Eosinophilic Granulomatosis With Polyangiitis Presenting as an Acute Coronary Syndrome.

Eosinophilic granulomatosis with polyangiitis, formerly Churg-Strauss Syndrome, is an uncommon disorder that carries a high mortality when coronary artery disease develops. Early recognition and treatment is crucial. We highlight an unusual presentation of acute coronary syndrome not associated with atherosclerotic coronary disease. (Level of Difficulty: Intermediate.).

Echocardiographic Evaluation of the Right Heart.

The appropriate use of echocardiography may reduce the need for invasive diagnostic cardiac procedures. The right side of the heart has recently gained interest among cardiologists as it became clear that abnormalities of the right heart morphology and function are associated with increased morbidity and mortality. Echocardiography is easy to perform, relatively cheap, readily available and do not pose the risk of ionizing radiation. Conventional 2D and, more recently, 3D echocardiography provides pertinent anatomic and physiologic information about the right side of the heart. Because of the advantages and simplicity of echocardiography it continues to be an excellent tool for evaluating the structure and function of the right side of the heart. This review outlines the uses of echocardiography in evaluating the right heart structure and function.

Impact of ventricular ectopic burden in a premature ventricular contraction-induced cardiomyopathy animal model.

BACKGROUND: Frequent premature ventricular contractions (PVCs) have been associated with PVC-induced cardiomyopathy (CM) in some patients. OBJECTIVE: The purpose of this study was to understand the cardiac consequences of different PVC burdens and the minimum burden required to induce left ventricular (LV) dysfunction. METHODS: Right ventricular apical PVCs at a coupling interval of 240 ms were introduced at different PVC burdens in 9 mongrel canines. A stepwise increase in PVC burden was implemented every 8 weeks from 0% (baseline), 7%, 14%, 25%, 33% to 50% using our premature pacing algorithm. Echocardiogram and 24-hour Holter were obtained at 4- and 8-week period for each PVC burden with a single blinded reader assessing all echocardiographic parameters including those assessed by speckle tracking imaging (EchoPAC workstation, General Electric). CM was defined as left ventricular ejection fraction (LVEF) <50% or LVEF drop >10% points. Interleukin-6 and pro-brain natriuretic peptide levels were obtained at the end of each PVC burden. RESULTS: The mean LVEF (mean heart rate) at 8 weeks for each PVC burden (0%, 7%, 14%, 33%, and 50%) were 57% ± 2.9% (85 ± 13 beats/min), 54.4% ± 3% (81 ± 10 beats/min), 53.3% ± 5% (77 ± 12 beats/min), 51.1% ± 4.2% (79 ± 14 beats/min), 47.7% ± 3.8% (80 ± 14 beats/min), and 44.7% ± 1.9% (157 ± 43 beats/min). PVC-induced CM was present in 11.1%, 44.4%, and 100% of animals with 25%, 33%, and 50% PVC burden, respectively. E/A ratio and radial strain decreased while left atrial size increased beyond 33% PVC burden. No changes in pro-brain natriuretic peptide and interleukin-6 levels were noted at any PVC burden. CONCLUSION: LV systolic function (LVEF and radial strain) declined linearly as PVC burden increased. PVC-induced CM developed in some canines with 25% and 33% PVC burden, but developed in all animals with 50% PVC burden.

Abnormal Left Ventricular Mechanics of Ventricular Ectopic Beats: Insights Into Origin and Coupling Interval in Premature Ventricular Contraction-Induced Cardiomyopathy.

BACKGROUND: Left ventricular (LV) dyssynchrony caused by premature ventricular contractions (PVCs) has been proposed as a mechanism of PVC-induced cardiomyopathy. We sought to understand the impact of different PVC locations and coupling intervals (prematurity) on LV regional mechanics and global function of the PVC beat itself. METHODS AND RESULTS: Using our premature pacing algorithm, pentageminal PVCs at coupling intervals of 200 to 375 ms were delivered from the epicardial right ventricular apex, RV outflow tract, and LV free wall, as well as premature atrial contractions, from the left atrial appendage at a coupling interval of 200 ms in 7 healthy canines. LV short-axis echocardiographic images, LV stroke volume, and dP/dtmax were obtained during all ectopic beats and ventricular pacing. LV dyssynchrony was assessed by dispersion of QRS-to-peak strain (earliest-last QRS-to-peak strain) between 6 different LV segments during each of the aforementioned beats (GE, EchoPac). LV dyssynchrony was greater during long-coupled rather than short-coupled PVCs and PVCs at 375 ms compared with rapid ventricular pacing at 400 ms (P<0.0001), whereas no difference was found between PVC locations. Longer PVC coupling intervals were associated with greater stroke volume and dP/dtmax despite more pronounced dyssynchrony (P<0.001). CONCLUSIONS: PVCs with longer coupling intervals demonstrate more pronounced LV dyssynchrony, whereas PVC location has minimal impact. LV dyssynchrony cannot be attributed to prematurity or abnormal ventricular activation alone, but rather to a combination of both. This study suggests that late-coupled PVCs may cause a more severe cardiomyopathy if dyssynchrony is the leading mechanism responsible for PVC-induced cardiomyopathy.

Patient-centered disease management (PCDM) for heart failure: study protocol for a randomised controlled trial.

BACKGROUND: Chronic heart failure (HF) disease management programs have reported inconsistent results and have not included comorbid depression management or specifically focused on improving patient-reported outcomes. The Patient Centered Disease Management (PCDM) trial was designed to test the effectiveness of collaborative care disease management in improving health status (symptoms, functioning, and quality of life) in patients with HF who reported poor HF-specific health status. METHODS/DESIGN: Patients with a HF diagnosis at four VA Medical Centers were identified through population-based sampling. Patients with a Kansas City Cardiomyopathy Questionnaire (KCCQ, a measure of HF-specific health status) score of < 60 (heavy symptom burden and impaired quality of life) were invited to enroll in the PCDM trial. Enrolled patients were randomized to receive usual care or the PCDM intervention, which included: (1) collaborative care management by VA clinicians including a nurse, cardiologist, internist, and psychiatrist, who worked with patients and their primary care providers to provide guideline-concordant care management, (2) home telemonitoring and guided patient self-management support, and (3) screening and treatment for comorbid depression. The primary study outcome is change in overall KCCQ score. Secondary outcomes include depression, medication adherence, guideline-based care, hospitalizations, and mortality. DISCUSSION: The PCDM trial builds on previous studies of HF disease management by prioritizing patient health status, implementing a collaborative care model of health care delivery, and addressing depression, a key barrier to optimal disease management. The study has been designed as an 'effectiveness trial' to support broader implementation in the healthcare system if it is successful. TRIAL REGISTRATION: Unique identifier: NCT00461513.

Left ventricular systolic dysfunction induced by ventricular ectopy: a novel model for premature ventricular contraction-induced cardiomyopathy.

BACKGROUND: Premature ventricular contractions (PVCs) commonly coexist with cardiomyopathy. Recently, PVCs have been identified as a possible cause of cardiomyopathy. We developed a PVC-induced cardiomyopathy animal model using a novel premature pacing algorithm to assess timeframe and reversibility of this cardiomyopathy and examine the associated histopathologic abnormalities. METHODS AND RESULTS: Thirteen mongrel dogs were implanted with a specially programmed pacemaker capable of simulating ventricular extrasystoles. Animals were randomly assigned to either 12 weeks of bigeminal PVCs (n = 7) or no PVCs (control, n = 6). Continuous 24-hour Holter monitoring corroborated ventricular bigeminy in the PVC group (PVC, 49.8% versus control, < 0.01%; P<0.0001). After 12 weeks, only the PVC group had cardiomyopathy, with a significant reduction in left ventricular ejection fraction (PVC, 39.7 ± 5.4% versus control, 60.7 ± 3.8%; P < 0.0001) and an increase in left ventricular end-systolic dimension (PVC, 33.3 ± 3.5 mm versus control, 23.7 ± 3.6 mm; P < 0.001). Ventricular effective refractory period showed a trend to prolong in the PVC group. PVC-induced cardiomyopathy was resolved within 2 to 4 weeks after discontinuation of PVCs. No inflammation, fibrosis, or changes in apoptosis and mitochondrial oxidative phosphorylation were observed with PVC-induced cardiomyopathy. CONCLUSIONS: This novel PVC animal model demonstrates that frequent PVCs alone can induce a reversible form of cardiomyopathy in otherwise structurally normal hearts. PVC-induced cardiomyopathy lacks gross histopathologic and mitochondrial abnormalities seen in other canine models of cardiomyopathy.