Left ventricular wall motion abnormality is associated with cryptogenic stroke.

BACKGROUND: Left ventricular wall motion abnormality (LVWMA) unrelated to known cardiac risk factors is an uncertain risk for stroke. AIMS: We evaluated whether LVWMA was associated with cryptogenic stroke. METHODS: This retrospective, observational study included 4316 acute ischemic stroke patients, and the association between cryptogenic stroke and LVWMA was examined in comparison with other stroke subtypes. RESULTS: The prevalence of LVWMA was 10.0% in the study population. In a fully adjusted, binary logistic regression, LVWMA was independently associated with cryptogenic stroke compared with stroke from large artery atherosclerosis (odds ratio = 1.627, 95% confidence interval = 1.129-2.345), small vessel occlusion (odds ratio = 1.948, 95% confidence interval = 1.261-3.010), or other causes (odds ratio = 4.950, 95% confidence interval = 1.145-21.412). Meanwhile, the association of LVWMA with cryptogenic stroke was similar to the associations of LVWMA with cardioembolic stroke (odds ratio = 0.758, 95% confidence interval = 0.525-1.094) and stroke with two or more causes (odds ratio = 0.992, 95% confidence interval = 0.609-1.615). In multinomial regression, LVWMA had the strongest association with cardioembolic stroke, followed by cryptogenic stroke and stroke from two or more causes. The strength of the associations with LVWMA then decreased sequentially in patients with large artery atherosclerosis, small vessel occlusion, and other causes. CONCLUSIONS: The association of LVWMA with cryptogenic stroke was comparable to that of LVWMA with cardioembolic stroke but stronger than that of LVWMA with non-cardioembolic stroke. LVWMA unrelated to known cardiac risk factors could be considered an independent risk factor for cryptogenic stroke.

Impact of glycemic variability on myocardial infarct size in patients with ST-segment elevation myocardial infarction: quantitative assessment of left ventricular wall motion severity.

Glycemic variability (GV) is relevant to impaired myocardial salvage in acute ST-elevation myocardial infarction (STEMI). Severity of hypokinesis at the infarct site as assessed from contrast left ventriculography can reportedly predict infarct size in STEMI. We prospectively studied 58 consecutive patients (mean age, 63 ± 11 years) with anterior or inferior STEMI who underwent successful reperfusion therapy. Mean amplitude of glucose excursion (MAGE) was obtained from continuous glucose monitoring system. Patients were divided into the upper tertile of MAGE as Group H, and the other two-thirds as Group L. Serial regional wall motion severity at the infarct site was computed postprocedure and at follow-up using a quantitative left ventricular analysis system. Impaired myocardial salvage was defined as severity recovery ratio < 20%. Significantly shorter onset-to-balloon time (196.9 vs. 279.0 min, p = 0.033) and relatively lower postprocedural wall motion severity (2.4 vs. 2.9, p = 0.096) were observed in Group H, but absolute severity recovery was significantly smaller in Group H (0.5 vs. 1.3, p = 0.017). Multivariate analysis showed higher MAGE as predictive of impaired myocardial salvage (OR, 406.10; 95% CI, 4.41-37,366.60; p = 0.009). Recovery of reginal wall motion severity at the infarct site was compromised in STEMI patients with higher MAGE. Our results suggest that final infarct size is potentially larger than expected in STEMI patients with higher GV.

Electrocadiographic Scoring Helps Predict Left Ventricular Wall Motion Abnormality Commonly Observed after Subarachnoid Hemorrhage.

BACKGROUND: Cardiac wall motion abnormality (WMA) is a common complication in patients with subarachnoid hemorrhage (SAH) and is one determinant of their prognosis. The aim of this study was to examine whether the electrocardiography (ECG) findings at admission could predict WMA commonly observed after SAH. MATERIALS AND METHODS: We studied 161 SAH patients with SAH who were hospitalized in our institution between April 2007 and November 2010. We performed bedside 2-dimensional transthoracic echocardiography and 12-lead surface ECG within 24hours of SAH onset. Each of the following ECG changes was scored as having 1 point: ST elevation, ST depression and T wave inversion. We summed up the points in every patient and compared with WMA evaluated by echocardiography. RESULTS: The study subjects were classified into 2 groups based on the presence of WMA. Multivariate analysis revealed that ST elevation, ST depression and T wave inversion were strong independent predictors of WMA. Receiver operating characteristic curve determined that the threshold value to predict WMA was 4 points (sensitivity 86.5%, specificity 83.1%, AUC 0.94, P < .0001). CONCLUSIONS: In conclusion, a novel ECG score may well predict WMA after SAH which may associate with an increased risk of mortality.

Characterizing left ventricular mechanical and electrical activation in patients with normal and impaired systolic function using a non-fluoroscopic cardiovascular navigation system.

PURPOSE: Cardiac disease frequently has a degenerative effect on cardiac pump function and regional myocardial contraction. Therefore, an accurate assessment of regional wall motion is a measure of the extent and severity of the disease. We sought to further validate an intra-operative, sensor-based technology for measuring wall motion and strain by characterizing left ventricular (LV) mechanical and electrical activation patterns in patients with normal (NSF) and impaired systolic function (ISF). METHODS: NSF (n = 10; ejection fraction = 62.9 ± 6.1%) and ISF (n = 18; ejection fraction = 35.1 ± 13.6%) patients underwent simultaneous electrical and motion mapping of the LV endocardium using electroanatomical mapping and navigational systems (EnSite™ NavX™ and MediGuide™, Abbott). Motion trajectories, strain profiles, and activation times were calculated over the six standard LV walls. RESULTS: NSF patients had significantly greater motion and systolic strains across all LV walls than ISF patients. LV walls with low-voltage areas showed less motion and systolic strain than walls with normal voltage. LV electrical dyssynchrony was significantly smaller in NSF and ISF patients with narrow-QRS complexes than ISF patients with wide-QRS complexes, but mechanical dyssynchrony was larger in all ISF patients than NSF patients. The latest mechanical activation was most often the lateral/posterior walls in NSF and wide-QRS ISF patients but varied in narrow-QRS ISF patients. CONCLUSIONS: This intra-operative technique can be used to characterize LV wall motion and strain in patients with impaired systolic function. This technique may be utilized clinically to provide individually tailored LV lead positioning at the region of latest mechanical activation for patients undergoing cardiac resynchronization therapy. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov . Unique identifier: NCT01629160.

Positron Emission Tomography-Determined Hyperemic Flow, Myocardial Flow Reserve, and Flow Gradient-Quo Vadis?

Positron emission tomography/computed tomography (PET/CT) applied with positron-emitting flow tracers such as 13N-ammonia and 82Rubidium enables the quantification of both myocardial perfusion and myocardial blood flow (MBF) in milliliters per gram per minute for coronary artery disease (CAD) detection and characterization. The detection of a regional myocardial perfusion defect during vasomotor stress commonly identifies the culprit lesion or most severe epicardial narrowing, whereas adding regional hyperemic MBFs, myocardial flow reserve (MFR), and/or longitudinal flow decrease may also signify less severe but flow-limiting stenosis in multivessel CAD. The addition of regional hyperemic flow parameters, therefore, may afford a comprehensive identification and characterization of flow-limiting effects of multivessel CAD. The non-specific origin of decreases in hyperemic MBFs and MFR, however, prompts an evaluation and interpretation of regional flow in the appropriate context with the presence of obstructive CAD. Conversely, initial results of the assessment of a longitudinal hyperemic flow gradient suggest this novel flow parameter to be specifically related to increases in CAD caused epicardial resistance. The concurrent assessment of myocardial perfusion and several hyperemic flow parameters with PET/CT may indeed open novel avenues of precision medicine to guide coronary revascularization procedures that may potentially lead to a further improvement in cardiovascular outcomes in CAD patients.

4D left ventricular resultant wall motion and blood flow assessed by phase-shift velocity mapping at high-field 3T MRI.

BACKGROUND: Contractility and elasticity of the myocardium are important variables for detecting anomalies that may influence pump function. It is important to assess both wall motion and blood flow to detect regional left ventricular (LV) dysfunction and abnormal flow patterns. This study discusses four-dimensional (4D) phase-contrast magnetic resonance imaging (MRI) for simultaneous quantification and visualization of LV wall motion and blood flow. METHODS: In thirteen healthy subjects, a three-directional retrospective cardiac triggered phase-shift velocity mapping technique was used to acquire velocity data of the LV throughout the cardiac cycle. All short-axis slices of the LV wall were segmented in six sectors of 60° starting from the anterior hinge point between the right and left ventricles, from base to apex. Velocity data in resultant, radial, circumferential and longitudinal directions were calculated and presented as coloured three-directional vectors. RESULTS: Our findings showed a reduction in maximum wall velocities from base to apex, whereas for the radial and circumferential directions no significant differences were noted (13·1 ± 2·7 and 13·0 ± 2·9 cm s-1 , respectively. P = 0·9). The longitudinal maximum velocities (21·0 ± 0·6 cm s-1 ) were significantly higher than the radial and circumferential components (P = 0·002). We found that the inclination angle of the resultant blood flow was changed towards the left ventricular outflow tract during systole. CONCLUSIONS: Using this 4D MRI velocity mapping technique, we present an improved method for quantification and visualization of ventricular wall velocities in the radial, circumferential and longitudinal directions, as well as for the intracavity blood flow.

Could quantitative longitudinal peak systolic strain help in the detection of left ventricular wall motion abnormalities in our daily echocardiographic practice?

BACKGROUND: Transthoracic echocardiography is the most commonly used tool for the detection of left ventricular wall motion (LVWM) abnormalities using "naked eye evaluation". This subjective and operator-dependent technique requires a high level of clinical training and experience. Two-dimensional speckle-tracking echocardiography (2D-STE), which is less operator-dependent, has been proposed for this purpose. However, the role of on-line segmental longitudinal peak systolic strain (LPSS) values in the prediction of LVWM has not been fully evaluated. AIM: To test segmental LPSS for predicting LVWM abnormalities in routine echocardiography laboratory practice. METHODS: LVWM was evaluated by an experienced cardiologist, during routine practice, in 620 patients; segmental LPSS values were then calculated. RESULTS: In this work, reflecting real life, 99.6% of segments were successfully tracked. Mean (95% confidence interval [CI]) segmental LPSS values for normal basal (n=3409), mid (n=3468) and apical (n=3466) segments were -16.7% (-16.9% to -16.5%), -18.2% (-18.3% to -18.0%) and -21.1% (-21.3% to -20.9%), respectively. Mean (95% CI) segmental LPSS values for hypokinetic basal (n=114), mid (n=116) and apical (n=90) segments were -7.7% (-9.0% to -6.3%), -10.1% (-11.1% to -9.0%) and -9.3% (-10.5% to -8.1%), respectively. Mean (95% CI) segmental LPSS values for akinetic basal (n=128), mid (n=95) and apical (n=91) segments were -6.6% (-8.0% to -5.1%), -6.1% (-7.7% to -4.6%) and -4.2% (-5.4% to -3.0%), respectively. LPSS allowed the differentiation between normal and abnormal segments at basal, mid and apical levels. An LPSS value≥-12% detected abnormal segmental motion with a sensitivity of 78% for basal, 70% for mid and 82% for apical segments. CONCLUSIONS: Segmental LPSS values may help to differentiate between normal and abnormal left ventricular segments.

Myocardial blood flow: Putting it into clinical perspective.

In recent years, positron emission tomography/computed tomography (PET/CT)-determined myocardial perfusion in conjunction with myocardial blood flow (MBF) quantification in mL·g(-1)·min(-1) has emerged from mere research application to initial clinical use in the detection and characterization of the coronary artery disease (CAD) process. The concurrent evaluation of MBF during vasomotor stress and at rest with the resulting myocardial flow reserve (MFR = MBF during stress/MBF at rest) expands the scope of conventional myocardial perfusion imaging not only to the detection of the most advanced and culprit CAD, as evidenced by the stress-related regional myocardial perfusion defect, but also to the less severe or intermediate stenosis in patients with multivessel CAD. Due to the non-specific nature of the hyperemic MBF and MFR, the interpretation of hyperemic flow increases with PET/CT necessitates an appropriate placement in the context with microvascular function, wall motion analysis, and eventually underlying coronary morphology in CAD patients. This review aims to provide a comprehensive overview of various diagnostic scenarios of PET/CT-determined myocardial perfusion and flow quantification in the detection and characterization of clinically manifest CAD.

Left ventricular wall motion analysis to guide management of CRT non-responders.

AIMS: A discordant left ventricular (LV) lead position can be responsible for cardiac resynchronization therapy (CRT) non-response. In this study, tailored optimization of the individual LV wall motion was evaluated for the outcome in these patients. METHODS AND RESULTS: Two hundred and forty-six CRT outpatients were screened for non-response due to a discordant LV lead. In 17 patients, three-dimensional data of fluoroscopic rotation scan and echocardiography were integrated to analyse the individual LV wall motion with respect to the LV lead position. Optimization was guided by the systolic dyssynchrony index (SDI) and LV ejection fraction (LVEF) during different interventricular (VV)-delay programming. If re-programming failed, implantation of a second LV lead was performed. A discordant or partly concordant LV lead position was found in nearly all patients (16/17, 94%), which contributed to an unchanged baseline amount of LV dyssynchrony with either CRT on or off (SDI 11.3 vs. 11.0%; P = 0.744). In the majority of patients, VV-delay re-programming achieved better resynchronization, 4/17 patients needed implantation of a second LV lead. After 3 months, significant improvement of NYHA functional class (1 class; P = 0.004), peak oxygen consumption (10 vs. 13 mL/min/kg; P = 0.008), LVEF (27 vs. 39%; P = 0.003), and SDI (11.0 vs. 5.8; P = 0.02) was observed. Clinical and echocardiographic responses were found in 77 and 59%, respectively, with even good results on long-term follow-up. CONCLUSION: Tailored optimization of the individual LV wall motion can lead to significant clinical and echocardiographic improvements in previous CRT non-responders with a discordant LV lead position.

Plausible mechanisms of the rapid conversion of ST-segment elevation to T-wave inversion in Takotsubo syndrome.

Takotsubo syndrome (TTS) is characterized by electrocardiogram (ECG) diffuse ST-segment elevations (+ST), and T-wave inversions with prolongation of the QTc interval. Thus ECG-wise, TTS is not different from acute coronary syndromes (ACSs). However unlike acute ST-elevation myocardial infarction, one type of ACS, a rapid conversion of+ST to T-wave inversion with prolongation of the QTc interval is seen in TTS. The author hypothesizes that this conversion is paralleled by a change of segmental myocardial dyskinesis to akinesis, development of myocardial edema, and reversion of the cardioinhibitory ß-2 adrenergic receptor function, to its cardiostimulatory normal status. This hypothesis does not negate the plausibility that the ECG changes in TTS are due to myocardial ischemia/injury as traditionally perceived in ACSs. The reasons of the counterintuitive concurrence of the cardiac contractility to normal, or previous baseline status, while myocardial edema and T-wave inversions persist for several weeks in patients with TTS, are still elusive.

Efficiency of quantitative longitudinal peak systolic strain values using automated function imaging on transthoracic echocardiogram for evaluating left ventricular wall motion: new diagnostic criteria and agreement with naked eye evaluation by experienced cardiologist.

PURPOSE: To evaluate the efficiency of automated function imaging (AFI) on transthoracic echocardiogram (TTE) for detecting left ventricular (LV) wall motion (LVWM) abnormalities, we compared longitudinal peak systolic strain (LPSS) measurements using AFI with naked eye TTE evaluations by experienced cardiologists and non-experienced residents. MATERIALS AND METHODS: A total of 352 segments of LV myocardium from 22 consecutive subjects with LVWM abnormalities based on American Heart Association classifications (11 male, mean age 58 ± 14 years) on previous TTE (Vivid-7, GE) were evaluated. LPSS was measured using stored AFI data. Naked eye evaluation of LVWM was performed by 2 experienced cardiologists and 2 non-experienced residents. RESULTS: AFI successfully tracked 342 (97%) of all segments (mean LPSS -14.8 ± 8.1%). A significant strong negative correlation was observed between LV ejection fraction using method of disks and global LPSS (R=-0.8974). Temporary AFI criteria of LPSS were normal <-12; hypokinesis -12-2; and akinesis >2. Of 342 segments, 239, 87, and 16 segments were diagnosed as normal, hypokinesis, and akinesis, respectively. Level of agreement and kappa coefficients between qualitative evaluation of LVWM by AFI temporary criteria and qualitative evaluation of LVWM by experienced cardiologist 2 (0.784 and 0.479, respectively) were inferior to those comparing experienced cardiologists (0.845 and 0.595) but superior comparing experienced cardiologist with non-experienced resident (0.696 and 0.323), and between the 2 non-experienced-residents (0.682 and 0.347). CONCLUSION: Qualitative evaluation of LVWM using temporary AFI criteria had a 97% success rate and agreed well with findings of an experienced cardiologist. AFI can be a useful tool for training residents.

Myocardial motion analysis for determination of Tei-index of human heart.

The Tei index, an important indicator of heart function, lacks a direct method to compute because it is difficult to directly evaluate the isovolumic contraction time (ICT) and isovolumic relaxation time (IRT) from which the Tei index can be obtained. In this paper, based on the proposed method of accurately measuring the cardiac cycle physical phase, a direct method of calculating the Tei index is presented. The experiments based on real heart medical images show the effectiveness of this method. Moreover, a new method of calculating left ventricular wall motion amplitude is proposed and the experiments show its satisfactory performance.