Influence of Intramyocardial Adipose Tissue on the Accuracy of Endocardial Contact Mapping of the Chronic Myocardial Infarction Substrate (original) (raw)
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Frontiers in Cardiovascular Medicine
BackgroundOver the past years, information about the crosstalk between the epicardial adipose tissue (EAT) and the cardiovascular system has emerged. Notably, in the context of acute myocardial infarction (AMI), EAT might have a potential role in the pathophysiology of ventricular structural changes and function, and the clinical evolution of patients. This study aims to assess the impact of EAT on morpho-functional changes in the left ventricle (LV) and the outcome of patients after an AMI.MethodsWe studied prospectively admitted patients to our hospital with a first episode of AMI. All patients underwent percutaneous coronary intervention (PCI) during admission. Transthoracic echocardiography (TTE) was performed within 24–48 h after PCI, as well as blood samples to assess levels of galectin-3 (Gal-3). Cardiac magnetic resonance (CMR) was performed 5–7 days after PCI. Clinical follow-up was performed at 1 and 5 years after MI.ResultsMean age of our cohort (n = 41) was 57.5 ± 10 yea...
JACC: Clinical Electrophysiology, 2020
OBJECTIVES This study sought to investigate the sensitivity of electroanatomical mapping (EAM) to detect scar as identified by late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR). BACKGROUND Previous studies have shown correlation between low voltage electrogram amplitude and myocardial scar. However, voltage amplitude is influenced by the distance between the scar and the mapping surface and its extent. The aim of this study is to examine the reliability of low voltage EAM as a surrogate for myocardial scar using LGE-derived scar as the reference. METHODS Twelve swine underwent anterior wall infarction by occlusion of the left anterior descending artery (LAD) (n ¼ 6) or inferior wall infarction by occlusion of the left circumflex artery (LCx) (n ¼ 6). Subsequently, animals underwent CMR and EAM using a multielectrode mapping catheter. CMR characteristics, including wall thickness, LGE location and extent, and EAM maps, were independently analyzed, and concordance between voltage maps and CMR characteristics was assessed. RESULTS LGE volume was similar between the LCx and LAD groups (8.5 AE 2.2 ml vs. 8.3 AE 2.5 ml, respectively; p ¼ 0.852). LGE scarring in the LAD group was more subendocardial, affected a larger surface area, and resulted in significant wall thinning (4.88 AE 0.43 mm). LGE scarring in the LCx group extended from the endocardium to the epicardium with minimal reduction in wall thickness (scarred: 5.4 AE 0.67 mm vs. remote: 6.75 AE 0.38 mm). In all the animals in the LAD group, areas of low voltage corresponded with LGE and wall thinning, whereas only 2 of 6 animals in the LCx group had low voltage areas on EAM. Bipolar and unipolar voltage amplitudes were higher in thick inferior walls in the LCx group than in thin anterior walls in the LAD group, despite a similar LGE volume. CONCLUSIONS Discordances between LGE-detected scar areas and low voltage areas by EAM highlighted the limitations of the current EAM system to detect scar in thick myocardial wall regions.
Circulation, 1999
Background —Catheter ablation for ventricular tachycardia in healed infarction is limited to patients with inducible, tolerated arrhythmias. Strategies that would allow mapping during sinus rhythm might obviate this limitation. Methods and Results —Two sets of experiments were performed in adult pigs to refine a new technique for left ventricular mapping. First, detailed endocardial maps were done in 5 normal pigs and 7 pigs 6 to 10 weeks after left anterior descending coronary artery infarction to characterize electrograms in normal and infarcted tissue by electroanatomic mapping (CARTO, Biosense). Electrogram recording sites were verified by intracardiac echo (ICE, 9 MHz) and grouped by location: infarct (area of akinesis by ICE), border (0.5-cm perimeter of akinetic area), and remote. Compared with remote sites, electrograms from infarct sites had smaller amplitudes (1.2±0.5 versus 5.1±2.1 mV, P <0.001), longer durations (74.2±26.3 versus 36.3±6.4 ms, P <0.001), and more fr...
Pacing and Clinical Electrophysiology, 2015
Background: Endocardial mapping for scars and abnormal electrograms forms the most essential component of ventricular tachycardia ablation. The utility of ultra-high resolution mapping of ventricular scar was assessed using a multielectrode contact mapping system in a chronic canine infarct model. Methods: Chronic infarcts were created in five anesthetized dogs by ligating the left anterior descending coronary artery. Late gadolinium-enhanced magnetic resonance imaging (LGE MRI) was obtained 4.9 ± 0.9 months after infarction, with three-dimensional (3D) gadolinium enhancement signal intensity maps at 1-mm and 5-mm depths from the endocardium. Ultra-high resolution electroanatomical maps were created using a novel mapping system (Rhythmia Mapping System,
Heart rhythm, 2018
Measurement of myocardial electrical impedance can allow recognition of infarct scar and is theoretically not influenced by changes in cardiac activation sequence, but this is not known. The objectives of this study were to evaluate the ability of endocardial electrical impedance measurements to recognize areas of infarct scar and to assess the stability of the impedance data under changes in cardiac activation sequence. One-month-old myocardial infarction confirmed by cardiac magnetic resonance imaging was induced in 5 pigs submitted to coronary artery catheter balloon occlusion. Electroanatomic data and local electrical impedance (magnitude, phase angle, and amplitude of the systolic-diastolic impedance curve) were recorded at multiple endocardial sites in sinus rhythm and during right ventricular pacing. By merging the cardiac magnetic resonance and electroanatomic data, we classified each impedance measurement site either as healthy (bipolar amplitude ≥1.5 mV and maximum pixel i...
The American Journal of Cardiology, 2017
According to the so-called obesity paradox, obesity might present a protective role in patients with myocardial infarction. We aimed to assess the influence of the epicardial adipose tissue (EAT) volume on cardiac healing and remodeling in patients with acute ST-elevation myocardial infarction (STEMI). We prospectively included 193 consecutive patients presenting a first STEMI without known coronary artery disease. Cardiac magnetic resonance imaging (CMR) was performed at baseline and after a 3month follow-up. EAT volume was computed and the population was divided into quartiles-the highest quartile of EAT defining the high EAT group (h-EAT). hEAT was associated with increased body mass index, higher rate of history of hypertension, and smaller infarct size at initial CMR assessment (18.3±11.9 vs 23±13.7% of total left ventricular (LV) mass, p=0.041). Moreover, microvascular obstruction was less frequent in the hEAT group (36.2 vs 59.3%, p=0.006). There were no differences in LV ejection fraction (LVEF), LV volumes, systolic wall stress, coronary artery burden and clinical events during the index hospitalization between the EAT groups at baseline and at follow-up. Linear regression analysis showed hEAT to be associated with smaller infarct size at baseline (β coefficient=-3.25 [95% CI:-5.89;-0.61], p=0.016). hEAT also modified positively the effect of infarct size on LV remodeling, as assessed by the change in LVEF (p = 0.046). In conclusion, hEAT was paradoxically related to smaller infarct size and acted as an effect modifier in the relation between the extent of infarct size and LVEF changes. Patients with higher extent of EAT presented better cardiac healing.
Experimental and clinical cardiology, 2008
Left ventricular electromechanical mapping (EMM) determines myocardial viability on the basis of endocardial electrograms. The aim of the present study was to validate EMM in differentiating infarcted myocardium from viable myocardium by histopathological analysis. Sixty days after implanting an ameroid constrictor over the left circumflex artery to create chronic ischemia in 19 pigs, EMM was performed to construct unipolar voltage (UPV), bipolar voltage (BPV) and linear local shortening (LLS) maps. Noninfarcted and infarcted myocardium were identified by histopathology. Threshold determinations comparing noninfarcted tissue with scarred tissue were made by measuring the area under the receiver operating characteristic curves. From the 19 hearts, 149 myocardial segments were divided into noninfarcted myocardium (n=128) and transmural infarct (n=21). UPV, BPV and LLS values (4.7+/-1.2 mV, 2.8+/-2.5 mV and 10.0+/-5.1%, respectively) of infarcted segments were significantly lower than ...
Journal of Electrocardiology, 2002
The uniform double layer (UDL) source model can be used to estimate the activation sequence of the heart at the ventricular surface from electrocardiogram (ECGs) measured on the body surface. Over the past decade, promising results have been obtained. However, the clinical value of the UDL model still has to be demonstrated. This paper reports on the results of experiments to validate the UDL-based method in patients who underwent open-chest surgery. The patients had previously suffered from ventricular arrhythmias after myocardial infarction. Prior to surgery, the ECG was recorded in 123 leads on the body surface at Helsinki University Central Hospital (HUCH). Based on MR images an individual volume conductor model was constructed for each patient. During surgery at HUCH, potentials were recorded invasively in 102 bipolar leads on the epicardium. Based on these data, activation maps were constructed. These maps were compared to the activation maps obtained by the UDL based inverse applied to the body-surface ECG data. The results showed that the overall pattern of the activation sequence found by the UDL corresponded well to the actual activation pattern for some patients. However, the results were poor for those patients whose heart had an infarcted region of considerable size. In a follow-up study a method was developed to take infarction into account in the UDL-based inverse procedure. The results of this study showed that one cannot expect good results from the UDL-based inverse in the presence of an old myocardial infarction unless that infarction is accounted for in the inverse procedure.
Journal of Cardiovascular Magnetic Resonance, 2009
Introduction: Prophylactic implantation of a cardioverter/ defibrillator (ICD) has been shown to reduce mortality in patients with chronic myocardial infarction (CMI) and an increased risk for life threatening ventricular arrhythmia (VA). The use of ICDs in this large patient population is still limited by high costs and possible adverse events including inappropriate discharges and progression of heart failure. VA is related to infarct size and seems to be related to infarct morphology. Contrast enhanced cardiovascular magnetic resonance imaging (ceCMR) can detect and quantify myocardial fibrosis in the setting of CMI and might therefore be a valuable tool for a more accurate risk stratification in this setting. Hypothesis: ceCMR can identify the subgroup developing VA in patients with prophylactic ICD implantation following MADIT criteria. Methods: We prospectively enrolled 52 patients (49 males, age 69 ± 10 years) with CMI and clinical indication for ICD therapy following MADIT criteria. Prior to implantation (36 ± 78 days) patients were investigated on a 1.5 T clinical scanner (Siemens Avanto © , Germany) to assess left ventricular function (LVEF), LV end-diastolic volume (LVEDV) and LV mass (sequence parameters: GRE SSFP, matrix 256 × 192, short axis stack; full LV coverage, no gap; slice thickness 6 mm). For quantitative assessment of infarct morphology late gadolinium enhancement (LGE) was performed including measurement of total and relative infarct mass (related to LV mass) and the degree of transmurality (DT) as defined by the percentage of transmurality in each scar. (sequence parameters: inversion recovery gradient echo; matrix 256 × 148, imaging 10 min after 0.2 μg/kg gadolinium DTPA; slice orientation equal to SSFP). MRI images were analysed using dedicated software (MASS © , Medis, Netherlands). LGE was defined as myocardial areas with signal intensity above the average plus 5 SD of the remote myocardium. After implantation, patients were followed up including ICD readout after 3 and than every 6 months for a mean of 945 ± 344 days. ICD data were evaluated by an experienced electrophysiologist. Primary endpoint was the occurrence of an appropriate discharge (DC), antitachycard pacing (ATP) or death from cardiac cause. Results: The endpoint occurred in 10 patients (3 DC, 6 ATP, 1 death). These patients had a higher relative infarct mass (28 ± 7% vs. 22 ± 11%, p = 0.03) as well as high degree of transmurality (64 ± 22% vs. 44 ± 25%, p = 0.05). Their LVEF (29 ± 8% vs. 30 ± 4%, p = 0.75), LV mass (148 ± 29 g vs. 154 ± 42 g, p = 0.60), LVEDV (270 ± 133 ml vs. 275 ± 83 ml, p = 0.90) or total infarct mass (43 ± 19 g vs. 37 ± 21 g, p = 0.43) were however not significant from the group with no events. In a cox proportional hazards regression model including LVEF, LVEDV, LV mass, DT and age, only degree of transmurality and relative infarct mass emerged as independent predictors of the primary end point (p = 0.009). Conclusion: In CMI-patients fulfilling MADIT criteria ceCMR could show that the extent and transmurality of myocardial scarring are independent predictors for life threatening ventricular arrhythmia or death. This additional information could lead to more precise risk stratification and might reduce adverse events and cost of ICD therapy in this patient population. Larger trials are needed to confirm this finding.