The role of endomyocardial biopsy in the management of cardiovascular disease: a scientific statement from the American Heart Association, the American College of Cardiology, and the European Society of Cardiology

Influenza myocarditis and myositis: case presentation and review of the literature

Myocarditis, a general inflammatory condition of the heart muscle, can result from a variety of etiologies, the most common being viral. Despite common pathogens, concomitant myocarditis and myositis remains a rare event. Although a common cause of respiratory illness, extrapulmonary infections with influenza are infrequent. We describe the case of a patient who presented to our centre with concomitant "seasonal" H1N1 influenza A myocarditis further complicated by pan-myositis. The patient's condition rapidly declined, eventually requiring biventricular mechanical support, in addition to multilimb fasciotomies. The cardiac support required was progressive, from a percutaneous left ventricular assist device, to extracorporeal membrane oxygenation, to eventual biventricular assist device support for bridge-to-transplantation. This case motivated a detailed review of the literature (a total of 29 cases were identified), in which we found that patients with influenza myocarditis/myositis were predominantly female (63%) and young (mean age 33.2 years) and continue to have a high incidence of morbidity and mortality (27%). As a result of its atypical pattern, the 2009 H1N1 pandemic strain has gained attention. From our review, we found 7 patients with of 2009 H1N1 pandemic influenza myocarditis. Serial serum cytokine analysis did not demonstrate a "cytokine storm," which has been associated with other virulent influenza strains. The PB1-F2 marker in particular has been associated with a vigorous cytokine response. The 2009 H1N1 and "seasonal" influenza strains lack this marker. In those patients with community-acquired influenza, interleukin-6 has been shown to correlate with symptoms. For patients with myocarditis resulting in shock, mechanical circulatory support has gained acceptance as a means to recovery or transplantation.

Salmonella enteritidis Infection Complicated by Acute Myocarditis: A Case Report and Review of the Literature

Salmonella spp. is the cause of commonly encountered infections, with seasonal pattern of occurrence and worldwide distribution. Some of the clinical manifestations such as gastroenteritis and bacteremia are common, whereas others like mycotic aneurysms and osteomyelitis are infrequent especially in immunocompetent patients. Salmonella has been rarely described as a cause of myocarditis in the literature. We describe a case of an 18-year-old previously healthy male patient with myocarditis after Salmonella enteritidis infection. Clinical manifestations and diagnostic approach of this severe complication are discussed with a review of the literature.

Transcriptomic biomarkers for the accurate diagnosis of myocarditis

BACKGROUND

Lymphocytic myocarditis is a clinically important condition that is difficult to diagnose and distinguish. We hypothesized that the transcriptome obtained from an endomyocardial biopsy would yield clinically relevant and accurate molecular signatures.

METHODS AND RESULTS

Microarray analysis was performed on samples from patients with histologically proven lymphocytic myocarditis (n=16) and idiopathic dilated cardiomyopathy (n=32) to develop accurate diagnostic transcriptome-based biomarkers using multiple classification algorithms. We identified 9878 differentially expressed genes in lymphocytic myocarditis versus idiopathic dilated cardiomyopathy (fold change >1.2; false discovery rate <5%) from which a transcriptome-based biomarker containing 62 genes was identified that distinguished myocarditis with 100% sensitivity (95% confidence interval, 46 to 100) and 100% specificity (95% confidence interval, 66 to 100) and was generalizable to a broad range of secondary cardiomyopathies associated with inflammation (n=27), ischemic cardiomyopathy (n=8), and the normal heart (n=11). Multiple classification algorithms and quantitative real-time reverse-transcription polymerase chain reaction analysis further reduced this subset to a highly robust molecular signature of 13 genes, which still performed with 100% accuracy.

CONCLUSIONS

Together, these findings demonstrate that transcriptomic biomarkers from a single endomyocardial biopsy can improve the clinical detection of patients with inflammatory diseases of the heart. This approach advances the clinical management and treatment of cardiac disorders with highly variable outcome.

Cardiac magnetic resonance visualizes acute and chronic myocardial injuries in myocarditis

Our objective was to evaluate the ability of CMR to visualize myocardial injuries over the course of myocarditis. We studied 42 patients (39 males, 3 females; age 37 ± 14 years) with myocarditis during the acute phase and after 12 ± 9 months. CMR included function analyses, T2-weighted imaging (T2 ratio), T1-weighted imaging before and after i.v. gadolinium injection (global relative enhancement; gRE), and late gadolinium enhancement (LGE). In the acute phase, the T2 ratio was elevated in 57%, gRE in 31%, and LGE was present in 64% of the patients. In 32 patients (76%) were any two (or more) out of three sequences abnormal. At follow-up, there was an increase in ejection fraction (57.4 ± 11.9% vs. 61.4 ± 7.6; P < 0.05) while both T2 ratio (2.04 ± 0.32 vs. 1.70 ± 0.28; P < 0.001) and gRE (4.07 ± 1.63 vs. 3.11 ± 1.22; P < 0.05) significantly decreased. The LGE persisted in 10 patients. Dilated cardiomyopathy was present in 3 patients and 4 patients received a defibrillator or a pacemaker. A comprehensive CMR approach is a useful tool to visualize myocardial tissue injuries over the course of myocarditis. CMR may help to differentiate acute from healed myocarditis, and add information for the differential diagnoses.

Adiponectin expression in patients with inflammatory cardiomyopathy indicates favourable outcome and inflammation control

AIMS

Circulating adiponectin (APN) is an immunomodulatory, pro-angiogenic, and anti-apoptotic adipocytokine protecting against acute viral heart disease and preventing pathological remodelling after cardiac injury. The purpose of this study was to describe the regulation and effects of APN in patients with inflammatory cardiomyopathy (DCMi).

METHODS AND RESULTS

Adiponectin expression and outcome were assessed in 173 patients with DCMi, 30 patients with non-inflammatory DCM, and 30 controls. Mechanistic background of these findings was addressed in murine experimental autoimmune myocarditis (EAM), a model of human DCMi, and further elucidated in vitro. Adiponectin plasma concentrations were significantly higher in DCMi compared with DCM or controls, i.e. 6.8 ± 3.9 µg/mL vs. 5.4 ± 3.6 vs. 4.76 ± 2.5 µg/mL (P< 0.05, respectively) and correlated significantly with cardiac mononuclear infiltrates (CD3+: r(2)= 0.025, P= 0.038; CD45R0+: r(2)= 0.058, P= 0.018). At follow-up, DCMi patients with high APN levels showed significantly increased left ventricular ejection fraction improvement, decreased left ventricular end-diastolic diameter, and reduced cardiac inflammatory infiltrates compared with patients with low APN levels. A multivariate linear regression analysis implicated APN as an independent prognostic factor for inhibition of cardiac inflammation. In accordance with these findings in human DCMi, EAM mice exhibited elevated plasma APN. Adiponectin gene transfer led to significant downregulation of key inflammatory mediators promoting disease. Mechanistically, APN acted as a negative regulator of T cells by reducing antigen specific expansion (P< 0.01) and suppressed TNFα-mediated NFκB activation (P< 0.01) as well as release of reactive oxygen species in cardiomyocytes.

CONCLUSION

Our results implicate that APN acts as endogenously upregulated anti-inflammatory cytokine confining cardiac inflammation and progression in DCMi.

Presumptive myocarditis with ST-Elevation myocardial infarction presentation in young males as a new syndrome. Clinical significance and long term follow up

BACKGROUND

Acute myocarditis may mimic myocardial infarction, since affected patients complain of "typical" chest pain, the ECG changes are identical to those observed in acute coronary syndromes, and serum markers are increased. We describe a case series of presumptive myocarditis with ST segment elevation on admission ECG.

METHODS AND RESULTS

From 1998 to 2009, 21 patients (20 males; age 17-42 years) were admitted with chest pain, persistent ST segment elevation, serum enzyme and troponine release. All but one patients had fever and flu-like symptoms prior to admission. No abnormal Q wave appeared in any ECG tracing, and angiography did not show significant coronary artery disease. Patients remained asymptomatic at long term follow-up, except 2 who experienced a late relapse, with the same clinical, electrocardiographic and serum findings as in the first clinical presentation.

CONCLUSION

Presumptive myocarditis of possible viral origin characterized by ST elevation mimicking myocardial infarction, good short term prognosis and some risk for recurrence is relatively frequent in young males and appears as a distinct clinical condition.

Virus serology in patients with suspected myocarditis: utility or futility?

AIMS

Serological analyses of viral infection in suspected myocarditis are still widely used, although convincing evidence for their value is lacking. We determined prospectively the diagnostic value of virus serology in comparison with endomyocardial biopsy (EMB) including viral genome detection and immunohistochemistry in patients with clinically suspected myocarditis.

METHODS AND RESULTS

Virus serology and state-of-the-art evaluation of EMB were performed in 124 patients (age 40 ± 15 years) with suspected myocarditis. Endomyocardial biopsy was studied for inflammation with histological and immunohistological criteria. The viral genome was detected in the myocardium by polymerase chain reaction. Acute viral infection with enterovirus, adenovirus, parvovirus B19, cytomegalovirus, human herpesvirus, and Epstein-Barr virus was diagnosed by IgM or IgA in the initial sample or IgG seroconversion in the follow-up sample. Immunohistological signs of inflammation were present in 54 patients. The viral genome was detected in the myocardium of 58 patients (47%). In 20 patients (16%), acute viral infection was diagnosed by serology. Only in 5 out of 124 patients (4%), there was serological evidence of an infection with the same virus that was detected by EMB. Sensitivity and specificity of virus serology were 9 and 77%, respectively. The positive predictive value was 25% and the negative predictive value was 49%. The lack of correlation between serology and EMB remained also for patients with biopsy-proven myocarditis and patients with time from initial symptoms to EMB procedure of ≤1 month.

CONCLUSIONS

For patients with suspected myocarditis, virus serology has no relevance for the diagnosis of myocardial infection. Endomyocardial biopsy remains the gold standard in the diagnostic of viral myocarditis.

Myocarditis in the setting of RSV bronchiolitis

Myocarditis in the pediatric population is commonly caused by viral pathogens, notably entero virus and adeno virus. Respiratory syncytial virus, although widespread among this population, is rarely associated with myocarditis. The incidence of myocarditis is unknown due to the variability of clinical presentation and diagnostic limitations. Data regarding prognosis is lacking in children. Patients should be monitored in a pediatric intensive care unit secondary to the risk of hemodynamic compromise. We present the case of fulminant myocarditis in a seven-month old female in the setting of respiratory syncytial virus bronchiolitis.

Myocarditis and pericarditis in children

Myocarditis and pericarditis are rare but important causes of pediatric chest pain. The diagnostic criteria, clinical course, causes, and treatment of myocarditis is reviewed. There is particular attention to the relationship of myocarditis with dilated cardiomyopathy. Supportive therapy remains the standard of care for pump dysfunction. The identification and treatment of pericarditis with associated large pericardial effusion can be lifesaving. This article reviews the important clinical features that might lead the clinician to diagnose either myocarditis or pericarditis and thus separate the few patients with either of these conditions from the legions of children with noncardiac chest pain.

Myocardial parvovirus B19 persistence: lack of association with clinicopathologic phenotype in adults with heart failure

BACKGROUND

Multiple viruses have been isolated from the heart, but their significance remains controversial. We sought to determine the prevalence of cardiotropic viruses in endomyocardial biopsy (EMB) samples from adult patients with heart failure (HF) and to define the clinicopathologic profile of patients exhibiting viral positivity.

METHODS AND RESULTS

EMB from 100 patients (median ejection fraction, 30%; interquartile range [IQR], 20% to 45%) presenting for cardiomyopathy evaluation (median symptom duration, 5 months; IQR, 1 to 13 months) were analyzed by polymerase chain reaction for adenovirus, cytomegalovirus, enteroviruses, Epstein-Barr virus, and parvovirus B19. Each isolate was sequenced, and viral load was determined. Parvovirus B19 was the only virus detected in EMB samples (12% of subjects). No patient had antiparvovirus IgM antibodies, but all had IgG antibodies, suggesting viral persistence. The clinical presentation of parvovirus-positive patients was markedly heterogeneous with both acute and chronic HF, variable ventricular function, and ischemic cardiomyopathy. No patient met Dallas histopathologic criteria for active or borderline myocarditis. Two patients with a positive cardiac MRI and presumed "parvomyocarditis" had similar viral loads to autopsy controls without heart disease. The oldest parvovirus-positive patients were positive for genotype 2, suggesting lifelong persistence in the myocardium.

CONCLUSIONS

Parvovirus B19 was the only virus isolated from EMB samples in this series of adult patients with HF from the United States. Positivity was associated with a wide array of clinical presentations and HF phenotypes. Our studies do not support a causative role for parvovirus B19 persistence in HF and, therefore, advocate against the use of antiviral therapy for these patients.

Ventricular Remodeling and Survival Are More Favorable for Myocarditis Than For Idiopathic Dilated Cardiomyopathy in Childhood

Background—

Myocarditis is a cause of a new-onset dilated cardiomyopathy phenotype in children, with small studies reporting high rates of recovery of left ventricular (LV) function.

Methods and Results—

The presenting characteristics and outcomes of children with myocarditis diagnosed clinically and with biopsy confirmation (n=119) or with probable myocarditis diagnosed clinically or by biopsy alone (n=253) were compared with children with idiopathic dilated cardiomyopathy (n=1123). Characteristics at presentation were assessed as possible predictors of outcomes. The distributions of time to death, transplantation, and echocardiographic normalization in the biopsy-confirmed myocarditis and probable myocarditis groups did not differ ( P ≥0.5), but both groups differed significantly from the idiopathic dilated cardiomyopathy group (all P ≤0.003). In children with myocarditis, lower LV fractional shortening z -score at presentation predicted greater mortality (hazard ratio, 0.85; 95% confidence interval, 0.73 to 0.98; P =0.03) and greater LV posterior wall thickness predicted transplantation (hazard ratio, 1.17; 95% confidence interval, 1.02 to 1.35; P =0.03). In those with decreased LV fractional shortening at presentation, independent predictors of echocardiographic normalization were presentation with an LV end-diastolic dimension z -score >2 (hazard ratio, 0.36; 95% confidence interval, 0.22 to 0.58; P <0.001) and greater septal wall thickness (hazard ratio, 1.16; 95% confidence interval, 1.01 to 1.34; P =0.04).

Conclusions—

Children with biopsy-confirmed or probable myocarditis had similar proportions of death, transplantation, and echocardiographic normalization 3 years after presentation and better outcomes than those of children with idiopathic dilated cardiomyopathy. In children with myocarditis who had impaired LV ejection at presentation, rates of echocardiographic normalization were greater in those without LV dilation and in those with greater septal wall thickness at presentation.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00005391.

Usefulness of magnetic resonance imaging to distinguish hypertensive and hypertrophic cardiomyopathy

Different pathophysiologic pathways in the development of left ventricular (LV) hypertrophy can be reflected in phenotypical differences. A total of 119 subjects (39 with hypertension [HTN]; 43 with nonobstructive hypertrophic cardiomyopathy [HC], and 37 control subjects) underwent a standardized cardiac magnetic resonance imaging protocol for assessment of global and regional morphology and function using balanced steady-state free precession sequences and late gadolinium enhancement studies. Compared to controls, both hypertrophic groups had significantly greater maximal wall thickness and LV mass index (p <0.01). The patients with HTN had reduced ejection fraction, increased heart cavities, and increased LV wall stress (p <0.01). The HC group had supernormal ejection fraction and reduced LV wall stress (p <0.01). The HTN group had reduced anteroseptal systolic strains (p <0.02), and the HC group displayed a marked decrease in longitudinal systolic strain (p <0.01). In the HC group, an inverse relation was seen between a globally increased late gadolinium enhancement score and the ejection fraction (r = -0.5, p = 0.01), and between regional late gadolinium enhancement scores and regional systolic strain in the inferoseptal segments. Increased LV wall stress was identified as the hallmark of HTN (odds ratio 1.2, p = 0.002), while HC was best characterized by reduced total longitudinal strain (odds ratio 1.3, p = 0.002). In conclusion, our findings indicate the presence of distinctive hypertrophic phenotypes detectable by means of multiparametric magnetic resonance imaging. In HTN, impaired deformation follows the distribution of LV wall stress. On the contrary, HC is characterized by reduced global and regional deformation, in association with fibrosis.

Anticancer therapy induced cardiotoxicity: review of the literature

Innovative anticancer strategies have contributed to an improved survival of patients suffering from malignancies, and in some cases, have turned cancer into a chronic disease. Therefore, the early and particularly late onsets of adverse cardiovascular effects of systemic anticancer treatments are of increasing interest. Among a rapidly increasing variety of anticancer drugs, the anthracyclines and the monoclonal antibody, trastuzumab, are the agents with a well-known cardiotoxicity. The diagnostic work-up, the cardiotoxic risk of anthracyclines and trastuzumab, and additionally, cardiotoxicity as a risk factor of a multimodal therapeutic approach in breast cancer patients is discussed in this study.

[The heart in viral infections]

Between 10 and 20% of patients with histologically proven inflammatory disease of the heart muscle develop a chronic disorder after acute myocarditis which results in dilated cardiomyopathy with increasing cardiac insufficiency. Viral infections are a frequent cause of inflammatory heart muscle diseases and thus also responsible for myocardial damage in the initial phase. In the past, evidence for enterovirus, adenovirus, and cytomegalovirus was in the focus of attention. In the meantime, "new" cardiotropic pathogens such as parvovirus B19, Epstein-Barr virus, and human herpesvirus 6 have been detected in patients with dilated cardiomyopathy with and without inflammation. Their persistence in the myocardium correlates with a decline in pumping capability within 6 months. While the virus is still being eliminated, the second phase of the disease begins, which is characterized by autoimmune phenomena and often a cardiac inflammatory response which likewise correlates with a worsening prognosis. The transition to the third and final phase with development of dilated cardiomyopathy occurs gradually and can take years. The goal of every diagnostic and therapeutic intervention must be to eradicate the virus and eliminate the inflammatory response to prevent the disease from progressing to terminal cardiac insufficiency.

Echocardiography in patients with hypertrophic cardiomyopathy: usefulness of old and new techniques in the diagnosis and pathophysiological assessment

Hypertrophic cardiomyopathy (HCM) is one of the most common inherited cardiomyopathy. The identification of patients with HCM is sometimes still a challenge. Moreover, the pathophysiology of the disease is complex because of left ventricular hyper-contractile state, diastolic dysfunction, ischemia and obstruction which can be coexistent in the same patient. In this review, we discuss the current and emerging echocardiographic methodology that can help physicians in the correct diagnostic and pathophysiological assessment of patients with HCM.

Mitral valve surgery in advanced heart failure

The appropriateness and timing of mitral valve surgery in patients with advanced heart failure and severe mitral regurgitation remains controversial. Recent surgical results provide evidence for beneficial effects on left ventricular remodeling and functional capacity. Given the absence of randomized trials comparing the outcomes of mitral valve surgery to medical therapy, however, clinical decision making regarding surgery for these fragile patients poses a dilemma to thoughtful clinicians. This paper reviews the pathophysiology of mitral regurgitation in heart failure and proposes an integrated approach to management.

Myocarditis

Myocarditis is an uncommon, potentially life-threatening disease that presents with a wide range of symptoms in children and adults. Viral infection is the most common cause of myocarditis in developed countries, but other etiologies include bacterial and protozoal infections, toxins, drug reactions, autoimmune diseases, giant cell myocarditis, and sarcoidosis. Acute injury leads to myocyte damage, which in turn activates the innate and humeral immune system, leading to severe inflammation. In most patients, the immune reaction is eventually down-regulated and the myocardium recovers. In select cases, however, persistent myocardial inflammation leads to ongoing myocyte damage and relentless symptomatic heart failure or even death. The diagnosis is usually made based on clinical presentation and noninvasive imaging findings. Most patients respond well to standard heart failure therapy, although in severe cases, mechanical circulatory support or heart transplantation is indicated. Prognosis in acute myocarditis is generally good except in patients with giant cell myocarditis. Persistent, chronic myocarditis usually has a progressive course but may respond to immunosuppression.

Interferon beta-1b therapy in chronic viral dilated cardiomyopathy--is there a role for specific therapy?

BACKGROUND

Myocardial biopsy can be used for the detection of viral genome in dilated cardiomyopathy (DCM). Pilot studies have previously reported beneficial effects on clinical outcome and safety of an antiviral therapy using interferon beta-1b in chronic viral DCM.

METHODS AND RESULTS

Myocardial biopsies were taken from patients with DCM. Using polymerase chain reaction and Southern Blot analysis, viral genome could be detected in 49% of patients. In 42 patients with viral infection, off-label use with interferon beta-1b was initiated. A further 68 patients formed the control group. The outcome was evaluated after follow-up with echocardiography, exercise electrocardiogram, and New York Heart Association class. A total of 81 men and 29 women with a median left ventricular ejection fraction of 34% were included. The follow-up period was 36 months. In 33 (79%) patients with interferon beta-1b treatment, minor adverse reactions occurred, but no major adverse events were reported. No significant benefit for interferon beta-1b treatment on clinical outcome could be detected during follow-up.

CONCLUSIONS

Off-label use with interferon beta-1b in patients with viral DCM is feasible and safe under routine clinical practice. Concerning the herein evaluated clinical outcome parameters, promising results from pilot studies could not be confirmed. High prevalence of parvovirus B19 (92%) might influence the results.

Cardiovascular magnetic resonance imaging of non-ischaemic heart disease: established and emerging applications

This review aims to summarise state-of-the-art CMR-methodology, established applications, future directions and potentials in the assessment of patients with NonIschaemic-Heart Disease. CMR offers the unique possibility to differentiate myocardial tissue changes. One of the most challenging tasks in cardiology is the differentiation of the underlying cause of a wall motion abnormality in case of unclear or conflicting results of conventional clinical assessment CMR offers the unique chance to fill that gap. Most of the presented data are ready for use in clinical routine.

Clinical consequences of iron overload from chronic red blood cell transfusions, its diagnosis, and its management by chelation therapy

Iron overload from chronic transfusion therapy can be extremely toxic. Excess transfusional iron is deposited in the liver, heart, and other organs as free iron, which can cause organ dysfunction and damage over time. Increased awareness of the risk of iron overload in patients requiring chronic transfusion therapy is needed, and such patients should be screened for hyperferritinemia. Those with serial serum ferritin levels exceeding 1000 ng/mL and a total infused red blood cell volume of 120 mL/kg of body weight or more should be treated with chelation therapy and then monitored to ensure that treatment adequately reduces iron levels.

A transatrial pericardial access: lead placement as proof of concept

A safe, easy, and quick access into the pericardial space may provide a window for diagnostics and therapeutics to the heart. The objective of this study was to provide proof of concept for an engagement and access catheter that allows access to the pericardial space percutaneously. A multilumen catheter was developed to allow navigation and suction fixation to the right atrial appendage/wall in a normal swine model. Advancement through the multilumen catheter using a second catheter with a distal needle tip allows access to the pericardial space without pericardial puncture and advancement of a standard guide wire into the space. Navigation into the pericardial space was undertaken by fluoroscopy alone and was accomplished in 10 swine (5 acute and 5 chronic). As a specific application of this pericardial access method, a pacing lead was implanted on the epicardial surface. Five chronic swine experiments were conducted with successful pacing engagement verified by lead impedance and pacing threshold and sensing. Lead impedance exceeded 1,000 Ω preengagement and dropped by an average of 200 Ω upon implant (769 ± 498 Ω). Pacing thresholds at 0.4 ms ranged from ∼0.5 to 2.1 V acutely (1.03 ± 0.92 V). No cardiac effusion or tamponade was observed in any of the acute or chronic studies. The ability to engage, maintain, and retract the right atrial appendage/wall and to engage an epicardial lead was successfully demonstrated. These findings support the feasibility of safe access into the pericardial space in a normal swine model and warrant further investigations for clinical translation.

Viral myocarditis: diagnosis, aetiology and management

Myocarditis is an inflammatory disease of the cardiac muscle caused by myocardial infiltration of immunocompetent cells following any kind of cardiac injury. Classic myocarditis mainly occurs as a result of the host's immune response against organisms that cause common infectious illnesses, as a manifestation of hypersensitivity or as a toxic reaction to drug therapy. Chronic inflammatory events may survive successful clearance of initial cardiotoxic agents, be triggered or amplified by autoimmunological processes, or develop in the context of systemic diseases. If the underlying infectious or immune-mediated causes of the disease are carefully defined by clinical and biopsy-based tools, specific immunosuppressive and antiviral treatment options may improve the prognosis of patients with acute and chronic disease.

Right ventricular substrate mapping using the Ensite Navx system: Accuracy of high-density voltage map obtained by automatic point acquisition during geometry reconstruction

BACKGROUND

Contact point-to-point electroanatomic mapping (Pt-Map) is a validated tool to evaluate right ventricular (RV) substrate. When using the EnSite NavX system (St. Jude Medical, St Paul, Minnesota), geometry reconstruction by dragging the mapping catheter (Geo-Map) allows for quicker acquisition of a large number of points and better definition of anatomy, but it is not validated for substrate mapping.

OBJECTIVE

This study evaluates the feasibility and accuracy of Geo-Map.

METHODS

Thirteen patients (mean age 38 +/- 12 years) with RV arrhythmias and an apparently normal heart underwent cardiac magnetic resonance imaging (MRI), Pt-Map, and Geo-Map. The 2 maps were compared in terms of mapping procedural time, radiation time, and total number of points acquired. We finally compared the number and characteristics of low-potential areas on each patient's Pt-Map, Geo-Map, and cardiac MRI.

RESULTS

Geo-Map required significantly shorter mapping and radiation times in comparison to Pt-Map (12.4 +/- 4.6 vs. 31.9 +/- 10.1 and 5.8 +/- 2.1 vs. 12.1 +/- 3.9, P <.001). Furthermore, Geo-Map was based on a significantly higher density of points in comparison to Pt-Map (802 +/- 205 vs. 194 +/- 38, P <.001). Taking into consideration the total number of RV regions analyzed, the Pt-Map and Geo-Map disagreed in 2 of 65 (3%) regions (P = NS), which only Geo-Map identified as low-potential areas and indeed corresponded to wall motion abnormalities on MRI.

CONCLUSION

Voltage maps obtained through RV geometry acquisition have accuracy comparable to that of conventional point-by-point mapping in detecting low-voltage areas, have a good correlation with MRI wall motion abnormalities, and allow a significant reduction in procedural time and x-ray exposure.