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PloS One 2021Regulating excessive activation of fibroblasts may be a promising target to optimize extracellular matrix deposition and myocardial stiffness. Fibroblast activation...
INTRODUCTION
Regulating excessive activation of fibroblasts may be a promising target to optimize extracellular matrix deposition and myocardial stiffness. Fibroblast activation protein alpha (FAP) is upregulated in activated fibroblasts after myocardial infarction (MI), and alters fibroblast migration in vitro. We hypothesized that FAP depletion may have a protective effect on left ventricular (LV) remodeling after MI.
MATERIALS AND METHODS
We used the model of chronic MI in homozygous FAP deficient mice (FAP-KO, n = 51) and wild type mice (WT, n = 55) to analyze wound healing by monocyte and myofibroblast infiltration. Heart function and remodeling was studied by echocardiography, morphometric analyses including capillary density and myocyte size, collagen content and in vivo cell-proliferation. In non-operated healthy mice up to 6 months of age, morphometric analyses and collagen content was assessed (WT n = 10, FAP-KO n = 19).
RESULTS
Healthy FAP-deficient mice did not show changes in LV structure or differences in collagen content or cardiac morphology. Infarct size, survival and cardiac function were not different between FAP-KO and wildtype mice. FAP-KO animals showed less LV-dilation and a thicker scar, accompanied by a trend towards lower collagen content. Wound healing, assessed by infiltration with inflammatory cells and myofibroblasts were not different between groups.
CONCLUSION
We show that genetic ablation of FAP does not impair cardiac wound healing, and attenuates LV dilation after MI in mice. FAP seems dispensable for normal cardiac function and homeostasis.
Topics: Animals; Dilatation, Pathologic; Endopeptidases; Female; Heart Ventricles; Membrane Proteins; Mice; Mice, Knockout; Monocytes; Myocardial Infarction; Myocardium; Myofibroblasts
PubMed: 33667270
DOI: 10.1371/journal.pone.0248196 -
JACC. Clinical Electrophysiology Jan 2020The goal of this study was to examine the safety and efficacy of radiofrequency ablation (RFA) with irrigated catheters operated in a temperature-controlled mode for...
OBJECTIVES
The goal of this study was to examine the safety and efficacy of radiofrequency ablation (RFA) with irrigated catheters operated in a temperature-controlled mode for ventricular ablation.
BACKGROUND
Techniques to increase RFA dimensions are associated with higher risk for steam-pops. A novel irrigated catheter with circumferential thermocouples embedded in its ablation surface provides real-time surface temperature data. This study hypothesized that RFA operated in a temperature-controlled mode may allow maximizing lesion dimensions while reducing the occurrence of steam-pops.
METHODS
RFA with an irrigated catheter incorporating surface thermocouples was examined in 6 swine thigh muscle preparations and 15 beating ventricles at higher (50 W/60 s, T50C) and lower (50 W/60 s, T45C) temperature limits. Biophysical properties, lesion dimensions, and steam-pop occurrence were compared versus RFA with a standard catheter operated in power-control mode at higher (50 W/60 s) and lower (40W/60 s) power, and additionally at high power with half-normal saline (50 W/60 s).
RESULTS
In the thigh muscle preparation, lesion depth and width were similar between all groups (p = 0.90 and p = 0.17, respectively). Steam-pops were most frequent with power-controlled ablation at 50 W/60 s (82%) and least frequent with temperature-controlled ablation at 50 W/60 s, T45C (0%; p < 0.001). In the beating ventricle, lesion depth was comparable between all RFA settings (p = 0.09). Steam-pops were most frequent using power-controlled ablation at 50 W/60 s (37%) and least frequent with temperature-controlled ablation at 50 W/60 s, T45C (7%; p < 0.001). Half-normal saline had no incremental effect on lesion dimensions at 50 W in either the thigh muscle or the beating heart.
CONCLUSIONS
RFA using a novel irrigated catheter with surface thermocouples operated in a temperature-controlled mode can maximize lesion dimensions while reducing the risk for steam-pops.
Topics: Animals; Catheter Ablation; Catheters; Equipment Design; Heart Ventricles; Swine; Temperature; Therapeutic Irrigation
PubMed: 31971910
DOI: 10.1016/j.jacep.2019.08.015 -
JACC. Clinical Electrophysiology Dec 2021Stereotactic body radiotherapy (SBRT) has been suggested as a promising therapeutic alternative in cases of failed catheter ablation for recurrent ventricular... (Review)
Review
Stereotactic body radiotherapy (SBRT) has been suggested as a promising therapeutic alternative in cases of failed catheter ablation for recurrent ventricular tachycardias (VTs) in patients with structural heart disease. This case series is the first postmortem immunohistochemical analysis of morphologic changes in the myocardium early and late after SBRT. The present findings are in line with experimental observations on apoptosis followed by fibrosis. This may explain why the effect of SBRT on VT is not predominantly immediate. Together with observation of early recurrences after SBRT for VT, these data suggest that this strategy may have rather delayed antiarrhythmic effects.
Topics: Catheter Ablation; Heart Ventricles; Humans; Myocardium; Radiosurgery; Tachycardia, Ventricular
PubMed: 34600851
DOI: 10.1016/j.jacep.2021.07.012 -
Texas Heart Institute Journal Feb 2020We evaluated whether an irrigated contact force-sensing catheter would improve the safety and effectiveness of radiofrequency ablation of premature ventricular...
We evaluated whether an irrigated contact force-sensing catheter would improve the safety and effectiveness of radiofrequency ablation of premature ventricular contractions originating from the right ventricular outflow tract. We retrospectively reviewed the charts of patients with symptomatic premature ventricular contractions who underwent ablation with a contact force-sensing catheter (56 patients, SmartTouch) or conventional catheter (59 patients, ThermoCool) at our hospital from August 2013 through December 2015. During a mean follow-up of 16 ± 5 months, 3 patients in the conventional group had recurrences, compared with none in the contact force group. Complications occurred only in the conventional group (one steam pop; 2 ablations suspended because of significantly increasing impedance). In the contact force group, the median contact force during ablation was 10 g (interquartile range, 7-14 g). Times for overall procedure (36.9 ± 5 min), fluoroscopy (86.3 ± 22.7 s), and ablation (60.3 ± 21.4 s) were significantly shorter in the contact force group than in the conventional group (46.2 ± 6.2 min, 107.7 ± 30 s, and 88.7 ± 32.3 s, respectively; <0.001). In the contact force group, cases with a force-time integral <560 gram-seconds (g-s) had significantly longer procedure and fluoroscopy times (both <0.001) than did those with a force-time integral ≥560 g-s. These findings suggest that ablation of premature ventricular contractions originating from the right ventricular outflow tract with an irrigated contact force-sensing catheter instead of a conventional catheter shortens overall procedure, fluoroscopy, and ablation times without increasing risk of recurrence or complications.
Topics: Adult; Aged; Cardiac Catheterization; Cardiac Catheters; Catheter Ablation; Equipment Design; Female; Heart Rate; Heart Ventricles; Humans; Male; Middle Aged; Operative Time; Recurrence; Retrospective Studies; Time Factors; Transducers, Pressure; Treatment Outcome; Ventricular Premature Complexes
PubMed: 32148445
DOI: 10.14503/THIJ-17-6441 -
JACC. Clinical Electrophysiology Aug 2019
Topics: Catheter Ablation; Cicatrix; Heart Ventricles; Humans
PubMed: 31439294
DOI: 10.1016/j.jacep.2019.05.016 -
BioMed Research International 2021The study was aimed at exploring the electrophysiological characteristics (EPS) of the optimal ablation site and its relationship with electroanatomic voltage mapping...
BACKGROUND
The study was aimed at exploring the electrophysiological characteristics (EPS) of the optimal ablation site and its relationship with electroanatomic voltage mapping (EVM) in idiopathic premature ventricular contractions (PVCs) originating from the right ventricular outflow tract (RVOT).
METHODS
A total of 28 patients with idiopathic RVOT PVCs underwent successful ablation and EVM using a 3D electroanatomical mapping (CARTO) system.
RESULTS
Both bipolar and unipolar EVM showed a similar band-like lower-voltage area (LVA) under the pulmonary valve in all the patients; 21.4% of the targets were located in the band-like LVA. 42.9% of the targets were at the border of the band-like LVA on the bipolar voltage map, but unipolar mapping showed that 53.6% of the targets were located in the band-like LVA, and 35.7% of the targets at the border of the band-like LVA. A significant difference was found in both unipolar and bipolar voltage values between the regions within 0-5 mm above the optimal ablation site and the other regions. A similar difference was observed only in unipolar voltage values below the optimal ablation site. At the ablation site, there were frequent occurrences of a fragmented wave and voltage reversion in the bipolar electrograms, frustrated falling limbs, W bottom, and a QS configuration width > 150 ms in the unipolar electrograms.
CONCLUSIONS
EVM showed that the band-like LVA was an interesting area for the search of the optimal ablation sites of idiopathic RVOT-PVCs, especially the border area. There was focal microscarring around the ablation targets; some characteristics of EPS proved significant for successful ablation.
Topics: Adult; Catheter Ablation; Electrocardiography; Electrophysiologic Techniques, Cardiac; Female; Heart Ventricles; Humans; Male; Middle Aged; Ventricular Premature Complexes
PubMed: 33997005
DOI: 10.1155/2021/5551325 -
Revista Espanola de Cardiologia Aug 1997Arrhythmogenic right ventricular dysplasia is a disease of the cardiac muscle of unknown etiology. Landmarks of this disease are the presence of muscular atrophy and... (Review)
Review
Arrhythmogenic right ventricular dysplasia is a disease of the cardiac muscle of unknown etiology. Landmarks of this disease are the presence of muscular atrophy and replacement of ventricular myocardium by adipous and fibroadipous tissue. This disease was originally described by Fontaine et al in 1977 during surgical ablation of drug refractory ventricular tachycardias in patients without evident structural heart disease. During surgery anomalies in contractility of the right ventricle and the presence of adipous tissue were documented. Some years later, Markus et al reported the first clinical series of patients with arrhythmogenic right ventricular dysplasia. Since then, this disease has been widely recognized and must be considered in the differential diagnosis of all patients with ventricular arrhythmias originating in the right ventricle.
Topics: Arrhythmias, Cardiac; Heart Ventricles; Humans; Muscular Atrophy; Myocardium; Tachycardia, Ventricular; Ventricular Dysfunction, Right
PubMed: 9340694
DOI: 10.1016/s0300-8932(97)73261-5 -
International Journal of Medical... 2021To investigate the potential mechanism of ventricular arrhythmias (VAs) after acute ischemic stroke and explore the effects of left stellate gangling (LSG) ablation on...
To investigate the potential mechanism of ventricular arrhythmias (VAs) after acute ischemic stroke and explore the effects of left stellate gangling (LSG) ablation on VAs induced by stroke in canines. Twenty canines were randomly divided into the sham-operated group (n=6), AS group (n=7) and SGA group (n=7). Cerebral ischemic model was established in the AS group and the SGA group by right acute middle cerebral artery occlusion (MCAO). LSG ablation was performed in the SGA group as soon as MCAO. After 3 days, atrial electrophysiology and neural activity were measured in vivo. The levels of norepinephrine (NE) in plasma and ventricle were detected by ELISA. The levels of monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-α (TNF-α) and NF-κB p65 in ventricle were detected by western blotting. The pro-inflammatory polarization of macrophages in ventricle was detected by immunofluorescence. Higher ventricular tachycardia (VT) inducibility and lower ventricular fibrillation threshold (VFT) were observed in the AS group compared with those in the sham-operated group, associated with higher LSG activity and NE levels, increased number of M1 macrophages and secretion of inflammatory cytokines in ventricle (all P<0.001). Compared with the AS group, the SGA group had lower VT inducibility and higher VFT, combined with lower NE levels, and reduced number of M1 macrophages and secretion of inflammatory cytokines in ventricle (all P<0.001). LSG ablation could reduce VAs vulnerability after acute stroke by preventing the macrophages polarization and activation induced by sympathetic hyperactivity.
Topics: Animals; Arrhythmias, Cardiac; Catheter Ablation; Disease Models, Animal; Dogs; Electrocardiography; Heart Ventricles; Humans; Ischemic Stroke; Macrophages; Magnetic Resonance Imaging; Stellate Ganglion
PubMed: 33456346
DOI: 10.7150/ijms.50976 -
Journal of the American College of... Dec 2015Idiopathic ventricular arrhythmias (VAs) originating from the pulmonary sinus cusp (PSC) have not been sufficiently clarified.
Idiopathic Ventricular Arrhythmias Originating From the Pulmonary Sinus Cusp: Prevalence, Electrocardiographic/Electrophysiological Characteristics, and Catheter Ablation.
BACKGROUND
Idiopathic ventricular arrhythmias (VAs) originating from the pulmonary sinus cusp (PSC) have not been sufficiently clarified.
OBJECTIVES
The goal of this study was to investigate the prevalence, electrocardiographic characteristics, mapping, and ablation of idiopathic VAs arising from the PSC.
METHODS
Data were analyzed from 218 patients undergoing successful endocardial ablation of idiopathic VAs with a left bundle branch block morphology and inferior axis deviation.
RESULTS
Twenty-four patients had VAs originating from the PSC. In the first 7 patients, initial ablation performed in the right ventricular outflow tract failed to abolish the clinical VAs but produced a small change in the QRS morphology in 3 patients. In all 24 patients, the earliest activation was eventually identified in the PSC, at which a sharp potential was observed preceding the QRS complex onset by 28.2 ± 2.9 ms. The successful ablation site was in the right cusp (RC) in 10 patients (42%), the left cusp (LC) in 8 (33%), and the anterior cusp (AC) in 6 (25%). Electrocardiographic analysis showed that RC-VAs had significantly larger R-wave amplitude in lead I and a smaller aVL/aVR ratio of Q-wave amplitude compared with AC-VAs and LC-VAs, respectively. The R-wave amplitude in inferior leads was smaller in VAs localized in the RC than in the LC but did not differ between VAs from the AC and LC.
CONCLUSIONS
VAs arising from the PSC are not uncommon, and RC-VAs have unique electrocardiographic characteristics. These VAs can be successfully ablated within the PSC.
Topics: Adult; Arrhythmias, Cardiac; Brugada Syndrome; Bundle-Branch Block; Cardiac Conduction System Disease; Catheter Ablation; China; Echocardiography; Electrocardiography; Electrophysiological Phenomena; Epicardial Mapping; Female; Heart Conduction System; Heart Ventricles; Humans; Male; Middle Aged; Outcome Assessment, Health Care; Prevalence; Pulmonary Artery; Radiography; Tachycardia, Ventricular
PubMed: 26670064
DOI: 10.1016/j.jacc.2015.09.094 -
JACC. Clinical Electrophysiology Oct 2019This study aimed to develop a novel premature ventricular contraction (PVC) mapping method to predict PVC origins in whole ventricles by merging a magnetocardiography...
OBJECTIVES
This study aimed to develop a novel premature ventricular contraction (PVC) mapping method to predict PVC origins in whole ventricles by merging a magnetocardiography (MCG) image with a cardiac computed tomography (CT) image.
BACKGROUND
MCG can noninvasively discriminate PVCs originating from the aortic sinus cusp from those originating from the right ventricular outflow tract.
METHODS
This study was composed of 22 candidates referred for catheter ablation of idiopathic PVCs. MCG and CT were performed the same day before ablation. Estimated origins by MCG-CT imaging using the recursive null steering spatial filter algorithm were compared with origins determined by electroanatomic mapping (CARTO, Biosense Webster, Inc., Diamond Bar, California) during the ablation procedure. Radiopaque acrylic markers for the CT scan and coil markers generating a weak magnetic field during MCG measurements were used as reference markers to merge the 2 images 3-dimensionally.
RESULTS
PVC origins were determined by endocardial and epicardial mapping and ablation results in 18 (86%) patients (right ventricular outflow tract in 10 patients, aortic sinus cusp in 2 patients, interventricular septum in 1 patient, near His bundle in 1 patient, right ventricular free wall in 1 patient, and left ventricular free wall in 3 patients). Estimated origins by MCG-CT imaging matched the origins determined during the procedure in 94% (17 of 18) of patients, whereas the electrocardiography algorithms were accurate in only 56% (10 of 18). Discrimination of an epicardium versus an endocardium or right- versus left-sided septum was successful in 3 of 4 patients (75%).
CONCLUSIONS
The diagnostic accuracy of noninvasive MCG-CT mapping was high enough to allow clinical use to predict the site of PVC origins in the whole ventricles.
Topics: Adult; Aged; Aged, 80 and over; Bundle-Branch Block; Catheter Ablation; Female; Heart Ventricles; Humans; Imaging, Three-Dimensional; Magnetocardiography; Male; Middle Aged; Multimodal Imaging; Sinus of Valsalva; Tomography, X-Ray Computed; Treatment Outcome; Ventricular Premature Complexes
PubMed: 31648739
DOI: 10.1016/j.jacep.2019.06.010