To determine the presence and distribution of cardiac myosin isozymes in the human conduction system, we performed an immunohistochemical study using monoclonal antibodies CMA19 and HMC14, which are specific for myosin heavy chains of human atrial type (alpha-type) and ventricular type (beta-type), respectively. Serial frozen sections of human hearts were ...

The hemodynamic effects of vecuronium 0.2 mg/kg were investigated in 11 patients with coronary artery disease. Vecuronium, at a dose double the ED90, produced 90% neuromuscular block in a mean time of 163 +/- 7 s, and was not associated with any significant hemodynamic changes. The results suggest that vecuronium ...

The objective of the study was to evaluate the acute effect of intravenous celiprolol on the electrophysiologic properties of the cardiac conduction system in man and to assess potential problems in terms of its causing heart block or sinus bradycardia. Eight patients with controlled coronary artery disease and hypertension but ...

Between January 1, 1980, and March 1, 1986, congenital complete heart block (CCHB) was diagnosed in 11 fetuses utilizing 2-dimensional and M-mode fetal echocardiography. Four of the eleven cases (36.4%) had otherwise structurally normal hearts; 3 survived the perinatal and neonatal period and 1 patient died at 22 days of ...

To clarify the presence of concealed conduction in the reentrant pathway of extrasystoles, 20 patients with ventricular extrasystoles were studied in whom two forms of interectopic periods were found in the same recording. One form is the XS1S2X period, in which two sinus QRS complexes (S1 and S2) intervene between ...

The 3rd coronary artery, whose anatomical significance is defined, is a normal variant of the conus branch of the right coronary artery. This study involved the stereoscopic comparative investigation of human fetal hearts from 13 to 40 weeks of age and human adult hearts from 18 to 88 a of ...

Heart block is a relatively common arrhythmia in the adult horse. It may be a normal physiologic phenomenon or it may have pathologic implication. Four foals in which advanced heart block developed during anesthesia were unresponsive to atropine sulfate and supportive treatment alone. Resolution of the heart blocks was achieved ...

Atrioventricular (AV) junctional ablation was performed in a 59-year-old woman with recurrent atrial fibrillation refractory to treatment with digoxin, beta-blockers, verapamil, quinidine, procainamide, and amiodarone. She received two shocks of 500 J which produced complete AV block. After six weeks, both 24-hour ECG recordings and an exercise tolerance test showed ...

Normal hearts: Refractory periods were determined at 12 to 15 intramural sites of the normal canine left ventricle during steady state regularly driven rates, after each of a series of four early premature beats, and after a long pause following a series of three premature beats. The dispersion in recovery ...

Three patients with primary congestive cardiomyopathy (COCM), complete left bundle branch block (LBBB) and right axis deviation in the standard leads are described. Review of 50 additional patients from the literature since 1950 indicates that the uncommon combination of LBBB and RAD is a marker of severe myocardial disease, especially ...

The mechanisms of aberrant conduction at the onset of induced orthodromic tachycardia in the Wolff-Parkinson-White syndrome were analyzed in 20 consecutive patients in whom this tachycardia was initiated by the atrial (A2) and/or right ventricular (V2) extrastimulus techniques. Of 13 patients in whom orthodromic tachycardia was induced by the A2 ...

A 53-year-old man with myocardial infarction was found to have frequent premature ventricular beats. The predominant pattern was classical concealed trigeminy; i.e., the number of conducted sinus beats, S, between extrasystoles satisfied the equation S = 3n + 2, where "n" is zero or any positive integer. Two other transient ...

The cardiac output has been determined by radionuclide angiocardiography and by impedance cardiography in 93 elderly patients. The agreement between the two methods was excellent in patients in sinus rhythm, without regurgitant valvular lesions, and without severe airways obstruction or right bundle branch block. In atrial fibrillation the lack of ...

An early pericardial friction rub was noted in 23.4% of a population of 1264 consecutive patients admitted with acute myocardial infarction. The incidence of the rub did not vary with age, sex or past cardiac history. The pericardial rub, however, was more often a complication of Q- than non-Q-wave infarcts ...

Isochronal maps of ventricular activation were analyzed in dogs 3-5 days after ligation of the left anterior descending coronary artery utilizing a 64-channel multiplexer. Isochronal maps of the effective refractory period were determined from 62 epicardial sites and correlated with the activation maps. The ischemia occurring in the surviving epicardial ...

Twelve patients with persistent fetal bradycardia were referred for echocardiographic assessment; in 10 patients the fetus had complete heart block, six isolated and four with associated structural heart disease. In the remaining two patients an atrial arrhythmia was producing a fetal sinus bradycardia. Complete heart block with structural heart disease ...

The incidence of conduction block by lidocaine 0.3 mmol/l (8.1 mg/dl) in several successive lengths of individual afferent axons of rabbit was compared. The conduction velocity of the axons was either "slow," "intermediate" (1.3-4 m/s), or "fast." The "intermediate" group showed a higher incidence of proximal acceleration of conduction (P ...

Four children aged 2 to 15 years are described who had Stokes-Adams syndrome as the primary cardiac manifestation of complete heart block. All had mild, nonspecific antecedent symptoms without signs of congestive heart failure. Viral neutralizing antibody titers (coxsackievirus B1 and B2) rose significantly in two patients. Electrocardiography demonstrated complete ...

The electrocardiographic findings in 102 consecutive patients with scleroderma were reviewed to determine the frequency and nature of the electrocardiographic abnormalities associated with this disease. Septal infarction pattern unassociated with QRS prolongation was present in 10 percent, compared with none of 96 control subjects (p less than 0.001). Ventricular conduction ...

A 77-yr-old man presented with severe episodes of hypotension, flushing and sweating starting immediately after infarcting his only remaining functioning testis. The attacks were shown to be mediated by the cervical sympathetic chain, the reaction on the face and neck being abolished by a stellate ganglion block. The severity and ...

Nine premedicated patients, chronically maintained on beta-adrenergic blocking agents and demonstrating good ventricular function without significant valvular or left main coronary artery disease, were investigated to determine their haemodynamic responses to rapid induction of anaesthesia and tracheal intubation during elective coronary artery bypass surgery. Fentanyl 50 micrograms X kg-1 and ...

Seven patients with complete AV heart block and wide QRS complexes, atypical chest pain and no specific serum enzymes modifications for myocardial necrosis are reported. The patients showed no prior complete AV heart block although myocardial perfusion scintigraphy showed localized uptake demonstrating a small area of acute myocardial necrosis. These ...

Ligation of the anterior septal artery was used to produce acute ischaemia of the specialised conduction system in ten dogs. Activation times at selected positions within the specialised conduction system were recorded. Marked delays of activation occurred between several discrete anatomic sites within the specialised conduction system. This study demonstrates ...

Paroxysmal complete atrioventricular (AV) block without associated electrocardiographic (ECG) abnormality is not a well recognized entity. A mother and her daughter had recurrent syncopal episodes, but a normal ECG. The episodes were preceded by nausea and vomiting. ECG during these episodes revealed complete heart block. In the mother, one episode ...

We evaluated the initial electrocardiogram as a predictor of complications in 469 patients with suspected acute myocardial infarction. An electrocardiogram was classified as positive if it showed one or more of the following: evidence of infarction, ischemia, or strain; left ventricular hypertrophy; left bundle-branch block; or paced rhythm. Forty-two (14 ...

Compare the chest film with previous films, if possible. Changes in heart size and interstitial and vascular markings can thus be seen more readily, as can air trapping; this also aids in differentiation of acute from chronic changes. A Holter monitor study should be obtained if dyspnea occurs irregularly, has ...

Electrophysiologic study was performed in a patient with tachycardia-dependent paroxysmal atrioventricular block. The site of block was within the His bundle. The effective refractory period of the His bundle was markedly prolonged and it was comparable to the critical atrial cycle length producing type II His bundle block. The most ...

Ten aviators with cardiac symptoms or electrocardiographic abnormalities underwent electrophysiologic testing. Four patients were studied because of symptoms including palpitations, nearsyncope, and sudden cardiac death. Six patients were studied because of electrocardiographic abnormalities including AV block, right bundle branch block, sinus bradycardia, ventricular tachycardia, and questionable Wolff-Parkinson-White syndrome. Three patients ...

In a review of the records of 81 patients with the discharge diagnosis of digitalis toxicity, I found a preponderance of very old patients, many of whom had anorexia, nausea, and prerenal azotemia. Arrhythmias were common (93%) and reflected enhanced automaticity, enhanced AV block, or both. Atrial fibrillation with complete ...

The effect of direct impact on the right ventricle was investigated in an anesthetized open-chest canine preparation. At each of five impact sites, direct local loading produced immediate ventricular asystole followed by varying degrees of AV conduction block, lasting 70 +/- 35 seconds. Sinus rhythm temporarily resumed in most cases ...

Carotid sinus massage is a simple bedside maneuver that helps to clarify the type and sometimes also the mechanism of different rhythm disturbances. The major indication for carotid sinus massage is the diagnosis of tachyarrhythmias in which the atrial activity is either absent or intermittently present. Carotid sinus massage is ...

In patients with ischemic heart disease, fascicular conduction disturbances are associated with increased mortality. This study reveals that increased mortality also exists for certain types of fascicular conduction disturbances after myocardial revascularization. In 227 consecutive patients undergoing bypass surgery, 24 had preoperative and an additional 52 developed at surgery a ...

Structural and electrophysiological properties of the epicardial muscle which survives on the surface of transmural infarcts of the canine heart (epicardial border zone) were studied at different times after occlusion of the left anterior coronary artery (LAD). Isolated preparations were superfused in vitro, transmembrane potentials recorded, and impulse propagation mapped. ...

Syncopal attacks in patients with bifascicular block may be due to both ventricular tachyarrhythmias and intermittent atrioventricular block in addition to non-cardiac causes and lead to antiarrhythmic treatment with drugs or pacemaker or both. The acute electrophysiological effect of intravenous disopyramide 2 mg/kg body weight given over five minutes on ...

The modified Fontan operation, which consists of ventricular exclusion by obliteration of the right atrioventricular ostium, requires a technique that provides firm and permanent occlusion while preserving the atrioventricular node and bundle. Ten patients underwent such an operation. In 5 of them, closure of the right atrioventricular ostium was achieved ...

The term "linking" has been used specifically to describe the mechanism for perpetuation of functional anterograde bundle branch block: namely, repetitive transseptal retrograde concealed penetration by impulses propagating along the contralateral bundle. We present selected examples that demonstrate tht linking-type phenomena actually have a wide spectrum of expression in human ...

The cardiac conduction systems of three patients who died in the perinatal period were studied histologically. Rhythm disturbances were observed in these patients immediately before death. The sinus node was notably hypoplastic without increase in fibrous content in all cases. The atrioventricular node was smaller than expected in all, and ...

The clinical and angiographic significance of isolated left anterior fascicular block occurring during the early stage of acute myocardial infarction was studied in 141 consecutive patients who underwent cardiac catheterization before hospital discharge. Left anterior fascicular block occurred in 15 of the 62 patients with an anterior wall infarction and ...

A comparative analysis was carried out of 126 patients (group I) with chronic right bundle branch block (RBBB) and left anterior (LAFB) or left posterior fascicle block (LPFB), and of 44 patients (group II) with the same bifascicular block associated with an ECG pattern of incomplete left bundle branch block ...

To determine the origin of conduction disturbances commonly seen in the ECG after correction of Fallot's tetralogy, 36 children underwent electrophysiologic studies; these included endocardial recordings of right ventricular (RV) and left ventricular (LV) apical activation and His-bundle recordings. The surface ECG showed a pattern of complete right bundle branch ...

This study of biventricular segmental timing sequences compared patterns of the first-harmonic phase with those of multiharmonic Fourier-analysis-derived parameters to determine their suitability for the classification of patients using an automatic pattern recognition scheme. The study involved nine patients with normal ECGs, six with left bundle branch block, 4 with ...

A fluorescence histochemical study was performed to describe the adrenergic innervation of the coronary arteries and the left ventricular myocardium in the pig. Large bundles of adrenergic nerve fibres were almost exclusively found running along the large coronary arteries. The arteries usually show a dense innervation of the vessel wall, ...

A forty-year-old man was admitted to our hospital because of dizziness, palpitations and an oppressive feeling in the precordium. Physical examination was normal. A chest roentgenogram revealed mild cardiomegaly and the electrocardiogram showed ventricular tachycardia of a left bundle branch block configuration which was terminated by the intravenous injection of ...

Many electrocardiographic criteria have been proposed for the differentiation of ventricular extrasystole and supraventricular conduction with aberrancy in atrial fibrillation but the validity of these have not been confirmed by intracardiac studies. We recorded His bundle electrograms in nineteen patients (eleven men, eight women) referred for diagnosis of abnormal QRS ...

Owing to the impossibility of fixation, in the human being, by means of perfusion in vivo and the rare availability of fresh comparatively intact hearts resected at transplantation, the possibility was explored of using post-mortem material in instances where the autopsies were performed within 2 hours of demise of the ...

To study the changes in sulfhydryl and disulfide distribution in myocardial infarction we applied the fluorescent sulfhydryl reagent, monobromobimane to sections of myocardium from patients dying of infarction of 24 h to 7 days duration. Staining for both sulfhydryls and for disulfide after reduction of slides blocked with N-Ethyl maleimide ...

Coinciding left bundle-branch block and Wolff-Parkinson-White syndrome type B, a very rare electrocardiographic occurrence, was found in a patient with dilated cardiomyopathy. Electrophysiologic study revealed eccentric retrograde atrial activation during ventricular pacing, suggesting right-sided accessory pathway. At programmed atrial pacing, effective refractory period of the accessory pathway was 310 ms; ...

To determine the electrophysiologic effects of stellate ganglion (SG) block on the human heart, the two SGs were anesthetized separately, with a 24-hour interval between the two procedures, in 13 patients with episodes of supraventricular tachycardia (six had Kent bundles). Left SG block caused: (1) a lengthening of the AH ...

The clinical presentation and natural history of congenital complete heart block (CHB) differ from those of acquired third-degree heart block. Although perioperative prophylactic cardiac pacing is considered mandatory in patients with acquired CHB, it is not usually necessary in children with asymptomatic congenital heart block. The anaesthetist should be able ...

Two patients with complete heart block complicating extensive anterior myocardial infarction underwent late (greater than 40 hours) coronary reperfusion with angioplasty. One to one atrioventricular conduction was restored within minutes of reperfusion despite a lack of measurable ventricular muscle salvage as demonstrated by ventriculography 1 week later. The evidence favors ...