Showing papers in "Circulation in 1968"
TL;DR: It is postulated that a defect in the mechanical performance of the heart is responsible for the abnormal systolic time intervals in human heart failure.
Abstract: The duration of the systolic time intervals in nondigitalized patients with heart failure was determined from simultaneous fast speed recordings of the electrocardiogram, phonocardiogram, and carotid arterial pulsation. These were compared with the systolic time intervals corrected for heart rate and sex in 211 normal subjects. The failing left ventricle is characterized by a prolongation in the systolic pre-ejection period and a diminution in the left ventricular ejection time while total electromechanical systole remains relatively unaltered. Both components of the pre-ejection period, the Q-1 interval and the isovolumic contraction time, were prolonged. These alterations in the phases of systole occur in the absence of a measurable change in ventricular depolarization time. The prolongation in the pre-ejection period is well correlated with the reduced stroke volume and cardiac output in heart failure and is independently augmented by high levels of arterial pressure. The abbreviation in left ventricul...
1,272 citations
TL;DR: The evidence presented supports the hypothesis that the positive inotropic response to the catecholamines is mediated by cyclic AMP.
Abstract: Cyclic AMP (adenosine 3',5'-monophosphate or cyclic adenylate) has now been established as a second messenger mediating many of the effects of a variety of hormones. Several of the metabolic effects mediated by cyclic AMP are discussed, and it is suggested that certain other ("functional" or "mechanical") hormonal effects may be similarly mediated. In particular, the evidence presented supports the hypothesis that the positive inotropic response to the catecholamines is mediated by cyclic AMP. Although knowledge of the biological role of cyclic AMP has not been widely applied clinically, sufficient knowledge has now accumulated to make research in this area desirable.
980 citations
TL;DR: Blood lipids, red cell volume, heart volume, dynamic spirometry, electrocardiograms made at rest and during exercise, and maximal oxygen uptake were determined in 29 former athletes 45 to 70 years old that had been very successful competitors in endurance events before the age of 30.
Abstract: Blood lipids, red cell volume, heart volume, dynamic spirometry, electrocardiograms made at rest and during exercise, and maximal oxygen uptake were determined in 29 former athletes 45 to 70 years old. The subjects had been very successful competitors in endurance events before the age of 30, but for at least 10 years preceding this study had been sedentary. Maximal oxygen uptake averaged 40 ml/kg/min which is 20% higher than that of sedentary middle-aged men but 25% lower than that of still active athletes of the same ages. Vital capacity, forced expiratory volume, and maximal voluntary ventilation showed normal values. Heart volume was large in relation to maximal oxygen uptake and was of the same magnitude as in still active athletes. Red cell volume was also large in relation to maximal oxygen uptake, but normal in relation to the body weight. Cholesterol in serum averaged 260 mg/100 ml. Values for neutral fat averaged 1.6 mM, which was higher than that for still active athletes. In the athletes still...
947 citations
Journal Article•
768 citations
TL;DR: The clinical courses of 126 patients with hemodynamically documented IHSS, examined repeatedly for up to 12 years, were analyzed, and the patients who were asymptomatic initially tended to remain so, while those who were more disabled generally deteriorated, died, or improved spontaneously.
Abstract: While considerable information concerning the hemodynamic and angiographic features of idiopathic hypertrophic subaortic stenosis (IHSS) is available, data concerning the natural history of the disease are limited. The clinical courses of 126 patients with hemodynamically documented IHSS, examined repeatedly for up to 12 years, were analyzed. The older patients tended to be more severely symptomatic. Although the course was extremely variable, the patients who were asymptomatic initially tended to remain so, while those who were more disabled generally deteriorated, died, or improved spontaneously. Bacterial endocarditis occurred in three patients. Ten patients died as a consequence of the natural history of IHSS; six of these deaths were unexpected. Sudden deaths occurred usually in patients with no or mild obstruction, and in patients with both the familial and sporadic forms of the disease. Atrial fibrillation was observed in 8% of the patients, and abnormalities of atrioventricular conduction, in 30%....
675 citations
639 citations
TL;DR: Although the greatest surgical therapy experience has been with obliteration of the anomalous left coronary artery at its connection with the pulmonary artery, anastomosis between aorta and ALCA provides an additive supply for both the present and the future.
Abstract: The congenital anomaly in which the left coronary artery arises from the main pulmonary artery is infrequent, but lethal, and since it can be alleviated surgically, its recognition and hemodynamic consequences are important. On the basis of 140 reported cases and our seven cases, it seems to present in one of four ways: (1) in infancy with angina-like symptoms or as cardiomyopathy, and later (2) as mitral insufficiency, (3) continuous murmur, or in adults (4) by sudden death. Visualization of the coronary arteries provides the definitive diagnosis, and the problem is the selection for this procedure. The electrocardiogram, the most helpful laboratory aid, is diagnostic of infarction in 80% of the infant group; in the remainder other forms of cardiomyopathy may be confused. Although blood flows directly into the pulmonary artery in the majority of cases, it flows in the reverse direction in a few and this must be determined preoperatively. Some unanswered questions are the subject of discussion: Why the ma...
605 citations
TL;DR: Surgical transection of the atrioventricular junction at that point abolished the electrocardiographic features of WPW and the recurrent tachycardia, and five months after surgery the signs and symptoms of congestive heart failure have subsided, and the patient has returned to work.
Abstract: Recurrent supraventricular tachycardia is a frequent complication in patients with the Wolff-Parkinson-White (WPW) syndrome. Our patient was unusual in that the arrhythmia was the predominant rhythm, and it was felt that the sustained tachycardia was responsible for signs and symptoms of congestive heart failure. The arrhythmia could not be controlled adequately with digitalis, quinidine, diphenylhydantoin, or propranolol. Atrial or ventricular pacing also failed to prevent recurrent episodes of tachycardia. Physiological and pharmacological studies suggested that an anomalous pathway was responsible for the WPW abnormality and participated in a re-entrant circuit which sustained the episodes of tachycardia. Isopotential body surface mapping suggested anomalous ventricular excitation at the lateral aspect of the right atrioventricular groove. Epicardial mapping at the time of surgery was used to localize the earliest area of anomalous ventricular activation, and surgical transection of the atrioventricula...
368 citations
TL;DR: The multifactorial hypothesis is proposed as a working hypothesis which encompasses both the genetic and environmental factors known to participate in the etiology of congenital heart diseases.
Abstract: A systematic investigation into the etiology of congenital heart diseases (CHD) has been undertaken through the testing of four alternative hypotheses. Data was obtained for six common congenital heart lesions from the investigation of familial aggregates, twin studies, and chromosomal evaluations. Animal homologies were also considered in the evaluation of the hypotheses. Hypothesis 1—no genetic basis for the etiology of congenital heart diseases—was tested and rejected. Then in an effort to define the possible genetic basis of congenital cardiovascular malformations hypothesis 2—the genetic basis of CHD is determined by gross chromosomal aberrations—was evaluated by reviewing karyotypes of nonsyndrome CHD patients in the literature as as well as 104 personal cases. Rejection of hypothesis 2 is required by all available evidence. Hypothesis 3—the genetic basis of common isolated congenital heart lesions is determined by single mutant genes—was also tested and rejected. Hypothesis 4—congenital heart disea...
317 citations
TL;DR: A series of 128 consecutive cases of atrial septal defect in adult patients was analyzed from the standpoint of the course and prognosis, revealing significant pulmonary hypertension in 22% of the series, of which 15% had high pulmonary vascular resistance, and significant arterial hypoxemia.
Abstract: A series of 128 consecutive cases of atrial septal defect in adult patients was analyzed from the standpoint of the course and prognosis. The ages of the patients ranged from 18 to 67 years and the ratio of men to women was 1 to 2. Age distribution when compared with life expectancy tables indicated reduced life expectancy. Clinical analysis revealed that three quarters of the patients were symptomatic, but symptoms were mild to moderate and usually nonprogressive. Hemodynamic analysis revealed significant pulmonary hypertension in 22% of the series, of which 15% had high pulmonary vascular resistance, and significant arterial hypoxemia in 14%. The most serious risk factor in atrial septal defect is severe pulmonary hypertension. This complication, which develops in about 14% of patients with atrial septal defect when they are between 20 and 40 years of age, may be rapidly progressive, leading to shunt reversal, disability, and death. Once established, pulmonary hypertension may progress even when the def...
299 citations
TL;DR: Pressures and pulse waves provide a sensitive method for diagnosis and follow-up of patients with AOD and indicate that the majority of limbs with Aod had abnormally prolonged CT and WD.
Abstract: Measurements were carried out in 146 limbs with angiographically documented arterial occlusive disease (AOD) and in 85 limbs without AOD. Ankle systolic pressure (AP) was equal to or higher than brachial systolic pressure in limbs without AOD. It was below 82% of the brachial in all limbs with complete occlusion, usually below 50% in those with multiple occlusions, and above 50% in limbs with single block. AP was below normal in 19 of 25 limbs with severe and in five of nine with mild stenosis. All limbs with complete occlusion and 14 of 16 with stenosis had abnormal pressures in the thigh. The foot-to-peak time (CT) and the width of pulse waves at half amplitude (WD) were related to heart rate in normal limbs. Considering the heart rate, the majority of limbs with AOD had abnormally prolonged CT and WD. Normal pressures and pulse waves were found together in only two limbs with stenosis and symptoms. The findings indicate that pressures and pulse waves provide a sensitive method for diagnosis and follow-...
TL;DR: A congenital constriction of the aorta in the distal part of theAortic arch, usually in the isthmus region and close to the site of insertion of the ductus arteriosus, is a congenital condition.
Abstract: Coarctation of the aorta is a congenital constriction of the aorta in the distal part of the aortic arch, usually in the isthmus region and close to the site of insertion of the ductus arteriosus.
TL;DR: Patients with occasional elevation of blood pressure have an abnormal peripheral resistance in relation to cardiac output both at rest and at low levels of exercise, which may indicate a prehypertensive state.
Abstract: Ninety-four patients with occasionally elevated (borderline) blood pressure, 61 patients with asymptomatic established hypertension, and 63 normal subjects have been studied at rest and during a progressive exercise test on a cycle ergometer. Subjects with borderline blood pressure had increased cardiac output in the resting recumbent position, but this was not maintained in the sitting position or during exercise. In the resting recumbent position there was overlap in the total peripheral resistance of normal subjects and patients with borderline blood pressure, but when analyzed in relation to the cardiac output, the total peripheral resistance of patients with borderline blood pressure was significantly elevated. In the sitting position the peripheral resistance of the patients with borderline blood pressure was elevated and remained elevated during light exercise, but fell into the normal range at higher loads. In this respect patients with borderline blood pressure differed from hypertensive patients...
TL;DR: The effects of long-term treatment with propranolol, a beta-adrenergic blocking drug, were determined in 19 hypertensive patients whose vascular disease was of mild to moderate severity.
Abstract: The effects of long-term treatment with propranolol, a beta-adrenergic blocking drug, were determined in 19 hypertensive patients (five with renal arterial disease, two with renal parenchymal disease, and 12 with essential hypertension) whose vascular disease was of mild to moderate severity. The drug reduced arterial pressure in 16 patients during 32 weeks of treatment (average); daily dose was 180 mg (average). No side effects required discontinuance of treatment. Orthostatic hypotension did not occur, an unusual finding for an antihypertensive drug which acts to inhibit autonomic neural function. In seven patients, hemodynamic studies, performed during treatment (after 10 months, average), confirmed reduction of arterial pressure and heart rate, and demonstrated associated diminution of cardiac output and increased peripheral resistance.
TL;DR: It is concluded that estimates of stress on aortic and cerebral vessel walls and central baroreceptors would be grossly overestimated by use of peripheral pulse pressures.
Abstract: Blood pressures were recorded simultaneously from the aortic arch and radial artery using two manometric systems with identical static and dynamic sensitivities. Measurements were made in four normal young men at rest and upright exercise requiring 29, 49, 78, and 100% of maximal oxygen uptake. Average radial arterial pressure rose from 133/66 mm Hg at rest to 236/58 mm Hg at maximal exercise. At the same time, average aortic pressures were 112/68 and 154/70 mm Hg, respectively. From rest to maximal exercise, pulse pressures at central and peripheral sites increased by factors of 1.95 and 2.60, respectively. Inducing reactive hyperemia in the arm abolished peripheral amplification. This amplification also diminished with time during prolonged heavy exercise. Mean pressures were nearly identical at the two sites at any oxygen uptake; mean pressures rose from 87 to 104 mm Hg from mild to maximal exercise. We conclude that estimates of stress on aortic and cerebral vessel walls and central baroreceptors woul...
TL;DR: It is concluded that two of the major mechanisms responsible for the hypotension of vasovagal syncope initiated by orthostasis or lower body negative pressure are bradycardia and dilatation of the resistance vessels.
Abstract: Withdrawal of sympathetic tone to the veins resulting in peripheral pooling of blood has been suggested as an important factor contributing to the decrease in cardiac output and hence arterial pressure that occurs during vasovagal syncope. However, no measurements of venous tone during syncope have been reported. In the course of other studies on the circulatory effects of negative pressure below the iliac crests, and 80° head-up tilt, vasovagal reactions occurred in 10 subjects. Heart rate, central venous pressure, arterial pressure, forearm blood flow, forearm vascular resistance, and forearm or hand venous tone were measured. The typical vasovagal reaction could be divided into two phases. A gradual fall in arterial pressure signified the onset of phase I, during which forearm vascular resistance did not change significantly. The duration of phase I was highly variable. The onset of phase II was denoted by an abrupt fall in arterial pressure and heart rate and a decrease of 62% in forearm vascular resi...
TL;DR: The results provide a rational basis for the induction of prophylactic anticoagulant therapy without large loading doses of warfarin and should reduce the danger of hemorrhage in patients who are sensitive to the drug because of advanced age, sepsis, liver disease, congestive heart failure, or recent surgery or trauma.
Abstract: Thirty normal subjects were given a single loading dose of warfarin sodium, 1.5 mg/kg of body weight. The drug was metabolized slowly (mean biological half-life, 47 hr) and showed a prolonged biological effect (over 6 days). In two separate experiments no loading dose was given; instead, daily doses of 15 mg and 10 mg were administered to 15 of the subjects. The prothrombin complex responses were compared with those obtained in the same subjects after the large loading dose. The mean time in days to reach the therapeutic range (prothrombin complex activity<35% of normal) was 1.1 days with the dose of 1.5 mg/kg of body weight, 2.7 days with the dose of 15 mg/day, and 5.2 days with 10 mg/day. With all three methods the therapeutic range was reached soon after a level of warfarin of 2 mg/L plasma was attained. The rates of fall of the four vitamin K-dependent clotting factors (II, VII, IX, and X) with the large loading dose and with the daily dosage of 15 mg were compared in six of the subjects. With the loa...
TL;DR: It is suggested that a history of syncope or dizziness in a patient with the above pattern may denote that episodes of transient heart block have occurred.
Abstract: The pattern of complete right bundle-branch block (RBBB) combined with abnormal left axis deviation is shown to be the predominant conduction abnormality during orthograde (antegrade) conduction in patients who have experienced transient or permanent complete heart block (59% of a series of 44 patients). Sequential records on the same patient are presented showing progressive development of the complete pattern from left parietal and peri-infarction block alone and also from RBBB with normal axis deviation. Underlying abnormality is a partial bilateral bundle-branch block, that is, complete RBBB and involvement of the anterior-superior subdivision of the left bundle. The incidence of this pattern in 5,500 consecutive hospital records was 1%. Of these, 10% manifested complete heart block. It is suggested that a history of syncope or dizziness in a patient with the above pattern may denote that episodes of transient heart block have occurred.
TL;DR: The sequence of events characterizing the onset and course of exercise-induced angina pectoris was studied in 10 patients with ischemic heart disease during cardiac catheterization and pathways occurring during angina are described.
Abstract: The sequence of events characterizing the onset and course of exercise-induced angina pectoris was studied in 10 patients with ischemic heart disease during cardiac catheterization. Exercise produced a precipitous rise in left ventricular end-diastolic pressure prior to the onset of angina and electrocardiographic ischemia. A corresponding abnormal increase in pulmonary artery pressure occurred. Cardiac output increased commensurate with the degree of exertion and was accompanied by a slight reduction in stroke volume. Left ventricular work and stroke work paralleled the changes in cardiac output and stroke volume. Determinants of myocardial oxygen consumption, that is, heart rate, left ventricular systolic pressure, and left ventricular first derivative, were monitored continuously and noted to increase by 43%, 20%, and 38%, respectively, prior to angina. Ischemic ST-segment depression corresponded closely in time with angina. Angina and electrocardiographic and hemodynamic abnormalities persisted throug...
TL;DR: It is concluded that there is an impairment of left ventricular filling in IHSS and that obstruction to ventricular inflow, as well as to outflow, contributes to the hemodynamic changes in this condition.
Abstract: In order to determine whether there is any interference with left atrial emptying or left ventricular filling in idiopathic hypertrophic subaortic stenosis (IHSS) and aortic stenosis, the fall in pressure (y descent) of the left atrial v wave following the opening of the mitral valve was analyzed in 27 patients with IHSS and in 22 patients with valvular aortic stenosis, and the results were compared to those for 13 normal subjects and 24 patients with mitral stenosis. The y descent in 0.1 sec and the mean rate of the y descent, as well as the maximum rate of decline, were reduced in all three groups of patients, as compared to those of the normal group. The changes in IHSS were more marked than those occurring in patients with aortic stenosis or mitral stenosis. These findings in patients with IHSS and valvular aortic stenosis appear to result from reduced left ventricular compliance. It is concluded that there is an impairment of left ventricular filling in IHSS and that obstruction to ventricular inflow, as well as to outflow, contributes to the hemodynamic changes in this condition.
TL;DR: Catecholamine depletion inhyperthyroid subjects with adequate administration of intramuscular reserpine induced no changes in cardiac output and oxygen consumption and caused no alteration in different phases of ventricular systole; consequently it had no effect on enhancement of hyperthyroid myocardial contractility.
Abstract: Although the circulatory changes in various thyroid states are well known, the alterations of myocardial contractility of hypothyroidism and hyperthyroidism have remained controversial. The changes in the length of the ejection time (ET) and isovolumic contraction time (ICT) are used as indicative of alterations in inotropic state of the myocardium. Isovolumic contraction time, ejection time, and pre-ejection period were measured externally in 10 normal, 13 hyperthyroid, and five hypothyroid subjects. Cardiac outputs, mean rate of left ventricular ejection index, and predicted ejection times were calculated. More shortening of ICT and ET in hyperthyroid and more prolongation of these intervals in hypothyroid subjects than could be attributed to other factors were interpreted as indicative of increased and decreased myocardial contractility, respectively. Catecholamine depletion in hyperthyroid subjects with adequate administration of intramuscular reserpine induced no changes in cardiac output and oxygen ...
TL;DR: In this article, immediate hemodynamic effects of beta-adrenergic blockade were determined in six normal subjects and 21 hypertensive patients following intravenous administration of propranolol.
Abstract: Immediate hemodynamic effects of beta-adrenergic blockade were determined in six normal subjects and 21 hypertensive patients following intravenous administration of propranolol. Arterial pressure was not reduced, but cardiac output fell by approximately 20% in both groups. Nevertheless, beta-adrenergic inhibition seemed to have different effects in the two groups: Propranolol produced a greater inhibition of chronotropic activity in the hypertensive patients, and of stroke volume in the normotensive individuals whose pretreatment heart rate was slower than that of the hypertensives. This difference suggests that chronotropic beta-adrenergic activity may be increased in hypertension but does not explain reduction in arterial pressure following oral treatment with propranolol.
TL;DR: Prolongation of the Q-T interval was a prominent electrocardiographic feature in both patients and is postulated to have resulted from a loss of intracellular potassium secondary to hypomagnesemia.
Abstract: Paroxysmal ventricular fibrillation unassociated with heart block occurred in two patients with hypomagnesemia. In neither patient were other causes of the arrhythmia apparent. Temporary transvenous pacing successfully suppressed the episodes after drug therapy failed. Prolongation of the Q-T interval was a prominent electrocardiographic feature in both patients and is postulated to have resulted from a loss of intracellular potassium secondary to hypomagnesemia.
TL;DR: A method of rapidly effective oral therapy of arrhythmias with diphenylhydantoin is described, and a method of transition from intravenous to oral therapy is demonstrated.
Abstract: The effect of diphenylhydantoin sodium (DPH, Dilantin) on a variety of arrhythmias was studied in relation to its plasma levels. DPH was administered in one of three ways: (1) multiple intravenous doses, (2) single intravenous doses, and (3) oral doses. Ventricular arrhythmias occurring in many clinical conditions and atrial tachycardia, particularly if caused by digitalis excess, responded well to treatment with DPH. Three fourths of the responsive arrhythmias were abolished at plasma levels of DPH of 10 to 18 µg/ml. In most cases a critical, effective plasma level could be demonstrated; this level had to be exceeded in order to suppress the arrhythmia being treated. A method of rapidly effective oral therapy of arrhythmias with diphenylhydantoin is described, and a method of transition from intravenous to oral therapy is demonstrated. The antiarrhythmic action of diphenylhydantoin was accompanied by neither depression of sinoatrial nodal activity nor atrioventricular or intraventricular conduction distu...
TL;DR: Recent clinical observations which strongly correlate abnormality of the BCG wave form with the onset of coronary heart disease are called into question and the implications of this finding are discussed.
Abstract: FROM THE early ballistocardiographic (BCG) studies of Starr there developed much hope that the technique would fill an important need in clinical cardiology. Unfortunately the technical deficiencies of certain early methods, their indiscriminate use, and thoughtless interpretation soon caused the method to become clinically discredited in the minds of many people. In spite of this, careful hemodynamic, biophysical and clinical studies continued and recent results of these should go far to reestablish ballistocardiography as a technique which can provide unique information.' 2 The purpose of this editorial is to call attention to recent clinical observations which strongly correlate abnormality of the BCG wave form with the onset of coronary heart disease and to discuss the implications of this finding.3 For years it has been known that the BCGs of healthy youths are monotonously similar, so much so that they have become accepted as the standard of normal wave form. Deviations from this wave form are seen in most but by no means all whose circulations are known to be abnormal. Between these extremes, there is a third group com-
TL;DR: All of the cases of abnormal pulmonary venous connections collected to the middle of 1965 and verified at surgery or autopsy have been reviewed by means of diagrams and tabulations, using a specially devised code to facilitate the survey.
Abstract: All of our cases of abnormal pulmonary venous connections collected to the middle of 1965 and verified at surgery or autopsy have been reviewed by means of diagrams and tabulations, using a specially devised code to facilitate the survey. The material consisted of 52 autopsy cases (half of them obtained after surgery) and the cases of 72 patients who survived operation. The postmortem group was much younger than the surgical group and differed also from the latter by showing male preponderance as well as relatively many instances of total abnormal pulmonary venous connection and frequently associated cardiac anomalies. Partial anomalous connection of right pulmonary veins was 10 times more frequent than that of the left pulmonary veins. This was caused by (1) the frequent drainage of some of the right pulmonary veins into the junctional area between right atrium and superior vena cava in the presence of normal left pulmonary veins, and (2) the complete absence of isolated left pulmonary venous connection to the right atrium. Abnormal connection of solitary pulmonary veins was always effected to the most proximal venous structure among the four possible ones which are derived from the main embryonic channels (superior vena cava and inferior vena cava on the right side, and left superior vena cava and coronary sinus on the left side). Common pulmonary veins from one lung also drained in accordance with this proximity rule, if this may be taken to apply also to the drainage of right pulmonary veins into the right atrium. The one exception in our material was the drainage of all right pulmonary veins into the portal venous system. Total abnormal pulmonary venous connection may be found with all structures mentioned, but most frequently with the left superior vena cava, or coronary sinus, or both, usually by way of a common pulmonary vein. In a few cases however, drainage into different sites, all of them abnormal, did occur. Then again the proximity rule seemed to apply. A tentative embryological explanation is given for the patterns described.
TL;DR: An hypothesis is formulated which attributes the cobalt toxicity in chronic alcoholics, to a dietary deficiency of sulfhydryl-groups containing amino acids and a dietary deficiencies of protein.
Abstract: The natural history of a new disease entity in chronic beer drinkers consisting of pericardial effusion, a low cardiac output, and in about half of the cases of polycythemia is presented. Normalization of the heart volume, the hemoglobin value, and the hemodynamic state was obtained in patients who stopped drinking. Further evidence of the importance of cobalt in the development of the disease is presented. All patients drank beer to which cobalt was added and the disease was not seen in chronic alcoholics drinking wine or other alcoholic beverages. In view of the rather small quantity of cobalt consumed, an hypothesis is formulated which attributes the cobalt toxicity in chronic alcoholics, to a dietary deficiency of sulfhydryl-groups containing amino acids and a dietary deficiency of protein.
TL;DR: The observations of Mahaim,4 Yater and associates,5 Lev and Unger,6 and Lenegre and Moreau7 strongly suggest that bilateral bundle-branch block may be the usual anatomic substrate of type II A-V block.
Abstract: THE USE OF artificial pacing has greatly intensified interest in chronic A-V block. This interest, in turn, has brought into sharp focus the rare type of A-V block described independently in 1906 by Wenckebach' and by Hay2 and classified by Mobitz in 1924 as type 11.3 This type of block is characterized by failure of a ventricular response, without antecedent progressive lengthening of A-V conduction time. Furthermore, in its more advanced form several consecutive atrial impulses are blocked, giving rise to high degree partial block and to intermittent periods of prolonged ventricular asystole. Although Mobitz had appreciated the distinction between the functional nature of type I and the organic nature of type II block and had stated clearly that type II block was apt to be a forerunner of complete A-V block and Stokes-Adams attacks, it is surprising how the distinction between the genesis and prognosis of these two types of block has become blurred in clinical electrocardiography. Although a definitive anatomic-electrocardiographic study that would relate type II block to a particular anatomic lesion is still missing, the observations of Mahaim,4 Yater and associates,5 Lev and Unger,6 and Lenegre and Moreau7' 8 strongly suggest that bilateral bundle-branch block may be the usual anatomic substrate of type II A-V block. Recent
TL;DR: Photographs and a geometric horizontal plane diagram of the original Taussig-Bing heart' are published here for the first time at the suggestion of the editors and with the kind permission of Dr. Dio-drast.
Abstract: IN 1949, under the title \"complete transposition of the aorta and a levoposition of the pulmonary artery,\" Taussig and Bing' presented the clinical, physiological and pathological findings in a 52-year-old white girl, cyanotic from birth, who died 3 minutes after a third injection of iodopyracet (Dio-drast) for angiocardiography. During the subsequent two decades, a controversy arose concerning the pathological criteria for this diagnosis.2 6 The question became: What, in fact, is the Taussig-Bing malformation? In an endeavor to resolve this persisting controversy, photographs and a geometric horizontal plane diagram of the original Taussig-Bing heart' are published here for the first time at the suggestion of the editors and with the kind permission of Dr. The original Taussig-Bing heart' (fig. 1) may be summarized as a double-outlet right ventricle with semilunar valves side-by-side and approximately at the same height, a bilateral conus, and a subpulmonary ventricu-lar septal defect (VSD).
TL;DR: In this paper, a patient with a large congenital aneurysm or diverticulum of the right atrium caused repeated attacks of supraventricular arrhythmia and a strikingly reduced cardiac output.
Abstract: A patient is described in whom a large congenital aneurysm or diverticulum of the right atrium caused repeated attacks of supraventricular arrhythmia and a strikingly reduced cardiac output. The aneurysm, which contained a large thrombus, was demonstrated by preoperative angiographic examinations. At the time of operation, regular rhythm returned at the moment the aneurysm was transsected. The patient is asymptomatic after operation, and has maintained sinus rhythm. A normal cardiac index was recorded at postoperative cardiac catheterization.