos com CMH, mas pouco se conhece a respeito destas alterações nos estágios iniciais da afecção. Em gatos da raça Maine Coon, a mutação no gene MyBPC-A31P está relacionada com a CMH de origem familial, porém, a correlação exata entre o genótipo e o fenótipo ainda é inconclusiva. A ecocardiografia tecidual é uma modalidade não invasiva que permite avaliação da função miocárdica e é mais sensível que a ecocardiografia convencional. Para avaliar as funções sistólica e diastólica, antes ou após a ocorrência de hipertrofia ventricular, gatos da raça Maine Coon (n=57), geneticamente testados para a mutação, foram avaliados por meio de ecocardiografias convencional e tecidual (nas modalidades Doppler tecidual pulsado e Doppler tecidual colorido). Posteriormente, foram fenotipicamente classificados em: normais (n=45), suspeitos (n=7) e acometidos pela CMH (n=5); e genotipicamente classificados em: negativos (n=28), heterozigotos (n=26) e homozigotos para a mutação (n=3). Valores de velocidades miocárdicas (Doppler tecidual pulsado e colorido) medidos na região basal e média do septo interventricular (SIV), da parede livre do ventrículo esquerdo (PVE), da parede anterior do ventrículo esquerdo (PAVE), da parede posterior do ventrículo esquerdo (PPVE) e do segmento radial da PVE, foram comparados nos diferentes grupos. Observou-se que as velocidades longitudinais Em (Doppler tecidual pulsado) na região média da PVE foram menores nos gatos com CMH quando comparados com suspeitos e normais. Os valores de Em/Am (Doppler tecidual colorido), na região basal do SIV, foram inferiores nos gatos com CMH quando comparados com suspeitos e normais. A relação E/Em (Doppler tecidual colorido), na região basal do SIV, foi maior nos gatos com CMH em relação aos suspeitos e normais, enquanto que os valores de Sm (Doppler tecidual colorido), em região basal da PVE, foram menores nos gatos heterozigotos quando comparados com os negativos, ambos sem hipertrofia ventricular. Observou-se correlação positiva entre a ocorrência de fusão das ondas Em e Am e a frequência cardíaca, assim como correlação positiva entre valores de Sm e Em e a frequência cardíaca (Doppler tecidual pulsado e colorido). A ecocardiografia tecidual é uma nova modalidade ecocardiográfica reprodutível em gatos que, isoladamente, não permite diferenciar gatos portadores da mutação antes do desenvolvimento de hipertrofia ventricular. Apresenta utilidade como auxílio no diagnóstico em fases iniciais, mas, apesar da expectativa para a identificação precoce de indivíduos portadores da CMH, ainda há necessidade de estudos mais extensos e com maior número de indivíduos.

Relation between QRS Duration and Atrial Synchronicity in Patients with Systolic Heart Failure

The association of QRS duration (QRSd) with ventricular dyssynchrony is well-known in systolic heart failure (HF). However, there are no data regarding the relationship between QRSd and atrial dyssynchrony in patients with HF. We aimed to investigate the association of QRSd with intra-atrial and inter-atrial dyssynchrony in patients with systolic HF by using color tissue Doppler imaging (TDI). The study consisted of 70 systolic HF patients and 35 healthy controls. According to QRSd, HF patients were categorized into 2 subgroups as narrow QRS (n=35) and wide QRS (n=35) groups. Time intervals between the onset of P-wave and the onset of A-wave on color TDI from the right atrium (P-RA), inter-atrial septum (P-IAS) and left atrium (P-LA) were measured. Atrial dyssynchrony was defined as differences between P-RA and P-IAS (RA dyssynchrony), between P-LA and P-IAS (LA dyssynchrony) and between P-RA and P-LA (inter-atrial dyssynchrony). In patients with either HF groups, we observed significant impairment in intra-atrial and inter-atrial synchronicity compared with the controls (P<0.001). Moreover, LA, RA and inter-atrial synchrony were found to be significantly impaired in the wide QRS group compared to narrow QRS group. There was also a positive and strong correlation between atrial and ventricular dyssynchrony parameters. In stepwise multivariate analysis, QRSd was found to be the independent predictor of intra-atrial and inter-atrial dyssynchrony in systolic HF. Among patients with systolic HF, prolonged QRSd is associated with impaired intra-atrial and inter-atrial synchrony. Atrial and ventricular dyssynchrony parameters were well-correlated with each other.

Evaluation of the long-term effect of percutaneous balloon valvuloplasty on right ventricular function using tissue Doppler imaging in patients with mitral stenosis

We investigated the effects of percutaneous mitral balloon valvuloplasty (PMBV) on right ventricular function in the long term using tissue Doppler imaging. Twenty-seven patients who underwent successful PMBV were enrolled in the study. Echocardiographic examination, including color tissue Doppler imaging, was done from the lateral tricuspid annulus 24 hours before the intervention, and the examination was repeated 24 hours and 6 months after the intervention. At 24 hours after the intervention, S wave velocity and A' wave velocity were seen to have increased significantly (9.52±1.85 cm/s vs. 10.92±1.20 cm/s, p=0.012; -10.44±2.64 cm/s vs. -11.73±2.05 cm/s, p=0.029, respectively). E' wave velocity and E'/A' ratio did not change significantly (p>0.05 for both). In the late period, S wave velocity was similar to the value in the early period and significantly higher than the basal level (9.52±1.85 cm/s vs. 10.69±1.72 cm/s, p=0.023). However, A' wave velocity in the late period was decreased compared to the early period and was not different from the basal level (-10.44±2.64 cm/s vs. -10.74±2.63 cm/s, p>0.05). The increase in E' wave velocity in the late period when compared to the basal level was found to be statistically significant (-7.85±1.54 cm/s vs. -9.21±1.81 cm/s, p=0.046). Right ventricular systolic function improved in the early period, and this improvement was seen to continue in the late period of PMBV. Diastolic function did not improve in the early period, but did improve in the late period. Right atrium systolic function improved in the early period; however, in the late period, levels were similar to the basal levels.

The tissue Doppler imaging derived post-systolic velocity notch originates at the aortic annulus.

BackgroundA distinct velocity pattern represented by a "notch" is observed during the time interval between the end of the systolic and the onset of the early diastolic velocity wave on longitudinal myocardial velocity curve. The origin of the post-systolic velocity notch (PSN) has not been resolved.MethodsThe high frame rate color tissue Doppler imaging of the apical longitudinal axis was performed in 32 healthy subjects.ResultsThe time delays of the PSN onset at the posterior aortic wall (AW), the mid anteroseptal wall (MAS) and the posterior mitral annulus (MA) relatively to the anterior aortic annulus (AA) were found to be significantly longer than zero (5.1 ± 2.2, 6.0 ± 2.3, 6.8 ± 2.8 ms; p < 0.001). The amplitude was the highest at the AA when compared to the AW, the MAS and the MA (4.77 ± 1.28 vs. 2.88 ± 1.11, 2.15 ± 0.73, 2.44 ± 1.17 cm/s; p < 0.001). A second PSN spike was identifiable in 10/32 (31%) of the studied subjects at the AA. Of these, 9 (28%) exhibited a second PSN spike at the AW, 3 (9%) at the MAS and no one at the MA.ConclusionThe AA represents the site of the earliest onset and maximal amplitude of the PSN on the longitudinal velocity curve suggesting its mechanism to be that of an energy release at the instant of the aortic valve closure causing an apically directed acceleration of the myocardium. A substantial number of healthy subjects exhibit a second PSN spike predominantly at the level of the AA. Its mechanism remains to be elucidated.

Doppler Tissue Imaging Is an Independent Predictor of Outcome in Patients with ST-Segment Elevation Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention

Doppler tissue imaging (DTI) detects early signs of left ventricular (LV) dysfunction; however, the prognostic significance of DTI after ST-segment elevation myocardial infarction (STEMI) is unknown. The aim of this study was to evaluate the prognostic value of DTI after STEMI in patients treated with primary percutaneous coronary intervention. In total, 391 patients who were admitted with STEMIs and treated with primary percutaneous coronary intervention were prospectively included. All participants were examined by echocardiography 2 days (interquartile range, 1-3 days) after STEMI. Longitudinal systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities were measured using color DTI at six mitral annular sites and averaged to provide global estimates. The median follow-up period was 25 months (interquartile range, 19-32 months). The primary end point was a composite of death, heart failure, or a new myocardial infarction. Patients with low global systolic function (s') or low global diastolic function (e') had >2 times greater risk for the combined end point compared with patients with high global s' (hazard ratio, 2.60; 95% confidence interval, 1.64-4.13; P < .001) or e' (hazard ratio, 2.26; 95% confidence interval, 1.44-3.55; P < .001), respectively. After adjustment for age, gender, peak troponin I, previous myocardial infarction, LV ejection fraction, LV mass index, and LV dimension in a multivariate Cox model, patients with low values of both global s' and e' remained at significantly higher risk than patients with high s' and/or e' (hazard ratio, 1.69; 95% confidence interval, 1.02-2.81; P = .043). A pattern of low systolic and diastolic performance as assessed by DTI is a paramount marker of adverse prognosis for patients with STEMIs independent of conventional echocardiographic parameters. DTI velocities should be evaluated together as they interact with the prognosis.

Tissue Doppler Imaging and Two-dimensional Speckle Tracking of Left Ventricular Function in Horses Affected with Recurrent Airway Obstruction before and after Clenbuterol Treatment

Cardiac effects of the β2-adrenergic agent clenbuterol have been the focus of many studies, but effects on myocardial velocities and myocardial deformation parameters have not yet been evaluated in horses affected with recurrent airway obstruction (RAO) using tissue Doppler imaging (TDI) and two-dimensional speckle tracking (2DST). In our study, 7 horses affected by RAO were treated over 14 days with clenbuterol, 0.8 μg/kg every 12 hours. Standard echocardiographic, TDI (pulsed wave and color TDI), and 2DST examinations were performed before and after the treatment period. Myocardial function was recorded in the right parasternal short-axis view. Percent of fractional shortening and two-dimensional echocardiography (2DE) measurements did not show any significant changes after 2 weeks of treatment. Early diastolic velocity, E, increased significantly after clenbuterol in the left ventricular free wall (LVFW; P = .001). The E/late diastolic velocity (A) quotient (P = .003) and the isovolumetric contractility (P = .035) also increased significantly after treatment. Time parameters, particularly the time interval between the Q-wave in the echocardiograph and atrial release, the time of diastole and Tei index (parameter of global ventricular function), decreased significantly after clenbuterol administration in the LVFW (P = .014/P = .028/P = .015, respectively). The 2DE speckle tracking revealed a significant increase of the early diastolic systolic strain rate (P = .01) in the LVFW after therapy. In conclusion, 2 weeks of treatment with clenbuterol at a dosage of 0.8 μg/kg every 12 hours led to improved cardiac function in severely RAO-affected horses. This could be a sign of myocardial restoration (re-remodeling) after therapy.

Fetal color tissue Doppler imaging (cTDI): Assessment of fetal arrhythmias

Fetal color tissue Doppler imaging (cTDI): Assessment of fetal arrhythmias

Fetal color tissue Doppler imaging (cTDI): Analysis of time intervals during second and third trimester using different sized regions of interest

Fetal color tissue Doppler imaging (cTDI): Analysis of time intervals during second and third trimester using different sized regions of interest

Quantitation of Fetal Heart Function With Tissue Doppler Velocity Imaging—Reference Values for Color Tissue Doppler Velocities and Comparison With Pulsed Wave Tissue Doppler Velocities

Quantitative assessment of fetal heart function has been difficult. Increasingly, tissue Doppler imaging (TDI) is used to measure fetal cardiac function noninvasively. There are two principal techniques, spectral pulsed wave (PW) TDI and color TDI (CTDI). Published reference values for fetal myocardial velocities are based on spectral PW TDI only. However, previous phantom, adult, and animal studies have shown that PW TDI velocities are systematically higher than CTDI velocities. There are no fetal studies so far. We hypothesized that myocardial velocities derived by PW TDI and CTDI are significantly different in the fetus. This prospective observational study included 91 fetuses (gestational age 28.6 ± 6.6 weeks; range 19-40 weeks) seen for routine prenatal ultrasound. From apical 4-chamber views, tricuspid ring (right ventricle), lateral and septal mitral ring were sampled by PW TDI and CTDI. Bland-Altman analysis was used for comparisons. PW and CTDI S' velocities correlated strongly in all three cardiac segments (r = 0.6 to 0.9; P < 0.01). There was a systematic bias toward higher velocities with PW TDI versus CTDI (bias 0.96 cm/s; 95% CI 1.08-0.85 cm/s). However, the strength of the correlation and bias varied depending on the region of the fetal heart sampled. PW TDI and CTDI velocity measurements are feasible in the fetus and correlate well. However, PW TDI velocities are higher than CTDI velocities with significant regional variation. This precludes a mathematical conversion of PW to CTDI in vivo. As PW TDI and color TDI vary, different reference values for fetal CTDI velocities were generated.

Longitudinal assessment of atrioventricular annulus excursion by grey-scale m-mode and colour tissue Doppler imaging in premature infants

BackgroundThere is a lack of standardized echocardiographic parameters to quantify ventricular function in newborn infants. Long-axis systolic ventricular shortening is a useful parameter of global ventricular function. AimsSerial assessment of long-axis systolic atrioventricular annulus excursion in premature infants. MethodsTwo-centre, prospective observational study. Fifty-seven premature infants (26 girls), median (range) gestational age 33+5 (310–34+6) weeks+days, birth weight 1925 (1127–2836) grams were included. Echocardiographic examinations were performed at the first three days of life and at expected term. Outcome measuresSystolic annulus excursion by grey-scale m-mode and colour tissue Doppler imaging (cTDI). ResultsA consistent longitudinal pattern was found for annulus excursion by grey-scale m-mode and cTDI. All parameters showed a pronounced increase at expected term (p<0.001). After normalizing for ventricular size the increase at term was less pronounced. Results were lower by cTDI than by grey-scale m-mode for the left and right ventricular walls (p<0.001). Intraobserver variability (range 1.5–9.8%) was lower than interobserver variability (5.5–18%). ConclusionsSerial assessment of longitudinal ventricular shortening in premature infants by grey-scale m-mode and cTDI was feasible and the measurements displayed a consistent pattern. cTDI excursion measurements were lower and more dependent on image quality than m-mode measurements. Lower intraobserver variability suggests that repeated measurements should preferably be performed by the same observer. Annulus excursion varies with ventricular size and we suggest normalizing measurements by ventricular size.

Tissue Doppler imaging in very preterm infants during the first 24 h of life: an observational study

BackgroundVery preterm newborn infants often need cardiovascular support. More knowledge about myocardial function and factors that influence the immature myocardium may be helpful for optimising cardiovascular support in these infants.ObjectiveSerial...

Noninvasive determination of atrial fibrillation cycle length by atrial colour tissue Doppler imaging in horses

Atrial fibrillation cycle length (AFCL) is an indicator of atrial electrical remodelling during atrial fibrillation (AF). To compare AFCL measured invasively from an intra-atrial electrogram (AFCLEGM ) with AFCL measured noninvasively by atrial colour tissue Doppler imaging (AFCLTDI ). Prospective descriptive clinical study. Measurements were performed in 31 episodes of AF or flutter in 29 horses (588 ± 61 kg bwt, 9 ± 3 years old) admitted for transvenous electrical cardioversion. The AFCLEGM was measured from an intracardiac electrogram using a bipolar sensing/pacing electrode inserted into the right atrium. The AFCLTDI was measured from atrial colour tissue velocity curves in the following 5 regions: 1) left atrial free wall from a right parasternal 4-chamber view, 2) left atrial free wall from a short-axis view, 3) left atrial free wall from a left parasternal long-axis view, 4) interatrial septum, and 5) right atrial dorsal wall near the tuberculum intervenosum. The AFCLEGM and AFCLTDI from the 5 regions were compared using a one-way repeated-measures ANOVA with Bonferroni correction for multiple comparisons and calculation of the Bland-Altman mean bias and limits of agreement of AFCLEGM and AFCLTDI . The AFCLEGM was 161 ± 18 ms in 29 AF episodes. Two horses showed atrial flutter and had an AFCLEGM of 244 and 324 ms. The mean bias between AFCLTDI and AFCLEGM ranged from -18 to +9 ms depending on the atrial wall region. The AFCLTDI was significantly shorter in the left atrial free wall from the right parasternal 4-chamber view and short-axis view than in the other regions (P<0.001). Tissue Doppler imaging allows noninvasive measurement of AFCL in horses with AF and is able to identify spatial differences within the equine atria. Atrial fibrillation cycle length is an indicator of atrial electrical remodelling and is an important parameter to study AF pathophysiology or the effect of antiarrhythmic drugs.

Total average diastolic displacement by colour tissue doppler imaging as an assessment of diastolic function

Total average diastolic displacement by colour tissue doppler imaging as an assessment of diastolic function

Usefulness of segmental tissue doppler imaging in predicting outcome in patients with ST segment elevation myocardial infarction treated with primary percutaneous coronary intervention

Purpose: To investigate the prognostic value of segmental Tissue Doppler Imaging (TDI) after an ST-elevation myocardial infarction (STEMI). Method: In total 391 patients were admitted with a STEMI. Echocardiography was performed median 2 days after the STEMI. The longitudinal systolic (s'), early diastolic (e') and late diastolic (a') myocardial velocities together with the maximal longitudinal systolic displacement (LD) were measured by color TDI at 6 mitral annular sites. Median-follow-up: 25 months. Primary endpoint: Death, heart failure or a new myocardial infarction. Results: Using the mean value of s', e', a' and LD at each of the 6 myocardial segments as cutoff, each segment was classified as high or low segmental s', e', a' or LD, respectively. Patients were stratified into three groups defined by having 4 segments with low s', e', a' or LD, respectively. Patients with >4 segments with low s', e' or LD had more than two times the risk of the combined endpoint, than patients with <2 myocardial segments of low s', e' or LD, respectively (s': HR 2.52, p=0.007; e': HR 2.66, p= 0.001; LD: HR 2.78, p<0.001). The septal and inferior myocardial segments seemed to provide most prognostic information, since only the TDI parameters obtained from these two segments generally remained as independent predictors of the combined endpoint after multivariate adjustment (Table). View this table: Segmental TDI parameters as predictors Conclusion: The risk of an adverse outcome increases incrementally with increasing number of impaired myocardial segments determined by TDI for patients with STEMI. Impaired septal and inferior myocardial performances are paramount markers of an adverse prognosis.