Successful Catheter Ablation of Hemodynamically Unstable Monomorphic Ventricular Tachycardia in a Patient with Hypertrophic Cardiomyopathy and Apical Aneurysm

Cardiomyopathy and Sudden Cardiac Death: Bridging Clinical Practice with Cutting-Edge Research

Sudden cardiac death (SCD) prevention in cardiomyopathies such as hypertrophic (HCM), dilated (DCM), non-dilated left ventricular (NDLCM), and arrhythmogenic right ventricular cardiomyopathy (ARVC) remains a crucial but complex clinical challenge, especially among younger populations. Accurate risk stratification is hampered by the variability in phenotypic expression and genetic heterogeneity inherent in these conditions. This article explores the multifaceted strategies for preventing SCD across a spectrum of cardiomyopathies and emphasizes the integration of clinical evaluations, genetic insights, and advanced imaging techniques such as cardiac magnetic resonance (CMR) in assessing SCD risks. Advanced imaging, particularly CMR, not only enhances our understanding of myocardial architecture but also serves as a cornerstone for identifying at-risk patients. The integration of new research findings with current practices is essential for advancing patient care and improving survival rates among those at the highest risk of SCD. This review calls for ongoing research to refine risk stratification models and enhance the predictive accuracy of both clinical and imaging techniques in the management of cardiomyopathies.

Outcomes of concomitant myectomy and left ventricular apical aneurysm repair in patients with hypertrophic cardiomyopathy

OBJECTIVES

Hypertrophic cardiomyopathy with left ventricular apical aneurysm is a phenotype associated with a 4-fold increase in the risk for sudden cardiac death. In this study, we describe the surgical outcome of concomitant apical aneurysm repair in patients undergoing transapical myectomy for hypertrophic cardiomyopathy.

METHODS

We identified 67 patients with left ventricular apical aneurysms who underwent transapical myectomy and apical aneurysm repair between July 2000 and August 2020. Long-term survival was compared with that of 2746 consecutive patients undergoing transaortic septal myectomy for obstructive hypertrophic cardiomyopathy with subaortic obstruction.

RESULTS

Transapical myectomy was indicated for midventricular obstruction (n = 44) or left ventricular remodeling for diastolic heart failure (n = 29). Preoperatively, 74.6% (n = 50) of patients were in New York Heart Association class III/IV heart failure, and 34.3% (n = 23) of patients had experienced syncope or presyncope. Atrial fibrillation was documented in 22 patients (32.8%), and episodes of ventricular arrhythmias were recorded in 30 patients (44.8%). Thrombus was present in the apical aneurysm in 6 patients. During a median (interquartile range) follow-up of 4.9 (1.8-7.6) years, the estimated 1- and 5-year survivals were 98.5% and 94.5%, respectively, which were not significantly different from that of patients undergoing transaortic septal myectomy for obstructive hypertrophic cardiomyopathy (P = .52) or an age- and sex-matched US general population (P = .40).

CONCLUSIONS

Apical aneurysm repair in conjunction with septal myectomy is a safe procedure, and the good long-term survival of patients suggests that the procedure may reduce cardiac-related death in this high-risk hypertrophic cardiomyopathy population.

2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy" provides recommendations to guide clinicians in the management of patients with hypertrophic cardiomyopathy.

METHODS

A comprehensive literature search was conducted from September 14, 2022, to November 22, 2022, encompassing studies, reviews, and other evidence on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through May 23, 2023, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Hypertrophic cardiomyopathy remains a common genetic heart disease reported in populations globally. Recommendations from the "2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy" have been updated with new evidence to guide clinicians.

2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy" provides recommendations to guide clinicians in the management of patients with hypertrophic cardiomyopathy.

METHODS

A comprehensive literature search was conducted from September 14, 2022, to November 22, 2022, encompassing studies, reviews, and other evidence on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through May 23, 2023, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Hypertrophic cardiomyopathy remains a common genetic heart disease reported in populations globally. Recommendations from the "2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy" have been updated with new evidence to guide clinicians.

The Paradigm of Sudden Death Prevention in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a relatively common and, often, inherited cardiac disease, once regarded as largely untreatable with ominous prognosis and, perhaps, most visibly as a common cause of sudden cardiac death (SCD) in the young. However, HCM is now more accurately considered a treatable disease with management options that significantly alter its clinical course. This is particularly true for SCD because the penetration of implantable cardioverter-defibrillators into HCM practice enables primary prevention device therapy that reliably terminates potentially lethal ventricular tachyarrhythmias (3% to 4%/year). This therapeutic advance is largely responsible for >10-fold decrease in the overall disease-related mortality to 0.5%/year, independent of patient age. A guideline-based clinical risk stratification algorithm has evolved, which included variables identifiable with cardiac magnetic resonance: ≥1 risk markers judged major within the clinical profile of an individual patient, associated with a measure of physician judgment and shared decision-making, can be sufficient to consider the recommendation of a prophylactic defibrillator implant. Implantable cardioverter-defibrillator decisions using the American College of Cardiology and the American Heart Association traditional major risk marker strategy are associated with a 95% sensitivity for identifying those patients who subsequently experience appropriate therapy, albeit often 5 to 10+ years after implant but without heart failure deterioration or death after a device intervention. A mathematical SCD risk score proposed by European Society of Cardiology is associated with a relatively low sensitivity (33%) for predicting and preventing SCD events but with potential for less device overtreatment.

High-risk imaging characteristics in left ventricular apex for the life-threatening arrhythmic events in Japanese hypertrophic cardiomyopathy patients

Left ventricular (LV) apical aneurysm is known to be associated with the life-threatening arrhythmic events in hypertrophic cardiomyopathy (HCM). However, the current 2014 ESC guideline has not included apical aneurysm as a major risk factor for sudden cardiac death and 2018 JCS guideline includes it only as a modulator, while it has been included as a new major risk marker in 2020 AHA/ACC guideline. Therefore, we sought to identify high-risk imaging characteristics in LV apex which is associated with a higher occurrence of ventricular tachycardia/fibrillation (VT/VF). In 99 consecutive Japanese HCM patients (median age, 65 years; 59 males) undergoing implantable cardioverter-defibrillator (ICD) implantation for primary prevention following cardiac magnetic resonance including late gadolinium enhancement (LGE), the occurrence of appropriate ICD interventions for VT/VF was evaluated for 6.2 (median) years after ICD implantation. Overall, appropriate ICD interventions occurred in 43% with annual rates of 7.0% for appropriate interventions. Kaplan-Meier analysis demonstrated that the presence of LV apical aneurysm was significantly associated with a higher occurrence of appropriate interventions (annual rates 18.9% vs. 6.4%, P = 0.013). Similarly, patients with high LV mid-to-apex pressure gradient (annual rates 14.9% vs. 6.2%, P = 0.022) and presence of apical LGE (annual rates 10.9% vs. 4.0%, P = 0.001) experienced appropriate interventions more frequently. An aneurysm, high-pressure gradient, and LGE in an apex are associated with VT/VF. These characteristics in apex should be kept in mind when implanting ICD in Japanese HCM patients as a primary prevention.

Syncope in hypertrophic cardiomyopathy (part I): An updated systematic review and meta-analysis

AIMS

To describe the proportion of patients with syncope among those affected by hypertrophic cardiomyopathy (HCM) and the relevance of syncope as risk factor for sudden cardiac death and life-threatening arrhythmic events.

METHOD AND RESULTS

Systematic review of original articles that assessed syncope in HCM patients. Literature search of PubMed including all English publications from 1973 to 2021.We found 57 articles for a total of 21.791 patients; of these, 14 studies reported on arrhythmic events in the follow-up. Syncope was reported in 15.8% (3.452 of 21.791) patients. It was considered unexplained in 91% of cases. Life-threatening arrhythmic events occurred in 3.6% of non-syncopal patients and in 7.7% of syncopal patients during a mean follow-up of 5.6 years. A relative risk of 1.99 (95%CI 1.39 to 2.86) was estimated for syncope patients by the random effect model using Haldane continuity correction for 0 events.

CONCLUSIONS

In the current practice, the cause of syncope remained unexplained in most patients affected by HCM. The management of patients seems mainly driven by risk stratification rather than identification of the aetiology of syncope. There is a need of precise instructions how to apply the recommendations of current guidelines to this disease, which tests are indicated and how to interpret their findings. The protocol was registered in Prospero (ID: 275963).

Prognostic implications of different clinical profiles in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a myocardial genetic disease relatively common in the general population with heterogenous clinical presentation, natural history and prognosis. About 60% of HCM patients have a stable clinical course, while others may experience a variety of HCMrelated complications which follows relatively independent pathways, and that can be distinguished in different subgroups. These subgroups are represented by patients with left ventricular outflow tract obstruction; patients with end-stage disease and reduced or preserved systolic function; patients with apical hypertrophy; patients with apical aneurysm; patients with atrial fibrillation, patients at high risk of sudden death and patients with pre-clinical HCM. The purpose of this review is to describe each of these clinical profiles with its prognostic implications.

Evolution of risk stratification and sudden death prevention in hypertrophic cardiomyopathy: Twenty years with the implantable cardioverter-defibrillator

Hypertrophic cardiomyopathy (HCM) is a relatively common inherited myocardial disorder, once regarded as largely untreatable with ominous prognosis and most visibly as a common cause of sudden death (SD) in the young. Over the last several years, HCM has been transformed into a contemporary treatable disease with management options that significantly alter clinical course. With the use of implantable cardioverter-defibrillators (ICDs) in the HCM patient population, a new paradigm has emerged, with primary prevention device therapy reliably terminating potentially lethal ventricular tachyarrhythmias (3%-4% per year) and being largely responsible for a >10-fold decrease in disease-related mortality (to 0.5% per year), independent of age. An evidenced-based and guideline directed clinical risk stratification algorithm has evolved, including variables identified with cardiac magnetic resonance. One or more risk markers judged major and relevant within a patient's clinical profile can be considered sufficient to recommend a primary prevention implant (associated with a measure of physician judgment and shared decision-making). ICD decisions using the prospective individual risk marker strategy have been associated with 95% sensitivity for identifying patients who subsequently experienced appropriate ICD therapy, (albeit often delayed substantially for >5 or >10 years after implant), but without heart failure deterioration or HCM death following device intervention. A rigid mathematically derived statistical risk model proposed by the European Society of Cardiology is associated with low sensitivity (ie, 33%) for predicting SD events. Introduction of prophylactically inserted ICDs to HCM 20 years ago has significantly altered the clinical course and landscape of this disease. SD prevention has reduced HCM mortality significantly, making preservation of life and the potential for normal longevity a reality for most patients.

2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the hypertrophic cardiomyopathy clinical practice guideline provides recommendations and algorithms for clinicians to diagnose and manage hypertrophic cardiomyopathy in adult and pediatric patients as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to April 30, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases.

STRUCTURE

Many recommendations from the earlier hypertrophic cardiomyopathy guidelines have been updated with new evidence or a better understanding of earlier evidence. This summary operationalizes the recommendations from the full guideline and presents a combination of diagnostic work-up, genetic and family screening, risk stratification approaches, lifestyle modifications, surgical and catheter interventions, and medications that constitute components of guideline directed medical therapy. For both guideline-directed medical therapy and other recommended drug treatment regimens, the reader is advised to follow dosing, contraindications and drug-drug interactions based on product insert materials.

2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

Aim This executive summary of the hypertrophic cardiomyopathy clinical practice guideline provides recommendations and algorithms for clinicians to diagnose and manage hypertrophic cardiomyopathy in adult and pediatric patients as well as supporting documentation to encourage their use. Methods A comprehensive literature search was conducted from January 1, 2010, to April 30, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Structure Many recommendations from the earlier hypertrophic cardiomyopathy guidelines have been updated with new evidence or a better understanding of earlier evidence. This summary operationalizes the recommendations from the full guideline and presents a combination of diagnostic work-up, genetic and family screening, risk stratification approaches, lifestyle modifications, surgical and catheter interventions, and medications that constitute components of guideline directed medical therapy. For both guideline-directed medical therapy and other recommended drug treatment regimens, the reader is advised to follow dosing, contraindications and drug-drug interactions based on product insert materials.

Ablation of Ventricular Arrhythmias From the Left Ventricular Apex in Patients Without Ischemic Heart Disease

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.

Paradigm of Sudden Death Prevention in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a worldwide genetic heart disease and a common cause of sudden death in the young. Penetration of the implantable cardioverter-defibrillator (ICD) into this patient population over the past 20 years has made accurate selection of patients for primary prevention ICDs a priority. Consequently, a new paradigm has emerged in the management of this complex disease with ICD therapy responsible for a substantial decrease in overall HCM-related mortality (to 0.5%/y) and independent of patient age. Selection of candidates for ICDs has matured substantially with the formulation of an enhanced risk stratification algorithm. One or more contemporary risk markers judged major within a given patient’s clinical profile, in association with physician judgment and shared decision-making, is sufficient to consider a primary prevention ICD implant. An enhanced American College of Cardiology/American Heart Association risk factor model (including new contrast-magnetic resonance–based markers, such as left ventricular apical aneurysm) used prospectively to make ICD decisions proved to be 95% sensitive for identifying patients who would experience ≥1 appropriate device therapies terminating ventricular tachycardia/fibrillation. The number of HCM patients required to treat with ICDs to save 1 patient with abolition of lethal ventricular tachyarrhythmias was 6:1, similar to randomized defibrillator trials in other cardiomyopathies. In contrast to patients with ischemic heart disease, after ICD shock HCM patients rarely experience transformation to heart failure deterioration or sudden arrhythmic death. The mathematically derived risk score model proposed by the European Society of Cardiology was inferior for identifying high-risk patients susceptible to arrhythmic sudden death with a sensitivity of only 33%, leaving many patients exposed to the possibility of sudden death without ICDs. In conclusion, introduction of the ICD associated with a matured risk stratification algorithm has altered management strategy and clinical course of many HCM patients, making the likelihood of sudden death prevention a reality and fulfilling the aspiration of preservation of life and reduced mortality for this vulnerable patient population.

Recommendations for the use of electrophysiological study: Update 2018

The field of cardiac electrophysiology has greatly developed during the past decades. Consequently, the use of electrophysiological studies (EPSs) in clinical practice has also significantly augmented, with a progressively increasing number of certified electrophysiology centers and specialists. Since Zipes et al published the Guidelines for Clinical Intracardiac Electrophysiology and Catheter Ablation Procedures in 1995, no official document summarizing current EPS indications has been published. The current paper focuses on summarizing all relevant data of the role of EPS in patients with different types of cardiac pathologies and provides up-to-date recommendations on this topic. For this purpose, the PubMed database was screened for relevant articles in English up to December 2018 and ESC and ACC/AHA Clinical Practice Guidelines, and EHRA/HRS/APHRS position statements related to the current topic were analyzed. Current recommendations for the use of EPS in clinical practice are discussed and presented in 17 distinct cardiac pathologies. A short rationale, evidence, and indications are provided for each cardiac disease/group of diseases. In conclusion, because of its capability to establish a diagnosis in patients with a variety of cardiac pathologies, the EPS remains a useful tool in the evaluation of patients with cardiac arrhythmias and conduction disorders and is capable of establishing indications for cardiac device implantation and guide catheter ablation procedures.

Left ventricular aneurysms in hypertrophic cardiomyopathy with midventricular obstruction: A systematic review of literature

BACKGROUND

Hypertrophic cardiomyopathy (HCM) with or without left ventricular apical aneurysm (LVA) had been studied in the past. Midventricular obstruction associated with HCM and LVA is a unique entity that has not been distinguished previously as a separate phenotypic disease in HCM patients.

METHODS

A systematic review of Pubmed and Google Scholar was conducted from inception until September 2017 for all observational studies conducted on HCM with midventricular obstruction and LVA.

RESULTS

A total of 94 patients from 39 studies were included in our analysis. The mean age of the patients was 58.05 ± 11.76 years with 59.6% being males. The most common electrocardiographic finding was T wave inversion occurring in 13.8% of the cases followed by ST elevation (9.5%). Maximal left ventricle (LV) wall thickness was reported 18.89 ± 5.19 mm on transthoracic echocardiography and paradoxical jet flow was detected in 29.8% of patients. Beta-blockers (58.5%) were the most common drug therapy at baseline and amiodarone (10.6%) was the most common antiarrhythmic used for ventricular tachycardia (VT). The most common complication, VT, occurred in 39.3% of cases and the incidence of all-cause mortality was 13.8 % over 16 ± 20.1 months follow-up. Implantable cardioverter defibrillator (ICD) was used in 37.2% of patients; 25.7% of patients with ICD received appropriate shock therapy.

CONCLUSION

HCM with LVA and midventricular obstruction is a unique entity that appears to be associated with high incidence of morbidity and mortality. Thus, early diagnosis and therapeutic intervention is recommended for management of this condition.

Hypertrophic Cardiomyopathy With Left Ventricular Apical Aneurysm: Implications for Risk Stratification and Management

BACKGROUND

A previously under-recognized subset of hypertrophic cardiomyopathy (HCM) patients with left ventricular (LV) apical aneurysms is being identified with increasing frequency. However, risks associated with this subgroup are unknown.

OBJECTIVES

The authors aimed to clarify clinical course and prognosis of a large cohort of HCM patients with LV apical aneurysms over long-term follow-up.

METHODS

The authors retrospectively analyzed 1,940 consecutive HCM patients at 2 centers, 93 of which (4.8%) were identified with LV apical aneurysms; mean age was 56 ± 13 years, and 69% were male.

RESULTS

Over 4.4 ± 3.2 years, 3 of the 93 patients with LV apical aneurysms (3%) died suddenly or of heart failure, but 22 (24%) survived with contemporary treatment interventions: 18 experienced appropriate implantable cardioverter-defibrillator discharges, 2 underwent heart transplants, and 2 were resuscitated after cardiac arrest. The sudden death (SD) event rate was 4.7%/year, which includes sudden death, successful resuscitation from cardiac arrest or appropriate ICD interventions triggered by VF or rapid VT. Notably, recurrent monomorphic ventricular tachycardia requiring ≥2 implantable cardioverter-defibrillator shocks occurred in 13 patients, including 6 who underwent successful radiofrequency ablation of the arrhythmic focus without ventricular tachycardia recurrence. Five non-anticoagulated patients experienced nonfatal thromboembolic events (1.1%/year), whereas 13 with apical clots and anticoagulation did not incur embolic events. There was no consistent relationship between aneurysm size and adverse HCM-related events. Rate of HCM-related deaths combined with life-saving aborted disease-related events was 6.4%/year, 3-fold greater than the 2.0%/year event rate in 1,847 HCM patients without aneurysms (p < 0.001).

CONCLUSIONS

HCM patients with LV apical aneurysms are at high risk for arrhythmic sudden death and thromboembolic events. Identification of this phenotype expands risk stratification and can lead to effective treatment interventions for potentially life-threatening complications.

Mid-ventricular Hypertrophic Obstructive Cardiomyopathy with Apical Aneurysm Complicated with Syncope by Sustained Monomorphic Ventricular Tachycardia

Mid-ventricular hypertrophic obstructive cardiomyopathy with secondary formation of apical aneurysm is a rare variant of hypertrophic cardiomyopathy. They have a unique behavior because unlike other variants it causes sustained monomorphic ventricular tachycardia, which makes it particularly severe.

The role of cardiovascular magnetic resonance in sudden death risk stratification in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden death in young patients, but current risk stratification strategies do not identify all patients at risk. Contrast-enhanced cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) can identify areas of abnormal myocardial substrate comprising fibrosis, the structural nidus for potentially life-threatening ventricular arrhythmias. More recently, follow-up studies have demonstrated a strong relationship between extent of LGE in patients with HCM and increased risk of adverse disease-related events, including sudden death.

Long-term Outcomes of Ventricular Tachycardia Ablation in Different Types of Structural Heart Disease

Ventricular tachycardia (VT) often occurs in the setting of structural heart disease and can affect patients with ischaemic or nonischaemic cardiomyopathies. Implantable cardioverter-defibrillators (ICDs) provide mortality benefit and are therefore indicated for secondary prevention in patients with sustained VT, but they do not reduce arrhythmia burden. ICD shocks are associated with increased morbidity and mortality, and antiarrhythmic medications are often used to prevent recurrent episodes. Catheter ablation is an effective treatment option for patients with VT in the setting of structural heart disease and, when successful, can reduce the number of ICD shocks. However, whether VT ablation results in a mortality benefit remains unclear. We aim to review the long-term outcomes in patients with different types of structural heart disease treated with VT ablation.

Coronary embolization in hypertrophic cardiomyopathy with left ventricular apical aneurysm

Patients with left ventricular apical aneurysms represent a unique patient subgroup in the broad clinical spectrum of hypertrophic cardiomyopathy (HC) associated with the risk for sudden death, heart failure, and peripheral thromboembolism. Routine chronic anticoagulation has not been a standard recommendation for these patients. We present a 36-year-old patient with HC with features of acute coronary syndrome, likely secondary to coronary thromboembolism as a complication of left ventricular apical aneurysm. Our experience with this patient raises consideration for prophylactic anticoagulant therapy for this unusual subset of patients with HC.

Clinical utility of cardiovascular magnetic resonance in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is characterized by substantial genetic and phenotypic heterogeneity, leading to considerable diversity in clinical course including the most common cause of sudden death in young people and a determinant of heart failure symptoms in patients of any age. Traditionally, two-dimensional echocardiography has been the most reliable method for establishing a clinical diagnosis of HCM. However, cardiovascular magnetic resonance (CMR), with its high spatial resolution and tomographic imaging capability, has emerged as a technique particularly well suited to characterize the diverse phenotypic expression of this complex disease. For example, CMR is often superior to echocardiography for HCM diagnosis, by identifying areas of segmental hypertrophy (ie., anterolateral wall or apex) not reliably visualized by echocardiography (or underestimated in terms of extent). High-risk HCM patient subgroups identified with CMR include those with thin-walled scarred LV apical aneurysms (which prior to CMR imaging in HCM remained largely undetected), end-stage systolic dysfunction, and massive LV hypertrophy. CMR observations also suggest that the cardiomyopathic process in HCM is more diffuse than previously regarded, extending beyond the LV myocardium to include thickening of the right ventricular wall as well as substantial morphologic diversity with regard to papillary muscles and mitral valve. These findings have implications for management strategies in patients undergoing invasive septal reduction therapy. Among HCM family members, CMR has identified unique phenotypic markers of affected genetic status in the absence of LV hypertrophy including: myocardial crypts, elongated mitral valve leaflets and late gadolinium enhancement. The unique capability of contrast-enhanced CMR with late gadolinium enhancement to identify myocardial fibrosis has raised the expectation that this may represent a novel marker, which may enhance risk stratification. At this time, late gadolinium enhancement appears to be an important determinant of adverse LV remodeling associated with systolic dysfunction. However, the predictive significance of LGE for sudden death is incompletely resolved and ultimately future large prospective studies may provide greater insights into this issue. These observations underscore an important role for CMR in the contemporary assessment of patients with HCM, providing important information impacting diagnosis and clinical management strategies.

Long-Term Outcomes of Combined Epicardial and Endocardial Ablation of Monomorphic Ventricular Tachycardia Related to Hypertrophic Cardiomyopathy

Background—

Monomorphic ventricular tachycardia (MMVT) is rare in patients with hypertrophic cardiomyopathy (HCM). There are limited data on the utility of catheter ablation for the treatment of MMVT in this population. This study details a series of case reports from multiple centers where combined epicardial-endocardial ablation was performed in a highly selected group of patients with HCM-related MMVT.

Methods and Results—

The cohort consisted of 10 patients with HCM-related MMVT. Pericardial access was achieved using the percutaneous subxyphoid approach. Epicardial and endocardial ventricular 3D bipolar voltage maps were generated. Ablation sites were identified using a combination of entrainment, activation, late/fractionated potential, and pace mapping. Electrophysiological-identified epicardial scar was present in 8 (80%) patients, endocardial scar in 6 (60%), and no scar in 1 (10%). In the 5 patients with inducible, stable MMVT, 3 cases were successfully terminated with ablation from the epicardium and 1 from the endocardium. The case that failed catheter ablation required surgical cryoablation to abolish the incessant VT. In the remaining 5 patients, 4 underwent epicardial and endocardial ablation of sites with good pace maps and late/fractionated potentials. No ablation was performed in the remaining patient because of noninducibility and lack of identifiable scar. After 37±17 months (limits, 2 to 62 months; median, 37 months), the freedom from recurrent implantable cardioverter-defibrillator shocks was 78% (7/9 patients) in those who underwent ablation.

Conclusions—

In highly selected patients with HCM, combined epicardial and endocardial mapping and ablation is a feasible and reasonably efficacious option for MMVT if refractory to aggressive trials of antiarrhythmic drugs and antitachycardia pacing.