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

Ventricular tachycardia is the diagnosis in approximately 80% of cases of WCT and in approximately 95% of cases with structural heart disease. The presence of atrioventricular dissociation, fusion beats, capture beats, and concordance are important findings strongly suggesting VT; whereas, QRS frontal axis and ventricular rate provide less definitive diagnostic information. A QRS width greater than 160 msec. for LBBB configuration WCT or greater than 140 msec. for RBBB configuration argues strongly for VT. The QRS morphology may be very helpful in selected cases. The duration of the arrhythmia does not discriminate between the etiologies of WCT, as all rhythms may be hemodynamically stable for prolonged periods. Finally, response to treatment may give diagnostic information in addition to therapeutic benefit.
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PMID:The diagnosis of wide complex tachycardia. 842 2

Verapamil-sensitive ventricular tachycardia (VT) is a well-recognized clinical entity that some authorities believe may result from triggered activity. Despite its uniform response to verapamil, however, there is evidence that this uncommon form of VT may not be as homogeneous as first believed. Standard intracardiac electrophysiologic techniques were used to study verapamil-sensitive VT in 32 patients (aged 38 years +/- 20 years) without evidence of structural heart disease. More than half of these patients (69%) exhibited VT with a right bundle branch block-type QRS pattern, with the remainder (31%) displaying VT with a left bundle branch block pattern. In 31% of the patients the VT could be induced by fixed-cycle length atrial pacing, whereas in 59% of patients fixed-cycle length ventricular pacing was necessary. A critical range of cycle lengths for VT induction was required in 66% of the patients. Ventricular tachycardia was initiated with single atrial premature extrastimuli in 16% of patients, single ventricular extrastimuli in 50% of patients, and double ventricular premature extrastimuli in 9% of patients. Ventricular tachycardia displaying cycle-length alternans was observed in 28% of patients. In only 19% of patients was it possible to entrain VT during pacing from the right ventricular apex. Isoproterenol infusion was required for tachycardia induction in 50% of patients, 44% of whom had VT with a left bundle branch block QRS pattern, with the remaining 56% exhibiting VT with a right bundle branch block pattern. Beta-adrenergic blockers suppressed 53% of verapamil-sensitive VT in patients tested, whereas adenosine terminated VT in 50% of patients, with 81% of these patients exhibiting either a left bundle branch block QRS pattern or isoproterenol dependence. Ventricular tachycardia exhibiting a left bundle branch block pattern was more likely to be isoproterenol dependent (p <0.05) and adenosine sensitive (p <0.001). However, verapamil-sensitive, catecholamine-dependent VT was no more likely to be adenosine sensitive than the catecholamine-independent form of the arrhythmia (p >0.5). Verapamil-sensitive VT exhibits properties expected of both a reentrant and triggered arrhythmia, and it is inconsistently dependent on both exogenous catecholamines for induction and intravenous adenosine for termination. Verapamil-sensitive VT encompasses a heterogeneous group of tachycardias that may result from multiple cellular electrophysiologic mechanisms.
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PMID:Spectrum of electrophysiologic and electropharmacologic characteristics of verapamil-sensitive ventricular tachycardia in patients without structural heart disease. 864 47

Conventional ECG still plays an important role in the overall knowledge of Chagas' cardiopathy, because of its importance in longitudinal and epidemiological studies, its diagnostic value, and its utility in prognostic evaluation. The authors discuss these aspects, as well as the use of eCG in the acute phase and the significance of a normal ECG in Chagas' disease. Correlations were made between ECG and Hemodynamic/angiographic variables among 1010 patients with positive laboratory tests for Chagas' disease: a) in the group with normal ECG there was no significant differences between symptomatic and non-symptomatic patients with regard to ejection fraction and angiographic abnormalities; b) slight abnormalities on the ECG corresponded to an intermediate level of severity of the disease, that is, between normal ECG and ECG with significant abnormalities C) fibrosis on the ECG was not predictive of akinesia in the related area on the angiography; d) combined ECG abnormalities generally correlated with greater myocardial compromises compared to isolated abnormalities; e) under multiple regression analysis the ECG abnormalities that independently correlated with depressed ejection fraction were: premature ventricular beats, ventricular tachycardia, left bundle branch block, atrial fibrillation, complete AV block, and anterior and inferior fibrosis. Male sex, cardiac insufficiency and cardiomegaly on the throat radiography were also significantly related.
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PMID:Electrocardiography in Chagas' heart disease. 865 Apr 80

The correlation between the right posterior surface of the QRS complex in the horizontal plane and the various parameters characterizing the right ventricle on TM and 2D echocardiography on left parasternal longitudinal sections and subcostal sections was investigated by the Chi-square independence test and Student's t test in 185 cases of heart disease due to various aetiologies. The right posterior surface (Octant III) of the QRS complex in the horizontal plane is independent of the diastolic thickness of the right ventricular posterior wall (RVPW); the diastolic thickness of the right ventricular anterior wall (RVAW); the right ventricular ejection fraction (RVEF); the systolic diameter and diastolic diameter of the right ventricle; the percentage thickening of the RVPW and the RVAW; and, finally, there is no significant relationship between the diastolic thickness of the RVPW and that of the RVAW. Its variance according to the presence or absence and the nature of an associated conduction disorder (RBBB, RIBBB, RBBB + LAHB, LAHB, LBBB, LIBBB or Kent) was not significant for a risk of error of 5% and 1%. The right posterior surface (Octant III) of the QRS complex in the horizontal plane is significantly correlated with the right ventricular mass (RVM), calculated from the diastolic thickness of the right ventricular posterior wall (RVPW): alpha < 0.001; according to a simplified formula: RVM g/m2 = (RVDD + 2 RVPW)3. The correlation between these last two quantitative parameters is borderline significant r = 0.11 t = 1.25, 0.20 < alpha < 0.30 according to a linear regression equation: y = 55.15-34.71 x; Po = 549 t = 1.48, increasing from 0 to 0.137 and decreasing beyond 0.137, linearity hypothesis: admissible, p = 0.04.
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PMID:[Vector-echocardiographic correlations in type B right ventricular hypertrophy]. 876 47

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

Arrhythmogenic right ventricular dysplasia (ARVD) is a heart disease characterized by a total or partial fat replacement of the myocardium. A total of 30 patients were studied with a suspected diagnosis of ARVD. Clinical criteria used for evaluation of ARVD were: (a) ventricular origin arrhythmias with a left bundle branch block configuration, (b) T-wave inversion in the anterior precordial leads, (c) ventricular kinetic alterations observed using echocardiography and angiography and (d) cardiac failure when there are no pathologies attributable to other heart diseases. All patients had serial EKG and echocardiography tests. One third of patients underwent angiocardiography; 7 of 30 had Holter; 7 of 30 had exercise test just to evaluate the effectiveness of the anti-arrhythmic therapy. All patients underwent MRI examination. The following MRI criteria were used: (a) high-intensity areas indicating the fatty substitution of the myocardium, (b) ectasia of the right ventricular outflow tract, (c) dyskinetic bulges, (d) dilation of the right ventricle and (e) enlargement of the right atrium. The diagnosis of ARVD was classified as highly probable for patients manifesting at least three positive criteria, probable with two positive criteria, dubious with one and negative in the absence of all criteria. Highly probable diagnosis of ARVD was made in 8 patients, probable in 4, dubious in 7 and negative in 11. The MRI technique is very effective in the assessment of ARVD. The MRI criteria may be helpful in the diagnosis of this condition.
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PMID:Arrhythmogenic right ventricular dysplasia: MR features. 908 46

Exercise-induced left bundle branch block is a relatively rare finding during exercise tolerance testing. A 36-year-old female with intermittent exercise-induced left bundle branch block, a MIBI study suggesting anterior ischemia and normal coronary arteries is reported. A review of the English and French language literature published from January 1985 to January 1996 is presented. Exercise-induced left bundle branch block has been reported in association with and without structural heart disease. Pooled mortality in the group with structural heart disease was 2.7% per year, and mortality was 0.17% per year when no structural heart disease was identified. Exercise-induced left bundle branch block has been reported to resolve with therapy. Noninvasive testing appears to have limited ability to detect or exclude coronary artery disease in this group. If a definitive cardiac diagnosis is required, strong consideration should be given to coronary angiography.
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PMID:Exercise-induced left bundle branch block: a case report of false positive MIBI imaging and review of the literature. 917 91

Aim of this study was to elucidate the diagnostic significance of left axis deviation (LAD) in patients (pts) with chronic (> 6 months) left bundle branch block (LBBB). We retrospectively studied 2094 consecutive pts who underwent cardiac catheterization. All pts had left heart catheterization and coronary angiography, whereas right heart catheterization or endomyocardial biopsy were performed on indication. Our study group consisted of 43 pts with LBBB (29 men, 14 women, mean age 60.3 +/- 7.9 years). Pts with acute myocardial infarction or prior high degree AV-block were excluded. Initial evaluation included history, physical examination, chest X-ray, serial ECGs, 2D-echo and Doppler studies. ECG-criteria for LBBB were a QRS duration of > 0.12 secs, a predominantly negative QRS deflection in V1 and a widened R-wave in V6. LAD was considered present when the mean frontal QRS axis was between -30 degrees and -90 degrees. The mean frontal QRS axis was considered normal if it was between -29 degrees and +90 degrees. Twenty-nine pts had normal axis and 14 had LAD. According to angiographic data, among coronary disease pts, 12 (31.48%) had normal axis and 4 (28.57%) LAD (p = 0.041). Among mitral valve disease pts, 3 (10.35%) had normal axis and none LAD. Among pts with aortic valve disease, I (3.45%) had normal axis and 8 (57.15%) LAD (p = 0.0001). Among pts with dilated cardiomyopathy, 2 (6.9%) had normal axis and 1 (7.14%) LAD. Among pts with no organic heart disease, 11 (37.93%) had normal axis and 1 (7.14%) LAD (p = 0.035). The presence of LAD had a 41.9% sensitivity and a 91.6% specificity for the presence of organic heart disease. These findings point towards a statistically significant difference in the presence of organic heart disease in LBBB pts with LAD compared to normals. Aortic valve disease in LBBB pts seems to be frequently accompanied by LAD.
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PMID:Complete left bundle branch block with left QRS axis deviation: defining its clinical importance. 921 20

A 48-year-old woman with no cardiovascular risk factors was admitted to the hospital because of acute dyspnea. At 27-year-old, she developed Hodgkin's disease, that was successfully treated with splenectomy, combined chemotherapy (nitrogen mustard, vincristine, procarbazine, prednisone-MOPP regimen) and radiotherapy (4500 rads). At 43-year-old the lymphoma relapsed and she had further chemotherapy with doxorubicin, bleomycin, vinblastina and dacarbazine. After this treatment, she had an episode of pulmonary edema, attributed to doxorubicin acute cardiotoxicity. She responded to digitalis and diuretics and was discharged with an electrocardiogram (ECG) showing left bundle branch block and a normal echocardiogram. The patient enjoyed good health for several years and 4 months before the present admission the ECG and echocardiogram were unchanged. On this admission there were signs of left ventricular failure with acute pulmonary edema, and a new soft apical murmur (3-4 Levine). The patient required endotracheal intubation and high doses of diuretics, digitalis and vasodilators. The cardiac enzymes were negative, the serial ECGs confirmed left bundle branch block, while the echocardiogram showed moderate to severe mitral regurgitation, akinesia of the interventricular septum and inferior wall with dilation of the left ventricle. A previous silent myocardial infarction was suspected. After recovery, she underwent cardiac catheterization confirming akinesia of the interventricular septum and inferior wall with moderate mitral regurgitation, while coronary angiography showed a critical ostial stenosis of the right coronary artery. In view of a dipyridamole-thallium scan negative for myocardial viability, reperfusion was not attempted. With changes in radiotherapeutic techniques, the incidence of radiation-induced heart disease (pericarditis, myocarditis, conduction abnormalities and, rarely, occlusive coronary artery disease) is declining. Nevertheless, after irradiation of the chest and mediastinum a longterm cardiological follow-up is useful in selecting patients at higher risk of radiation-induced coronary artery disease, who will eventually require coronary angiography and reperfusion intervention.
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PMID:[Silent myocardial infarction in a patient treated with radiation therapy and polychemotherapy for Hodgkin's lymphoma]. 928 80

Ventricular tachycardia (VT) without structural heart disease or any identifiable predisposing causes for arrhythmia is an uncommon but well-recognized clinical entity. The purpose of this study is to assess the results of catheter ablation therapy and the long-term outcome of patients with idiopathic monomorphic VT in a large patient group. Sixty-one consecutive patients (male/female=40/21; mean age 38+/-16 years) with idiopathic VT underwent electrophysiologic study and an attempt of catheter ablation therapy. The 'left VT' group included 31 patients with QRS morphology of right bundle branch block during VT suggestive of the VT originating from the left ventricle (LV), and the 'right VT' group consisted of 30 patients with QRS morphology of left bundle branch block with normal or right frontal axis deviation suggestive of VT arising from right ventricular outflow tract (RVOT). Idiopathic left VT has sustained VT during the clinical attacks, baseline electrophysiologic study or after isoproterenol infusion; it can be entrained by overdrive ventricular pacing, terminated by verapamil, but not by adenosine (except one case with VT focus at left ventricular free wall). Catheter ablation was successful in 22 (84%) of 26 patients, with recurrence rate of 9%. The successful ablation sites were located at LV inferior-apical septum (16 patients), mid-septum (three patients), high septum (two patients) and high anterior wall (one patient). In the right VT group, 20 (67%) of 30 patients presented clinically repetitive monomorphic VT. Most of the idiopathic right VT (22/30) required isoproterenol to facilitate induction of VT, and were sensitive to both verapamil and adenosine. Successful catheter ablation was achieved in 21 (84%) of 25 patients, with recurrence rate 19%. The successful ablation sites were located at RVOT-septum in 18 patients, and RVOT-free wall in three patients. During a mean follow-up period of 29.2+/-21.7 months (range 1-76 months) after hospital discharge, all patients were alive but one left VT case died of non-cardiovascular cause. We concluded that idiopathic left side and right side VTs have their distinct clinical, electrophysiologic and electropharmacological characteristics suggestive of different underlying mechanisms, and both have a benign prognosis. Furthermore, catheter ablation can be effective in eliminating idiopathic VT originating from the right ventricular outflow tract and left ventricle.
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PMID:Idiopathic monomorphic ventricular tachycardia: clinical outcome, electrophysiologic characteristics and long-term results of catheter ablation. 943 65


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