Anteroseptal Scar Research Articles

Case series on stereotactic body radiation therapy in non-ischemic cardiomyopathy patients with recurrent ventricular tachycardia.

The efficacy of stereotactic body radiation therapy (SBRT) as an alternative treatment for recurrent ventricular tachycardia (VT) is still unclear. This study aimed to report the outcome of SBRT in VT patients with nonischemic cardiomyopathy (NICM). The determination of the target substrate for radiation was based on the combination of CMR results and electroanatomical mapping merged with the real-time CT scan image. Radiation therapy was performed by Flattening-filter-free (Truebeam) system, and afterward, patients were followed up for 13.5 ± 2.8 months. We analyzed the outcome of death, incidence of recurrent VT, ICD shocks, anti-tachycardia pacing (ATP) sequences, and possible irradiation side-effects. A total of three cases of NICM patients with anteroseptal scar detected by CMR. SBRT was successfully performed in all patients. During the follow-up, we found that VT recurrences occurred in all patients. In one patient, it happened during a 6-week blanking period, while the others happened afterward. Re-hospitalization due to VT only appeared in one patient. Through ICD interrogation, we found that all patients have reduced VT burden and ATP therapies. All of the patients died during the follow-up period. Radiotherapy-related adverse events did not occur in all patients. SBRT therapy reduces the number of VT burden and ATP sequence therapy in NICM patients with VT, which had a failed previous catheter ablation. However, the efficacy and safety aspects, especially in NICM cases, remained unclear.

Prior myocarditis and ventricular arrhythmias: The importance of scar pattern

Multiple studies have addressed the importance of anteroseptal scar in patients with nonischemic cardiomyopathy. However, this pattern has never been fully evaluated in patients with prior myocarditis. The purpose of this study was to evaluate whether anteroseptal scar is associated with worse outcome in patients with prior myocarditis and how it affects the efficacy of catheter ablation (CA). This was a retrospective study of consecutive patients with prior myocarditis and arrhythmic presentation. Cardiac magnetic resonance and electroanatomic voltage mapping were used to identify the scar pattern. Patients were referred for either CA or escalated antiarrhythmic drug (AAD) therapy. The main outcome was ventricular arrhythmia (VA)-free survival according to the presence of anteroseptal scar. A total of 144 consecutive patients with prior myocarditis were included. Mean age was 42.1 ± 14.9 years, and 58% were men. Ejection fraction was normal in 73% of patients. Anteroseptal scar was present in 44% of cases. Sixty-one patients (42%) underwent CA. Overall, at 2-year follow-up, VA-free survival was 77% in the CA group. After CA, the mean number of AADs taken by each patient decreased from 1.8 to 0.9 per day (p<0.001). The presence of anteroseptal scar was found to be an independent predictor of VA relapse both in patients treated with CA (hazard ratio [HR] 3.6; 95% confidence interval [CI] 1.1-11.4; P = .03) and in the overall population (HR 2.0; 95% CI 1.2-3.5; P = .02) . In patients with prior myocarditis and VA, the presence of anteroseptal scar negatively predicts outcomes irrespective of treatment strategy.

Abstract MP164: Electrophysiologic Conservation of Epicardial Conduction Dynamics After Myocardial Infarction in Newborn Piglets

Introduction: Newborn piglets reportedly exhibit natural heart regeneration after myocardial infarction (MI). However, the electrophysiologic properties of this regenerated muscle have not been examined. We hypothesized that epicardial electrical conduction is preserved after MI in newborn piglets. Methods: Yorkshire-Landrace piglets underwent left anterior descending coronary artery ligation on postnatal day 1 (P1, n=4) or postnatal day 7 (P7, n=7), infarcting the anteroseptal left ventricle through which the Purkinje conduction system passes. After 7 weeks, cardiac magnetic resonance imaging (MRI) was performed with late gadolinium enhancement for fibrosis analysis. Epicardial conduction mapping was performed using custom 3D-printed, 256-channel high-resolution mapping arrays (Fig 1A). Age- and weight-matched healthy pigs served as controls (n=7). Data are expressed as mean±SD. Results: MRI analysis revealed significant differences between the control, P1, and P7 groups in ejection fraction (47.6±3.1% vs 37.6±3.3% vs 30.2±6.6%, p&lt;0.001, Fig 1B) and the degree of transmural anteroseptal LV scar (0.0±0.0% vs 9.1±5.4% vs 15.4±4.2%, p&lt;0.001), respectively. Evidence of infarcted myocardium was identified with high-resolution mapping in the P1 and P7 piglets (black arrows, Fig 1C-F). Epicardial electrical conduction was preserved in control and all P1 pigs (Figs 1C-D), whereas variable conduction block or aberrant propagation were observed in all P7 pigs (Fig 1E-F, p=0.001). Conclusion: P1 piglets exhibited incomplete natural cardiac regeneration after MI but nevertheless demonstrated electrophysiologic conservation of epicardial conduction dynamics.

Mechanism of Abnormal Septal Motion in Left Bundle Branch Block: Role of Left Ventricular Wall Interactions and Myocardial Scar

ObjectivesThis study sought to investigate how regional left ventricular (LV) function modifies septal motion in left bundle branch block (LBBB). BackgroundIn LBBB, the interventricular septum often has marked pre-ejection shortening, followed by immediate relengthening (rebound stretch). This motion, often referred to as septal flash, is associated with positive response to cardiac resynchronization therapy (CRT). MethodsIn 10 anesthetized dogs, we induced LBBB by radiofrequency ablation and occluded the circumflex (CX) (n = 10) and left anterior descending (LAD) (n = 6) coronary arteries, respectively. Myocardial dimensions were measured by sonomicrometry and myocardial work by pressure-segment length analysis. In 40 heart failure patients with LBBB, including 20 with post-infarct scar and 20 with nonischemic cardiomyopathy, myocardial strain was measured by speckle-tracking echocardiography and myocardial work by pressure-strain analysis. Scar was assessed by cardiac magnetic resonance imaging with late gadolinium enhancement. ResultsDuring LBBB, each animal showed typical septal flash with pre-ejection shortening and rebound stretch, followed by reduced septal systolic shortening (p < 0.01). CX occlusion caused LV lateral wall dysfunction and abolished septal flash due to loss of rebound stretch (p < 0.0001). Furthermore, CX occlusion restored septal systolic shortening to a similar level as before induction of LBBB and substantially improved septal work (p < 0.001). LAD occlusion, however, accentuated septal flash by increasing rebound stretch (p < 0.05). Consistent with the experimental findings, septal flash was absent in patients with LV lateral wall scar due to lack of rebound stretch (p < 0.001), and septal systolic shortening and septal work far exceeded values in nonischemic cardiomyopathy (p < 0.0001). Septal flash was present in most patients with anteroseptal scar. ConclusionsLV lateral wall dysfunction and scar abolished septal flash and markedly improved septal function in LBBB. Therefore, function and scar in the LV lateral wall should be taken into account when septal motion is used to evaluate dyssynchrony.

Impact of ostium secundum atrial septal defect closure on the resolution of falsely positive electrocardiographic criteria for myocardial scarring

BackgroundElectrocardiographic (ECG) Selvester QRS score criteria with false indication of anteroseptal scarring consistent with myocardial infarction have been found in patients with ostium secundum atrial septal defect (OS-ASD). The objective of this study was to evaluate ECGs pre and post percutaneous transcatheter OS-ASD closure to test the hypothesis that the falsely positive criteria for anteroseptal scar decline 1 day post procedure. MethodsPatients (n=34, mean age 48 ±17 years, 79% female) that underwent OS-ASD closure and had undergone pre procedure cardiac magnetic resonance imaging showing no left ventricular (LV) scarring were included in this study. ECGs pre and 1 day post procedure were assessed according to the QRS Selvester scoring system and compared. ResultsMean Selvester score in anteroseptal regions pre procedure was 6.6 (0.0–6.8) % LV scar and decreased to 4.3 (0.0–6.0) % LV scar one day after the procedure (p=0.01). Mean Selvester score in lateral regions pre procedure was 3.7 (0.0–3.0) %LV scar and decreased to 2.8 (0.0–0.0) % LV scar one day post procedure (p=0.25). DiscussionOS-ASD patients with falsely positive anteroseptal scar criteria by the Selvester QRS score pre procedure have a significant decrease in anteroseptal Selvester score 1 day post procedure. The falsely positive anteroseptal scar criteria did not completely resolve 1 day post procedure. Further studies are needed to investigate the relationship between ECG criteria for anteroseptal scar and right ventricular volume overload in late follow up.

Contrast-Enhanced MRI–Derived Scar Patterns and Associated Ventricular Tachycardias in Nonischemic Cardiomyopathy

Background— There are limited data on typical arrhythmogenic substrates and associated ventricular tachycardias (VT) in patients with nonischemic cardiomyopathy. The substrate location may have implications for the ablation strategy. Methods and Results— Nineteen consecutive patients with nonischemic cardiomyopathy (age 58±14 years, 79% men, left ventricular ejection fraction 41±11%) who underwent contrast-enhanced MRI and VT ablation were included. On the basis of 3-dimensional contrast-enhanced MRI–derived scar reconstructions, 8 patients (42%) had predominant basal anteroseptal scar, 9 patients (47%) had predominant inferolateral scar, and 2 patients (11%) had other scar types. Three distinct VT morphologies (≥1 of 3 inducible in 16/19 patients) were associated with underlying scar type. In 9 patients with anteroseptal scar–related VT (8/9 predominant scar, 1/9 nonpredominant), ablation target sites (defined as sites with ≥11/12 pacemap, concealed entrainment or VT termination during ablation) were located in the aortic root and/or anteroseptal left ventricular endocardium in 8 patients (89%) and in the anterior cardiac vein in 1 patient (11%), with additional target sites at the right ventricular septum in 2 patients (22%) and at the epicardium in 1 patient (11%). In contrast, in 8 patients with predominant inferolateral scar–related VT, target sites were located at the epicardium in 5 patients (63%) and in the endocardial inferolateral left ventricle in 3 patients (37%). Conclusions— Two typical scar patterns (anteroseptal and inferolateral) account for 89% of arrhythmogenic substrates in patients with nonischemic cardiomyopathy. Three distinct VT morphologies are highly suggestive of the presence of these scars. Anteroseptal scars were, in general, most effectively approached from the aortic root or anteroseptal left ventricular endocardium, whereas inferolateral scars frequently required an epicardial approach.

Durability of epicardial ventricular restoration without ventriculotomy†

We previously presented early results employing a technique designed for beating heart, ventricular volume reduction (surgical ventricular restoration, SVR) without ventriculotomy for patients with antero-septal scar and dilated ischaemic cardiomyopathy. Significant volume reduction and clinical improvement were achieved. We now report durability in the first 11 patients available for assessment at 6 and 12 months after operation. After the Ethics Committee approval, 31 symptomatic patients with left ventricular (LV) dilatation and antero-septal scars underwent operation. The scarred lateral LV wall was apposed to the septal scar with serial paired anchors placed through epicardial transmural catheters, excluding non-viable portions of the chamber. Patients were followed at 1, 3, 6 and 12 months postoperatively with echocardiograms. Data are presented for the first 11 patients for whom core lab echocardiographic data were available at 12 months of follow-up. LV end-systolic index (LVESVI), percent decreases from baseline at 6 and 12 months were 36.2 ± 18.3 (P < 0.001) and 39.6 ± 14.8 (P < 0.001). LV end-diastolic volume index (LVEDVI) percent decreases from baseline at 6 and 12 months were 28.6 ± 18.8 (P < 0.001) at 6 months and 32.2 ± 14.9 (P < 0.005) at 12 months. All comparisons were by one-tailed t-tests using paired data. These results demonstrate the persistence of volume reduction employing a technique designed to be used on beating hearts without ventriculotomy or cardiopulmonary bypass. The extent of volume reduction was consistent with results of conventional SVR in experienced centres. These early data validate the further development of technical iterations leading to a clinical study employing a closed chest endovascular platform.

Right, But Not Left, Bundle Branch Block Is Associated With Large Anteroseptal Scar

This study sought to test the hypothesis that right bundle branch block (RBBB) patients have larger scar size than left bundle branch block (LBBB) patients do. A proximal septal perforating branch of the left anterior descending (LAD) coronary artery most commonly perfuses the right bundle branch and left anterior fascicle, but not the left posterior fascicle. Thus, proximal LAD occlusions should cause RBBB, not LBBB. We performed electrocardiograms and magnetic resonance imaging for scar quantification in 233 patients with left ventricular (LV) ejection fraction ≤35% who were receiving primary prevention implantable cardioverter-defibrillators (ICD cohort). Scar size and location were compared among patients with RBBB, LBBB, nonspecific LV conduction delay, and QRS <120 ms. A second cohort of 20 hypertrophic cardiomyopathy patients undergoing alcohol septal ablation was studied to determine whether controlled infarction in a proximal LAD septal perforator caused RBBB or LBBB. In the ICD cohort, LV ejection fraction was similar between RBBB and LBBB patients (24.9% vs. 25.0%; p = 0.98); however, RBBB patients had significantly larger scar size (24.0% vs. 6.5%; p < 0.0001). Patients with nonspecific LV conduction delay or QRS <120 ms had intermediate scar size (12.9% and 14.4%, respectively). Those with RBBB (compared with LBBB) were more likely to have ischemic heart disease (79% vs. 29%; p < 0.0001). In the alcohol septal ablation cohort, 15 of 20 patients (75%) developed RBBB, but no patients developed LBBB. In patients with LV ejection fraction ≤35%, RBBB is associated with significantly larger scar size than LBBB is, and occlusion of a proximal LAD septal perforator causes RBBB. In contrast, LBBB is most commonly caused by nonischemic pathologies.

Left Ventricular Surgical Remodeling after the STICH Trial

Surgical treatment of anteroseptal scars has been, and still is, a challenging task for cardiac surgeons. Most patients are in heart failure and the infarcted areas can include different parts of the septum and the anterior wall. The core problem of ischemic congestive heart failure is the undue demand placed on the residual viable left ventricle myocardium. The surgical techniques used to correct the mismatch between contractile and asynergic areas differ, but the evolution of surgical techniques for left ventricular surgical remodeling (LVSR) is still a work in progress. The most popular one was proposed by Dor et al. in the 1980s and is still in general use. This technique addressed the problem of recovering a predictable volume but not necessarily the problem of rebuilding a physiologically conical shape. This anatomical aspect is becoming increasingly important, and the purpose of septal reshaping, as proposed by us in 2004, is more to recover a conical shape than to achieve volume reduction. Thus, we use the Dor operation only when septoapical scars are present. The need for a different surgical strategy is emphasized by the result of the STICH trial, which reports the data of 1000 patients randomized for coronary artery bypass grafting (CABG, n = 499) or CABG and LVSR (n = 501) and which failed to show any benefit of LVSR. However, the only surgical technique used was the classic Dor operation, where the purpose was to reestablish volume and not to recreate a physiological shape. This study, however, does not provide a definitive answer, as echocardiography results included only 212 patients in the CABG arm and 161 in the CABG and LVSR arm. Furthermore, previous myocardial infarction (MI) was not a prerequisite for study inclusion (13 % of patients in each group had no previous MI) and whether a previous MI was Q-wave or not was not specified. In conclusion, the long-term results after LVSR are satisfactory but appear to be better if a conical shape has been recreated. The role of preemptive surgery in selected cases and how to establish the limits of LVSR (grade of preoperative diastolic dysfunction, diastolic diameter, ventricular volumes, function of the remote zone, etc.) is still unclear. The impact of each individual treatment in the individual patient (medical treatment, CABG alone, CABG and LVSR) has still to be identified.

Left ventricular surgical restoration for anteroseptal scars: Volume versus shape

We report the long-term results of left ventricular surgical restoration in which 2 different strategies were used, which had restoration of ventricular volume or ventricular shape as their target. From 1988 to 2008, 308 patients with anterior scars underwent elective left ventricular surgical restoration. Before 2002, a Dor procedure was performed in 107 cases to reduce left ventricular volume (group V); from 1998 to 2001, a Guilmet procedure was performed in 32 patients to rebuild a left ventricular conical shape (group S). From 2002, 169 patients (group S) underwent left ventricular surgical restoration to reshape a conical left ventricle by means of the Dor procedure (n = 29, septoapical scars) or septal reshaping (n = 140, when the septum was more involved than the anterior wall). The 2 groups were similar for all features but age, mitral regurgitation grade, mitral valve surgery rate (higher in group S), and ejection fraction (higher in group V). Early mortality was 7.8% (11.2% in group V vs 6.0% in group S, P = .102). Logistic regression showed that volume reduction was significantly related to higher early mortality. Five-year cardiac survival, cardiac event-free survival, and event-free survival were higher in group S. Cox analysis showed that the choice of volume reduction provided lower survival (hazard ratio, 2.1), cardiac survival (hazard ratio, 3.0), cardiac event-free survival (hazard ratio, 2.7), and event-free survival (hazard ratio, 2.2). When 30-day events were excluded, volume reduction was still a risk factor for cardiac event-free survival (hazard ratio, 2.2). When the main target of left ventricular surgical restoration is left ventricular reshaping rather than left ventricular volume reduction, early and late outcomes seem to improve.

Atrial Diastolic Friction Rubs

THE HALLMARK of pericarditis is a pericardial friction rub. Friction rubs are commonly triphasic, consisting of atrial systole (atrial or presystolic rub), ventricular systole (systolic rub), and ventricular diastole (protodiastolic rub). Pericardial rub is generated by active motion (atrial or ventricular systole) as well as by passive motion (ventricular diastole). We have recorded the unusual condition of pericardial friction occurring during atrial diastole. We found that previous documentation of this phenomenon in the literature is limited to a single case report.1 Report of Cases Case 1.— A 72-year-old man was admitted on March 19, 1975, to the intensive coronary care unit at Rothschild Hospital in Haifa, Israel. An acute diaphragmatic myocardial infarction had developed, and ECG evidence of an anteroseptal scar was found. At the time of admission, accelerated idioventricular rhythm and transient firstand second-degree atrioventricular block were diagnosed. On March 24, a triphasic pericardial friction rub developed in