Brugada-type electrocardiographic pattern induced by fever

ST-segment elevation in Brugada syndrome is caused by a shift in the ionic current balance and the creation of a voltage gradient between the epicardium and the endocardium. This ionic mechanism have been shown to be temperature dependent. We describe a 33-year-old man who presented with fever with the dynamic electrocardiographic changes similar to the Brugada syndrome. These electrocardiographic anomalies disappeared when the temperature returned to normal.     

Immunoscintigraphy for detecting acute myocardial infarction without electrocardiographic changes.

OBJECTIVE--To establish whether immunoscintigraphy with antibody to myosin may detect acute myocardial infarction without electrocardiographic changes. DESIGN--Prospective study of patients with suspected acute myocardial infarction or unstable angina with cardiac imaging with 111indium myosin antibody, estimation of cardiac enzyme concentrations, electrocardiography, 201thallium imaging, and radionuclide ventriculography. SETTING--Coronary care unit in a district general hospital. PATIENTS--119 Consecutive patients with suspected acute myocardial infarction or unstable angina. Patients with cardiomyopathy, myocarditis, valvular heart disease, myocardial infarction or cardiac surgery in the previous two weeks or with left bundle branch block and women of childbearing age were excluded. RESULTS--Of 75 patients with suspected acute myocardial infarction, seven had no diagnostic electrocardiographic changes despite normal conduction patterns. Immunoscintigraphy with myosin antibody disclosed necrosis in all seven patients, which was localised in regions supplied by diseased coronary arteries in all but one. Six patients had abnormal images on 201thallium imaging, and all seven had abnormal wall motion at the site of antibody uptake. One patient with minimal left main stem and right coronary artery atheroma had uptake of antibody at two discrete sites. CONCLUSIONS--Immunoscintigraphy with antibody to myosin confirms myocardial infarction in the absence of electrocardiographic changes and discloses the site of infarction.     

Electrocardiographic Examinations in Dogs With Experimental Hepatitis Contagiosa Canis

Dogs with experimentally produced Hepatitis contagiosa canis were subjected to repeated electrocardiographic examinations during the course of the disease. Varying degrees of depression of the STJ and S-T segments and deviations of the T-wave were noted. Serum-electrolyte studies made during the illness showed a decrease of potassium, sodium, and chlorides which did not seem to be the cause of the observed electrocardiographic abnormalities. Circulatory disturbances and changes in the endothelial cells described elsewhere are considered to be the cause of a disturbance in the metabolism and the function of the myocardium with resulting depression of the STJ and S-T segments and deviations of the T-wave.     

Comparison of Adrenergic Beta-blocking Drugs in Angina Pectoris

The symptomatic, electrocardiographic, and haemodynamic effects of two adrenergic beta-blocking drugs, oxprenolol and propranolol, have been compared in equipotent intravenous doses in six patients with uncomplicated angina pectoris during treadmill exercise. The method of comparison included double-blind assessment and analysis with placebo control and randomized serial comparison in each patient. Both drugs produced an equal amelioration in symptoms in most of the patients. This was closely correlated with improvement in the electrocardiographic changes and a significant reduction in the exercising heart rate and systemic arterial pressure. This method of double-blind combined subjective and objective assessment carries distinct advantages in the comparative assessment of drug treatments in angina pectoris.     

Electrocardiographic Manifestations of Chronic Physical Overexertion in Athletes

Electrocardiographic studies were performed in 85 endurance-training athletes with chronic physical overexertion. A new type of change in the T wave—atypical asymmetry—was revealed in addition to changes described earlier in the literature as corresponding to this pathological condition. A detailed theoretical foundation for impaired repolarization was given. An electrocardiographic picture of a left ventricular diastolic overload was also considered as a manifestation of chronic physical overexertion. A classification was suggested for electrocardiographic variants of dysadaptation of an athlete's heart to physical loads as a result of physical overexertion.     

Intravenous diazoxide in treatment of hypertension associated with recent myocardial infarction

Twenty patients with blood pressure over 180/110 mm Hg one hour after admission to a coronary care unit with recent acute myocardial infarction were given intravenous diazoxide in a bolus of 300 mg. The average blood pressure before diazoxide was 194/122 mm Hg. Blood pressure fell considerably in all patients, though six patients required two injections. The average fall was 58 mm Hg systolic and 40 mm Hg diastolic. No patient became severely hypotensive. The heart rate increased by an average of 10 beats/min. In nine patients the electrocardiographic changes immediately after the administration of diazoxide suggested an increase in myocardial injury. Though none of the patients seemed to deteriorate clinically from the diazoxide the electrocardiographic changes suggested that the use of intravenous diazoxide to lower blood pressure in patients with acute myocardial infarction might possibly be deleterious.     

THE ELECTROCARDIOGRAM IN PRIMARY COCCIDIOIDOMYCOSIS

Because in some cases of primary pulmonary coccidioidomycosis the principal complaint is pain in the chest resembling that of angina pectoris or coronary occlusion, the electrocardiograms of 20 cases of primary pulmonary coccidioidomycosis were studied, early in the illness and after recovery. In fifteen cases, no electrocardiographic abnormalities were noted. In five cases, findings during the acute illness differed from those after recovery. The changes noted were inversion of T waves and low voltages during the illness, reverting to upright T waves and normal amplitudes after recovery. In none of the cases studied were abnormalities found which might be confused with the electrocardiographic findings in angina pectoris or coronary artery occlusion.     

The conduction system of the heart in mice chronically infected with Trypanosoma cruzi: histopathological lesions and electrocardiographic correlations

Chronic focal and diffuse myocarditis with interstitial fibrosis developed in Swiss outbred mice and in the inbred AKR and A/J strains of mice which were chronically infected with several Trypanosoma cruzi strains belonging to three biological types (Type I, II and III). High incidence of electrocardiographic changes with predominance of intraventricular conduction disturbances, 1st. and 2nd. degree AV block, arrhythmias, comparable with those found in human Chagas' disease, were also present. Morphological study of the conduction tissue of the heart revealed inflammatory and fibrotic changes. The presence of inflammation in the inter-atrial septum almost always coincided with the inflammatory involvement of the ventricular conduction system. Focal inflammation was associated with vacuolization and focal necrosis of the specific fibers. Most of the lesions were seen affecting the His bundle (76.3% of the cases), the right bundle branch (73.3%), AV node (43.9%) and left bundle branch (37.5%). Correlation between morphological changes in the conduction tissue and electrocardiographic alteration occurred in 53.0 to 62.5% of the cases, according to the experimental groups.     

In vitro study, in perfused rabbit heart, of interaction between two anti-arrhythmia agents: amiodarone and disopyramide

The influence of 15 day's amiodarone administration (30 mg/kg/day) on myocardial uptake kinetics and electrocardiographic changes of disopyramide was examined on the isolated perfused rabbit heart (n = 24) under electrical stimulation. Amiodarone significantly reduced myocardial uptake and potentialized the effect of disopyramide on intraventricular conduction.     

Predictors of torsades de pointes in rabbit ventricles perfused with sedating and nonsedating histamine H1-receptor antagonists

Several nonsedating histamine H1-receptor antagonists are associated with torsades de pointes ventricular tachycardia. The objectives of this study were to: (i) compare electrocardiographic, monophasic action potential, and arrhythmogenic effects of sedating and nonsedating H1-receptor antagonists, and (ii) identify correlates of drug-induced torsades de pointes in an isolated ventricle model. Isolated, electrically paced (1-3 Hz) rabbit ventricles were Langendorff-perfused with either drug-free Tyrode's solution or one of the following: (i) the sedating H1-receptor antagonist hydroxyzine (0.1-30 microM), (ii) cetirizine, a nonsedating metabolite of hydroxyzine (1-300 microM), and (iii) the nonsedating, putatively arrhythmogenic H1-receptor antagonist astemizole (0.1-30 microM). Volume conducted electrocardiographic signals and monophasic action potentials from the periapical left ventricular endocardium and epicardium were recorded. There were no apparent changes in control (n = 15) or hydroxyzine-perfused (n = 7) hearts. Cetirizine (n = 13) produced a mild biphasic electrocardiographic QT interval prolongation and was associated with early afterdepolarizations, but not with torsades de pointes. Astemizole (n = 11) lengthened QT intervals, and at high concentration (30 microM) induced torsades de pointes in 10 of 11 hearts (P < 0.001 vs. all other groups). These findings are consistent with previously reported repolarizing current inhibition by cetirizine, but may additionally indicate "compensatory" inhibition of inward currents at higher concentrations. By contrast, astemizole-induced changes are consistent with unopposed repolarizing current inhibition.     

Experimental myocardial necrosis in rats: Role of arjunolic acid on platelet aggregation,coagulation and antioxidant status

Arjunolic acid, a new triterpene and a potent principle from the bark of Terminalia arjuna, has been shown to provide significant cardiac protection in isoproterenol induced myocardial necrosis in rats. To further explore the mechanism of action of arjunolic acid, antiplatelet activity, anticoagulant assays, electrocardiographic changes, serum marker enzymes, antioxidant status, lipid peroxide and myeloperoxidase (MPO) have been measured and the results are compared with a potent cardioprotective drug, acetyl salicylic acid (ASA). Administration of isoproterenol produces electrocardiographic changes such as decreased R amplitude and increased ST segment elevation and has resulted in an increase in serum marker enzyme levels as well as a decrease in enzymatic and nonenzymatic antioxidant levels. Arjunolic acid at an effective dosage of 15 mg/kg body weight (pre and post treatment),when administered intraperitoneally (i.p.), effects a decrease in serum enzyme levels and the electrocardiographic changes get restored towards normalcy. Arjunolic acid treatment is also shown to prevent the decrease in the levels of superoxide dismutase, catalase, glutathione peroxidase, ceruloplasmin, -tocopherol, reduced glutathione (GSH), ascorbic acid, lipid peroxide, MPO and the cardioprotection is confirmed by the histopathological studies.This study shows that the cardioprotection of arjunolic acid pre and post treatment could possibly be due to the protective effect against the damage caused by myocardial necrosis.     

Coronary hypertonia and angina

Coronary hypertonia was observed in a patient with unstable angina. It was possible on one occasion to reproduce the clinical picture, electrocardiographic changes, lactate production and coronary hypertonia by means of atrial pacing. He had a normal left coronary arteriogram when the diffuse spasm was relieved by nitroglycerin. Therefore hypertonia (or spasm) of the left coronary artery was believed to be the cause of his variant angina with subendocardial ischemia.     

Electrocardiographic abnormalities in patients with myotonic dystrophy.

In examining the incidence and progression of electrocardiographic abnormalities in 45 patients with myotonic dystrophy, 26 (58%) of whom at entry had at least 1 electrocardiographic abnormality, we found conduction abnormalities in 17 (38%). In 21 patients (47%), new abnormalities developed during follow-up (mean, 4.6 years). The overall incidence of electrocardiographic abnormalities increased to 78%, and the incidence of conduction defects increased to 62%. Second-degree or complete atrioventricular block did not develop in any of the patients. Pseudoinfarction patterns were common at entry and during follow-up and were not correlated with evidence of clinical coronary artery disease. There was no correlation between the presence of electrocardiographic abnormalities and apparent disease severity.     

Precordial electrocardiographic map using the IBM-Bonner program

The precordial electrocardiographic map may be useful for non-invasive assessment of the extent of the acutely infarcted myocardium. Rapid and serial precordial electrocardiographic maps also may be useful to evaluate the effects of intervensions of drugs and efforts on the ischemic myocardium. In this study, the IBM-Bonner program was applied to produce a system for the precordial electrocardiographic map. Six electrodes at one intercostal space were moved in parallel from the second to the seventh intercostal space. Thus electrocardiograms (ECGs) could be recorded from 36 precordial sites, 6 x 6 matrix, and analyzed using the IBM-Bonner program. The measured values of the ECG waveform make feasible the automatic procurement of the precordial electrocardiographic map. Our mapping program can be used readily and anywhere the IBM-Bonner program is in use.     

Electrocardiographic abnormalities associated with raised intracranial pressure.

Serial electrocardiographic (E.C.G.) recordings were taken in seven patients suffering from intracranial conditions, for which their intracranial pressure was directly and continuously monitored with a Konigsberg extradural transducer. The E.C.G. changes observed in patients with raised intracranial pressure were prominent U waves, ST-T segment changes, notched T waves, and shortening and prolongation of Q-T intervals. Two patients with normal intracranial pressure showed no E.C.G. abnormalities but also establish a relationship between E.C.G. abnormalities and changing intracranial pressure.     

Electrocardiographic Changes in Amitriptyline Poisoning

In imipramine and amitriptyline poisoning the electrocardiographic abnormalities comprise arrhythmias, widening of the QRS complex, and marked changes in die S–T segment. These features were found to be of value in the differential diagnosis of unknown poisoning. The unusual configuration of qR with raised S–T segment in V1, simulating myocardial infarction, was seen in one of our patients and has been noted in four cases reported by other workers.     

The Cardiomyopathy of Muscular Dystrophy: Report of Two Cases with a Review of the Literature

About 50% of patients with progressive muscular dystrophy have a cardiomyopathy, manifested commonly by tachycardia, but also by arrythmias, refractory congestive heart failure and sudden death. Studies from the literature report manifold but nonspecific electrocardiographic changes in 41% to 85% of patients with progressive muscular dystrophy. The principal lesion is a diffuse myocardial fibrosis with minor degenerative changes in myocardial fibres unaccompanied by significant inflammation. The heart is enlarged and has a prominent deposit of epicardial fat. The myocardium is pale, coarse, flabby and friable, often showing gross evidence of scarring. The dilated chambers often contain mural thrombus.     

Dimensional analysis of RR dynamic in 24 hour electrocardiograms

Using dimensional analysis, we demonstrate that it is possible to quantify changes in the topological structure of cardiac dynamics over long periods of time. A method was developed to calculate a dimension-like measure (referred to here as apparent dimension) from a correlation algorithm within a data window of 500 heart beats which is moved in equidistant steps over the time series of the RR intervals over 24 hours. The correspondence between the apparent dimension and the correlation dimension was tested using artificial data sequences. Furthermore 24 hour electrocardiographic recordings of two healthy subjects and of a patient with acute myocardial infarction were examined. The reliability of the analysis could be demonstrated and changes in dimension reflecting physiological as well as pathophysiological changes were observed.     

Cardiac Abnormalities in Poisoning with Tricyclic Antidepressants

Of 80 consecutive admissions to a general hospital for drug overdose, 10 had taken one or other of the tricyclic antidepressants. All 10 had abnormalities of cardiac conduction as shown by prolonged Q–T_e intervals, and eight had S–T segment and T-wave changes. Five of the 10 patients had arrhythmias and two of these died. Continuous electrocardiographic monitoring is recommended in patients with overdosage of tricyclic antidepressants.     

Relation of coronary heart disease and apolipoprotein E phenotype in patients with non-insulin dependent diabetes.

OBJECTIVES--To examine the relation between coronary heart disease and the apolipoprotein E phenotypes in patients with non-insulin dependent diabetes mellitus. DESIGN--Cross sectional study. SETTING--District around Kuopio University Central Hospital, East Finland. SUBJECTS--138 men with non-insulin dependent diabetes and 64 men without diabetes as controls. MAIN OUTCOME MEASURE--Apolipoprotein E phenotype, electrocardiographic abnormalities, other signs of coronary heart disease. RESULTS--The prevalences of definite myocardial infarction and ischaemic electrocardiographic changes were highest in the diabetic men with the phenotypes E4/4 or E4/3 (25% (95% confidence interval 18% to 32%) and 50% (42% to 58%) respectively), although the difference between the phenotype groups was not significant. The prevalence of angina pectoris was 69% (61% to 77%) in men with the phenotypes E4/4 or E4/3 (p = 0.005 compared with other phenotypes), 41% (33% to 49%) in men with phenotype E3/3, and 47% (39% to 55%) in those with phenotypes E2/2 or E2/3. Similarly, the simultaneous presence of angina pectoris and ischaemic electrocardiographic changes was highest in the diabetic men with the phenotypes E4/4 or E4/3 (42% v 22% in those with E3/3 and 29% in those with E2/2, E2/3; p = 0.038). Overall, the prevalence of any evidence of coronary heart disease among the diabetic subjects with the phenotypes E4/4 or E4/3 was 81% (p = 0.011 compared with other phenotypes), 58% in those with phenotype E3/3, and 53% in those with phenotypes E2/2 or E3/3. CONCLUSION--Apolipoprotein E phenotypes E4/4 and E4/3 modulate the risk of coronary heart disease in men with non-insulin dependent diabetes.