Leadless cardiac ventricular pacing using helix fixation: Step-by-step guide to implantation.

INTRODUCTION: Leadless cardiac pacemakers are an alternative modality to traditional transvenous pacemaker systems. Recently receiving Food and Drug Administration approval, the AVEIR VR leadless pacemaker system provides a helix based active fixation leadless pacemaker system. This step-by-step review will cover patient selection, preprocedural planning, device implantation technique, implant site evaluation, troubleshooting, short- and long-term complications as well as future directions for leadless pacing. METHODS: We collected and reviewed cases from primary operators to provide a step-by-step review for implanters. RESULTS: Our paper provides a guide to patient selection, pre-procedural planning, device im plantation technique, implant site evaluation, troubleshooting, short- and long-term complications as well as future directions for leadless pacing. CONCLUSION: The helix based active fixation leadless pacemaker system is a safe and efficacious way to provide pacing support to patients and provides an alternative to transvenous pacing systems. Our review provides a step-by-step guide to implantation.

Heart rate increase after pulmonary vein isolation predicts freedom from atrial fibrillation at 1 year.

INTRODUCTION: Ablation of atrial vagal ganglia has been associated with improved pulmonary vein isolation (PVI) outcomes. Disruption of vagal reflexes results in heart rate (HR) increase. We investigated the association between HR change after PVI and freedom from atrial fibrillation (AF) at 1 year. METHODS AND RESULTS: Patients who underwent PVI for paroxysmal AF were identified from the Johns Hopkins Hospital AF registry. Electrocardiograms taken pre-PVI and post-PVI were used to determine the change in HR. Patients followed-up at 3, 6, and 12 months. Of 257 patients (66% male, age 59+/-11 years), 134 (52%) remained free from AF at 1 year. The average HR increased from 60.6 ± 11.3 beats per minute (bpm) pre-PVI to 70.7 ± 12.0 bpm post-PVI. Patients with recurrence of AF had lower post-PVI HR than those who remained free from AF (67.8 ± 0.2 vs 73.3 ± 13.0 bpm; P <.001). The probability of AF recurrence at 1-year decreased as the change in HR increased (estimated odds ratio [OR], 0.83; 95% confidence interval [CI, 0.74-0.93]; P = .002). HR increase more than 15 bpm was associated with the lowest odds of AF recurrence (estimated OR, 0.39; 95% [0.17-0.85]; P = .018) compared to HR decrease. CONCLUSIONS: Resting HR was found to increase after PVI. Increase in HR more than 15 bpm has a positive association with remaining free from atrial fibrillation at 1 year.

Transcatheter left ventriculoplasty.

Despite significant advances in pharmacological, electrophysiological and valve therapies for heart failure with reduced ejection fraction (HFrEF), the associated morbidity, mortality and healthcare costs remain high. With a constantly growing heart failure population, the existing treatment gap between current and advanced heart failure therapies (e.g., left ventricular [LV] assist devices, heart transplantation) reflects a large unmet need, calling for novel therapeutic approaches. Left ventricular remodelling and dilatation, with or without scar formation, is the hallmark of cardiomyopathy and is associated with poor prognosis. In the era of exciting advances in structural heart interventions, the advent of minimally invasive, device-based therapies directly targeting the LV geometry and promoting physical reverse remodelling has created a new frontier in the battle against heart failure. Interventional heart failure therapy is a rapidly emerging field, encompassing structural heart and minimally invasive hybrid procedures, with two left ventriculoplasty devices currently under investigation in pivotal clinical trials in the US. This review addresses the rationale for left ventriculoplasty, presents the prior surgical and percutaneous attempts in the field, provides an overview of the novel transcatheter left ventriculoplasty devices and their respective trials, and highlights potential challenges associated with establishing such device-based therapies in our armamentarium against heart failure.

Obstructive Sleep Apnea and Cardiac Arrhythmias: A Contemporary Review.

Obstructive sleep apnea (OSA) is a highly prevalent disorder with a growing incidence worldwide that closely mirrors the global obesity epidemic. OSA is associated with enormous healthcare costs in addition to significant morbidity and mortality. Much of the morbidity and mortality related to OSA can be attributed to an increased burden of cardiovascular disease, including cardiac rhythm disorders. Awareness of the relationship between OSA and rhythm disorders is variable among physicians, a fact that can influence patient care, since the presence of OSA can influence the incidence, prevalence, and successful treatment of multiple rhythm disorders. Herein, we provide a review of this topic that is intentionally broad in scope, covering the relationship between OSA and rhythm disorders from epidemiology and pathophysiology to diagnosis and management, with a particular focus on the recognition of undiagnosed OSA in the general clinical population and the intimate relationship between OSA and atrial fibrillation.

State-of-the-art narrative review: multimodality imaging in electrophysiology and cardiac device therapies.

Cardiac electrophysiology procedures have evolved to provide improvement in morbidity and mortality for many patients. Cardiac resynchronization therapy (CRT), implantable cardioverter/defibrillator (ICD) placement and lead extraction procedures are proven procedures, associated with significant reductions in patient morbidity and mortality as well as improved quality of life. The applications and optimization of these therapies are an evolving field. The optimal use and outcomes of cardiac electrophysiology procedures require a multidisciplinary approach to patient selection, device selection, and procedural planning. Cardiac imaging using echocardiography plays a key role in selection of patients for CRT therapy, for guidance of left ventricular (LV) lead placement, and for optimization of atrioventricular pacing delays in patients with CRT. Cardiac computed tomography (CT) is an important tool in assessment of lead perforation, as well as assessing risk of lead extraction and procedural planning. Cardiac magnetic resonance imaging (MRI) is an important adjunct to transthoracic echocardiography for patient selection and risk stratification for defibrillator therapy for multiple disease states including ischemic cardiomyopathy, hypertrophic cardiomyopathy, cardiac sarcoidosis, and arrhythmogenic right ventricular cardiomyopathy (ARVC). Cardiac positron emission tomography (PET) is a useful adjunct to the diagnosis of device infections as well as inflammatory conditions including cardiac sarcoidosis. Our review attempts to summarize the contemporary roles of multimodality imaging in CRT therapy, ICD therapy and lead extraction therapy.

Toronto hypertrophic cardiomyopathy genotype score for prediction of a positive genotype in hypertrophic cardiomyopathy.

BACKGROUND: Genotyping in hypertrophic cardiomyopathy has gained increasing attention in the past decade. Its major role is for family screening and rarely influences decision-making processes in any individual patient. It is associated with substantial costs, and cost-effectiveness can only be achieved in the presence of high-detection rates for disease-causing sarcomere protein gene mutations. Therefore, our aim was to develop a score based on clinical and echocardiographic variables that allows prediction of the probability of a positive genotype. METHODS AND RESULTS: Clinical and echocardiographic variables were collected in 471 consecutive patients undergoing genetic testing at a tertiary referral center between July 2005 and November 2010. Logistic regression for a positive genotype was used to construct integer risk weights for each independent predictor variable. These were summed for each patient to create the Toronto hypertrophic cardiomyopathy genotype score. A positive genotype was found in 163 of 471 patients (35%). Independent predictors with associated-risk weights in parentheses were as follows: age at diagnosis 20 to 29 (-1), 30 to 39 (-2), 40 to 49 (-3), 50 to 59 (-4), 60 to 69 (-5), 70 to 79 (-6), ≥80 (-7); female sex (4); arterial hypertension (-4); positive family history for hypertrophic cardiomyopathy (6); morphology category (5); ratio of maximal wall thickness:posterior wall thickness <1.46 (0), 1.47 to 1.70 (1), 1.71 to 1.92 (2), 1.93 to 2.26 (3), ≥2.27 (4). The model had a receiver operator curve of 0.80 and Hosmer-Lemeshow goodness-of-fit P=0.22. CONCLUSIONS: The Toronto genotype score is an accurate tool to predict a positive genotype in a hypertrophic cardiomyopathy cohort at a tertiary referral center.

Myocardial mechanical remodeling after septal myectomy for severe obstructive hypertrophic cardiomyopathy.

BACKGROUND: Septal myectomy for symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM) is a well-established procedure for symptomatic relief. Myocardial mechanics are abnormal in patients with HOCM, demonstrating low longitudinal strain, high circumferential strain, and high apical rotation compared with healthy subjects. The aim of this study was to determine whether functional improvement after myectomy is associated with improved myocardial mechanics. METHODS: Clinical data and paired echocardiographic studies before and after myectomy (6-18 months) were retrospectively analyzed and compared in 66 patients (mean age, 54 ± 13 years; 64% men) with HOCM. Myocardial mechanics including longitudinal and circumferential strain and rotation were assessed using two-dimensional strain software (Velocity Vector Imaging). RESULTS: Patients had significant symptomatic alleviation (mean New York Heart Association class, 2.8 ± 0.4 at baseline and 1.3 ± 0.5 after myectomy; P < .05). Left ventricular outflow gradient decreased dramatically (from 93 ± 26 to 17 ± 12 mm Hg; P < .05), and left atrial volume index decreased (from 48 ± 16 to 37 ± 13 cm(3)/m(2); P < .05). Low longitudinal strain decreased at the myectomy site, increased in the lateral segments, and remained unchanged globally (-16 ± 4). High circumferential strain decreased (from -31 ± 5 to -25 ± 6, P < .05). High left ventricular twist normalized (from -15.5 ± 6.2° to 12.8 ± 4.2°, P < .05). Independent predictors of symptomatic response included younger age before myectomy, thinner posterior wall, and higher lateral early diastolic velocity (e'). CONCLUSION: In patients with HOCM, surgical myectomy alleviated symptoms, relieved obstruction, and decreased left atrial volume index. Longitudinal strain remained unchanged, but circumferential strain and rotation decreased, demonstrating different mechanical adaptations to chronic elevated afterload seen in patients with severe aortic stenosis undergoing valve replacement. Disease extent (age, posterior wall involvement) and the presence of diastolic dysfunction seem to be related to partial symptomatic response to myectomy.