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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report a patient with Brugada syndrome who developed sustained monomorphic ventricular tachycardia (SMVT). The patient was a 29-year-old man who experienced recurrent episodes of palpitation and syncope after drinking alcohol. Electrocardiogram showed right bundle branch block and ST-segment elevation in precordial leads V1-3 without Q-Tc prolongation. Organic heart disease and coronary artery disease were excluded by noninvasive and invasive tests. Ventricular fibrillation was induced by the application of a single extra-stimulus to the right ventricular outflow tract. During isoproterenol infusion, SMVT of left bundle branch block morphology (240/min) was induced by the application of a single extrastimulus to the right ventricular apex. SMVT also developed spontaneously. Pace mapping disclosed that SMVT originated at the free wall of the right ventricular outflow tract. Head-up tilt test and an alcohol provocation test both induced similar SMVT that was associated with hypotension and near syncope. SMVT was not terminated by intravenous administration of lidocaine, procainamide or adenosine triphosphate (10 mg), but was terminated by propranolol. Thus, a beta-adrenoceptor-mediated mechanism appears to play an important role in SMVT in this patient. The site of origin of SMVT might be closely related to the lesion that causes ST-segment elevation.
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PMID:Sustained monomorphic ventricular tachycardia in a patient with Brugada syndrome. 884 3

We present the case of 44-yr-old man who presented syncope with ventricular tachycardia in the setting of Brugada syndrome. In addition to the electrocardiographic evidence of the syndrome and the absence of apparent structural heart disease, clear defects of myocardial neuronal metaiodobenzylguanidine (MIBG) uptake on MIBG SPECT imaging also were found in inferior, apical and septal walls. Thallium-201 SPECT distribution was homogeneous along the left ventricle. Thus, cardiac MIBG scintigraphy provides information about left ventricular dysinnervation in a patient with Brugada syndrome, enhancing the clinical utility of myocardial MIBG SPECT imaging in life-threatening ventricular arrhythmias.
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PMID:Iodine-123-metaiodobenzylguanidine SPECT of regional cardiac adrenergic denervation in Brugada syndrome. 966 81

Most arrhythmias occur in patients with structural heart disease, where anatomical factors play an important role. Patients without structural heart disease may also suffer from arrhythmias, and recently the genetic basis for such so-called idiopathic arrhythmias has been elucidated. In the congenital long QT syndrome, characterized by a prolonged QT interval, torsade de pointes and sudden death, three aberrant ionic currents have been identified, resulting in a prolongation of the ventricular action potential, which in its turn may cause early afterdepolarization and torsade de pointes. In LQTS1, mutations in the KvLQT1 gene reduce the slow component of the delayed rectifier Iks; in LQTS, mutations in the Human Ether a-go-go Related Gene (HERG) reduce the rapid component of the delayed rectifier Iks. Both potassium currents are important determinants of repolarization: a reduction in outward currents carried by K+ ions prolongs the action potential. In LQTS3, there are mutation in the NA+ channel gene (SCN5A) which causes the channel to inactivate incompletely; the persistent inward current carried by Na+ ions also prolongs the action potential. In the Brugada syndrome, characterized by right bundle branch block, ST elevation in V1-V3 and sudden death, mutations have been observed in the Na+ channel gene, but it is as yet unclear which functional changes in the NA+ channel are responsible for the typical ECG changes and the arrhythmias. Various cardiac disorders may lead to changes in gene expression that modify channel function. In hypertrophy, the ventricular action potential is prolonged by a decrease in the inward rectifier and the transient outward current. After prolonged episodes of rapid electrical activity, the atrial action potential is shortened, because of a reduction in the Iks type calcium current. Finally, many carriers of mutated genes display no abnormalities on the ECG. It is conceivable that such individuals may show excessive QT prolongation when taking cardiac or noncardiac drugs (such as neuroleptics, antidepressants, antihistamines, antimicrobials, antimalarials) that block potassium currents.
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PMID:Molecular mechanisms of arrhythmias. 983 81

Most ventricular tachycardias encountered in clinical practice occur in patients who have structural heart disease. Idiopathic ventricular tachycardia refers to those arrhythmias that occur in patients without structural heart disease, metabolic/electrolyte abnormalities, or the long QT syndrome. Three commonly recognized forms of idiopathic ventricular tachycardia include: (a) ventricular tachycardia associated with mitral valve prolapse, (b) ventricular tachycardia originating from the right ventricular outflow tract, and (c) ventricular tachycardia originating from the left ventricle. Recently, a fourth type of idiopathic ventricular tachycardia, termed the Brugada syndrome, has been identified as responsible for some cases of cardiac arrest in persons without apparent structural heart disease. Each form of ventricular tachycardia may be considered a discrete syndrome based on its electrocardiographic characteristics, mechanisms, responses to pharmacologic intervention, and prognosis (good in most cases). Ventricular tachycardias range from the common to the exotic, but all represent syndromes with which the internist and general cardiologist should be familiar.
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PMID:Idiopathic ventricular tachycardia. 1007 70

About 10-20% of patients dying suddenly and unexpectedly do not have structural heart disease. The major causes of sudden death in this population are acute ischemia, the syndrome of right bundle branch block, and ST-elevation from V1 to V3, the long QT-syndrome, and the Wolff-Parkinson-While syndrome. In some patients, none of these syndromes can be recognized and ventricular fibrillation is classified as idiopathic. There are good preventive and therapeutic methods against acute ischemia and there are also curative treatments for the Wolff-Parkinson-White syndrome. Patients with idiopathic ventricular fibrillation cannot be recognized beforehand. However, there are electrocardiographic and genetic markers for the Brugada syndrome and the long QT syndrome. It is, therefore, justified to discuss the possible role of the prophylactic defibrillator to prevent sudden death in these 2 syndromes for which no effective treatment exists. Patients with Brugada syndrome have a high incidence of sudden death, and prophylactic defibrillators are indicated in patients with inducible arrhythmias at electrophysiologic study, irrespective of symptoms. On the contrary, the incidence of sudden death in the long QT syndrome is very low, making prophylactic defibrillator implantation not cost-effective.
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PMID:Use of the prophylactic implantable cardioverter defibrillator for patients with normal hearts. 1008 49

A 48-year-old patient with recurrent episodes of palpitations and syncope presented with transient ST segment elevation in the right precordial ECG leads. Structural heart disease was excluded. No arrhythmias were inducible by programmed ventricular stimulation. Parallel to ST elevation after intravenous ajmaline, a gradual and reversible delay in the upstroke of right ventricular (RV) monophasic action potentials (MAPs) occurred that was most marked in the RV outflow tract and nearly absent at right free-wall recordings. Ajmaline led to a cycle length-dependent increase in RV dispersion of repolarization. Thus, right endocardial MAPs may demonstrate regionally different action potential changes that may contribute to the ECG changes in Brugada syndrome.
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PMID:Transient local changes in right ventricular monophasic action potentials due to ajmaline in a patient with Brugada Syndrome. 1041 81

In 1992, Brugada and Brugada reported a distinct subgroup of patients with episodes of "idiopathic"polymorphic ventricular tachycardia or ventricular fibrillation characterized by a unique electrocardiographic (ECG) pattern, which consisted of right bundle branch block and ST-segment elevation from V1 to V2-V3. As in patients with long QT syndrome, the ECG changes and the ventricular electrical instability could not be explained by structural heart disease, myocardial ischemia, or electrolyte disturbances. The syndrome can be inherited and predominantly affects males. Clinical presentation includes cardiac arrest or syncope caused by rapid ventricular tachycardia or fibrillation characteristically occurring at rest or during sleep. The clinical outcome of affected patients is poor unless they receive an implantable cardioverter defibrillator. The ECG pattern and the electrical ventricular instability have been explained by the dispersion of repolarization between the right ventricular epicardium and endocardium, which predisposes to local reexcitation of myocytes with different action potential durations. A disease-causing missense mutation in the cardiac sodium channel gene SCN5A has been recently reported in patients with Brugada syndrome. It is mandatory for the clinician to carefully rule out any organic heart disease before suggesting a diagnosis of Brugada syndrome, because the typical ECG pattern with the risk of sudden arrhythmic death is also observed in patients with structural heart diseases in the setting of arrhythmogenic right ventricular cardiomyopathy.
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PMID:What is the Brugada syndrome? 1042 70

Sudden cardiac death without ischaemic heart disease may be due to a hereditary heart disease with an autosomal dominant heredity. The occurrence, if any, of sudden death in such a family is a main indicator for the risk of sudden cardiac death in other family members. Cardiological and/or genetic investigation may reveal a hereditary disease in relatives without symptoms. Of some of these pathological conditions, the corresponding chromosomal localizations and sometimes the gene mutations have been identified. The psychic burden of family investigation and the socio-economic consequences (insurances, occupation, family relationships) are potentially heavy. Prophylactic treatment of asymptomatic persons in whom a gene mutation is established may comprise advice about lifestyle (e.g. avoidance of peak exercise in patients with hypertrophic cardiomyopathy), medication (e.g. beta-receptor blockers in patients with a long QT interval) or implantation of a pacemaker or internal defibrillator (e.g. in asymptomatic persons with the Brugada syndrome, a form of right bundle branch block). Presymptomatic investigation must be performed multidisciplinary.
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PMID:[Presymptomatic screening after a sudden cardiac death in the family]. 1049 98

We report on the case of a 33-year-old man with recurrent syncopes appearing suddenly due to sustained monomorphic ventricular tachycardias. The electrocardiogram (ECG) showed a right bundle branch block pattern and ST segment elevation in the precordial leads V1 to V2, not explained by ischemia, electrolyte disturbances, toxic ingestion, or structural heart disease (coronary and right ventricle angiograms as well as biopsies of the right ventricle were normal). ECG image was compatible with the so-called Brugada syndrome, first described in 1992. This entity is very rare. Missed diagnosis can be disastrous because life-threatening ventricular arrhythmias often develop in patients.
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PMID:A young man with recurrent syncopes, right bundle branch block and ST segment elevation. 1053 May 45

The Brugada syndrome is characterized by in a electrocardiographic pattern of right bundle branch block and ST-segment elevation in the right precordial leads, absence of any structural heart disease and syncope episodes or sudden death. We report the case of a 50 year-old men with Brugada syndrome and manifold changes of the precordial morphology of ST segment.
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PMID:[Multiple changes of the morphology of ST segment in a patient with Brugada syndrome]. 1091 15


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