Laser Lead Extraction in Adult Congenital Heart Disease

BACKGROUND

In adults with congenital heart disease (ACHD), lead extraction procedures are expected to parallel increasing transvenous pacemaker and defibrillator implantations. We sought to assess the safety and feasibility of laser lead extraction in ACHD.

METHODS AND RESULTS

All laser lead extractions (Spectranectics, Colorado Springs, CO, USA) performed at the Montreal Heart Institute between September 2000 and August 2005 were prospectively registered. Efficacy and complications in patients with ACHD were compared to the larger cohort. Laser lead extraction was attempted on 270 leads in 175 patients. In ACHD, 23 (five atrial, 15 ventricular pacing, and three defibrillator) leads were targeted in 16 patients. Indications were: infection 44%, dysfunction 25%, upgrade 25%, and pain 6%. Patients with ACHD were younger (43.0 +/- 13.5 vs 63.7 +/- 14.7 years, P < 0.0001) and had a higher proportion of active fixation leads (74% vs 37%, P = 0.0013). Lead age in patients with and without ACHD was 9.0 +/- 5.2 vs 7.7 +/- 5.2 years (P = 0.2713). Overall, 21 of 23 leads (91%) were successfully extracted in ACHD compared with 220 of 247 leads (89%) (P = 0.7405). One major complication (6.3%) occurred in ACHD (tricuspid valve laceration) compared with five major (3.0%) and eight minor (5.0%) complications in patients without ACHD. Presence of ACHD did not modulate procedural success (OR 1.3, 95% CI [0.3, 5.8]) or complications (OR 1.0, 95% CI [0.2, 4.4]). Median procedural time was 27 minutes longer in ACHD (127 vs 100 minutes, P = 0.0595).

CONCLUSION

In selected patients with ACHD, laser lead extraction may be performed with a safety and efficacy profile comparable to patients without ACHD.

Death Caused by Myocarditis in Wayne County, Michigan

This paper reviews 72 cases of death caused by myocarditis between the years 1996 and 2004, autopsied at the Office of the Wayne County Medical Examiner in Michigan. Myocarditis as a cause of sudden and unexpected death represented 1.3% of all natural deaths in Wayne County during said period. The year 1999 contained the highest number of deaths of this cause (18), where the average number of myocarditis deaths was 8 per year for this 9-year span. In this study, each case was reviewed based on information gathered from investigative, autopsy, and toxicology reports. Significantly, 58% of these cases were male, and 63.4% were African American. Myocarditis caused death in every age group between 7 months and 67 years, but adults between the ages of 19 and 67 were most significantly affected (75%). Flu and/or cold were the most common symptoms experienced in the days directly proceeding death (28%), followed by shortness of breath (17%) and sudden collapse (15%). Sixty-nine percent of these 72 cases were pronounced dead after ACLS (advanced cardiac life support) protocol by emergency medical services or hospital attendants. Cardiomegaly was observed in 24 cases of adults aged 19 or older (54%), and flabby/soft myocardial tissue was observed grossly in 16% of all 72 cases.

Presentation, Patterns of Myocardial Damage, and Clinical Course of Viral Myocarditis

BACKGROUND

Enteroviruses and adenoviruses have been considered the most common causes of viral myocarditis, but parvovirus B19 (PVB19) and human herpesvirus 6 (HHV6) are increasingly found in endomyocardial biopsy samples.

METHODS AND RESULTS

Consequently, our aim was to evaluate the prevalence and clinical presentation of cardiac PVB19 and/or HHV6 infection in a cohort of myocarditis patients and to follow its clinical course. In addition, we sought to demonstrate patterns of myocardial damage and to determine predictors for chronic heart failure. Our study design consisted of a cardiovascular magnetic resonance protocol as well as endomyocardial biopsies in the myocardial region affected as indicated by cardiovascular magnetic resonance. One hundred twenty-eight patients were enrolled by clinical criteria. In the group of myocarditis patients (n=87), PVB19 (n=49), HHV6 (n=16), and combined PVB19/HHV6 infections (n=15) were detected most frequently. The remaining patients were diagnosed with healing myocarditis (n=15) or did not have myocarditis (n=26). Patients with PVB19 presented in a manner similar to that of myocardial infarction; most had typical subepicardial late gadolinium enhancement in the lateral wall and recovered within months. Conversely, patients with HHV6 and especially with HHV6/PVB19 myocarditis presented with new onset of heart failure, had septal late gadolinium enhancement, and frequently progressed toward chronic heart failure.

CONCLUSIONS

Our data indicate that PVB19 and HHV6 are the most important causes for viral myocarditis in Germany and that the clinical presentation is related to the type of virus. Furthermore, clinical presentation, type of virus, and pattern of myocardial damage are related to the clinical course.

Predictive factors of a fulminant course in acute myocarditis

BACKGROUND

Patients who develop fulminant myocarditis often die of sudden cardiac arrest, arrhythmia, or severe heart failure soon after onset if they do not receive percutaneous cardiopulmonary support in time. The purpose of this study was to identify the risk factors of clinical symptoms/signs or laboratory findings that could predict the fulminant course of acute myocarditis.

METHODS AND RESULTS

Thirty-five patients (mean age 28 +/- 8 years, 17 males) who had been admitted to intensive care unit with the diagnosis of acute myocarditis by clinical presentations were retrospectively recruited. They were divided into the fulminant group (n = 11) and the non-fulminant group (n = 24). Clinical features, laboratory data, and images on admission were analyzed. Overall in-hospital mortality was 17% (6/35). Mortality was higher in the fulminant group (45% vs. 4%, p = 0.027). Multivariate analysis revealed that prolongations of the QRS complex (118 +/- 27 vs. 88 +/- 10 ms, p = 0.048) and depressed left ventricular ejection fraction (41 +/- 7% vs. 57 +/- 7%, p = 0.027) were the only independent factors significantly associated with the fulminant course of acute myocarditis.

CONCLUSION

The in-hospital mortality of acute fulminant myocarditis was high. Prolongations of the QRS complex and depressed left ventricular ejection fraction on admission were independent positive predictors for the development of acute fulminant myocarditis.

Myocarditis and heart failure associated with hepatitis C virus infection

BACKGROUND

The aim of study is to determine the prevalence of hepatitis C virus (HCV) infection and myocardial injury among patients enrolled in the Myocarditis Treatment Trial. HCV infection has recently been noted in patients with cardiomyopathies and myocarditis. However, prevalence of HCV infection in myocarditis and heart failure remains to be clarified.

METHODS AND RESULTS

Patients with heart failure up to 2 years in duration without a distinct cause were enrolled in the trial between 1986 and 1990. Frozen blood samples were available from 1355 among 2233 patients enrolled and examined for presence of anti-HCV antibodies, circulating cardiac troponins I and T, and N-terminal pro-brain natriuretic peptide (NT-proBNP). Anti-HCV antibodies were identified in 59 of 1355 patients (4.4%). This higher prevalence of HCV infection than that observed in the general US population (1.8%), varied widely (0-15%) among the different medical centers and regions. The concentrations of circulating cardiac troponin (cTn) I were elevated in 17 of 56 patients (30%), and cTnT was detectable in 28 of 59 patients (48%) with HCV antibodies, suggesting the persistence of ongoing myocardial injury. The concentrations of NT-proBNP were elevated in 42 of 42 patients (100%) with HCV antibodies, (10,000 +/- 5860 pg/mL), a mean value significantly greater than in 1276 patients without HCV antibody (2508 +/- 160 pg/mL, P < .0001).

CONCLUSION

Anti-HCV antibodies were identifiable in sera stored for 13 to 17 years and were more prevalent in patients with myocarditis and HF than in the general population. In regions where its prevalence is high, HCV infection may be an important cause of myocarditis and HF. NT-proBNP is a more sensitive marker of myocardial injury than cardiac troponins in patients with heart failure from HCV myocarditis.

Review of 609 patients with rheumatic fever in terms of revised and updated Jones criteria

BACKGROUND

To investigate the findings and prognosis of rheumatic fever (RF) patients seen in the past 20 years and to compare the last two decades.

METHODS

The medical records of all RF patients admitted to Gazi University Department of Pediatric Cardiology during 1982-2002 were reviewed. The decade from 1.1.1982 to 31.12.1991 was designated as 1980s and the following decade as the 1990s.

RESULTS

Among the 609 RF cases, there was no difference between the two decades regarding mean age, male/female ratio, most of the minor manifestations and findings of the preceding streptococcal infection. As the rate of carditis declined in 1990s, rates of arthritis and chorea increased. Severity of carditis and admissions with reactivation decreased during 1990s. The two decades did not differ regarding mean age, gender ratio, pericarditis rate, number and type of valvular involvement and sequel of carditis cases. Severity of carditis and number of valvular involvement influenced the first-year prognosis. Almost one-third of the arthritis cases had monoarthritis in both decades. Atypical cases with small-joint involvement were detected number of which increased during the 1990s.

CONCLUSIONS

The two decades do not seem to differ regarding most of the manifestations of RF. More emphasis should be given to atypical cases such as small-joint involvement and monoarthritis and silent carditis.

Diabetes and myocarditis in voles and lemmings at cyclic peak densities--induced by Ljungan virus?

Although it is well-documented from theoretical studies that pathogens have the capacity to generate cycles, the occurrence and role of pathogens and disease have been poorly empirically studied in cyclic voles and lemmings. In screening for the occurrence of disease in cyclic vole and lemming populations, we found that a high proportion of live-trapped Clethrionomys glareolus, C. rufocanus, Microtus agrestis and Lemmus lemmus at high collective peak density, shortly before the decline, suffered from diabetes or myocarditis in northern Scandinavia. A high frequency of animals had abnormal blood glucose (BG) levels at the time of trapping (5-33%). In contrast, C. rufocanus individuals tested at a much lower overall density, and at an earlier stage relative to the decline in the following cycle, showed normal BG concentrations. However, a high proportion (43%) of a sample of these individuals kept in captivity developed clinical diabetes within five weeks, as determined by BG levels and a glucose tolerance test performed at that later time. A new picornavirus isolated from the rodents, Ljungan virus (LV), was assumed to cause the diseases, as LV-induced diabetes and myocarditis, as well as encephalitis and fetal deaths, were observed in laboratory mice. We hypothesize that LV infection significantly affects morbidity and mortality rates in the wild, either directly or indirectly, by predisposing the rodents to predation, and is at least involved in causing the regular, rapid population declines of these cyclic voles and lemmings. Increased stress at peak densities is thought to be an important trigger for the development of disease, as the occurrence of disease in laboratory mice has been found to be triggered by introducing stress to LV-infected animals.

Longitudinal study of a natural outbreak of heart and skeletal muscle inflammation in Atlantic salmon, Salmo salar L

Heart and skeletal muscle inflammation (HSMI) is a transmissible disease of farmed Atlantic salmon, Salmo salar L. It is characterized by significant epi-, endo- and myocarditis, as well as myositis, particularly involving red skeletal muscle. The aetiology of HSMI is currently unresolved, though a viral cause is suspected. Since its discovery in 1999, HSMI has become an increasing problem for the Norwegian farming industry, with some farms experiencing yearly outbreaks and subsequent economic losses. In the present study an Atlantic salmon farm was studied from December 2003 to April 2005. Samples from apparently healthy as well as clinically diseased fish were collected monthly and examined histopathologically. The first fish to be diagnosed with HSMI was sampled in May, 8 months after transfer to sea. A clinical outbreak of HSMI followed in June, when all fish in the sample had lesions consistent with HSMI. Subsequent samples revealed that cardiac lesions decreased in severity 2 months after the start of the outbreak, but that multiple foci of cellular infiltration and necrosis persisted throughout the year. There appeared to be a shift in lesion location from being most severe in the compact myocardium in early stages of disease to a greater involvement of the atrium and spongy layer of the ventricle in later samples. Late samples also showed increased fibrosis of cardiac tissue. In conclusion, HSMI appears to be a severe disease with elevated mortality, morbidity close to 100% and prolonged duration.

Myocarditis Outbreak among Adults, Illinois, 2003

An outbreak of myocarditis occurred among adults in Illinois in 2003. Diagnostic testing of myocardial tissues from 3 patients and comprehensive tests for enterovirus and adenovirus of other specimens from patients were inconclusive. Appropriate specimen collection from patients with idiopathic cardiomyopathy and further enhancement of diagnostic techniques are needed.

The role of echocardiography in diagnosing carditis in the setting of acute rheumatic fever

OBJECTIVES

Acute rheumatic fever and its sequel, rheumatic heart disease, is a major problem in children, adolescents and young adults. Despite the widespread application of the Jones criterions, carditis is either underdiagnosed or overdiagnosed. Echocardiography is rarely used optimally for precise diagnosis. The objective of our study, therefore, was to define the potential role of echocardiography in detecting carditis in the setting of acute rheumatic fever.

MATERIALS AND METHODS

We performed echocardiography in 452 consecutive patients with acute rheumatic fever, clinically diagnosed by the strict Jones criterions, using the patients as part of a multi-centric and double blinded prospective study.

RESULTS

Of our 452 patients, 230 were males, and 222 were females. The youngest was aged 1 year 11 months, while the oldest was a 51-year-old female. Out of the 452 cases of acute rheumatic fever, 239 patients (52.8%) had arthritis. Out of 164 cases of clinically diagnosed carditis, only 141 cases had echocardiographic evidence of carditis (85.97%). The remaining 23 patients (14%) had functional murmurs, tachycardia, or anaemia. Of the patients, 2 also had congenitally malformed hearts. Of 40 patients with rheumatic chorea, 28 (70%) had echocardiographic evidence of carditis or valvitis. Polyarthralgia was seen in 213 cases (47.12%), from which only 38 patients (17.8%) had carditis clinically, albeit that 88 patients (41.3%) showed echocardiographic evidence of subclinical carditis or valvitis.

CONCLUSION

Echocardiography, when carried out in patients with acute rheumatic fever diagnosed strictly according to the Jones criterion, can avoid both overdiagnosis and underdiagnosis of carditis. A high incidence of carditis, or subclinical carditis, is detected by echocardiography when performed in patients with rheumatic chorea or arthralgia.

Real or media-mediated outbreak of coxsackie infections in 2002 in Greece?

The purpose of this study was to provide evidence about the existence of a coxsackie B outbreak in Greece in 2002 by comparing data of laboratory confirmed coxsackie B recent infections in northern Greece between 1998-2001 with data from 2002. The infections were confirmed serologically, using the indirect immunofluorescence method detecting IgM antibodies for coxsackie B1-B6 viruses. Sera from 2701 patients residents of northern Greece who were suspected to be suffering from coxsackie B virus infections were examined: 2056 between 1998 and 2001, and 645 in 2002. The comparison between the results of laboratory confirmed cases and data available at the laboratory between the two periods showed that: The total number of patients examined per year was higher in 2002 (645 versus an annual average of 514 in 1998-2001). The proportion of laboratory confirmed recent infections was lower in 2002 (27.8% versus 32.7%) and the estimated incidence was 0.66/10,000 for 2002 and 0.32-0.84/10,000 for 1998-2001. The age distribution differed: the proportions of cases in children versus cases in adults were reversed in 2002 compared with 1998-2001, with a higher proportion among children in 2002. The difference between the two periods was statistically significant. Children aged 3-5 years were the age group most affected in 2002. Seasonal distribution remained the same for both periods (peaks in spring and autumn). In 2002, three fatal cases occurred in April, but no deaths were reported in 1998-2001. The clinical syndromes involved also differed: cases of respiratory infections, mainly pneumonia, rose from 5.75% to 24.3% in children in 2002 and cases of myopericarditis rose in adults from 13% in 1998-2001 to 29.5% in 2002. The last finding, combined with the involvement of the media (because of the three fatal cases) and the panic in the general public that followed suggested that an outbreak had occurred, but we conclude that there was no outbreak.

Myocarditis, pericarditis and cardiomyopathy in patients treated with clozapine

Clozapine is known to cause cardiac side-effects, including myocarditis, pericarditis and cardiomyopathy. Prompted by a case of clozapine-related pericarditis in our hospital we undertook a review of the literature for reports of myocarditis, pericarditis and cardiomyopathy occurring in patients treated with clozapine. This is the first comprehensive review of the literature on this topic.

[Primary acute myocarditis. A 10- years institutional experience]

Acute myocarditis (AM) is associated with viral infections: Coxsackie and ECHOviruses among others. Autoimmunity has been proposed as a pathogenic mechanism. Benefit of classic immunosuppression (prednisone-azathioprine) or immunomodulation (monomeric-human IgG) is still uncertain.

OBJECTIVE

To review incidence and clinical approach to AM at a Cardiology referral center.

MATERIAL AND METHODS

A 10-yeard period (1992-2003) is reviewed. A standard questionary was applied to 49 consecutive patients referred by clinicians with a diagnosis of AM.

RESULTS

AM was found in 17 women and 32 men, median age 24 and 28 years, respectively. They presented heart failure with dyspnea/ortopnea (70-47%), peripheral edema/jugular vein plethora (41-37%), chest pain, and tachycardia (50%), NYHA functional class was Ill-IV in 22. The EKG showed sinus tachycardia or conduction defects. Transthoracic echocardiograms in 47 cases showed EF (mean) of 41% with enlarged left ventricle diameter. Antivirus antibodies were present in 54% of those cases studied, Coxsackie or ECHOvirus were identified through a serologic assay. Twenty-nine (61%) of our cases developed dilated cardiomyopathy, three patients died. It is not possible to reach a conclusion regard to immunomodulation therapy, because it was applied to only 12 patients.

CONCLUSIONS

At the Instituto Nacional de Cardiología "I. Chávez", AM depicts an incidence of 1/1,000 patients a year. It is necessary to standardize the clinical approach for diagnosis and treatment, progression to dilated cardiomyopathy and death during acute stage occurs in two-thirds of our patients.

Adverse cardiac effects associated with clozapine

OBJECTIVE

To review the published literature on serious adverse cardiac events associated with the atypical antipsychotic agent, clozapine, and to make recommendations for cardiac assessment of candidates for clozapine treatment and for monitoring of cardiac status after treatment is initiated.

DATA SOURCES

We searched the PubMed and MEDLINE databases for articles published from 1970 to 2004 that contain the keywords "clozapine and myocarditis," "clozapine and cardiomyopathy," "clozapine and cardiotoxicity," "clozapine and sudden death" or "clozapine and mortality." We also manually searched the bibliographies of these articles for related sources.

STUDY SELECTION

We reviewed the 30 case reports, case series, laboratory and clinical trials, data mining studies, and previous reviews identified by this search.

DATA SYNTHESIS

Recent evidence suggests that clozapine is associated with a low (0.015% to 0.188%) risk of potentially fatal myocarditis or cardiomyopathy. The drug is not known to be independently associated with pathologic prolongation of the QTc interval, but it may contribute to pathologic QTc prolongation in patients with other risk factors for this condition.

CONCLUSIONS

The low risk of a serious adverse cardiac event should be outweighed by a reduction in suicide risk for most patients taking clozapine. We provide recommendations for assessing and monitoring cardiac status in patients prior to and after initiation of treatment with clozapine.

Myocarditis: emergency department recognition and management

Myocarditis is an acute inflammatory syndrome involving the heart and related structures. In many instances, the presentation is obvious, and appropriate treatment and disposition follow accordingly. In other situations, patients present with viral illness of the respiratory or gastrointestinal tracts (or both) or nonspecific symptoms such as fatigue and weakness,leading the clinician astray. Management is largely supportive, including aggressive cardiorespiratory support.

Clozapine-related myocarditis and cardiomyopathy in an Australian metropolitan psychiatric service

OBJECTIVES

Myocarditis and cardiomyopathy are rarely reported complications of clozapine treatment. The incidence of clozapine-related myocarditis has been variably reported at between 0.03% and 0.19% of initiations and cardiomyopathy has been reported even less commonly. In our Brisbane-based service, nine of 94 patients initiated on clozapine over the previous 3 years appeared to have experienced myocarditis or cardiomyopathy. The unique co-location of our service with a major cardiothoracic hospital facilitated a review of identified cases to inform decisions regarding clozapine treatment and rechallenge in this service.

METHOD

Cases were identified by survey of psychiatric and cardiac medical staff at The Prince Charles Hospital and subjected to re-evaluation by a multidiscipline consensus panel. The panel compared cases to international reports and identified the clinical features that supported a diagnosis of clozapine-related myocarditis or cardiomyopathy.

RESULTS

This process resulted in the stratification of the nine cases into the following categories of diagnostic likelihood: three highly probable, three probable, and two possible cases of clozapine-related myocarditis, and one possible case of clozapine-related cardiomyopathy. Successful clozapine rechallenge/continuation was undertaken in two patients and the panel agreed that this was a viable future option for several other patients.

CONCLUSIONS

Findings of the panel review supported the initial clinical diagnoses. This confirmed that there was an apparent high incidence of clozapine-related myocarditis within this service, for which there was no clear reason. Mechanisms underlying clozapine-related myocarditis and cardiomyopathy, as well as successful clozapine continuation and rechallenge were considered, but definitive explanations remain unknown. This review highlighted the clinician's role in post-marketing drug surveillance to guide rational management of suspected adverse drug effects.

Incidence and follow-up of inflammatory cardiac complications after smallpox vaccination11The views expressed in this study are those of the authors and do not reflect the official policy or position of the U.S. government

OBJECTIVES

The purpose of this study was to assess the follow-up of patients with vaccinia-associated myocarditis.

BACKGROUND

With the threat of biological warfare, the U.S. Department of Defense resumed a program for widespread smallpox vaccinations on December 13, 2002. One-year afterwards, there has been a significant increase in the occurrence of myocarditis and pericarditis among those vaccinated.

METHODS

Cases were identified through sentinel reporting to military headquarters, systematic surveillance, and spontaneous reports.

RESULTS

A total of 540,824 military personnel were vaccinated with a New York City Board of Health strain of vaccinia from December 2002 through December 2003. Of these, 67 developed myopericarditis at 10.4 +/- 3.6 days after vaccination. The ST-segment elevation was noted in 57%, mean troponin on admission was 11.3+/- 22.7 ng/dl, and peak cardiac enzymes were noted within 8 h of presentation. On follow-up of 64 patients (96%) at a mean of 32 +/- 16 weeks, all patients had objective normalization of echocardiography, electrocardiography, laboratory testing, graded exercise testing, and functional status; 8 (13%) reported atypical, non-limiting persistent chest discomfort.

CONCLUSIONS

Post-vaccinial myopericarditis should be considered in patients with chest pain within 30 days after smallpox vaccination. Normalization of echocardiography, electrocardiography, and treadmill testing is expected, and nearly all patients have resolution of chest pain on follow-up.

Frequency and quantity of the parvovirus B19 genome in endomyocardial biopsies from patients with suspected myocarditis or idiopathic left ventricular dysfunction

Parvovirus B19 (PB19) has been identified as a possible cause of myocarditis and heart failure in both children and adult patients. This study used real time PCR analysis, to determine the frequency and to quantify PB19 viral genomes in endomyocardial tissue samples from 80 adult patients with clinically suspected myocarditis or idiopathic left ventricular dysfunction and from 36 controls. Histological (Dallas classification) and immunohistological analyses were performed to detect myocardial inflammation in the endomyocardial biopsies.PB19 genomic DNA was found in nine of 80 patients (11.2%), 4 out of 31 (12.9%) patients with inflammatory infiltrates detected via immunohistological methods and 5 out of 49 (10.2%) patients with left ventricular dysfunction without myocardial inflammation. The copy numbers for PB19 DNA ranged between 30 and 3900 per microg of cellular DNA. Four patients with clinically suspected myocarditis had copy numbers for PB19 DNA of 70, 740, 3400 and 3900, respectively, per microg of cellular DNA in the endomyocardial biopsy. Five patients with idiopathic left ventricular dysfunction had copy numbers for PB19 DNA of 30, 38, 52, 58 and 90, respectively, per microg of cellular DNA in the endomyocardial biopsy. The amplicon of one of the nine positive PCR fragment was sequenced and was found to be fully identical in the highly conserved sequence of published Parvovirus B19 VP1/VP2 genes (NCBI gene bank). In all patients, acute myocarditis was excluded according to the Dallas classification. All biopsies of 36 controls with no history of myocarditis or recent viral infection were negative for myocardial inflammation and parvovirus B19 genomes. In summary, Parvovirus B19 DNA is present within the myocardium of patients with suspected myocarditis and idiopathic left ventricular dysfunction and can be detected and quantified in endomyocardial specimens via real time PCR.