Delayed Enhancement Magnetic Resonance Imaging Research Articles

Findings on magnetic resonance imaging of fascicular ventricular tachycardia

Idiopathic left ventricular tachycardia (ILVT) with right bundle branch block and left axis deviation originates from the left posterior fascicle--Purkinje fiber network. Scar-related ventricular tachycardias (VTs) with Purkinje fibers as a part of the reentry circuit have also been described in patients with structural heart disease. Nine patients with fascicular VT (left posterior, n = 8; left anterior, n = 1) with preserved left ventricular ejection fraction (60 ± 10%) underwent cardiac magnetic resonance imaging (MRI) including functional analysis and delayed enhancement magnetic resonance imaging (DE-MRI). No definite structural abnormalities were detected by DE-MRI in four patients. DE-MRI revealed unifocal or multifocal areas of fibrosis or scar in three patients corresponding to the regions where typical Purkinje potentials guided successful ablation of the sustained fascicular VT. A false tendon extending from the free wall to the septum was found in one patient. Moderate reduction of left ventricular ejection fraction associated with septal or multifocal left ventricular fibrosis was detected in two patients with ventricular bigeminy originating from the left posterior fascicle. During the follow-up of 29 ± 22 months after successful catheter ablation in the nine patients, one patient with septal fibrosis detected by DE-MRI had VT recurrence and received an implantable cardioverter defibrillator. Detection of local areas of fibrosis or scar by DE-MRI may help to distinguish idiopathic fascicular tachycardia from scar-related fascicular VT in patients with preserved left ventricular function.

Characteristics of Intramural Scar in Patients With Nonischemic Cardiomyopathy and Relation to Intramural Ventricular Arrhythmias

Ventricular arrhythmias have been described to originate from intramural locations. Intramural scar can be assessed by delayed-enhanced MRI, but MRIs cannot be performed on every patient. The objective of this study was to assess the value of voltage mapping to detect MRI-defined intramural scar and to correlate the scar with ventricular arrhythmias. In 15 consecutive patients (3 women; age 55±16 years; ejection fraction, 49±13%) with structural heart disease, intramural scar was detected by delayed-enhanced MRI. All patients underwent endocardial unipolar and bipolar voltage mapping guided by the registered intramural scar. Scar volume by MRI was 11.7±8 cm3 with a scar thickness of 4.6±0.7 mm and a preserved endocardial/epicardial rim of 3.3±1.6 and 4.8±2.6 mm, respectively. Endocardial bipolar voltage was 1.6±1.73 mV at the scar, 2.12±2.15 mV in a 1 cm perimeter around the scar, and 2.83±3.39 mV in remote myocardium without scar. The corresponding unipolar voltage was 4.94±3.25, 6.59±3.81, and 8.32±3.39 mV, respectively (P<0.0001). Using receiver-operator characteristic curves, a unipolar cut-off value of 6.78 mV (area under the curve, 0.78) and a bipolar cut-off value of 1.55 mV (area under the curve, 0.69) best separated endocardial measurements overlying scar as compared with areas not overlying a scar. At least 1 intramural ventricular arrhythmia was eliminated in all but 2 patients in this series. Intramural scar can be detected by unipolar and bipolar voltage, unipolar voltage being more useful. Mapping and ablation of intramural arrhythmias originating from an intramural focus can be accomplished.

Three‐Dimensional Speckle Tracking Echocardiography for the Evaluation of the Infarct Size and Segmental Transmural Involvement in Patients with Acute Myocardial Infarction

To compare parameters between three-dimensional speckle tracking echocardiography (3DSTE) and delayed enhancement magnetic resonance imaging (DE-MRI) for estimating myocardial infarct size, peak systolic strain, and transmural involvement of infarct segments in patients with acute myocardial infarction (AMI). Delayed enhancement MRI was conducted to determine myocardial infarction (MI) position, size, and transmural involvement in 26 patients with AMI. 3DSTE was conducted to measure global peak systolic strain in the left ventricle and to estimate longitudinal, circumferential, and radial peak systolic strain in papillary muscle segments. Conventional echocardiography was used to calculate the wall-motion score index (WMSI) and left ventricular ejection fraction (LVEF). Left ventricular strain parameters and LVEF were statistically significantly lower in patients with large-size MI than in those with small-size MI. Global longitudinal strain (GLS) and global circumferential strain (GCS) were significantly lower in patients with moderate-size MIs than in those with small-size MIs. All parameters except ejection fraction (EF) were lower in patients with large-size MI compared with those with moderate-size MI (P<0.05). Pearson analysis revealed that left ventricular GCS, GLS, GRS, WMSI, and LVEF of AMI patients correlated with the myocardial infarct area (MIA) measured by MRI (r=0.86, 0.81, -0.71, 0.64, and -0.66, respectively; all P-values <0.01). Transmural infarct segments exhibited significantly lower longitudinal, circumferential, and radial strains than normal segments (P<0.05). These findings indicate that 3DSTE can distinguish between MIs of different infarct sizes, and may provide an indirect means for the accurate determination of transmural involvement in infarct segments.

Is lone AF lonely yet? What about the atrial fibrosis in lone AF and implications on the cryoablation success?

Purpose: Structural (atrial fibrosis), electrical and contractile remodelling play major role in the development of a vulnerable atrial substrate for AF. Serum transforming growth factor (TGF)-β1 is the key mediator and related to the degree of atrial fibrosis. Although pulmonary vein isolation (PVI) is an effective therapetic method to eliminate triggers in the pathogenesis, the impact of atrial substrate on the PVI success remains unclear. In this study, we aimed to investigate the relation of serum TGF-β1 level and degree of left atrium (LA) fibrosis using delayed-enhanced magnetic resonance imaging (DE-MRI) and effects on the success of PVI in patients with lone paroxysmal AF. Methods: A total of 41 symptomatic lone paroxysmal AF patients (24 male, 58.5%; mean age: 49.2±7.6 years) underwent cryoballoon based catheter ablation. Cardiac DE-MRI to quantify atrial fibrosis, serum TGF- β1 levels, clinical and echocardiographic data were collected before cryoballoon ablation. Postablation blanking period was observed for 3 months. Results: Duration of the AF symptoms was median 60 months and mean EHRA score was 3.0±0.55. Mean LA anteroposterior diameter was 37.4±3.3 mm in all patients. DE-MRI revealed left atrial fibrosis in 27 (65.9%) patients [13 (31.7%) mild, 9 (22%) moderate and 5 (12.2%) severe fibrosis] with the median enhancement of 5% of the LA. At a median follow-up time of 18 months, 32 patients (78.1%) remained free of AF recurrence. While only serum TGF-β1 level (p=0.008) found as the predictor of the presence of LA fibrosis; both serum TGF-β1 level (p=0.001) and duration of AF episode (p=0.001) were found as the predictors of the extent of LA fibrosis. In multivariate cox regression analysis, extent of the LA fibrosis (p= 0.007) and early AF recurrence (p= 0.011) were found as the independent predictors of AF recurrence. Serum TGFβ-1 level of >15.894 pg/mL predicted the presence of LA fibrosis with a sensitivity of 70.37% and specificity of 100%. Also LA fibrosis extent of >20% predicted the development of AF recurrence with sensitivity of 100% and specificity of 93.75%. Conclusion: LA fibrosis determined by DE-MRI and increased serum TGFβ-1 level play major role in LA structural remodelling and has an impact on the success of PVI. Presence and extent of LA fibrosis using DE-MRI may help select appropriate patients for catheter based AF ablation and improve procedural outcome.

Role of delayed enhancement MRI and detection of esophageal complication

Role of delayed enhancement MRI and detection of esophageal complication

Efficacy of cyclosporine A-nanoparticles emulsion combined with stem cell transplantation therapy for acute myocardial infarction

To evaluate the efficacy of cyclosporine A-nanoparticles emulsion (CsA-NP) combined with adipose tissue-derived stem cells (ASCs)transplantation therapy for acute myocardial infarction (AMI) in a miniswine model. CsA-NP emulsion was prepared by the high-pressure homogenization method. Models were performed by coronary angioplasty for percutaneous balloon occlusion of left anterior descending artery (LAD). A total of 17 miniswines survived after AMI were divided into four groups: control group (n=5), CsA-NP group (n=4), ASCs group (n=4), and CsA-NP+ASCs group (n=4). ASCs or saline were delivered by intracoronary injection one week after AMI.Before cell transplantation and 8 weeks after cell transplantation, delayed-enhanced magnetic resonance imaging (DE-MRI) was performed to evaluate cardiac function and viability. The infarcted myocardium and implanted cells were histologically studied. Eight weeks after treatment, the left ventricular ejection fraction (LVEF)significantly increased in the CsA-NP+ASCs group when compared with the ASCs group [(53.6 ± 2.4)% vs. (48.3 ± 1.8)%, P<0.05]; meanwhile, the infarct size significantly decreased [(6.2 ± 1.7)cm(3) vs.(7.5 ± 0.6) cm(3), P<0.05] and the thickness of the ventricular wall significantly increased (P<0.05). Histology showed that the number of surviving cells increased nearly by three times in the CsA-NP+ASCs group, and the expressions of the cardiomyocyte specific markers (cTnT and α-actin) were detected. Histological samples also showed that CsA-NP+ASCs group reduced fibrotic tissue, and down-regulated the activation of Caspase-3. The CsA-NP+ASCs combination therapy can enhance the viability of ASCs by improving LVEF and preventing LV expansion, which may be explained that CsA-NP has the anti-apoptotic effect and can promote the survivals and proliferation of ASCs.

GW24-e0754 Cyclosporine A-nanoparticles emulsion enhances therapeutic benefit of adipose tissue-derived stem cells transplantation after acute myocardial infarction in a miniswine model

ObjectivesThis study assessed the potential enhancement therapeutic efficiency of adipose-derived stem cells (ASCs) combination with cyclosporine A nanoparticles emulsion (CsA-NP) in a swine model of myocardial infarction (MI).MethodsMIwas induced in...

Cardiac Remodeling After Atrial Fibrillation Ablation.

Radiofrequency catheter ablation procedures are considered a reasonable option for patients with symptomatic, drug refractory atrial fibrillation (AF). Ablation procedures have been reported to effectively restore sinus rhythm and provide long-term relief of symptoms. Both electrical and structural remodeling occurs with AF. A reversal of the electrical remodeling develops within 1 week after restoration to sinus rhythm following the catheter ablation. The recovery rate is faster in the right atrium than the left atrium. Reverse structural remodeling takes longer and is still present 2 to 4 months after restoration of sinus rhythm. The left atrial transport function also improves after successful catheter ablation of AF. Left atrial strain surveys from echocardiography are able to identify patients who respond to catheter ablation with significant reverse remodeling after ablation. Pre-procedural delayed enhancement magnetic resonance imaging is also able to determine the degree of atrial fibrosis and is another tool to predict the reverse remodeling after ablation. The remodeling process is complex if recurrence develops after ablation. Recent evidence shows that a combined reverse electrical and structural remodeling occurs after ablation of chronic AF when recurrence is paroxysmal AF. Progressive electrical remodeling without any structural remodeling develops in those with recurrence involving chronic AF. Whether progressive atrial remodeling is the cause or consequence during the recurrence of AF remains obscure and requires further study.

Inverse Relationship Between Fractionated Electrograms and Atrial Fibrosis in Persistent Atrial Fibrillation: Combined Magnetic Resonance Imaging and High-Density Mapping

This study sought to evaluate the relationship between fibrosis imaged by delayed-enhancement (DE) magnetic resonance imaging (MRI) and atrial electrograms (Egms) in persistent atrial fibrillation (AF). Atrial fractionated Egms are strongly related to slow anisotropic conduction. Their relationship to atrial fibrosis has not yet been investigated. Atrial high-resolution MRI of 18 patients with persistent AF (11 long-lasting persistent AF) was registered with mapping geometry (NavX electro-anatomical system (version 8.0, St. Jude Medical, St. Paul, Minnesota)). DE areas were categorized as dense or patchy, depending on their DE content. Left atrial Egms during AF were acquired using a high-density, 20-pole catheter (514 ± 77 sites/map). Fractionation, organization/regularity, local mean cycle length (CL), and voltage were analyzed with regard to DE. Patients with long-lasting persistent versus persistent AF had larger left atrial (LA) surface area (134 ± 38 cm(2) vs. 98 ± 9 cm(2), p = 0.02), a higher amount of atrial DE (70 ± 16 cm(2) vs. 49 ± 10 cm(2), p = 0.01), more complex fractionated atrial Egm (CFAE) extent (54 ± 16 cm(2) vs. 28 ± 15 cm(2), p = 0.02), and a shorter baseline AF CL (147 ± 10 ms vs. 182 ± 14 ms, p = 0.01). Continuous CFAE (CFEmean [NavX algorithm that quantifies Egm fractionation] <80 ms) occupied 38 ± 19% of total LA surface area. Dense DE was detected at the left posterior left atrium. In contrast, the right posterior left atrium contained predominantly patchy DE. Most CFAE (48 ± 14%) occurred at non-DE LA sites, followed by 41 ± 12% CFAE at patchy DE and 11 ± 6% at dense DE regions (p = 0.005 and p = 0.008, respectively); 19 ± 6% CFAE sites occurred at border zones of dense DE. Egms were less fractionated, with longer CL and lower voltage at dense DE versus non-DE regions: CFEmean: 97 ms versus 76 ms, p < 0.0001; local CL: 153 ms versus 143 ms, p < 0.0001; mean voltage: 0.63 mV versus 0.86 mV, p < 0.0001. Atrial fibrosis as defined by DE MRI is associated with slower and more organized electrical activity but with lower voltage than healthy atrial areas. Ninety percent of continuous CFAE sites occur at non-DE and patchy DE LA sites. These findings are important when choosing the ablation strategy in persistent AF.

Acute myocardial infarction: early CT aspects of myocardial microcirculation obstruction after percutaneous coronary intervention

To evaluate the capabilities of delayed enhanced multidetector CT (DE-MDCT), performed immediately after percutaneous coronary intervention (PCI), in predicting myocardial microvascular obstruction (MVO) formation assessed by delayed enhanced MRI (DE-MRI). Thirty-two patients presenting with a primary acute myocardial infarction, successfully recanalised by PCI, underwent a DE-MDCT immediately after PCI and a DE-MRI within 1week. The left ventricle was split into 64 subsegments, rated as "healthy", "infarcted" or "MVO" on DE-MRI. Their mean density was measured on DE-MDCT and calculated relative to the patient's mean healthy myocardium density. Hypoenhanced DE-MDCT subsegments, termed "CT early MVO", were also recorded. Sensitivity and specificity of DE-MDCT for MRI-assessed "MVO" subsegments detection was calculated for mean CT relative density (threshold determined from a ROC analysis), "CT early MVO" and both. Mean CT relative density was higher in MRI-assessed "MVO" than in "infarcted" and "healthy" subsegments (1.82 ± 0.46, 1.43 ± 0.36 and 1.0 ± 0.13 respectively; P < 0.001) leading to a sensitivity and specificity of 94.3% and 89.2% for a cutoff of 1.36. Sensitivity and specificity were respectively 16.9% and 99.8% for "CT early MVO" and 95.3% and 89.3% when considering the two patterns. DE-MDCT, performed immediately after PCI, allows for an accurate prediction of MVO formation. • Myocardial microvascular obstruction (MVO) is an important prognostic sequel following myocardial infarction. • MVO can be accurately predicted by multidector CT (MDCT). • Both hypo- and hyperenhanced myocardial areas can be analysed by MDCT. • MDCT may become a useful prognostic tool for acute MI outcome.

Intramural dissecting hemorrhage of the myocardium

A 59-year-old man suffering anterior myocardial infraction 3 months ago with persistent dyspnea. Echocardiography revealed marked hypokinesia of the anterior and septal left ventricular walls with reduced ejection fraction (30%.) as well as turbulent flow at the apical region was noted with suspected apical thrombus formation. Coronary artery angiogram images show total occlusion of the LAD at its proximal and mid segment, tight long 90% stenosis of the first obtuse marginal artery as well as 99% mid segment stenosis of the RCA. Cardiac MRI was done and steady state free precession (SSFP) cine images revealed localized myocardial tearing and a flap appeared at the LV apex with a small tear at the flap containing fresh blood. Delayed-enhancement magnetic resonance imaging (intravenous dosage of 0.2 mmol/kg of Gad-DTPA; inversion recovery delay 260 ms; delayed time 10 min) revealed that the flap was enhanced and deviated toward the LV cavity and scarred enhanced myocardium deviated toward the epicardial border denoting the diagnosis of an intramural dissecting hemorrhage of the myocardium at the LV apical region. This entity accounts for fewer than 10% of cardiac ruptures and may occur after myocardial infarction, chest trauma, or surgery, or even spontaneously. Preoperative diagnosis is difficult, with differential diagnosis including pseudoaneurysm and intracavitary thrombus. Considering the poor prognosis of patients treated medically (less than 10% survival), corrective surgery is usually the treatment of choice.

Regional Myocardial Wall Thinning at Multidetector Computed Tomography Correlates to Arrhythmogenic Substrate in Postinfarction Ventricular Tachycardia

Background— A majority of patients undergoing ablation of ventricular tachycardia have implanted devices precluding substrate imaging with delayed-enhancement MRI. Contrast-enhanced multidetector computed tomography (MDCT) can depict myocardial wall thickness with submillimetric resolution. We evaluated the relationship between regional myocardial wall thinning (WT) imaged by MDCT and arrhythmogenic substrate in postinfarction ventricular tachycardia. Methods and Results— We studied 13 consecutive postinfarction patients undergoing MDCT before ablation. MDCT data were integrated with high-density 3-dimensional electroanatomic maps acquired during sinus rhythm (endocardium, 509±291 points/map; epicardium, 716±323 points/map). Low-voltage areas (&lt;1.5 mV) and local abnormal ventricular activities (LAVA) during sinus rhythm were assessed with regard to the WT. A significant correlation was found between the areas of WT &lt;5 mm and endocardial low voltage (correlation- R =0.82; P =0.001), but no such correlation was found in the epicardium. The WT &lt;5 mm area was smaller than the endocardial low-voltage area (54 cm 2 [Q1–Q3, 46–92] versus 71 cm 2 [Q1–Q3, 59–124]; P =0.001). Among a total of 13 060 electrograms reviewed in the whole study population, 538 LAVA were detected and analyzed. LAVA were located within the WT &lt;5 mm (469/538 [87%]) or at its border (100% within 23 mm). Very late LAVA (&gt;100 ms after QRS complex) were almost exclusively detected within the thinnest area (93% in the WT&lt;3 mm). Conclusions— Regional myocardial WT correlates to low-voltage regions and distribution of LAVA critical for the generation and maintenance of postinfarction ventricular tachycardia. The integration of MDCT WT with 3-dimensional electroanatomic maps can help focus mapping and ablation on the culprit regions, even when MRI is precluded by the presence of implanted devices.

Delayed Enhancement Magnetic Resonance Imaging in Nonischemic Myocardial Disease

This review highlights the role of delayed enhancement magnetic resonance imaging for the diagnosis of patients with nonischemic myocardial disease. The authors discuss the use of delayed enhancement for differentiation between ischemic and nonischemic myocardial disease and for narrowing the differential diagnosis when nonischemic etiologies are suspected. In addition, special focus is given to the prognostic applications of delayed enhancement magnetic resonance imaging.

DUAL CONTRAST CARDIAC MRI FOR EVALUATION OF TELMISARTAN AND AMLODIPINE COMBINATION THERAPY IN THE DIABETIC MURINE MYOCARDIAL INJURY MODEL

Background Combination therapy has been shown to improve cardiovascular outcomes in hypertensive, diabetic patients. Amlodipine demonstrates beneficial pleiotropic effects including improved endothelial function, enhanced angiogenesis, and reduced cardiovascular risk. Telmisartan exhibits similar beneficial cardiovascular effects in diabetic patients. Amlodipine in combination with telmisartan may provide a synergistic benefit. In this study, dual contrast CMR, using manganese (manganese-enhanced MRI; MEMRI) and gadolinium (delayed-enhanced MRI; DEMRI), will evaluate the viable myocardium and myocardial scar, respectively, to investigate the underlying mechanism of combined telmisartan and amlodipine therapy. Methods Acute myocardial injury (AMI) was created by ligation of the left anterior descending coronary artery (LAD) in db/db mice. The mice were allocated to two groups: (1) tap water (n = 17) and (2) addition of telmisartan (10 mg/kg/day) and amlodipine (10 mg/kg/day) in the tap water per os ad libitum following 1 week of convalescence after AMI (n = 23). Dual contrast CMR with manganese (MEMRI) and gadolinium (DEMRI) was performed weekly with treatment to obtain LVEF and assess viable myocardium and scar myocardium. After the 4-week follow up period, contractile function was assessed by pressure-volume (PV) loop analysis. Flow cytometry of venous blood was performed to determine the percentage of circulating endothelial progenitor cells. Real-time PCR of the explanted myocardium was performed to evaluate the expression of collagen I and III, CTGF, TGFb, fibronectin and Akt. Results We demonstrate significantly improved left ventricular function at weeks 1, 2, and 4 following combined telmisartan and amlodipine therapy (32.0% ± 4.8%*, 31.8% ± 3.9%*, and 35.3% ± 2.3%*) compared to control (18.9% ± 1.5%, 21.8% ± 1.3%, and 15.7% ± 3.4%, *p < .05). PV loop analysis also demonstrates improved systolic and diastolic parameters with significantly increased maximum pressure and dp/dt max and significantly decreased LV end-diastolic pressure and Tau. MEMRI demonstrates significantly increased viable myocardial volumes in the treated mice (87.2% ± 0.92%*, 90.2% ± 1.3%*, and 91.4% ± 1.1%*) compared to control (80.5% ± 7.6%, 79.9% ± 3.1%, and 79.9% ± 3.1%, *p<0.05) throughout the study. DEMRI scar volumes initially show no difference but demonstrate a significantly decreased scar volume after 4 weeks of treatment. Furthermore, the measurement of endothelial progenitor cells demonstrate a dramatic increase in the treated compared to control mice (98.1% ± 0.25%* vs. 5.0% ± 2.6%, *p<0.05). However, no differential expression of fibrotic genes by PCR was observed. Conclusions

Pre‐ and Intra‐Procedural Predictors of Reverse Remodeling After Cardiac Resynchronization Therapy: An MRI Study

Response rate after cardiac resynchronization therapy (CRT) remains suboptimal. We sought to identify pre- and intraprocedural predictors of response using MRI. Sixty patients underwent MRI before CRT. Left ventricular (LV) volumes and ejection fraction were assessed on cine images. Intra-LV dyssynchrony was defined as the maximal delay between first peaks of radial wall motion over 20 segments. Myocardial scar extent was quantified using delayed-enhanced MRI. After CRT, the paced LV segment was characterized on preprocedural MRI with respect to presence of scar and mechanical delay, the latter being quantified using time to first peak of wall motion, expressed in percentage of the total LV activation. Echocardiography was performed before and 6 months after CRT to quantify reverse remodeling (RR). Mean RR at 6 months was 30±29% of baseline LV end-systolic volume. At univariate analysis, RR related to baseline LV end-diastolic and end-systolic volumes (R(2) = 0.101, P = 0.01; R(2) = 0.072, P = 0.04), intra-LV mechanical dyssynchrony (R(2) = 0.351, P<0.0001), scar extent (R(2) = 0.273, P< 0.0001), and presence of scar at pacing site (R(2) = 0.100, P = 0.01). QRS duration and mechanical delay at pacing site were not found related to RR (R(2) = 0.041, P = 0.12 and R(2) = 0.012, P = 0.4, respectively). At multivariate analysis intra-LV mechanical dyssynchrony, scar extent, and LV end-diastolic volume were independent predictors of RR (R(2) = 0.307, P = 0.001; R(2) = 0.096, P = 0.002, R(2) = 0.078, P = 0.005, respectively). Intra-LV dyssynchrony and scar extent are independent predictors of RR after CRT. Scar at pacing site is associated to a lesser response to CRT. Mechanical delay at this site has no impact on the response.

Late gadolinium enhancement on cardiac magnetic resonance images predicts reverse remodeling in patients with nonischemic cardiomyopathy treated with carvedilol

Several studies have demonstrated the improvement of left ventricular ejection fraction (LVEF) in heart failure patients after the long-term treatment with beta blockers [ [1] Hori M. Sasayama S. Kitabatake A. et al. Low-dose carvedilol improves left ventricular function and reduces cardiovascular hospitalization in Japanese patients with chronic heart failure: the Multicenter Carvedilol Heart Failure Dose Assessment (MUCHA) trial. Am Heart J. 2004; 147: 324-330 Abstract Full Text Full Text PDF PubMed Scopus (133) Google Scholar ], although, not all patients have similar results. To date, it has not been fully investigated that patients with systolic heart failure respond uniformly to this therapy. Myocardial fibrosis triggers impaired cardiac systolic function and has an association with adverse cardiovascular events [ 2 Wu K.C. Weiss R.G. Thiemann D.R. et al. Late gadolinium enhancement by cardiovascular magnetic resonance heralds an adverse prognosis in nonischemic cardiomyopathy. J Am Coll Cardiol. 2008; 51: 2414-2421 Abstract Full Text Full Text PDF PubMed Scopus (444) Google Scholar , 3 Cho J.R. Park S. Choi B.W. et al. Delayed enhancement magnetic resonance imaging is a significant prognostic factor in patients with non-ischemic cardiomyopathy. Circ J. 2010; 74: 476-483 Crossref PubMed Scopus (25) Google Scholar ]. Nowadays, late gadolinium enhancement (LGE) on cardiac magnetic resonance images (CMR) is widely used to assess myocardial tissue viability [ 4 Schalla S. Bekkers S.C. Dennert R. et al. Replacement and reactive myocardial fibrosis in idiopathic dilated cardiomyopathy: comparison of magnetic resonance imaging with right ventricular biopsy. Eur J Heart Fail. 2010; 12: 227-231 Crossref PubMed Scopus (60) Google Scholar , 5 Park S. Choi B.W. Rim S.J. et al. Delayed hyperenhancement magnetic resonance imaging is useful in predicting functional recovery of nonischemic left ventricular systolic dysfunction. J Card Fail. 2006; 12: 93-99 Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar ]. This study was designed to investigate whether myocardial fibrosis determined by LGE on CMR would be useful to assess left ventricular reverse remodeling (LVRR) in patients with nonischemic cardiomyopathy (NICM) treated with beta blockers.

PET imaging with FDG to guide revascularization in patients with systolic heart failure

Abstract The assessment of myocardial viability is important in the management of patients with coronary artery disease and left ventricular systolic dysfunction. There are several different imaging modalities currently available for the identification of viable myocardium: dobutamine stress echocardiography, single photon emission computed tomography, delayed-enhancement cardiac magnetic resonance imaging, and F-18 fluorodeoxyglucose positron emission tomography. The goal of viability imaging is to determine the likelihood of recovery of systolic function after revascularization. Positron emission tomography with F-18 fluorodeoxyglucose (FDG-PET) provides information about perfusion as well as myocardial metabolism, requires meticulous patient preparation, and is currently the gold standard imaging modality for the assessment of myocardial viability. Viability imaging for the purposes of predicting which patients will have improvement in left ventricular systolic function is supported under current guidelines, but the results of the recent STICH-viability substudy have created uncertainty about the incremental benefit. This review article will provide a summary of the currently available imaging modalities with an emphasis on FDG-PET and discuss the clinical relevance of viability imaging in light of the STICH-viability substudy.

Detection of intramural scar by electroanatomic mapping versus MRI in patients with non-ischemic cardiomyopathy

Background Ventricular arrhythmias have been described to originate from intramural locations. Intramural scar can be assessed by delayed enhanced magnetic resonance imaging (DE-MRI ). The objective of this study was to determine whether endocardial voltage mapping by catheter can detect the presence and extent of scar deep within the myocardial wall thickness, using DE-MRI as gold standard.

Comparison of MRI and transthoracic echocardiography for detection of myocardial lesions in patients with coronary artery disease and preserved left ventricular function

Background The presens of myocardial scar tissue as a potential arrhythmogen substrate may influence the treatment of patients with coronary artery disease (CAD). Delayed enhancement MRI (DE-MRI) allows accurate detection and visualization of myocardial scar tissue. We thought to detect myocardial scar tissue in patients with CAD and preserved left ventricular (LV) function without regional wall motion abnormalities (RWMA) in transthoracic echocardiography (TTE) using DE-MRI.

Quantitative evaluation of scar, area at risk, and wall thickening in a porcine model of sub-acute myocardial infarction (MI)

Methods Acquisition Protocol: Basal, mid, and apical slices in short axis orientation were obtained in a pig (n=14) AMI model (LAD occlusion) at 3.0T (Ingenia, Philips Healthcare): a) Cine SSFP: TR/TE/a = 3/1.5 ms/45°; acquired temporal resolution: 12 ms. b) Delayed enhancement MRI (DE-MRI): 10 min after 0.2 mmol/kg of contrast, scar was visualized using a gated IR-TFE sequence with inversion delay (TI) adjusted to null normal myocardium. c) Dual-IR T2W imaging (BB): Effective TE/TR: 80 ms/2*RR interval; TSE readout. Data Analysis: Myocardial region was manually segmented from cine, DE-MRI, and BB images (Figure 1) using MATLABTM. Myocardial region was sub-divided into co-registered segments of equal mass for each animal to calculate the following quantitative parameters: 1) Normalized wall thickness (nWT) per segment = (WTES WTED)/( WTED), where ED = End-Diastole, ES-End-Systole. 2) Segmental scar burden, defined as ratio of pixels designated as scar to total number of pixels in each segment of DE-MRI. Scar pixel is one with SI > [mean + 5*Standard Deviation (SD) of normal remote myocardium]. 3) Segmental AAR, defined as regions in BB images with SI > mean + n*SD of normal remote myocardium (AAR with n = 2, 3, 4 are AAR_2SD, AAR_3SD, and AAR_4SD, respectively).