[Arrhythmogenic cardiomyopathy as cause of sudden death in Spain. Report of 21 cases]

INTRODUCTION AND OBJECTIVES

Arrhythmogenic cardiomyopathy is a myocardial disease of unknown origin characterized by progressive replacement of right and/or left ventricular myocardium by fibrofatty tissue. Young adult people are more frequently affected and symptoms include palpitations, syncopes or sudden death. The objective of this study is to assess the frequency and characteristics of arrhythmogenic cardiomyopathy as a cause of sudden death in a series of cases in Spain.

MATERIAL AND METHODS

Among the sudden death cases studied at the Toxicology Institute of Madrid between 1991 and 1997, those with arrhythmogenic cardiomyopathy diagnosis were analysed.

RESULTS

21 cases were diagnosed (0.62% of all sudden deaths and 6.8% of sudden deaths under 35 years). There were 20 males and one female (mean age 24.5 +/- 9.37 years); eleven (52.3%) died during sport activity and 8 (38%) had previous exercise related symptoms. In only two cases other members of the family had died suddenly and only one had been diagnosed in life. Biventricular involvement was observed in 13 cases; isolated involvement of the left ventricle in 4, and isolated involvement of the right ventricle in 4.

CONCLUSIONS

Arrhythmogenic cardiomyopathy is a relatively frequent cause of sudden death in the young population in Spain. It is very often the first manifestation of the disease. The myocardial involvement is more frequently biventricular than isolated in the right ventricle. The diagnosis could be difficult for cardiologists, pathologists and forensic doctors.

Erythropoietin therapy in chronic uremia: the impact of normalization of hematocrit

The target hematocrit to be achieved when treating anemia in hemodialysis patients with erythropoietin is controversial. Current evidence-based recommendations suggest a target hematocrit range of 33% to 36%. Small studies suggest that normalization of hematocrit with erythropoietin may benefit hemodialysis patients in terms of brain function, physical performance, quality of life, and prevention of progressive left ventricular dilatation. However a recent study of the effects of erythropoietin-induced normalization of hematocrit in hemodialysis patients with symptomatic heart disease has shown an increase in both mortality and the rate of vascular access thrombosis. Currently, normalization of hematocrit in patients with symptomatic heart disease is not recommended, nor is it possible to conclude that possible benefits of normalization of hematocrit will outweigh risks in hemodialysis patients without symptomatic heart disease.

Sudden cardiac death

SCD continues to be an important cause of death and morbidity. Despite expanding insight into the mechanisms causing SCD, the population at high risk is not being effectively identified. Although there is still much to do in the management phase of SCD (predicting the efficacy of various therapies), recent clinical trials have helped define the relative risks and benefits of therapies in preventing SCD. Trials are underway to determine whether treating other patient populations, including asymptomatic patients after MI, will improve survival rate. The approach to reducing mortality rate will always be multifaceted; primary prevention of coronary artery disease and prompt salvage of jeopardized myocardium are 2 important aspects of this approach. In addition to interventions for MI, such as myocardial revascularization when indicated, simple and easily administered therapies that are likely to remain the most effective prophylactic interventions are aspirin, ACE inhibitors, beta-blockers, and cholesterol-lowering agents. However, the MADIT and AVID data clearly demonstrate a role for ICD therapy in a subgroup of patients who have VT/VF and are at risk of cardiac arrest. Even though the absolute magnitude of benefit associated with ICDs is still to be determined, the AVID study and other recent reports provide convincing evidence that patients who have VT/VF fare better with ICDs than with antiarrhythmic drug therapy. For the high-risk population described in this article, in addition to aggressive anti-ischemic and heart failure therapy, ICDs are now a mainstay of life-saving treatment. Still to be surmounted is the challenge of identifying patients who have nonischemic substrates and of providing them with the appropriate therapy. Guided by genetic studies and new insight into the mechanisms of such problems as congenital long QT syndrome, life-saving and life-enhancing therapies may soon be available for the management of SCD.

[Cardiac sarcoidosis complicated by multivessel coronary spasm: a case report]

A 63-year-old woman with abnormal Q waves in leads II, III, aVF developed ventricular tachycardia after an operation for thyroid carcinoma. Coronary arteriography revealed no organic stenosis, but acetylcholine induced total occlusion of the right coronary artery and severe narrowing of the left coronary artery. Left ventriculography showed inferoposterior and septal akinesis, and echocardiography revealed slight thinning of these affected walls. She had old myocardial infarction due to spasm. One year later, she developed bilateral uveitis and recurrence of tachycardia. Cardiac sarcoidosis was diagnosed by endomyocardial biopsy. In our patient with cardiac sarcoidosis, the presence of multivessel coronary spasm made the diagnosis difficult and may have contributed to cardiac dysfunction. Coronary arteries are rarely involved, but the development of coronary spasm may be linked to sarcoidosis.

Histologic diagnostic rate of cardiac sarcoidosis: evaluation of endomyocardial biopsies

BACKGROUND

An early diagnosis of cardiac sarcoidosis is important, particularly when considering the need for administering corticosteroid therapy. However, no reports are available on the success rate of diagnosis on the basis of biopsy findings in patients with cardiac sarcoidosis. This study investigated the diagnostic success rate of histologic evaluation of endomyocardial biopsy specimens in patients with this disease.

METHODS AND RESULTS

Right ventricular endomyocardial biopsy was performed in 26 patients in whom cardiac sarcoidosis was strongly suspected according to the Diagnostic Criteria of Sarcoidosis, plus abnormalities on the electrocardiogram, cardiac radionuclide images, or in left ventricular wall motion. A mean of 4.0 sites were sampled per patient. In each case we determined whether a definitive diagnosis of cardiac sarcoidosis could be made histologically. Noncaseating granulomas were found in only 5 (19.2%) of the 26 cases, thus permitting a histologic diagnosis of cardiac sarcoidosis. A histologic diagnosis was made in 4 (36.4%) of 11 patients who exhibited a dilated cardiomyopathy-like clinical picture, in contrast to only 1 (6.7%) of 15 patients in whom conduction disturbances were the major clinical feature and whose left ventricular ejection fraction was within normal limits.

CONCLUSIONS

The diagnostic rate achieved with biopsy in cardiac sarcoidosis is low; the patients with sarcoidosis and evidence of significant cardiac involvement should be treated for cardiac sarcoidosis despite negative myocardial biopsies for this disease.

Experience with emergency cardiac surgery following institution of percutaneous cardiopulmonary support

Between August 1992 and February 1998, 43 patients were treated with percutaneous cardiopulmonary support (PCPS) in our institution, and 8 of them subsequently required emergency cardiac surgery. There were 3 males and 5 females with a mean age of 63 years (range, 37 to 81 years). The etiology of shock in these 8 patients was acute myocardial infarction in 3, postinfarction left ventricular (LV) free wall rupture in 1, postinfarction ventricular septal perforation (VSP) in 1, LV free wall rupture and VSP in 1, and fatal arrhythmia due to severe aortic valvular disease in 2. The mean time interval from the onset of cardiogenic shock to the institution of PCPS was 77 min (range, 18 to 183 min). The mean time interval from the institution of PCPS until surgery was 145 min (range, 40 to 603 min). The surgical procedures were coronary artery bypass grafting (CABG) in 3 patients, closure of the LV rupture and/or closure of VSP in 3, and aortic valve replacement in 2. Six patients were weaned from PCPS, and 2 patients were discharged from the hospital (discharge rate, 25%). Although the results of emergency cardiac surgery following PCPS still are not satisfactory, we continue to apply PCPS and perform appropriate surgical procedures to improve the survival rate of the patients who would die without PCPS.

Right ventricular cardiomyopathy. A rare and underdiagnosed cause of sudden death in young adults

We present an example of right ventricular cardiomyopathy, a very uncommon condition which caused sudden death in an adolescent boy. This case report is used to highlight the pathological features of this rare and poorly understood condition, which is often undiagnosed.

[Primary lung cancer (adenocarcinoma) associated with cardiac sarcoidosis]

A 56-year-old woman who had been given oral prednisolone for iridocyclitis by an ophthalmologist received a diagnosis of pulmonary sarcoidosis on the basis of transbronchial lung biopsy findings, and began receiving therapy at our hospital on an outpatient basis. Chest X-ray films disclosed hilar lymphadenopathy in both lungs. In addition, Holter electrocardiograms detected ventricular premature beat (Lown 4B) and echocardiograms detected reduced left ventricular wall motion with dilatation of the left ventricular chamber. Cardiac sarcoidosis developed in the patient. She was admitted to our hospital because of shortness of breath on exertion. Chest X-ray films on admission disclosed a large nodular heterogeneous mass in the right upper lobe. Histologically, transbronchial lung biopsy specimens of the mass disclosed an adenocarcinoma. Although lung cancer and sarcoidosis are common, their coexistence in the same patient is not. Furthermore, the coexistence of lung cancer with cardiac sarcoidosis, as in this case, is very rare.

Chlamydia pneumoniae infection and atherosclerotic coronary disease

BACKGROUND

Previous works have suggested an association between Chlamydia pneumoniae infection and coronary heart disease. We evaluated the prevalence of C. pneumoniae infection in patients with acute myocardial infarction (AMI) and coronary heart disease (CHD).

METHODS AND RESULTS

Ninety-eight patients with AMI, 80 patients with CHD, and 50 control subjects matched for age and sex were investigated. Immunoglobulin (Ig)M, IgG, and IgA antibodies to C pneumoniae were measured by the microimmunofluorescence test. IgM antibodies were not found; IgG positivity was found in 58.2% of the AMI group, 60.0% of the CHD group, and 38% of the control group, whereas for IgA, positivity was found in 33.7%, 43.7%, and 22% of cases in AMI, CHD, and control groups, respectively. Titers indicating reinfection were found in AMI and CHD groups in 6.1% and 10%, respectively, whereas titers indicating chronic infection were found in 14% of the AMI group and 25% of the CHD group. A significant correlation was found between chronic C pneumoniae infection and dyslipidemias in the AMI and CHD groups (P =.003; P =. 0006).

CONCLUSIONS

The results suggest that chronic C pneumoniae infection may be associated with the development of atherosclerotic coronary disease. In our next step, we will test whether antichlamydial antibiotics may help to reduce the risk of atherosclerotic disease.

Intraoperative use of automated external defibrillator

We report on the anesthetic management of a patient with peripartum cardiomyopathy and frequent episodes of ventricular tachycardia, who underwent surgery for tracheal stenosis. Prior to this surgery, the patient had been implanted with an automatic implantable cardioverter-defibrillator (AICD), placed abdominally. In the operating room, the AICD was deactivated, and an automated external defibrillator (AED) was placed. Intraoperatively, the AED identified and treated the patient's ventricular tachycardia. Advantages of the AED in this hospital setting included rapid response to the cardiomyopathy, safe, hands-free operation, and minimal disruption of the surgical procedure. Safety concerns when using the AED are also detailed.

Cardiopulmonary dysfunction in cirrhosis

Cirrhosis is associated with several circulatory abnormalities. These include hyperkinetic systemic and splanchnic circulation, hepatopulmonary syndromes including pulmonary hypertension, and cirrhotic cardiomyopathy. Hepatopulmonary syndrome generally refers to hypoxaemia seen in patients with chronic liver disease and appears to be relatively common, although often subclinical. However, significant pulmonary hypertension occurs in 0.2-0.7% of cirrhotic patients. Nitric oxide and/or other vasodilators appear to be involved in the pathogenesis of hepatopulmonary syndrome through induction of pulmonary capillary dilatation which increases the alveolar-arterial oxygen gradient. Cirrhotic cardiomyopathy refers to abnormal left ventricular function which is manifested under conditions of physiological or pharmacological stress. The emergence of liver transplantation as an effective treatment for end-stage liver disease has led to recognition of previously subclinical cardiomyopathy and congestive heart failure accounts for significant morbidity and mortality after this procedure. Diminished myocardial beta-adrenergic receptor function has been shown to play an important role in the pathogenesis of this condition. The contributions of other factors including nitric oxide, catecholamines and membrane fluidity changes are under investigation. Cirrhotic patients also have an increased incidence of other cardiac abnormalities, such as endocarditis and pericardial effusions.

Contribution of head-up tilt testing and ATP testing in assessing the mechanisms of vasovagal syndrome: preliminary results and potential therapeutic implications

BACKGROUND

In patients with vasovagal syndrome, head-up tilt testing may reproduce symptoms generally associated with vasodepression. Recent research suggests ATP testing identifies patients with abnormal vagal cardiac inhibition. This preliminary study examined the joint contribution of both tests in identifying underlying mechanisms in the general population with vasovagal syndrome.

METHODS AND RESULTS

Both tests were performed in random order during 1 session and outside of predominant sympathetic periods in 72 patients hospitalized for syncope (n=56) or presyncope (n=16) for whom no cardiac or extracardiac cause was found. For passive and isoproterenol-provocative tilt testing by standard protocol, reproduction of symptoms defined a positive test. The ATP test consisted of injecting ATP 20 mg IV at bedside, continuously monitoring ECG and blood pressure; a vagal cardiac pause >10 seconds defined a positive test. For most patients (64%), >/=1 test was positive. Of the 41 patients (57%) with a positive tilt test (either passive or provoked by isoproterenol), 32% had cardiac disease; none had significant bradycardia (<50 bpm). Of the 8 patients (11%) with a positive ATP test, 62% had cardiac disease; the probability of a positive result increased with age (P=0.015). Both tests were positive in 3 patients and negative in 26 patients; the tilt and ATP test results were uncorrelated (P=0.28).

CONCLUSIONS

Results suggest tilt and ATP tests individually and jointly determine the mechanism of vasovagal symptoms in most patients and that vagal cardiac inhibition increases with age.

Signal averaged electrocardiography of Japanese

Although studies show that the ventricular tachycardia and sudden cardiac deaths caused by ischemic heart diseases affect Japanese less than Westerners, predictive accuracy of the signal averaged ECG for ventricular tachycardia and sudden cardiac deaths are almost the same as the results for Westerners. The recent prognosis of ischemic heart diseases is showing improvements along with the development of re-perfusion therapy, which is changing the significance of the signal averaged ECG. Therefore a clinical use for signal averaged ECG should be discussed in cases of cardiomyopathy which cause sudden cardiac deaths and other heart diseases. So it is necessary to redetermine normal values of the signal averaged ECG parameters. In this article, the following was reviewed on the basis of our studies regarding the clinical significance of the signal averaged ECG of Japanese and normal signal averaged ECG values. (1) System and gender specific differences on signal averaged ECG of Japanese, (2) His-Purkinje system, pre-P deflection and atrial late potential on signal averaged ECG, (3) Ventricular late potentials of Japanese.

Protective effects of Ginkgo biloba extract EGb 761 on the myocardium of experimentally diabetic rats. II. Ultrastructural and immunohistochemical investigation on microvessels and interstitium

Interstitial and microvascular disorders are known as a characteristic part of the diabetic cardiomyopathy and to resist partly insulin therapy. Aim of this study was to demonstrate structure-protecting effects of Ginkgo Extract EGb 761 known as a natural radical scavenger in streptozotocin-diabetic rats on the microvascular compartment. Wistar rats (n = 5) were made diabetical by i.p. injection of 60 mg/kg body mass streptozotocin for 4 months. Rats of the protected group (n = 5) received daily 100 mg/kg body mass EGb 761 for 3 months, starting 1 month after induction of diabetes. 5 age-matched rats served as control. The volume fraction of interstitium was slightly but significantly increased only in the unprotected diabetic group. Diminishing of the capillary to the myocyte ratio was seen in the diabetic but not in the protected group. Immunostaining of collagen revealed a slight increase of type III, type IV, and type VI fibres in the interstitium, more expressed in the unprotected group. Ultrastuctural morphometry revealed significant thickening of endothelial and muscular basement membranes in diabetic animals, less expressed in the EGb- protected group. The capillary diameter was slightly increased in the diabetic and slightly decreased in the protected group. The number of plasmalemmal vesicles was tendentially more decreased, that of lysosomes more increased in the diabetic than in the protected group. It is concluded that EGb 761 can diminish partly interstitial fibrosis and reduce endothelial and muscular basement membrane thickening of the diabetic myocardium. It may contribute to prevent late diabetic complications.

Protective effects of Gingko biloba extract EGb 761 on myocardium of experimentally diabetic rats. I: ultrastructural and biochemical investigation on cardiomyocytes

Chronic diabetes in man and animal models develops cardiomyopathic alterations which cannot be absolutely avoided by insuline therapy. Since diabetic damage is partly attributed to oxidative stress antioxidative treatment could be able to reduce the alterations. Aim of this study was to investigate the cardioprotective effects of EGb 761, known as a radical scavenger, against diabetic alterations in rats. The diabetes was induced by i.p. injection of 60 mg/kg body weight streptozotocin. Duration of diabetes was 4 months, the protected group received 100 mg/kg body weight EGb 761 with the drinking water over 3 months. Electron and light microscopic morphometry of left-ventricular samples revealed typical diabetic alterations consisting in decrease of volume fraction of myofibrils, SR and t-tubules and diminishing of cardiomyocyte diameter, increase of interstitial volume, mitochondrial size and volume fraction, and of vacuoles and of lipid drops. EGb treatment could gradually prevent the loss of myofibrils and reduction of myocyte diameter but has only little influence on interstitial and mitochondria volume. The diabetic-induced increase of lipid and vacuoles and the decrease of SR and t-tubules were not influenced. Biochemical parameters of oxidative stress: malondialdehyde (MDA) was only insignificantly altered by diabetes and EGb. The superoxide dismutase (SOD) activity was increased by diabetes and more increased by EGb treatment. Creatine kinase (CK) activity was diminished by diabetes but slightly increased by EGb. The polymerase chain reaction (PCR) of i-NOS was not different between the diabetic and protected diabetic groups.

Preliminary clinical results of a biphasic waveform and an RV lead system

Biphasic defibrillation waveforms have provided a reduction in defibrillation thresholds in transvenous ICD systems. Although a variety of biphasic waveforms have been tested, the optimal pulse durations and tilts have yet to be identified. A multicenter clinical study was conducted to evaluate the performance of a new ICD biphasic waveform and new RV active fixation steroid eluting lead system. Fifty-three patients were entered into the study. Mean age was 63 years with a mean ejection fraction of 36.8%. Primary indication for implantation was monomorphic ventricular tachycardia alone (54.7%). Forty-eight patients (90.6%) were implanted with an RV shocking lead and active can alone as the anodal contact. The ICD can was the cathode. In four cases (7.5%), an additional SVC or CS lead was used due to a high DFT with the RV lead alone. In an additional case, a chronic SVC lead was used although the RV-Can DFT was acceptable. DFT for all cases at implant was 9.8 +/- 3.7 J. Repeat testing at 3 months for a subset of patients showed a reduction in DFT (7.4 +/- 3.0 J), P value = 0.03. Sensing and pacing characteristics of the RV lead system remained excellent during the study period (acute 0.047 +/- 0.005 ms at 5.4 V and 9.9 +/- 6.2 mV R wave; chronic 0.067 +/- 0.11 ms at 5.4 V and 9.3 +/- 5.4 mV R wave). It is concluded that this lead system provides good acute and chronic sensing and pacing characteristics with good DFT values in combination with this waveform.

[Nutritional evaluation and functional class in hospitalized cardiopathy patients]

The nutritional state evaluation of any patient with heart disease must include the anthropometric measures, organic metabolic and cellular immunity test. We evaluated the nutritional state of 75 hospitalized patients with heart disease, and its correlation with New York Heart Association class and heart disease type. There was 36 patients (48%) with normal nutritional state, 24 (32%) with grade I malnutrition, 12 (16%) with grade II malnutrition, and 3 (4%) with grade III malnutrition. Of 23 patients with rheumatic valvular heart disease 83.4% have some degree of malnutrition, 37 patients with ischemic heart disease 25% was under nourished. Fifty percent of patients with hypertensive cardiopathy, 75% of the patients with cardiomyopathy and 83% of the 7 patients with other type of heart disease had some degree of malnourishment. There was a direct correlation between nutritional state and functional class, we found no patient in IV class functional with normal nutritional state, or grade I malnutrition.

Thrombolysis with resolution of pulmonary hypertension in a heart transplant candidate

We report a patient with idiopathic cardiomyopathy and high pulmonary resistance due to pulmonary emboli of unknown age. Successful thrombolytic therapy returned his pulmonary resistance to normal, allowing orthotopic cardiac transplantation. This case underscores the need to aggressively diagnose and treat pulmonary emboli in potential transplant candidates.

Myocardial sarcoidosis in forensic medicine

Sudden death is the most common manifestation of myocardial sarcoidosis, which is often clinically silent. The disease is rarely encountered in forensic medicine, but the diagnosis is important because it may change the interpretation of the manner of death and thus have insurance implications. Six cases of myocardial sarcoidosis diagnosed at autopsy are reported, and the significance of the findings is discussed.