An underrecognized subepicardial reentrant ventricular tachycardia attributable to left ventricular aneurysm in patients with normal coronary arteriograms

Ventricular restoration in adults with huge congenital left ventricular aneurysm: report of two cases

Congenital ventricular aneurysms (CVA) are rare cardiac anomalies that have been predominantly described in the Black population. They are characterized by an akinetic ventricular protrusion that is commonly located at the basal and apical segments. Although the diagnosis is often incidental and the majority of patients are asymptomatic, life-threatening events such as persistent ventricular arrhythmias, CVA rupture, and heart failure are not uncommon. However, no standardized therapy is currently available and good outcomes have been reported with both conservative and surgical management. We report the cases of two young Black African patients with huge symptomatic CVA lesions who underwent successful surgical repair with a ventricular restoration technique. Both cases were consulted for chest pain and dyspnea. Chest X-ray and transthoracic Doppler echocardiography suggested the diagnosis. Thoracic angioscanner and thoracic magnetic resonance imaging confirmed the diagnosis. Both patients underwent successful surgery. This case report aims to revisit the diagnostic and therapeutic approach to this rare pathology, in our professional environment.

Surgical treatment of left ventricular aneurysm in patients with prior myocardial infarction in the absence of obstructive coronary artery disease (MINOCA): a cohort study

BACKGROUND

There is a paucity of studies examining the treatment of patients with prior myocardial infarction in the absence of obstructive coronary arteries (MINOCA) and with a concomitant left ventricular aneurysm. Our study aims to illustrate the clinical characteristics and report the mid-term surgical outcomes in this distinct entity.

METHODS

Ten patients with MINOCA and left ventricular aneurysm were investigated. The MINOCA was diagnosed according to Scientific Statement from the American Heart Association. The indication for left ventricular reconstruction was as follows: clear evidence of both an aneurysmal and akinetic left ventricle with a history of myocardial infarction accompanied by heart failure symptoms, angina, or ventricular arrhythmias. Major adverse cardiovascular and cerebrovascular events (MACCE), including death, myocardial infarction, stroke was considered the primary endpoints.

RESULTS

The median follow-up for the whole study population was 64.5 months. Seven MINOCA patients developed a left ventricular aneurysm within 4 years and three MINOCA patients were found to have a concomitant left aneurysm at the first admission. Before surgery, no patients were prescribed angiotensin-converting enzyme inhibitors. Statins, dual antiplatelet therapy, and β-blockers were prescribed in 2, 5, and 5 patients, respectively. After surgery, no MACCE occurred in the follow-up. There was a significant increase in ejection fraction (EF) in the follow-up (p = 0.0009).

CONCLUSIONS

Close monitoring and standard medical treatment are required before a left ventricular aneurysm occurs in MINOCA patients. Left ventricular reconstruction remains a viable option for MINOCA patients with left ventricular aneurysms and mid-term outcomes were satisfying in this distinct entity.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Long-term outcome after surgical repair of a rapid-grown ischemic ventricular aneurysm causing ventricular tachycardia

While improved treatment numerically decreased ventricular aneurysms after myocardial infarction, respective cases still represent a clinical challenge due to difficulties in diagnosis, complications like tachycardia, and controversies in state-of-the-art treatment. Our case illustrates good long-term outcome of surgical aneurysmectomy in cases where ventricular geometry can be restored to near-physiological dimensions.

Multiple left ventricular aneurysms in a young female

Multiple left ventricular aneurysms (LVAs) are rare, especially in a young female. A 29-year-old woman presented vague symptoms. Multiple LVAs were revealed and confirmed on different imaging modalities, including chest radiography, echocardiography, contrast ventriculography and cardiac magnetic resonance imaging. Detailed work-up for probable etiologies including ischemic, infectious, inflammatory and autoimmune causes was negative. In the absence of angina, decompensated congestive heart failure, arrhythmias and embolism, the patient was managed conservatively, with excellent mid-term outcome.

Endovascular catheter ablation of ventricular tachycardia in a patient with a surgically repaired congenital left ventricular aneurysm

We present a patient with a congenital left ventricular aneurysm who visited our outpatient clinic for a routine check-up and, during this visit, lost consciousness due to sustained ventricular tachycardia. In our patient, endocardial mapping revealed extensive conduction abnormalities, and successful ablation was accomplished at the endocardial surface.

Characteristics and outcome of congenital left ventricular aneurysm and diverticulum: Analysis of 809 cases published since 1816

BACKGROUND

Congenital left ventricular aneurysm (LVA) or diverticulum (LVD) is rare cardiac anomalies. We aimed to analyse the clinical characteristics and outcome in all ever published patients.

METHODS

MEDLINE, Web of science, Google and EMBASE, and reference lists of relevant articles were searched for publications reporting on LVA or LVD patients.

RESULTS

We identified 809 patients published since 1816 [354 (49.1%) LVA, 453 (50.6%) LVD, 2 (0.3%) both]. Mean age at diagnosis was 34.1±27 (LVA) and 29.7±27.6years (LVD; p=0.05). 48.9% were male. LVA was larger (38.7±22.5mm versus 31.4±21.2mm; p=0.002) and frequently found in submitral location (33% versus 4.9%; p<0.001), LVD was frequently located at the LV-apex (61.2% versus 28.7%; p<0.001). LVD was often associated with cardiac (34.2% versus 11%; p<0.001) or extracardiac anomalies (32.7% versus 3%; p<0.001). LVA patients presented more frequently with ventricular tachycardia/fibrillation (18.1% versus 13.1%; p=0.01), the incidences of rupture (4% versus 4.5%; p=0.9), syncope (8.3% versus 5.1%; p=0.1), and embolic events (4.9% versus 3.6%; p=0.4) at presentation were not different between LVA and LVD. Mean follow-up was 56.3±43months. Cardiac death occurred more frequently in the LVA group (11.5% versus 5.0%; p=0.05) at a median age of 0.8 [LVA] and 2.5 [LVD] years. The leading cause of cardiac death was congestive heart failure in the LVA-group (50.0% versus 0.0%; p=0.01), and rupture in the LVD-group (75.0% versus 27.3%; p=0.04).

CONCLUSIONS

LVA and LVD are distinct congenital anomalies with different clinical and morphological characteristics. The prognosis of LVA is significantly worse during long-term follow-up.

Adenosine sensitivity is associated with ablation success rate and recurrence rate with nonirrigated catheters in patients with ventricular premature contractions/tachycardia from the ventricular outflow tract

BACKGROUND

A high ablation success rate for ventricular arrhythmia (VA) from outflow tract has been achieved, but some of them cannot be eliminated from endocardium. We investigated the association between adenosine sensitivity and ablation success/recurrence rates with a nonirrigated or an irrigated catheter.

METHODS

According to adenosine test, all patients were divided into a sensitive group (S group) or an insensitive group (I group). The patients of each group were randomized into a nonirrigated catheter (NA) subgroup or an irrigated catheter (IA) subgroup with a 2:1 ratio.

RESULTS

In S group of 122 patients (84 in NA subgroup), the ablation success rate was similar between two subgroups (94.7% vs. 90.5%, P > 0.05), but in I group of 94 patients (60 in NA subgroup), it was higher in IA subgroup (94.1%) than that in NA subgroup (73.3%, P < 0.05). The success rate using nonirrigated catheter was significantly higher in S group (90.5%) than that in I group (73.3%, P < 0.01), and the recurrence rate was lower in S group than that in I group (1.3%, vs. 13.6%, P < 0.05). On the contrary, the success rate and the recurrence rate using irrigated catheter were similar between S group and I group (94.7%, 94.1%, P > 0.05, vs. 2.8%, 6.3%, P > 0.05).

CONCLUSIONS

Adenosine insensitivity is associated with a lower success rate and a higher recurrence rate for VA patients undergoing nonirrigated catheter ablation. Thus, irrigated catheters should be the first choice for VA ablation in adenosine insensitive patients.

New Imaging Technologies To Characterize Arrhythmic Substrate

The cornerstone of the new imaging technologies to treat complex arrhythmias is the electroanatomic (EAM) mapping. It is based on tissue characterization and in particular on determination of low potential region and dense scar definition. Recently, the identification of fractionated isolated late potentials increased the specificity of the information derived from EAM. In addition, non-invasive tools and their integration with EAM, such as cardiac magnetic resonance imaging and computed tomography scanning, have been shown to be helpful to characterize the arrhythmic substrate and to guide the mapping and the ablation. Finally, intracardiac echocardiography, known to be useful for several practical uses in the setting of electrophysiological procedures, it has been also demonstrated to provide important informations about the anatomical substrate and may have potential to identify areas of scarred myocardium.

Radiofrequency ablation of drug refractory ventricular tachycardia related to cocaine use: a feasibility, safety, and efficacy study

BACKGROUND

Cocaine use is a known but rare cause of cardiac arrhythmias. Ventricular arrhythmias related to cocaine may not respond to antiarrhythmic drugs and may need treatment with radiofrequency ablation.

OBJECTIVES

We describe the clinical and electrophysiological characteristics of cocaine-related ventricular tachycardia (VT) from a multicenter registry.

METHODS

Subjects presenting with VT related to cocaine use and being considered for radiofrequency ablation have been included in the study. Patients who were refractory to maximal medical therapy underwent radiofrequency ablation of the VT. Clinical, procedural variables, efficacy, and safety outcomes were assessed.

RESULTS

A total of 14 subjects met study criteria (age 44 ± 13, range 18- to 68-year-old with 79% male, 71% Caucasian). MRI showed evidence of scar only in 43% of patients (6/14). The mechanism of VT was focal in 50% (n = 7) and scar related reentry in 50% (n = 7) based on 3D mapping. The mean VT cycle length was 429 ± 96 milliseconds. The site of origin was epicardial in 16% (3/18) of VTs. Most clinical VTs were hemodynamically stable (75%). Mean ejection fraction at the time of admission was 44 ± 14%. Duration of procedure was 289 ± 50 minutes. One subject developed pericardial tamponade requiring drainage. At 18 ± 11 months follow-up, freedom from arrhythmia was seen in 86% (1 case lost to follow-up and 2 died).

CONCLUSION

Radiofrequency ablation is not only feasible but also safe and effective in patients who have drug refractory VT related to chronic cocaine use.

Rare case of left-dominant arrhythmogenic right ventricular cardiomyopathy with dramatic reverse remodeling after cardiac resynchronization as an adjunct to pharmacological therapy

A 57-year-old man presented with near syncope and hemodynamic compromise after exercise. A sustained ventricular tachycardia (VT) of right bundle-branch block morphology was evident upon examination at our emergency department. Baseline 12-lead electrocardiography revealed a sinus rhythm with a complete left bundle-branch block after successful cardioversion of the VT. Coronary angiography revealed patent coronary arteries, whereas left ventriculography demonstrated impaired systolic function, accompanied by a peculiar basal lateral aneurysm. Both echocardiography and magnetic resonance imaging were consistent with a diagnosis of left-dominant arrhythmogenic right ventricular cardiomyopathy. Four months later, substantial ventricular reverse remodeling and clinical improvements were observed after cardiac resynchronization therapy with a defibrillator, as an adjunct to conventional pharmacological therapy.

Dilated phase of hypertrophic cardiomyopathy caused by two different sarcomere mutations, treated with surgical left ventricular reconstruction and cardiac resynchronization therapy with a defibrillator

We herein report the case of a 61-year-old woman with dilated phase of hypertrophic cardiomyopathy (D-HCM) who had been diagnosed with HCM 17 years previously. On admission, her left ventricle (LV) had marked dilation, dyssynchrony with diffuse severe hypokinesis, and ventricular tachycardia. She had two mutations in the cardiac myosin binding protein-C gene, which were suspected to be the causes of the D-HCM. We performed LV reconstruction surgery and cardiac resynchronization therapy with a defibrillator for her drug-resistant severe heart failure. After surgery, her New York Heart Association class dramatically improved, and she has not been re-hospitalized since these treatments.

Hypertrophic cardiomyopathy with apical aneurysm: left ventricular reconstruction and cryoablation for ventricular tachycardia

This is a case study of a 58-year-old patient with hypertrophic cardiomyopathy, mid-ventricular obstruction, and apical aneurysm who had an episode of syncope due to ventricular tachycardia. Cardiovascular magnetic resonance imaging revealed asymmetrical left ventricular hypertrophy with mid-ventricular obstruction and an apical aneurysm. His coronary angiography was normal, and his ventricular tachycardia was induced by hypertrophic cardiomyopathy without ischemia. Apical aneurysmectomy, left ventricular reconstruction, and cryoablation at the rim of the aneurysm were performed. Fifteen days after the operation, an automatic implantable cardioverter-defibrillator was implanted. The postoperative course was uneventful, and ventricular tachyarrhythmia did not recur during 18 months of follow-up.

Congenital ventricular aneurysm as an unexpected complication of monomorphic premature ventricular contractions

Congenital ventricular diverticulum (CVD) in adults is a rare cardiac malformation, which includes fibrous type congenital ventricular aneurysm (CVA). CVA is often clinically asymptomatic and shows no abnormality in the electrocardiogram or chest X-ray. However, some cases of sudden death resulting from ventricular tachycardia, cardiac embolism or ventricular rupture have been reported. Therefore, physicians should perform further cardiac imaging studies to detect a CVA if ventricular arrhythmia originating from the left ventricle is observed. Here, we report two successfully followed cases of CVA which were diagnosed from premature ventricular contractions.

Prevalence and spectrum of abnormal electrocardiograms in patients with an isolated congenital left ventricular aneurysm or diverticulum

AIMS

Congenital left ventricular aneurysm (LVA) and diverticulum (LVD) are rare cardiac anomalies and can be associated with ECG abnormalities and rhythm disturbances. We sought to investigate the prevalence and the spectrum of ECG abnormalities in such patients.

METHODS AND RESULTS

We assessed 125 patients with isolated LVA or LVD for the prevalence of ECG abnormalities and compared the findings to an age- and gender-matched control group. The 12-lead ECG patterns were evaluated according to commonly used criteria and were classified into three subgroups (distinct, mildly, and minor). Fifty-four of the 125 patients (43.2%) had normal and 71 (56.8%) abnormal ECGs. Mean age was 66 years. Forty-nine (39.2%) were male. Distinct abnormal ECG patterns were more prevalent in patients with LVD (38.2 vs. 15.8%, P = 0.04), and apical location of the anomaly (36.6 vs. 16.6%, P = 0.02). Older age (>66 years) was associated with a trend for a higher prevalence of abnormal ECG pattern (33 vs. 18%, P = 0.06), whereas gender had no influence (32 vs. 16%, P = 0.14). This study also shows that the sensitivity, specificity, positive predictive value and negative predictive value of a 12-lead ECG for the diagnosis of LVA or LVD are low.

CONCLUSION

This large single-centre study suggests that the prevalence of abnormal ECG patterns in patients with isolated LVA or LVD is as high as 56.8%. However, ECG is not specific and sensitive to be used as a screening tool in such patients.

Prevalence, clinical significance, and natural history of left ventricular apical aneurysms in hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease characterized by a diverse clinical and phenotypic spectrum. This study reports the prevalence, morphology, clinical course, and management of an underrecognized subgroup of HCM patients with left ventricular apical aneurysms.

METHODS AND RESULTS

Of 1299 HCM patients, 28 (2%) were identified with left ventricular apical aneurysms, including a pair of identical twins. Aneurysms were recognized at a wide age range (26 to 83 years), including 12 patients (43%) who were <or=50 years of age. Apical aneurysms varied considerably in size (maximum dimension, 10 to 66 mm), were dyskinetic/akinetic with thin rims, and were associated with transmural (and often more extensive) myocardial scarring identified by late gadolinium enhancement cardiovascular magnetic resonance. Apical aneurysms were recognized by echocardiography in only 16 of 28 patients (57%) but by cardiovascular magnetic resonance in the 12 patients undetected by echocardiography. Left ventricular chamber morphology varied; however, 19 patients (68%) showed an "hourglass" contour, with midventricular hypertrophy producing muscular narrowing and intracavitary gradients in 9 patients (74+/-42 mm Hg). Sarcomeric protein missense mutations known to cause other phenotypic expressions of HCM were present in 3 patients. Over 4.1+/-3.7 years of follow-up, 12 patients (43%) with left ventricular apical aneurysms experienced adverse disease complications (event rate, 10.5%/y), including sudden death, appropriate implantable cardioverter-defibrillator discharges, nonfatal thromboembolic stroke, and progressive heart failure and death.

CONCLUSIONS

Patients with left ventricular apical aneurysms represent an underappreciated subset in the heterogeneous HCM disease spectrum with important clinical implications, often requiring a high index of suspicion and cardiovascular magnetic resonance for identification. Apical aneurysms in HCM are associated with substantial cardiovascular morbidity and mortality and raise novel treatment considerations.

Combined ventricular endocardial and epicardial substrate mapping using a sonomicrometry-based electroanatomical mapping system

BACKGROUND

Substrate mapping using a magnetic electroanatomical mapping system (MEAM) has been shown to accurately delineate the location/extent of scarred myocardium. This study examined the ability of a sonomicrometry-based electroanatomic mapping system (SEAM) to render endocardial and epicardial substrate maps of infarcted ventricular myocardium.

METHODS AND RESULTS

In 7 swine with healed myocardial infarctions, combined epicardial and endocardial left ventricular (LV) substrate maps were created with both SEAM and MEAM mapping systems using 246+/-68 and 244+/-44 points respectively. Scarred myocardium was identified based upon bipolar electrogram amplitude < 1.5 mV, and radiofrequency ablation lesions were delivered to the scar border as defined by the sonomicrometry mapping system. The LV endocardial chamber volume as defined by SEAM (125+/-46 ml) correlated well with that defined by the MEAM (137+/-45 ml, r=0.77, p < 0.05). The area of infarcted tissue as determined by SEAM was highly correlated with that determined by gross pathology (r=0.96 for endocardial scar and r=0.92 for epicardial scar p < 0.05). The scar area calculated by the SEAM system also correlated well with the scar area determined by the MEAM system (0.91 for endocardial scar and 0.90 for epicardial scar p < 0.05). Finally, the sonomicrometry-based system was able to guide the placement of radiofrequency ablation lesions to the borders of the scar.

CONCLUSIONS

This study demonstrates that the sonomicrometry-based mapping can accurately reconstruct three-dimensional voltage maps of the endocardial and epicardial ventricular surfaces and guide the placement of ablation lesions along the scar border zone.

Radiofrequency catheter ablation guided by noncontact mapping of ventricular tachycardia originating from an idiopathic left ventricular aneurysm

Idiopathic left ventricular aneurysm and diverticulum is known to be an arrhythmogenic substrate associated to ventricular tachyarrhythmias, generally based on a reentry mechanism. A case of a young woman affected by a monomorphic ventricular tachycardia, refractory to medical treatment, originating from an aneurysm of the membranous interventricular septum is reported. The left ventricular aneurysm was well characterized by multislice computed tomography and left ventricular angiography. Because of the nonsustained and poorly tolerated nature of the target arrhythmia, a noncontact mapping system was used to guide radiofrequency catheter ablation, allowing the elaboration of a three-dimensional activation map of the left ventricle on the basis of a ventricular tachycardia single beat. The procedure was acutely successful, and the patient remained free of ventricular tachycardia recurrences without antiarrhythmic drugs during a subsequent 6-month follow-up period. This is the first report of a successful radiofrequency catheter ablation guided by noncontact mapping system of a ventricular tachycardia originating from an idiopathic left ventricular aneurysm. This nonfluoroscopic mapping method allows a reliable reconstruction of the spatial relationships between the left ventricular main cavity and the aneurysm and can be safely and effectively used to map the ventricular tachycardia and guide the ablation procedure, particularly when conventional mapping is not indicated or not effective because of nonsustained or not-tolerated characters of ventricular tachycardia.

Epicardial catheter ablation of ventricular tachycardia using surgical subxyphoid approach

We report the case of a patient presenting with a previous inferior myocardial infarction complicated by incessant monomorphic ventricular tachycardia resistant to antiarrhythmic drugs. Because endocardial catheter ablation failed and because of focal endocardial activation arising from the left ventricular inferior wall, an epicardial location of the reentry circuit was suspected. Catheter mapping of the pericardial space through a surgical subxyphoid approach performed in the electrophysiological laboratory confirmed the epicardial location of the arrhythmogenic substrate and allowed us successfully to ablate and cure the patient. Surgical subxyphoid approach can be performed in the electrophysiological laboratory when epicardial ablation is needed in case of inadvisable, difficult, or failed non-surgical percutaneous access.

Epicardial catheter mapping and ablation of ventricular tachycardia

Percutaneous entry into the pericardial space allows epicardial catheter mapping and ablation in the electrophysiology laboratory, opening a perspective on cardiac electrophysiology that previously was limited largely to the operating room. Scar-related reentry after myocardial infarction usually involves the subendocardium but in some patients can only be ablated from the epicardium. Epicardial, scar-related reentry also is an important cause of ventricular tachycardia in nonischemic cardiomyopathies. Rare supraventricular tachycardias and idiopathic ventricular tachycardia that cannot be defined from the endocardium sometimes can be ablated from the epicardium. With appropriate precautions the procedural risks are low. Epicardial catheter techniques expand the options for investigating cardiac electrophysiology and treating arrhythmias in humans and may lead to insights into transmural properties influencing repolarization and the genesis of arrhythmias.

Idiopathic left ventricular aneurysm and sudden cardiac death in young adults

AIMS

We report three young patients presenting with life-threatening ventricular tachycardia (VT) or ventricular fibrillation (VF) and/or survived sudden cardiac arrest, who were admitted to our institution for further diagnostic evaluation.

METHODS AND RESULTS

In all patients, idiopathic left ventricular (LV) aneurysms were identified after a detailed non-invasive and invasive evaluation. Sustained VT/VF was inducible during programmed ventricular stimulation in two of the three patients. Left ventricular aneurysms were depicted and characterized by various imaging modalities (echocardiography, magnetic resonance imaging, LV angiography). To elucidate the pathogenesis further, both myocardial viability and regional sympathetic innervation were assessed by radionuclide imaging techniques. Defects of innervation and metabolism were documented in the area of the aneurysm but distal to the aneurysm there were no signs of downstream denervation.

CONCLUSION

Life-threatening arrhythmias may be the first manifestation of an idiopathic LV aneurysm, which can be reliably diagnosed with modern imaging techniques. Radionuclide imaging may yield additional information as to the involvement of the autonomic nervous system potentially associated with arrhythmogenesis. Management strategies in patients with an idiopathic LV aneurysm range from antiarrhythmic drug treatment, implantation of an automatic cardioverter-defibrillator to surgical aneurysmectomy.

Epicardial ablation of syncopal ventricular tachycardia. Utility of the electrocardiogram

We describe the case of a young man with syncopal ventricular tachycardia, normal left ventricular ejection fraction, normal coronary arteries, and a left ventricular aneurysm. The ECG during tachycardia suggested an epicardial origin. The arrhythmia was successfully treated using a non-surgical transthoracic epicardial approach.

Substrate in the interventricular septum for left ventricular and right ventricular outflow tract tachycardia: ablation from the right side of the septum

Simultaneous epicardial and endocardial mapping demonstrated that in a substantial number of ventricular tachycardias (VTs) endocardial, intramural, and epicardial structures are involved in the substrate of the reentrant circuits. Both right and left ventricular breakthrough has also been described during VT originating in the interventricular septum. We report the case of a patient with a nonischemic left ventricular aneurysm presenting with a left ventricular outflow tract (LVOT) tachycardia and a right ventricular outflow tract (RVOT) tachycardia. Mapping from the anterior interventricular vein and the endocardium of the RVOT revealed mid-diastolic potentials at the epicardium of the LVOT and the endocardium of RVOT, where the criteria of central isthmus sites could be demonstrated. Ablation targeting an isolated late potential during sinus rhythm in RVOT eliminated both the LVOT tachycardia and the RVOT tachycardia. In this patient with a nonischemic left ventricular aneurysm, the substrate of a LVOT tachycardia and RVOT tachycardia is described, and successful catheter ablation of the right and left ventricular tachycardia from the septal wall of RVOT is reported.

Congenital left ventricular aneurysms and diverticula: definition, pathophysiology, clinical relevance and treatment

A congenital left ventricular aneurysm or diverticulum is a rare cardiac malformation; 411 cases have been reported since its first description in 1816, and other cardiac, vascular or thoraco-abdominal abnormalities have been shown in about 70%. It appears to be a developmental anomaly, starting in the 4th embryonic week. Diagnosis can be made after exclusion of coronary artery disease, local or systemic inflammation or traumatic causes as well as cardiomyopathies. Clinically, most congenital left ventricular aneurysms and diverticula are asymptomatic or may cause systemic embolization, heart failure, valvular regurgitation, ventricular wall rupture, ventricular tachycardia or sudden cardiac death. Diagnosis is established by imaging studies such as echocardiography, magnetic resonance imaging or left ventricular angiography, visualizing the structural changes and accompanying abnormalities. Mode of treatment has to be individually tailored and depends on clinical presentation, accompanying abnormalities and possible complications; treatment options include surgical resection especially in symptomatic patients, anticoagulation after systemic embolization, radiofrequency ablation or implantation of an implantable cardioverter defibrillator in case of symptomatic ventricular tachycardia, occasionally combined with class I or III antiarrhythmic drugs.

Cardiac Histological Substrate in Patients With Clinical Phenotype of Brugada Syndrome

Background— The role of structural heart disease and sodium channel dysfunction in the induction of electrical instability in Brugada syndrome is still debated.

Methods and Results— We studied 18 consecutive patients (15 males, 3 females; mean age 42.0±12.4 years) with clinical phenotype of Brugada syndrome and normal cardiac structure and function on noninvasive examinations. Clinical presentation was ventricular fibrillation in 7 patients, sustained polymorphic ventricular tachycardia in 7, and syncope in 4. All patients underwent cardiac catheterization, coronary and ventricular angiography, biventricular endomyocardial biopsy, and DNA screening of the SCN5A gene. Biopsy samples were processed for histology, electron microscopy, and molecular screening for viral genomes. Microaneurysms were detected in the right ventricle in 7 patients and also in the left ventricle in 4 of them. Histology showed a prevalent or localized right ventricular myocarditis in 14 patients, with detectable viral genomes in 4; right ventricular cardiomyopathy in 1 patient; and cardiomyopathic changes in 3. Genetic studies identified 4 carriers of SCN5A gene mutations that cause in vitro abnormal function of mutant proteins. In these patients, myocyte cytoplasm degeneration was present at histology, whereas terminal dUTP nick end-labeling assay showed a significant increase of apoptotic myocytes in right and left ventricle versus normal controls ( P =0.014 and P =0.013, respectively).

Conclusions— Despite an apparently normal heart at noninvasive evaluation, endomyocardial biopsy detected structural alterations in all 18 patients with Brugada syndrome. Mutations in the SCN5A gene, identified in 4 of the 18 patients, may have induced concealed structural abnormalities of myocardiocytes that accounted for paroxysmal arrhythmic manifestations.