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Circulation Journal : Official Journal... Jul 2018Hypertrophic cardiomyopathy (HCM) is a complex and relatively common genetic cardiac disease that has been the subject of intense investigation for over 50 years. Most... (Review)
Review
Hypertrophic cardiomyopathy (HCM) is a complex and relatively common genetic cardiac disease that has been the subject of intense investigation for over 50 years. Most patients with HCM are asymptomatic, but some develop symptoms, often many years after the appearance of electrocardiographic or echocardiographic evidence of left ventricular hypertrophy. Symptoms due to the left ventricular outflow tract obstruction frequently worsen over time, requiring septal reduction therapy (SRT) despite optimal medical therapy. Percutaneous transluminal septal myocardial ablation (PTSMA) and surgical myectomy are collectively known as SRT. In this review, we will focus on the emerging concept and practical implication of SRT and the available evidence on either PTSMA or surgical myectomy in the literature.
Topics: Adult; Aged; Cardiac Surgical Procedures; Cardiomyopathy, Hypertrophic; Catheter Ablation; Drug Resistance; Female; Heart Septum; Heart Ventricles; Humans; Male; Middle Aged; Risk Factors
PubMed: 29910224
DOI: 10.1253/circj.CJ-18-0575 -
Current Cardiology Reviews Aug 2014T wave "memory" is a peculiar variety of cardiac remodeling caused by a transient change in the course of ventricular depolarization (due to ventricular pacing,... (Review)
Review
T wave "memory" is a peculiar variety of cardiac remodeling caused by a transient change in the course of ventricular depolarization (due to ventricular pacing, rate-dependent intraventricular block, ventricular preexcitation or tachyarrhythmias with wide QRS complexes). It is usually manifested by inverted T waves that appears when normal ventricular activation is restored. This phenomenon is cumulative and occurs earlier if the ventricular myocardium has previously been exposed to the same conditioning stimuli. In this article the different conditions giving rise to "classical" T wave memory development are reviewed and also "another" type of T wave memory is described. It is also shown that cardiac memory may induce not only negative (pseudo-primary) T waves but also a reversal of primary and pseudoprimary T waves leading to "normalization" of ventricular repolarization. The knowledge of these dissimilar consequences of T wave memory is essential to assess the characteristics of ventricular repolarization.
Topics: Arrhythmias, Cardiac; Bundle-Branch Block; Cardiac Pacing, Artificial; Catheter Ablation; Electrocardiography; Heart Conduction System; Heart Ventricles; Humans; Pre-Excitation Syndromes; Tachycardia; Ventricular Premature Complexes
PubMed: 24827802
DOI: 10.2174/1573403x10666140514102021 -
Heart Rhythm Sep 2020Successful bipolar radiofrequency catheter ablation (RFCA) of refractory ventricular arrhythmias (VAs) has been reported. However, the efficacy, safety, and long-term...
BACKGROUND
Successful bipolar radiofrequency catheter ablation (RFCA) of refractory ventricular arrhythmias (VAs) has been reported. However, the efficacy, safety, and long-term outcomes of bipolar RFCA of VAs are not fully determined.
OBJECTIVE
The purpose of this study was to evaluate the effectiveness and safety of bipolar RFCA in treating refractory VAs during long-term follow-up.
METHODS
Eighteen patients who underwent bipolar RFCA for ventricular tachycardia (VT) at 7 institutions were retrospectively investigated. Underlying heart diseases included remote myocardial infarction (n = 3 [17%]) and nonischemic cardiomyopathy (n = 15 [83%]). Although unipolar RFCA was performed in all patients, either it failed to suppress VT or VT recurred. The interventricular septum, left ventricular free wall, and left ventricular summit were targeted for bipolar RFCA.
RESULTS
Acute success (VT termination and/or noninducibility) was achieved with bipolar RFCA in 16 patients (89%). Complications during the procedure included complete atrioventricular block (n = 2) and coronary artery stenosis (n = 1). One patient underwent chemical ablation after bipolar RFCA failure. At 12-month follow-up, VT reoccurred in 8 patients (44%). However, in patients with recurrence, VT burden had decreased: only 4 patients underwent re-RFCA, and only 1 of the 4 required chemical ablation. In the remaining 4 patients, re-RFCA was not required, as VT was controlled by medication or an implantable cardioverter-defibrillator.
CONCLUSION
Bipolar RFCA is useful for acute suppression of refractory VT. Although VT recurrence rates during long-term follow-up were relatively high, we observed a significant reduction in VT burden.
Topics: Acute Disease; Aged; Catheter Ablation; Electrocardiography; Follow-Up Studies; Heart Conduction System; Heart Rate; Heart Ventricles; Humans; Male; Middle Aged; Retrospective Studies; Tachycardia, Ventricular; Time Factors; Treatment Outcome
PubMed: 32353585
DOI: 10.1016/j.hrthm.2020.04.028 -
JACC. Clinical Electrophysiology Sep 2020This study aimed to characterize the incidence, clinical characteristics, and electrocardiographic and electrophysiologic features of LVA VA in the absence of CAD and to...
OBJECTIVES
This study aimed to characterize the incidence, clinical characteristics, and electrocardiographic and electrophysiologic features of LVA VA in the absence of CAD and to describe the experience with catheter ablation (CA) in this group.
BACKGROUND
The left ventricular apex (LVA) is a well-described source of ventricular arrhythmias (VAs) in patients with coronary artery disease (CAD) and history of apical infarction but is a rare source of VA in the absence of CAD.
METHODS
Patients referred for CA of VA at our institution were retrospectively reviewed, and those with LVA VA in the absence of CAD were identified.
RESULTS
Of 3,710 consecutive patients undergoing VA ablation, CA of LVA VA was performed in 24 patients (20 with monomorphic ventricular tachycardia, 4 with premature ventricular contractions or nonsustained ventricular tachycardia; 18 men; mean age: 54 ± 15 years). These cases comprised 10 of 35 (29%) hypertrophic cardiomyopathy, 9 of 789 (1.2%) nonischemic cardiomyopathy, and 5 of 1,432 (0.4%) idiopathic VA ablation procedures. VA QRS morphology was predominantly right bundle with slurred upstroke and right superior frontal plane axis with precordial transition ≤V3. Epicardial ablation was performed in 14 of 24 (58%). After a median of 1 procedure (range 1 to 4) at this institution and median follow-up of 47 months (range 0-176), VA recurred in 1 patient (4%).
CONCLUSIONS
LVA VA in the absence of CAD is unusual and may occur in patients with hypertrophic cardiomyopathy or nonischemic cardiomyopathy or, rarely, in the absence of structural heart disease. It can be recognized by characteristic ECG features. CA of LVA VA is challenging; multiple procedures, including epicardial approaches, may be required to achieve VA control over long-term follow-up.
Topics: Catheter Ablation; Coronary Artery Disease; Heart Ventricles; Humans; Male; Middle Aged; Retrospective Studies; Tachycardia, Ventricular; Ventricular Premature Complexes
PubMed: 32972543
DOI: 10.1016/j.jacep.2020.04.021 -
Revista Portuguesa de Cardiologia Nov 2021
Topics: Heart Ventricles; Humans; Tachycardia, Ventricular
PubMed: 34857161
DOI: 10.1016/j.repce.2021.10.023 -
Texas Heart Institute Journal 2012
Topics: Ablation Techniques; Calcinosis; Cardiomyopathy, Hypertrophic; Ethanol; Female; Heart Aneurysm; Heart Ventricles; Humans; Incidental Findings; Male; Palliative Care; White People
PubMed: 23109785
DOI: No ID Found -
JACC. Clinical Electrophysiology Mar 2023Predictors of effective ablation lesion delivery in the human left ventricle are not established, particularly in scar. Impedance drop and electrogram (EGM) attenuation...
BACKGROUND
Predictors of effective ablation lesion delivery in the human left ventricle are not established, particularly in scar. Impedance drop and electrogram (EGM) attenuation are potential surrogates to assess this.
OBJECTIVES
This study sought to establish the relationships between ablation index (AI) and force-time integral (FTI) with impedance drop and EGM attenuation in the human left ventricle.
METHODS
Patients undergoing ventricular tachycardia ablation were recruited. EGMs were collected preablation and postablation, with impedance, AI, and FTI measured during. Based on preablation bipolar voltage, myocardium was adjudged a low-voltage myocardium (LVM) (<0.50 mV), intermediate-voltage myocardium (IVM) (0.51-1.50 mV), and normal-voltage myocardium (NVM) (>1.50 mV). Relationships between these parameters were explored.
RESULTS
A total of 402 ablations were analyzed in 15 patients. The percent impedance drop correlated with AI and FTI (P < 0.0005; repeated-measures correlation coefficient: 0.54 and 0.44, respectively), a relationship that became weaker with increased myocardial fibrosis, (repeated-measures correlation coefficient for NVM, IVM, and LVM, AI: 0.67, 0.60, and 0.52, respectively; FTI: 0.59, 0.51, and 0.42, respectively). The curve between AI/FTI and impedance drop plateaued at 763 AI and 713 gram-seconds, an impedance drop of 7.5%. Shallower curves occurred progressively from NVM to LVM (P < 0.0005). Mixed models demonstrated that AI and FTI had a greater effect on impedance drop than myocardial fibrosis, drift, or orientation, (standardized β: 0.54 and 0.48, respectively). EGMs were attenuated with ablation (29.3%; IQR: 4.4%-53.3%; P < 0.0005), but attenuation did not correlate with AI or FTI.
CONCLUSIONS
On biophysical analysis, ablation beyond an AI of 763 and FTI of 713 gs offers minimal additional efficacy on average. Fibrosis blunts ablation efficacy. AI is a stronger correlate with impedance drop than FTI. EGM attenuation does not correlate with ablation parameters. (Late Potentials and Ablation Index in Ventricular Tachycardia Ablation; NCT03437408).
Topics: Humans; Heart Ventricles; Myocardium; Catheter Ablation; Tachycardia, Ventricular; Fibrosis
PubMed: 36371330
DOI: 10.1016/j.jacep.2022.10.001 -
JACC. Clinical Electrophysiology Jul 2020
Topics: Heart Ventricles; Humans; Myocardial Infarction; Tachycardia, Ventricular
PubMed: 32703563
DOI: 10.1016/j.jacep.2020.04.013 -
Europace : European Pacing,... Mar 2020Pulsed field ablation (PFA) is a novel, non-thermal modality that selectively ablates myocardium with ultra-short electrical impulses while sparing collateral tissues....
AIMS
Pulsed field ablation (PFA) is a novel, non-thermal modality that selectively ablates myocardium with ultra-short electrical impulses while sparing collateral tissues. In a proof-of-concept study, the safety and feasibility of ventricular PFA were assessed using a prototype steerable, endocardial catheter.
METHODS AND RESULTS
Under general anaesthesia, the left and right ventricles of four healthy swine were ablated using the 12-Fr deflectable PFA catheter and a deflectable sheath guided by electroanatomic mapping. Using the study catheter, electrograms were recorded for each site and pre-ablation and post-ablation pacing thresholds (at 2.0 ms pulse width) were recorded in two of four animals. After euthanasia at 35.5 days, the hearts were submitted for histology. The PFA applications (n = 39) resulted in significant electrogram reduction without ventricular arrhythmias. In ablation sites where it was measured, the pacing thresholds increased by >16.8 mA in the right ventricle (3 sites) and >16.1 mA in the left ventricle (7 sites), with non-capture at maximum amplitude (20 mA) observable in 8 of 10 sites. Gross measurements, available for 28 of 30 ablation sites, revealed average lesion dimensions to be 6.5 ± 1.7 mm deep by 22.6 ± 4.1 mm wide, with a maximum depth and width of 9.4 mm and 28.6 mm, respectively. In the PFA lesions, fibrous tissue homogeneously replaced myocytes with a narrow zone of surrounding myocytolysis and no overlying thrombus. When present, nerve fascicles and vasculature were preserved within surrounding fibrosis.
CONCLUSION
We demonstrate that endocardial PFA can be focally delivered using this prototype catheter to create homogeneous, myocardium-specific lesions.
Topics: Animals; Arrhythmias, Cardiac; Catheter Ablation; Endocardium; Heart Ventricles; Myocardium; Swine; Tachycardia, Ventricular
PubMed: 31876913
DOI: 10.1093/europace/euz341 -
Europace : European Pacing,... Nov 2018Catheter ablation has an important role in the management of patients with ventricular tachycardia (VT) but is limited by modest long-term success rates. Magnetic... (Review)
Review
Catheter ablation has an important role in the management of patients with ventricular tachycardia (VT) but is limited by modest long-term success rates. Magnetic resonance imaging (MRI) can provide valuable anatomic and functional information as well as potentially improve identification of target sites for ablation. A major limitation of current MRI protocols is the spatial resolution required to identify the areas of tissue responsible for VT but recent developments have led to new strategies which may improve substrate assessment. Potential ways in which detailed information gained from MRI may be utilized during electrophysiology procedures include image integration or performing a procedure under real-time MRI guidance. Image integration allows pre-procedural magnetic resonance (MR) images to be registered with electroanatomical maps to help guide VT ablation and has shown promise in preliminary studies. However, multiple errors can arise during this process due to the registration technique used, changes in ventricular geometry between the time of MRI and the ablation procedure, respiratory and cardiac motion. As isthmus sites may only be a few millimetres wide, reducing these errors may be critical to improve outcomes in VT ablation. Real-time MR-guided intervention has emerged as an alternative solution to address the limitations of pre-acquired imaging to guide ablation. There is now a growing body of literature describing the feasibility, techniques, and potential applications of real-time MR-guided electrophysiology. We review whether real-time MR-guided intervention could be applied in the setting of VT ablation and the potential challenges that need to be overcome.
Topics: Catheter Ablation; Heart Ventricles; Humans; Magnetic Resonance Imaging, Cine; Surgery, Computer-Assisted; Tachycardia, Ventricular; Treatment Outcome
PubMed: 29584897
DOI: 10.1093/europace/euy040