Assessment of the left ventricular function in patients with uremia using layer-specific 2-dimensional speckle tracking echocardiography.

The aim of this research is to evaluate the longitudinal and circumferential systolic function of the left ventricle with different configurations from endocardium, midmyocardium, and epicardium, respectively, in patients with uremia using layer-specific 2-dimensional speckle tracking echocardiography (2D-STE).According to the different left ventricular (LV) configurations, 119 patients with uremia were divided into 2 groups: LV normal group (LVN group, n = 63) and LV hypertrophy group (LVH group, n = 56). In all, 66 healthy volunteers were selected as controls. High-frame rate 2-dimensional images were recorded from the apical 4-chamber view, apical 2-chamber view, parasternal LV long-axis view, and mitral annulus, papillary muscle, and apical levels of the parasternal LV short-axis view during 3 consecutive cardiac cycles. The peak systolic longitudinal strain (LS) and circumferential strain (CS) were measured in the endocardium, midmyocardium, and epicardium.In the 3 groups, the endocardium had the highest LS and CS, whereas the epicardium had the lowest LS and CS; the LS and CS of each group gradually decreased from the endocardium to the epicardium in all the 3 sections; the LS and CS of the myocardial layers were kept gradient features, namely, endocardium > midmyocardium > epicardium. The LS of the endocardium in the LVN and LVH groups was significantly lower than that in the control group (P < .05). The LS of the midmyocardium and epicardium in the LVH group were significantly lower than those in the control group (P < .05). The LS of the endocardium significantly decreased in the LVH group compared with that in the LVN group (P < .05). The CS of the endocardium and midmyocardium in the LVH group significantly decreased compared with those in the control and LVN groups (P < .05). There were no significant differences in the CS between the LVN and control groups (P > .05).In patients with uremia, the longitudinal and circumferential systolic function in 3 myocardial layers of the LVH group, and the longitudinal systolic function in endocardium of the LVN group were found significantly impaired by layer-specific 2D-STE.

Systematic review and meta-analysis of left ventricular endocardial pacing in advanced heart failure: Clinically efficacious but at what cost?

INTRODUCTION: Cardiac resynchronization using a left ventricular (LV) epicardial lead placed in the coronary sinus is now routinely used in the management of heart failure patients. LV endocardial pacing is an alternative when this is not feasible, with outcomes data sparse. OBJECTIVE: To review the available evidence on the efficacy and safety of endocardial LV pacing via meta-analysis. METHODS: EMBASE, MEDLINE, and COCHRANE databases with the search term "endocardial biventricular pacing" or "endocardial cardiac resynchronization" or "left ventricular endocardial" or "endocardial left ventricular." Comparisons of pre-and post-QRS width, LV ejection fraction (LVEF), and New York Heart Association (NYHA) functional classification was performed, and mean differences (and respective 95% confidence interval [CI]) applied as a measurement of treatment effect. RESULTS: Fifteen studies, including 362 patients, were selected. During a mean follow-up of 40 ± 24.5 months, death occurred in 72 patients (11 per 100 patient-years). Significant improvements in LVEF (mean difference 7.9%, 95% CI 5-10%, P < 0.0001; I2  = 73%), QRS width (mean difference: -41% 95% -75 to -7%; P < 0.0001; I2  = 94%), and NYHA class (mean difference: -1.06, 95% CI -1.2 to -0.9, P < 0.0001; I2  = 60%), (all P < 0.0001) occurred. Stroke rate was 3.3-4.2 per 100 patient-years, which is higher than equivalent heart failure trial populations and recent meta-analysis that included small case series. CONCLUSION: LV endocardial lead implantation is a potentially efficacious alternative to CS lead placement, but preliminary data suggest a potentially higher risk of stroke during follow-up when compared to the expected incidence of stroke in similar cohorts of patients.

The influence of masked hypertension on the right ventricle: is everything really masked?

We sought to investigate right ventricular (RV) structure, function, and mechanics in subjects with masked hypertension (MH), normotensive, and sustained hypertensive patients. This cross-sectional study included 186 untreated subjects who underwent 24-hour ambulatory blood pressure (BP) monitoring and complete two-dimensional echocardiographic (2DE) examination including multilayer strain analysis. MH was diagnosed if clinic BP was normal (<140/90 mm Hg) and 24-hour BP was increased (≥130/80 mm Hg). Global and free-wall RV longitudinal strains were significantly lower in MH and sustained hypertensive patients comparing with controls. Systolic and early diastolic RV strain rates were lower, whereas late diastolic strain rate was higher, among patients with MH and sustained hypertension than in control group. Endocardial and midmyocardial RV strains were also significantly lower in MH and hypertensive patients. There was no difference between MH and subjects with sustained hypertension. RV structure, function, and deformation are significantly changed in subjects with MH and sustained hypertension.

Application of phase coherence in assessment of spatial alignment of electrodes during simultaneous endocardial-epicardial direct contact mapping of atrial fibrillation.

AIMS: Mapping and interpretation of wave conduction patterns recorded during simultaneous mapping of the electrical activity on both endocardial and epicardial surfaces are challenging because of the difficulty of reconstruction of reciprocal alignment of electrodes in space. Here, we suggest a method to overcome this difficulty using a concept of maximized endo-epicardial phase coherence. METHODS AND RESULTS: Endo-epicardial mapping was performed in six humans during induced atrial fibrillation (AF) in right atria using two sets of 8 × 8 electrode plaques. For each electrode, mean phase coherence (MPC) with all electrodes on the opposite side of the atrial wall was calculated. Localization error was defined as a distance between the directly opposing electrode and the electrode with the maximal MPC. Overall, there was a linear correlation between MPC and distance between electrodes with R(2) = 0.34. Localization error obtained for electrodes of the plaque in six patients resulted in a mean 2.3 ± 1.9 mm for 25 s electrogram segment length. Eighty-four per cent of the measurements resulted in error smaller than 3.4 mm. The duration of the recording used to compute MPC was negatively correlated with localization error; however, the effect reached plateau for segment durations longer than 15 s. CONCLUSION: Application of the concept of maximized endo-epicardial phase coherence to electrograms during AF allows reconstruction of reciprocal alignment of the electrodes on the opposite side of the atrial wall. This approach may be especially useful in settings where the spatial position of endo- and epicardial electrodes for intracardiac mapping cannot otherwise be determined.

Global endocardial area change rate for the assessment of left ventricular relaxation and filling pressure: using 3-dimensional speckle-tracking study.

Early diastolic mitral inflow and annulus velocities ratio (E/e') is the parameter used to estimate left ventricular (LV) filling pressure, but their use for patients with reduced ejection fraction (EF) (<50 %) is controversial. LV endocardial area change rate with 3-dimensional (3-D) speckle-tracking can be used to evaluate the entire LV diastolic function, we tested the hypothesis that the early diastolic area change rate (E-ACR) represents LV relaxation, and E and E-ACR ratio (E/E-ACR) can accurately predict LV filling pressure in patients with reduced and preserved EF (≥50 %). We studied 125 patients with EF of 40 ± 17 %. E-ACR of all patients was measured using the global area change rate, and LV relaxation time constant (τ, n = 53) and pulmonary capillary wedge pressure (PCWP, n = 125) were measured by cardiac catheterization. E-ACR significantly correlated with τ (r = -0.60, p < 0.001). In the retrospective group (n = 101), E/E-ACR correlated with PCWP for patients with reduced EF as well as those with preserved EF (n = 79 and 22, r = 0.62 and 0.81, both p < 0.001). In overall patients, E/E-ACR ≥94 cm was a better predictor of elevated mean PCWP (>12 mmHg) (sensitivity: 69 %, specificity: 87 %, areas under the curves = 0.82; p < 0.001) and was a more accurate predictor than E/e' (p = 0.001) for the retrospective group. For the validation group (n = 24), E/E-ACR ≥94 cm was similarly predictive for elevated mean PCWP (sensitivity: 60 %, specificity: 100 %, positive predictive value: 100 %, negative predictive value: 78 %). In conclusions, global E-ACR by 3-D speckle-tracking proved to be dependent on LV relaxation. Moreover, E/E-ACR was found to be a powerful predictor of LV filling pressure regardless of EF.

Assessment of ventricular electrophysiological characteristics at periinfarct zone of postmyocardial infarction in rabbits following stellate ganglion block.

UNLABELLED: Assessment of Ventricular Electrophysiological Characteristics. INTRODUCTION: The aim of this study was to investigate the characteristics of ventricular electrophysiology following stellate ganglion block (SGB) at periinfarct zone in rabbits with myocardial infarction (MI). METHODS AND RESULTS: Sixty-four rabbits were randomly assigned to 2 groups: MI (n = 32), ligation of the anterior descending coronary and sham operation (SO) (n = 32), without coronary ligation. Both MI and SO groups were divided into 4 subgroups according to right or left SGB and corresponding control (n = 8, each). After 8 weeks, 90% of monophasic action potential duration (MAPD90) of epicardium, midmyocardium and endocardium, transmural dispersion of repolarization (TDR), effective refractory period (ERP), and ventricular fibrillation threshold (VFT) were measured at the infarct border zone (MI group) and corresponding zone (SO group) following SGB. For SGB, 0.5 mL of 0.25% bupivacaine was used. Compared with the corresponding control group, in both the MI and SO groups, left SGB (LSGB) prolonged the MAPD90 of the 3 layers, reduced TDR, and increased ERP and VFT (P < 0.05). However, right SGB (RSGB) shortened MAPD90, increased TDR, and reduced ERP and VFT (P < 0.05). CONCLUSION: The results of this study demonstrate that LSGB can increase the electrophysiological stability of ventricular myocardium.

Transient ischemic dilation ratio in 82Rb PET myocardial perfusion imaging: normal values and significance as a diagnostic and prognostic marker.

UNLABELLED: In myocardial perfusion SPECT, transient ischemic dilation ratio (TID) is a well-established marker of severe ischemia and adverse outcome. However, its role in the setting of (82)Rb PET is less well defined. METHODS: We analyzed 265 subjects who underwent clinical rest-dipyridamole (82)Rb PET/CT. Sixty-two subjects without a prior history of cardiac disease and with a normal myocardial perfusion study had either a low or a very low pretest likelihood of coronary artery disease or negative CT angiography. These subjects were used to establish a reference range of TID. In the remaining 203 patients with an intermediate or high pretest likelihood, subgroups with normal and abnormal TID were established and compared with respect to clinical variables, perfusion defect scores, left ventricular function, and absolute myocardial flow reserve. Follow-up was obtained for 969 ± 328 d to determine mortality by review of the social security death index. RESULTS: In the reference group, TID ratio was 0.98 ± 0.06. Accordingly, a threshold for abnormal TID was set at greater than 1.13 (0.98 + 2.5 SDs). In the study group, 19 of 203 patients (9%) had an elevated TID ratio. Significant differences between subgroups with normal and abnormal TID ratio were observed for ejection fraction reserve (5.0 ± 6.4 vs. 1.8 ± 7.9; P < 0.05), difference between end-systolic volume (ESV) at rest and stress (ΔESV[stress-rest]; 1.8 ± 7.4 vs. 12.3 ± 13.0 mL; P < 0.0001), difference between end-diastolic volume (EDV) at rest and stress (ΔEDV[stress-rest]; 10.8 ± 11.5 vs. 23.8 ± 14.6 mL; P < 0.0001), summed rest score (1.8 ± 3.8 vs. 3.8 ± 7.6; P < 0.05), summed stress score (3.0 ± 5.4 vs. 7.5 ± 9.8; P < 0.002), summed difference score (1.3 ± 2.6 vs. 3.7 ± 5.3; P < 0.02), and global myocardial flow reserve (2.1 ± 0.8 vs. 1.7 ± 0.6; P < 0.02). Additionally, TID-positive patients had a significantly lower overall survival probability (P < 0.05). In a subgroup analysis of patients without regional perfusion abnormalities, TID-positive patients' overall survival probability was significantly smaller (P < 0.03), and TID was an independent predictor (exponentiation of the B coefficients [Exp(b)] = 6.22; P < 0.009) together with an ejection fraction below 45% (Exp[b] = 6.16; P < 0.002). CONCLUSION: The present study suggests a reference range of TID for (82)Rb PET myocardial perfusion imaging that is in the range of previously established values for SPECT. Abnormal TID in (82)Rb PET is associated with more extensive left ventricular dysfunction, ischemic compromise, and reduced global flow reserve. Preliminary outcome analysis suggests that TID-positive subjects have a lower overall survival probability.

Subendocardial contractile impairment in chronic ischemic myocardium: assessment by strain analysis of 3T tagged CMR.

BACKGROUND: The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV) using tagged cardiovascular magnetic resonance (CMR) and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium. METHODS: 3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain) at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix). The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis. RESULTS: The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 ± 12.6%) than non-stenotic segment (-18.8 ± 10.2%, p < 0.0001). There was no difference in epicardial C-strain between the two groups. Use of cutoff thresholds for subendocardial C-strain differentiated stenotic segments from non-stenotic segments with a sensitivity of 77%, a specificity of 70%, and areas under the curve (AUC) of 0.76. The absolute subendocardial C-strain was significantly lower for ischemic (-6.7 ± 13.1%) than non-ischemic segments (-21.6 ± 7.0%, p < 0.0001). The absolute epicardial C-strain was also significantly lower for ischemic (-5.1 ± 7.8%) than non-ischemic segments (-9.6 ± 9.1%, p < 0.05). Use of cutoff thresholds for subendocardial C-strain differentiated ischemic segments from non-ischemic segments with sensitivities of 86%, specificities of 84%, and AUC of 0.86. CONCLUSIONS: Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest.

Endocardial surface area tracking for assessment of regional LV wall deformation with 3D speckle tracking imaging.

OBJECTIVES: The aim of this experimental study was to validate area tracking by 3-dimensional (3D) speckle tracking imaging (STI) as a method to measure changes in regional left ventricular (LV) endocardial surface area with sonomicrometry and to assess the usefulness as a wall motion evaluation method compared with 1-dimensional strain parameters. BACKGROUND: A 3D-STI allows for tracking a regional endocardial surface area during a cardiac cycle. Area tracking is a new concept that regional wall motion is quantified through the magnitude of deformation in an endocardial surface area. METHODS: In each of 8 anesthetized sheep, sonomicrometry crystals were implanted on the endocardium at the LV mid and apical anterior walls. Area change ratio (ACR) that was a novel parameter obtained by area tracking was measured as percentage change in a segmental area during systole. Segmental longitudinal (LS) and circumferential strain (CS) also were measured by 3D-STI. The ACR, LS, and CS were compared with those by sonomicrometry at baseline and during pharmacological stress tests (dobutamine and propranolol infusion) and acute myocardial ischemia induced by occlusion of mid-left ascending artery. RESULTS: The strong correlation was observed between ACR measurements by 3D-STI and those by sonomicrometry (Y = -4.20 + 0.84X, r = 0.87, p < 0.001). The ACR showed significant relations with both LS and CS (LS: Y = -15.1 + 1.73X, r = 0.73, p < 0.001; CS: Y = -5.85 + 1.06X, r = 0.79, p < 0.001). ACR showed significant differences among baseline, pharmacological stress, and acute myocardial ischemia. In contrast, LS and CS were reduced significantly during acute ischemia studies compared with those during the other studies; no differences were observed among baseline, propranolol infusion, and dobutamine infusion studies. CONCLUSIONS: Area tracking by 3D-STI can estimate changes in LV regional area and might be promising for regional wall motion evaluations.

Assessment of subendocardial structure and function.

The combination of high energy expenditure and the borderline adequacy of perfusion make the subendocardium uniquely vulnerable to injury. Selective subendocardial involvement is usually a marker of subclinical disease. Technical advances in new noninvasive imaging modalities, especially in spatial resolution, now permit qualitative and quantitative assessment of subendocardial structure, function, and perfusion. Many newer techniques have the potential to provide superior prognostic information to current standard assessment methods. This review describes the contemporary capabilities of multiple imaging modalities for assessment of the subendocardium, and seeks to guide the clinician regarding the information and technical deficiencies of each modality.

Assessment of myocardial function of the systemic right ventricle in patients with D-transposition of the great arteries after atrial switch operation by tissue Doppler echocardiography.

INTRODUCTION: The long-term follow-up of patients with D-transposition of the great arteries after atrial switch operation shows specific problems such as tricuspid valve insufficiency, rhythm disturbances and failure of the morphologic right ventricle in systemic position. Assessment of the myocardial contractility of the subaortic right ventricle by conventional echocardiography is limited. The usage of tissue Doppler echocardiography with strain combined with strain rate imaging provides a new approach for quantitative analysis of longitudinal myocardial function. The aim of this study was to assess patterns of wall motion and regional contractile function of the systemic right ventricle in patients after atrial switch operation for D-transposition of the great arteries and to compare them to those of normal subjects. PATIENTS AND METHODS: Twenty-four patients with Dtransposition of the great arteries after atrial switch operation with a mean age of 21.3 (range, 13 to 31) years and a postoperative period of 16.9 years were examined and compared to 22 control individuals with a mean age of 21.5 (range, 3 to 43) years. Tissue Doppler studies were obtained from apical 4- chamber view to determine regional systolic (Syst(T)) and diastolic (E(T), A(T)) velocities as well as E(T)/A(T) ratio at the basal free wall. The presystolic isovolumic contraction peak was assessed and the ratio of the presystolic peak velocity to the isovolumic acceleration time as the IVA index was calculated. Strain and peak systolic and diastolic strain rates were assessed on basal, middle and apical segments of the right ventricular free wall. Data obtained from the morphologic right systemic ventricle in patients were compared to those derived from the left and the right ventricle in controls. RESULTS: The right ventricular free wall systolic velocities were significantly reduced in patients compared to velocities obtained from the normal right and left ventricle. On the other hand, the IVA index was only reduced in patients compared to the IVA index in the normal subpulmonary right ventricle. Compared to data obtained from the normal systemic left ventricle, the IVA index in patients was not significantly different. In contrast, strain and strain rate parameters in all analyzed segments mostly showed a highly significant reduction compared to normal right and left ventricular data. CONCLUSION: Tissue Doppler echocardiography is a promising tool for the evaluation of regional myocardial contractile function of the morphologic right systemic ventricle in patients following atrial switch operation for D-transposition of the great arteries. Presystolic, systolic and diastolic regional ventricular function was reduced in the systemic right ventricle. However, further comparative studies using other quantitative parameters of global and regional myocardial function derived from cardiac catheterization or MRI should be performed in order to evaluate the reliability of tissue Doppler echocardiography for the assessment of global right ventricular function in these patients.

Correlation between endocardial voltage mapping and myocardial perfusion: implications for the assessment of myocardial ischemia.

BACKGROUND: Recent clinical studies using a non-fluoroscopic three-dimensional (3D) left ventricular (LV) mapping system suggested reduced endocardial voltage amplitudes measured in zones sustaining myocardial ischemia or infarction. However, the direct relationship between myocardial perfusion and endomyocardial voltage amplitudes has not been fully elucidated. METHODS: In a pig model of chronic myocardial ischemia (n = 20), LV endocardial unipolar voltage (UpV) mapping was performed using the Biosense 3D navigation system (Johnson and Johnson, Warren, New Jersey, USA) 4 weeks after ameroid constrictor placement around the left circumflex coronary artery. Echocardiography was used to assess regional changes in myocardial wall thickening (MT) and fluorescent microspheres (4 x 10/injection) were used to quantify rest regional myocardial blood flow (MBF) in ischemic (left circumflex) and remote non-ischemic (left anterior descending) regions. RESULTS: UpV measurements were reduced in ischemic compared to non-ischemic zones (9.9+/-3.3 compared with 13.3+/-3.3 mV, P = 0.03). This corresponded to changes in endocardial MBF and MT, which were both noted to be significantly reduced in the ischemic compared to the non-ischemic area (MBF, 0.50+/-0.16 compared with 0.74+/-0.15 ml/g per min, P = 0.001; MT, 26.1+/-12.0 compared with 37.4+/-10.1%, P=0.003). A positive linear correlation was found between UpV at rest and endomyocardial (but not epicardial) perfusion: UpV (mV) = 7.8+5.9xMBFendocardial (r = 0.32, P = 0.05). CONCLUSIONS: Chronic myocardial ischemia, resulting in reduced perfusion and function at rest (that is, hibernating myocardium), is characterized by a significant reduction ( approximately 25%) in endocardial UpV potentials, which correlates with reduced endomyocardial blood flow and tissue perfusion at rest.

Endoventricular patch reconstruction of ischemic failing ventricle. a single center with 20 years experience. advantages of magnetic resonance imaging assessment.

The left ventricular reconstruction (LVR) with endoventricular circular patch plasty (EVCPP) was reported in 1984 as a surgical method to rebuild left ventricular aneurysm or asynergy after myocardial infarction. Scarred LV wall can be dyskinetic or akinetic according to the type of infarction (transmural or not), and the progressive dilatation of LV (remodeling) depends on the size of the asynergic scar. Assessment of this extension and of LV volume and performances, is easy and reliable by magnetic resonance (CMR). The surgical technique is based on the insertion inside the ventricle on contractile myocardium, of a circular patch restoring curvature and physiological volume, and allowing exclusion of asynergic non resectable regions. The ventricular reconstruction method also has other components that include coronary revascularization (almost always), mitral repair (if needed) and endocardectomy when spontaneous or inducible ventricular tachycardia (VT) are present. The experience of the authors (> 1100 cases) and results obtained by other Centers, allows proposal of this technique as a way to treat the ischemic failing ventricle.

Quantification of myocardial blood flow and assessment of its transmural distribution with real-time power modulation myocardial contrast echocardiography.

BACKGROUND: The purpose of this study was to examine the ability of real-time myocardial contrast echocardiography (MCE) with power modulation to quantitate myocardial blood flow (MBF) and to assess its transmural distribution in open-chest dogs undergoing partial or total coronary stenoses. METHODS AND RESULTS: MBF was measured in 12 dogs instrumented with a cuff occluder around the left anterior descending coronary artery at rest, during partial coronary stenosis (during infusion of adenosine), and during coronary occlusion. The MCE-derived rate of microbubble velocity, beta, and myocardial blood volume, A, were obtained by curve fitting of videointensity versus time plots, after the transient destruction of microbubbles by high-energy ultrasound. The data were compared with MBF measured with radiolabeled microspheres. Significant correlations were found between radiolabeled microsphere-derived MBF and both beta (r = 0.93) and the product of A x beta (r = 0.91). MCE beta reserve also correlated well with microsphere-derived flow reserve. Comparing endocardial/epicardial MCE ratios and microsphere-derived MBF ratios, significant correlation was also found between endomicropsheres/epimicrospheres MBF ratio and both endo/epi beta (r = 0.90) and endo/epi A x beta (r = 0.88). CONCLUSIONS: Real-time power modulation MCE allows for an accurate quantification of MBF and of its transmural distribution in open-chest dogs undergoing partial or total coronary stenoses.

Contrast echocardiography is superior to tissue harmonics for assessment of left ventricular function in mechanically ventilated patients.

BACKGROUND: Assessment of left ventricular function by echocardiography is frequently challenging in mechanically ventilated patients. We evaluated the potential value of contrast-enhanced imaging and tissue harmonic imaging over standard fundamental imaging for endocardial border detection (EBD) in these patients. METHODS AND RESULTS: Fifty patients underwent standard transthoracic 2D echocardiography and were imaged in fundamental and tissue harmonic modes and subsequently with intravenous contrast (Optison). Two echocardiographers reviewed all studies for ease of visualization of endocardial border segments and scoring of wall motion. EBD for each wall segment was graded from 1 to 4 (1 = excellent EBD). Wall motion was scored by a standard 16-segment model and 1 to 5 scale. Studies were categorized as nondiagnostic if 4 of 6 segments in the apical 4-chamber view were either poorly seen or not seen (EBD score 3 or 4). Quantification of ejection fraction was independently performed offline. Visualization of 68% of all segments improved with contrast echocardiography versus 17% improvement with tissue harmonics compared with fundamental mode. Significant improvement (poor/not seen to good/excellent) occurred in 60% of segments with contrast echocardiography versus 18% with tissue harmonics. A total of 850 segments were deemed poor/not seen, 78% of which improved to good/excellent with contrast echocardiography versus 23% with tissue harmonics. Interobserver agreement on EBD was 64% to 70%. Conversion of nondiagnostic to diagnostic studies occurred in 85% of patients with contrast echocardiography versus 15% of patients with tissue harmonics. Scoring of wall motion with fundamental mode, tissue harmonics, and contrast echocardiography was possible in 61%, 74%, and 95% of individual segments, respectively (P <.001). Wall motion scoring was altered in 17% of segments with contrast echocardiography and in 8% with tissue harmonics. Interobserver agreement on wall motion scoring was 84% to 88%. Contrast echocardiography permitted measurement of ejection fraction 45% (P =.003) more often over fundamental mode versus a 27% (P =.09) increase with tissue harmonics. CONCLUSIONS: Contrast echocardiography is superior to tissue harmonic imaging for EBD, wall motion scoring, and quantification of ejection fraction in mechanically ventilated patients.

Quantitative assessment of regional right ventricular function with color kinesis.

We used color kinesis, a recent echocardiographic technique that provides regional information on the magnitude and timing of endocardial wall motion, to quantitatively assess regional right ventricular (RV) systolic and diastolic properties in 76 subjects who were divided into five groups, as follows: normal (n = 20), heart failure (n = 15), pressure/volume overload (n = 14), pressure overload (n = 12), and RV hypertrophy (n = 15). Quantitative segmental analysis of color kinesis images was used to obtain regional fractional area change (RFAC), which was displayed in the form of stacked histograms to determine patterns of endocardial wall motion. Time curves of integrated RFAC were used to objectively identify asynchrony of diastolic endocardial motion. When compared with normal subjects, patients with pressure overload or heart failure exhibited significantly decreased endocardial motion along the RV free wall. In the presence of mixed pressure/volume overload, the markedly increased ventricular septal motion compensated for decreased RV free wall motion. Diastolic endocardial wall motion was delayed in 17 of 72 segments (24%) in patients with RV pressure overload, and in 31 of 90 segments (34%) in patients with RV hypertrophy. Asynchrony of diastolic endocardial wall motion was greater in the latter group than in normal subjects (16% versus 10%: p < 0.01). Segmental analysis of color kinesis images allows quantitative assessment of regional RV systolic and diastolic properties.

Assessment of left ventricular wall motion abnormalities with the use of color kinesis: a valuable visual and training aid.

Accurate interpretation of left ventricular segmental wall motion by echocardiography is an important yet difficult skill to learn. Color-coded left ventricular wall motion (color kinesis) is a tool that potentially could aid in the interpretation and provide semiquantification. We studied the usefulness of color kinesis in 42 patients with a history of congestive cardiomyopathy who underwent two-dimensional echocardiograms and a color kinesis study. The expert's reading of the two-dimensional wall motion served as a reference for comparison of color kinesis studies interpreted by the expert and a cardiovascular trainee. Correlation between two-dimensional echocardiography and the expert's and trainee's color coded wall motion scores were r = 0.83 and r = 0.67, respectively. Reproducibility between reviewers and between operators was also assessed. Interobserver variability for color-coded wall motion showed a correlation of r = 0.78. Correlation between operators was also good; r = 0.84. Color kinesis is reliable and appears promising as an adjunct in the assessment of wall motion abnormalities by echocardiography. It is both a valuable visual aid, as well as a training aid for the cardiovascular trainee.

Quantitative assessment of left ventricular wall motion by two-dimensional echocardiography: validation during reversible ischemia in the conscious dog.

This study was designed to test the accuracy of echocardiographic radial shortening measurements during variable degrees of regional dysfunction produced by 14 transient (less than or equal to 10 min) coronary occlusions (8 left anterior descending coronary artery, 6 left circumflex coronary artery) followed by up to 24 h of reperfusion in chronically instrumented conscious dogs. Independent measurement of regional myocardial thickening was obtained using epicardial pulsed Doppler probes and served as a standard for comparison. Radial shortening fraction was derived from two-dimensional short-axis views along 12 equidistant radii. Six reference systems from the epicardial and endocardial centers of geometry (centroids) in a fixed or a floating position were explored. In the ischemic zone, percent thickening fraction averaged 22 +/- 5% at baseline, decreased to -4 +/- 4% during occlusion and gradually returned to baseline values after reperfusion. Percent change in radial shortening correlated significantly with percent change in thickening fraction in the ischemic zone. The worst correlation was seen with the floating endocardial centroid (r = 0.68), and the best was observed with the epicardial floating reference (r = 0.91). Moreover, the epicardial floating reference provided narrower 95% confidence limits of radial shortening and less heterogeneity among radii than did fixed reference systems. Thus, compared with an independent standard, echocardiographic measurement of radial shortening from the short axis provided recognition of discrete grades of regional dysfunction induced by transient reversible ischemia. This technique may be amenable for serial assessment of regional function after interventions on the ischemic myocardium.

Clinical benefits of telemetered electrograms in assessment of DDD function.

The advent of telemetry of the endocardial electrogram is a new capability. It must be convenient to use if it is to gain acceptance. Our experience is still growing but already it is confirming information that was either deduced or previously only available by active invasive procedures. The potential value of the technology has only been touched upon in this presentation. We are convinced that it will grow and that its value will be further established as more physicians have an opportunity to use it and gain additional experience.