Ventricular tachycardia targeted in the aortic sinuses of Valsalva in patients with prior myocardial infarction.

INTRODUCTION: Ventricular tachycardia (VT) in structurally normal hearts or nonischemic cardiomyopathy can originate from the aortic sinuses of Valsalva (SoV). It is unknown whether VT can originate from the SoVs in patients with prior myocardial infarction (MI). OBJECTIVE: To evaluate the prevalence, arrhythmogenic substrate, and ablation outcomes of postinfarction VT originating from the SoVs. METHODS: Among 217 consecutive patients with postinfarction VT undergoing ablation, we identified 13 (6%) patients who had ≥1 VT mapped in a SoV. Control groups of 13 patients with idiopathic SoV VT and 13 postinfarction patients without SoV VT were included. RESULTS: In the study group, 17 VTs were mapped in a SoV (right n = 5, left-right commissure n = 6, left n = 6). SoV VT target sites had low bipolar voltage during sinus rhythm [median 0.42 (IQR: 0.16-0.53) mV] which was significantly lower than target sites in patients with idiopathic SoV VTs [median 1.02 (IQR: 0.89-1.52) mV; p < .001]. An area of endocardial low voltage was found below the aortic valve in all patients with postinfarction SoV VTs compared to 9 (69%) of the patients in the postinfarction control group without SoV VT (p = .02). Morphology characteristics of postinfarction SoV VTs differed from idiopathic SoV VTs. None of the postinfarction SoV VTs were inducible after ablation and none recurred after a median follow-up of 14 months. CONCLUSION: In patients with prior MI, VT can be targeted in an aortic SoV. The SoVs should be routinely investigated in postinfarction patients with inferior axis VT and an area of low voltage below the aortic valve.

Atrial Flutter Following Shockwave Intravascular Lithotripsy During Percutaneous Intervention of Left Anterior Descending Disease.

A 72-year-old woman undergoing percutaneous intervention to a calcified proximal left anterior descending (LAD) coronary artery lesion using Shockwave Intravascular Lithotripsy (S-IVL) developed new atrial flutter. She then returned to sinus rhythm after treatment with amiodarone. S-IVL can cause cardiomyocyte depolarization. We hypothesize that pacing can occur during atrial repolarization, inducing supraventricular tachyarrhythmias and even triggering atrial macro re-entrant circuits. We recommend synchronizing shock wave delivery with R waves on the electrocardiogram to lower the risk of arrhythmias.

The Role of the Left Septal Fascicle in Fascicular Arrhythmias: Clinical Presentation and Laboratory Evaluation.

OBJECTIVES: This study describes a series of cases best explained by invoking the left septal fascicle (LSF) as a critical component of the arrhythmia circuit. BACKGROUND: Numerous anatomic studies have shown evidence of the LSF, but its precise role in the onset of arrhythmia is unclear. METHODS: This paper presents 5 cases that implicated the LSF as a critical component of arrhythmogenesis. RESULTS: The first case had ventricular fibrillation repeatedly documented after a single premature atrial complex, produced left-sided conduction delay and simultaneous earliest activation of the left anterior fascicle (LAF) and left posterior fascicle (LPF). The LSF was ablated, resulting in an arrhythmia cure. The second case showed narrow QRS morphology during fascicular re-entrant tachycardia. The earliest mid-septal diastolic potentials had distal-to-proximal activation suggesting an LSF as a retrograde common pathway. The third case, with multiple ectopic Purkinje-related premature complexes exhibited earliest Purkinje potentials in the mid-septum, with subsequent anterograde activation of the LAF and LPF. Ablation of the LSF eliminated the premature ventricular complexes (PVCs). The fourth case demonstrated LPF and LAF PVCs. The His-left bundle activation showed earliest potentials at the proximal insertion of the left bundle during LPF PVCs, as well as a distal-to-proximal activation pattern during LAF PVC, suggestive of LSF involvement. The fifth case had focal non-re-entrant fascicular beats successfully ablated over the LSF. CONCLUSIONS: Involvement of the LSF is suspected with presentation of multiform fascicular and narrow QRS complex ventricular episodes of arrhythmia. Diagnoses and ablation require detailed mapping of the entire left sided conduction system.

Role of wearable rhythm recordings in clinical decision making-The wEHRAbles project.

BACKGROUND: Multiple wearable devices for rhythm analysis have been developed using either photoplethysmography (PPG) or handheld ECG. HYPOTHESIS: The aim of this survey was to assess impact of these technologies on physicians' clinical decision-making regarding initiation of diagnostic steps, drug therapy, and invasive strategies. METHODS: The online survey included 10 questions on types of devices, advantages, and disadvantages of wearable devices as well as case scenarios for patients with supraventricular arrhythmias and atrial fibrillation (AF). RESULTS: A total of 417 physicians (median age 37 [IQR 32-43] years) from 42 countries world-wide completed the survey. When presented a tracing of a regular tachycardia by a symptomatic patient, most participants would trigger further diagnostic steps (90% for single-lead ECG vs 83% for PPG, P < .001), while a single-lead ECG would be sufficient to perform an invasive EP study in approximately half of participants (51% vs 22% for PPG, P < .001). When presented with a single-lead ECG tracing suggesting AF, most participants (90%) would trigger further diagnostic steps. A symptomatic AF patient would trigger anticoagulation treatment to a higher extent as an asymptomatic patient (59% vs 21%, P < .001). PPG tracings would only rarely lead to therapeutic steps regardless of symptoms. Most participants would like scientific society recommendations on the use of wearable devices (62%). CONCLUSIONS: Tracings from wearable rhythm devices suggestive of arrhythmias are most likely to trigger further diagnostic steps, and in the case of PPG recordings rarely therapeutic interventions. A majority of participants expect these devices to facilitate diagnostics and arrhythmia screening but fear data overload and expect scientific society recommendations on the use of wearables.

Postinfarction Myocardial Calcifications on Cardiac Computed Tomography: Implications for Mapping and Ablation in Patients With Nontolerated Ventricular Tachycardias.

BACKGROUND: Postinfarction ventricular tachycardia (VT) generally involves myocardial fibers surrounded by scar. Calcification of scar tissue has been described, but the relationship between calcifications within endocardial scar and VTs is unclear. The purpose of this study was to assess the prevalence of myocardial calcifications as detected by cardiac computed tomography (CT) and the benefit for mapping and ablation focusing on nontolerated VTs. METHODS: Fifty-six consecutive postinfarction patients had a cardiac CT performed before a VT ablation procedure. Another 56 consecutive patients with prior infarction without VT who had cardiac CTs served as a control group. RESULTS: Myocardial calcifications were identified in 39 of 56 patients (70%) in the postinfarction group with VT, compared with 6 of 56 patients (11%) in the control group without VT. Calcifications were associated with VT when compared with a control group. A calcification volume of 0.538 cm3 distinguished patients with calcification-associated VT from patients without calcification-associated VTs (area under the curve, 0.87; sensitivity, 0.87; specificity, 0.88). Myocardial calcifications corresponded to areas of electrical nonexcitability and formed a border for reentry circuits for 49 VTs (33% of all VTs for which target sites were identified) in 24 of 39 patients (62%) with myocardial calcifications. A nonconfluent calcification pattern was associated with VT target sites independent of calcification volume ( P=0.01). CONCLUSIONS: Myocardial calcifications detected by cardiac CT in patients with prior infarction are associated with VT. The calcifications correspond to areas of unexcitability and represent a fixed boundary of reentry circuits that can be visualized by CT. Calcifications correspond to effective ablation sites in >1/3 of patients with postinfarction VT.

Automated external defibrillator use in out-of-hospital cardiac arrest: Current limitations and solutions.

Out-of-hospital sudden cardiac arrest (OHCA) is a major public health issue, with a survival rate at hospital discharge that remains below 10% in most cities, despite huge investments in this domain. Early basic life support (BLS) and early defibrillation using automated external defibrillators (AEDs) stand as key elements for improving OHCA survival rate. Nevertheless, the use of AEDs in OHCA remains low, for a variety of reasons, including the number, accessibility and ease of locating AEDs, as well as bystanders' awareness of BLS manœuvres and of the need to use AEDs. Several measures have been proposed to improve the rate of AED use, including optimization of AED deployment strategies as well as the use of drones to bring the AEDs to the OHCA scene and of mobile applications to locate the nearest AED. If they are to be effective, these measures should be combined with large communication campaigns on OHCA, and wide-scale education of the public in BLS and AEDs, to reduce the burden of OHCA.

Out-of-hospital cardiopulmonary resuscitation: a position statement of the Lebanese Society of Cardiology and the Lebanese Society of Emergency Medicine.

Out of hospital cardiac arrest (OHCA) is a leading cause of death worldwide. Early cardiopulmonary resuscitation (CPR) and early defibrillation are key to improving outcomes of patients with OHCA including return of spontaneous circulation (ROSC) and survival to hospital discharge with good neurologic outcomes. Lebanon like other developing countries, suffers from absence of organized prehospital cardiac arrest care bundle and from absence of a legal framework for community involvement in cardiac arrest care. Scientific societies, involved non-governmental organizations (NGOs) and local governmental stakeholders organized a national meeting to launch a strategy aiming at improving OHCA outcomes in Lebanon. This article represents a position statement of the Lebanese Society of Cardiology and the Lebanese Society of Emergency Medicine summarizing the strategy to improve out-of-hospital CPR. Participating stakeholders developed and submitted a law proposal of a "Good Samaritan Law" to the Lebanese parliament. Several of activities were also launched aiming at establishing public access defibrillation programs and at training bystanders in different areas in Lebanon to perform bystander CPR and use automated external defibrillators (AEDs). Additional recommendations were proposed to local emergency medical system (EMS) agencies to improve prehospital care and introduce medical direction to prehospital activities.

Longitudinal pulsatility in arterial occlusion.

This pictorial essay aims to generate attention and inform sonographers and clinicians by remembering the "longitudinal pulsatility" as an evocative B-mode echographic sign of arterial occlusion, when the artery exhibits a systolic axial motion instead of its normal radial pulsatility.

Multimodality Imaging for Guiding EP Ablation Procedures.

Recent advances in 3-dimensional electroanatomical mapping have been met by continuous improvements in the field of cardiac imaging and image integration during ablation procedures. Echocardiography, computed tomography, cardiac magnetic resonance, and nuclear imaging provide information about cardiac anatomy and ultrastructure of the heart that may be crucial for a successful ablation procedure. Techniques and value of pre-procedural, intraprocedural, and post-procedural imaging and image integration are discussed in this review article. Pre-procedural imaging provides key anatomic information that can be complemented by intraprocedural imaging to minimize procedural complications. Furthermore, the presence and extent of structural heart disease can be assessed pre-procedurally and can be displayed intraprocedurally to limit and focus the mapping and ablation procedure to the area of interest. Pre-procedural imaging combined with imaging obtained during the ablation procedure further enhances procedural safety, reduces exposure to ionizing radiation from fluoroscopy, reduces procedure time, and may improve outcomes.

Value of Cardiac Magnetic Resonance Imaging in Patients With Failed Ablation Procedures for Ventricular Tachycardia.

BACKGROUND: Ventricular tachycardia (VT) in patients with cardiomyopathy originates in scar tissue. Intramural or epicardial scar may result in ineffective ablation if mapping and ablation are limited to the endocardium. The purpose of this study was to investigate whether preprocedural magnetic resonance imaging (MRI) is beneficial in patients with failed endocardial VT ablations in determining an appropriate ablation strategy. METHODS AND RESULTS: A cardiac MRI was performed in 20 patients with a failed ablation procedure and cardiomyopathy (nonischemic n = 12, ischemic n = 8). A subsequent ablation strategy was determined by a delayed enhanced MRI (DE-MRI) and an epicardial subxyphoid access was planned only in patients with epicardial or intramural free-wall scar. MRIs were performed in all patients with or without an implanted cardioverter defibrillator (ICD). The location of scar tissue in the MRI predicted the origin of VT in all patients. In 9/20 patients an epicardial procedure was performed based on the result of the MRI. An endocardial procedure was performed in the remaining 11 patients who had either endocardial or septal scarring and one patient in whom the MRI only showed artifact. Five patients remained inducible postablation and four patients had VT recurrence within a follow-up period of 17 ± 22 months. All of the latter patients had an intramural scar pattern. CONCLUSIONS: Imaging with DE-MRI prior to VT ablation in patients with previously failed endocardial ablation procedures is beneficial in identifying an ablation strategy, helps to focus on an area of interest intraprocedurally, and provides valuable outcomes information.

Selecting the Appropriate Ablation Strategy: the Role of Endocardial and/or Epicardial Access.

Percutaneous catheter ablation has emerged as an effective treatment modality for the management of ventricular tachycardia. Despite years of progress in this field, the role of epicardial mapping and ablation needs to be further refined. In this review, we discuss the relationship between the type of underlying heart disease and the location of the arrythmogenic substrate as it pertains to a procedural approach. We describe the contribution of preprocedural and intraprocedural diagnostic tools for the localisation of the arrhythmogenic substrate, with a special emphasis on cardiac MRI and electrophysiological mapping. In our opinion, the preferred approach to target ventricular tachycardia should depend on the patient's underlying heart disease and the location of scar tissue, which can be best visualised using cardiac MRI.

Single coronary ostium in right coronary sinus: previously unreported "one for all" configuration.

We report our identification of a single coronary ostium arising from the right coronary sinus of Valsalva, in a 63-year-old woman who presented with chest pain atypical of angina. Coronary angiograms showed that the left anterior descending coronary artery arose from a right ventricular branch and that the left circumflex coronary artery arose from a right posterolateral branch. Both arteries reconstituted themselves in a backward fashion from the apex to the base of the heart-a configuration that to our knowledge has not been reported. The patient was treated conservatively and reported no chest pain 24 months later.

Unexplained macrocytosis.

OBJECTIVES: Macrocytosis is a relatively common finding in adult patients undergoing blood cell counting. Approximately 10% of patients will have unexplained macrocytosis after laboratory evaluation. Data on the approach to patients with unexplained macrocytosis are limited. METHODS: To investigate this topic and help delineate an approach to this condition, the records of 9779 patients diagnosed in our institution between 1995 and 2005 as having macrocytosis were reviewed. Patients with evidence of liver disease, alcohol abuse, hypothyroidism, folate or vitamin B12 deficiency, hemolysis, or use of any drugs known to cause macrocytosis were excluded. RESULTS: Forty-three patients were found to have unexplained macrocytosis. The median follow-up was 4 years. A total of 11.6% patients developed a primary bone marrow disorder (two B-cell lymphomas, two with myelodysplastic syndrome, one plasma cell disorder), 16.3% developed worsening cytopenias, 69.7% had stable disease, and 2.3% resolved. The median time to first cytopenia was 18 months, and the mean time to diagnosis of bone marrow disorder was 31.6 months. The outcomes were not significantly different when comparing patients with or without anemia upon diagnosis. The probability of a bone marrow biopsy to establish a diagnosis of a primary disorder was 33.3% in patients with macrocytosis without anemia compared with 75% in patients with macrocytosis with anemia. CONCLUSIONS: Patients with unexplained macrocytosis still require close follow-up. We suggest a strategy of follow-up with blood cell counting every 6 months. Bone marrow biopsy should be performed when cytopenias are present because this approach may provide a higher yield of diagnosis and aid with therapeutic decisions.

Diabetes and coronary heart disease: a risk factor for the global epidemic.

Cardiovascular disease remains a leading cause of death in the United States and the world. In this we will paper focus on type 2 diabetes mellitus as a risk factor for coronary heart disease, review the mechanisms of atherogenesis in diabetics, the impact of hypertension and the treatment goals in diabetics, the guidelines for screening, and review the epidemiologic consequences of diabetes and heart disease on a global scale. The underlying premise to consider diabetes a cardiovascular disease equivalent will be explored as well as the recommendations for screening and cardiac testing for asymptomatic diabetic patients.

System-based approach to educating internal medicine residents on preventable hospital readmissions.

BACKGROUND: A literature gap exists in educating internal medicine residents about hospital readmissions and how to prevent them. INTERVENTION: The study aimed to implement a readmissions education initiative for general internal medicine inpatient resident teams in 3 general practice units at an urban, tertiary hospital. METHODS: Senior residents were given access to a daily list of readmissions, used a readmission assessment tool to investigate causes and to assess whether each readmission was preventable, led a monthly general practice unit team meeting to discuss each case, and presented their findings at the monthly multidisciplinary readmissions meeting for additional feedback. For program evaluation, we hypothesized that the "preventable" readmissions count tracked via the readmissions assessment tool would increase as residents became better educated on the root causes of readmissions. We also conducted a survey to assess perception of the readmissions education initiative. RESULTS: "Preventable" readmissions increased from 21% for the first 3 months of the intervention (September-November 2010) to 46% for the most recent 3 months (January-March 2011). The survey showed that 98% (41 of 42) of respondents who had attended a multidisciplinary readmissions meeting felt involved in an effort to review or improve the rate of hospital readmissions, whereas only 40% (21 of 53) of the group that never attended a session shared the same answer. CONCLUSIONS: This initiative required few resources, and it appeared to help residents identify "preventable" reasons for readmissions, as well as increased their perceptions of being actively involved in reducing hospital readmissions. The intervention was not associated with a statistically significant reduction in readmissions, which may be influenced primarily by multiple factors outside residents' control.

Gene therapy for heart failure.

Despite the progress achieved in conventional treatment modalities, heart failure remains a major cause of mortality and morbidity. The identification of novel signaling pathways has provided a solid scientific rationale which has stimulated preclinical development of gene-based therapies for heart failure. Advances in somatic gene transfer technologies have been crucial to the advent of the first human clinical trials which are currently in progress. As these and other trials of gene transfer-based therapies are initiated, these approaches have generated excitement and hope for novel treatments for cardiovascular disease. In this review, we present a summary of advancements in construction of different vectors and methods of delivery that have been used for specific myocardial gene delivery. In addition, we will show results from studies focusing on the use of gene therapy to target heart failure mechanisms in animal models of cardiac dysfunction. Finally, we discuss the limited but highly promising results from clinical studies that have served as catalysts to translate preclinical achievements towards new treatment modalities for heart failure.