bluuebunny/crossref_metadata_2025 huggingface dataset:
Serum lipoprotein profile in children from a biracial community: the Bogalusa Heart Study.
Authors: Srinivasan S R , Frerichs R R , Webber L S , Berenson G S
Published: June 2012

Serum lipoprotein profiles in 3182 children, ages 5-14 years, were studied in a biracial community as part of the Bogalusa Heart Study to describe the early natural history of atherosclerosis. White and black children showed similar mean levels of beta-lipoproteins. Pre-beta-lipoprotein levels, however, were significantly higher in white shildren, while significantly higher levels of alpha-lipoprotein were found in black children. Girls had generally higher levels of beta- and pre-beta-lipoprotein and lower levels of alpha-lipoprotein than boys, although the differences were not significant at each age group. With age there was little change in alpha-lipoprotein levels, a significant increase in pre-beta-lipoprotein levels and a slight but significant decrease between 11 and 14 years in beta-lipoprotein levels. The correlation of alpha-lipoprotein was negative with beta-lipoprotein and, to a greater extent, with pre-beta-lipoprotein. The above inverse relationships were significantly greater in white children than in black children, suggesting differences in lipoprotein profiles in the two groups. Lipoprotein values from a total community study are now available for comparison with the currently recommended upper normal limits for lipoproteins. Since only a very small percentage of children could be considered as hyperlipoproteinemic by those specific levels in this community, we suggest that distributions and percentiles be used to evaluate children for hyperlipoproteinemia.
Toward preventing coronary death from ventricular fibrillation.
Authors: Julian D G
Published: June 2012

Sudden coronary death from ventricular fibrillation is the biggest and possibly the most remediable of the major public health problems at the moment. Most of those liable to sudden death can be identified and it is possible that by the use of beta-adrenergic blocking or other antiarrhythmic drugs, by reducing the consumption of cigarettes and perhaps, by different therapies for hypertension, a substantial proportion of coronary deaths might be prevented or, at least, postponed.
Myocardial blood flow in congestive and hypertrophic cardiomyopathy: relationship to peak wall stress and mean velocity of circumferential fiber shortening.
Authors: Weiss M B , Ellis K , Sciacca R R , Johnson L L , Schmidt D H , Cannon P J
Published: June 2012

Myocardial blood flow/unit mass (MBF) and the determinants of myocardial oxygen consumption were measured in seven control subjects (group I) and 15 patients (pts) with cardiomyopathy (CM), group II (group IIa-congestive CM: 10 pts; group IIb-hypertrophic CM: 5 pts). In group I left ventricular (LV) MBF was 64 +/- 8 (SD) ml/100g-min; it was significantly lower in IIa (45 +/- 15 ml/100g-min, P less than 0.01) and IIb (39 +/- 7 ml/100g-min, P less than 0.01). However, calculated total LV flow (LV mass X MBF) was increased in the two CM groups. In nine CM pts, LV MBF increased in response to atrial pacing from 41 +/- 7 to 63 +/- 13 ml/100g-min. In group IIa, calculated peak wall stress was normal (4.39 +/hortening (MVcf) was significantly reduced (0.53 +/- 0;18 vs 1.26 +/- 0.12 circum/sec, P less than 0.01). In IIb, MVcf was normal but peak stress was significantly reduced (2.80 +/- 0.75 vs 4.51 +/- 1.10 dynes/cm2 X 10(5), P less than 0.05). Multiple regression analysis based on all pts yielded, MBF - 16.9 MVcf + 9.30 Stress + 0.26 Heart Rate - 26.4 (r=0.79). The data indicate that MBF is reduced in CM patients and the regression analysis suggests that MBF in these 22 pts with normal coronary arteriograms was determined largely by heart rate, peak stress, and ventricular performance.
Nitroglycerin-induced severe hypotension and bradycardia in patients with acute myocardial infarction.
Authors: Come P C , Pitt B
Published: June 2012

Seven episodes of simultaneous severe systemic arterial hypotension and absolute or relative bradycardia were observed in five patients receiving either sublingual nitroglycerin (two patients) or intravenous nitroglycerin (three patients) within the first 24 hours of onset of symptoms of acute myocardial infarction. Left ventricular filling pressure, measured as pulmonary artery diastolic pressure, decreased simultaneously in all four patients in whom pulmonary artery pressures were monitored. No initial increase in heart rate was observed in any of the five patients prior to the development of bradycardia. Possible mechanisms producing simultaneous bradycardia and hypotension during nitroglycerin administration are considered. The patient studies emphasize the importance of careful hemodynamic monitoring during administration of sublingual or intravenous nitroglycerin to patients with acute myocardial infarction.
Stress testing with ST-segment depression at rest. An angiographic correlation.
Authors: Kansal S , Roitman D , Sheffield L T
Published: June 2012

Near maximal graded exercise tests and coronary angiograms were compared in 37 patients with a history of chest pain and with ST segment depression at rest, who were free of obvious nonischemic causes of ST depression. Additional ST depression of 0.1 mV or more occurred with exercise in 26 patients and 23 of these had obstruction of one or more coronary arteries (sensitivity = 0.92). Eleven patients showed no additional ST-segment depression with exercise, and nine of these had normal coronary angiograms (specificity = 0.75). Patients with no increase in ST depression on exercise developed the highest heart rates; those with asymptomatic additional ST depression achieved intermediate rates; and those with anginal attacks during testing demonstrated the least heart rate acceleration. Those with less coronary obstruction exercised longer on the treadmill than those with more obstruction. Those showing added ST depression were predominantly men (18 of 26) and were older (mean 54 years) than those who did not (mean 44 years). No test complications were encountered. This study suggests that safe and effective stress testing may be accomplished not only in persons with normal resting ECGs but also in selected patients who have abnormal ST segments at rest.
The posterior aortic wall echocardiogram. Its relationship to left atrial volume change.
Authors: Strunk B L , Fitzgerald J W , Lipton M , Popp R L , Barry W H
Published: June 2012

The normal posterior aortic wall echocardiogram shows anterior motion during left ventricular systole and predominantly posterior motion in three phases during left ventricular diastole. In six patients undergoing simultaneous left atrial angiograms and posterior aortic wall echocardiograms, there was excellent correlation between the posterior aortic wall motion and the change in the left atrial angiographic area showing the value of the posterior aortic wall echocardiogram in describing the left atrial volume curve. Left atrial and left ventricular pressures were measured with manometer tip catheters and correlated with simultaneous posterior aortic wall and mitral valve echocardiograms in four patients with atrial septal defects. These echocardiographic, angiographic, and hemodynamic correlations, as well as other evidence reported in this paper suggest that a major portion of posterior aortic wall motion is related to left atrial events and describes the left atrial volume curve.
Effects of procainamide and quinidine sulfate in the Wolff-Parkinson-White syndrome.
Authors: Sellers T D , Campbell R W , Bashore T M , Gallagher J J
Published: June 2012

Thirty-three patients with Wolff-Parkinson-White syndrome were studied electrophysiologically before and after administration of intravenous procainamide and oral quinidine sulfate. Procainamide prolonged the shortest R-R (SRR) interval between two consecutive pre-excited beats during atrial fibrillation 20-70 msec in 15 of 21 patients with no change observed in 6 of 21 patients. Quinidine sulfate prolonged the SRR 20-170 msec in all 16. In 14 of 18 patients where procainamide and quinidine were comparable, quinidine prolonged the SRR 30-100 msec more than procainamide.
Temporary inhibition of permanently implanted demand pacemakers.
Authors: Latif P , Ewy G A
Published: June 2012

Temporary inhibition of permanently implanted demand pacemakers has been previously described. Demand pacemakers may be inhibited by waving a magnet over the region of the pacemaker generator or by chest wall stimulation. The former may not inhibit most of the bipolar pacemakers, whereas the latter may be time consuming and may casue patient discomfort. Another method is described which utilized a commercially available Cordis Omnicor Programmer, Model 166-B, to temporarily inhibit bipolar and unipolar pacemakers. By placing the programmer over the skin where the pacemaker generator is implanted and/or over the area of the subcutaneous pervenous lead and activating the programmer multiple times at a rate faster then the pacing rate, the demand pacemakers are inhibited. After testing the efficacy in vitro, the method was successfully tried on 45 patients. Fifteen of these patients had unipolar pacemakers. Pacemakers marketed by Medtronic, Cordis, Starr-Edwards, C.P.I., and Arco were tested. Temporary inhibition of permanent demand pacemakers is desirable under various clinical situations. The method herein described has the advantages of being simple, quick, painless, and is effective for both unipolar and bipolar pacemakers.
Body surface potential distribution following the production of right bundle branch block in dogs. Effects of breakthrough and right ventricular excitation on the body surface potentials.
Authors: Sugenoya J , Sugiyama S , Wada M , Niimi N , Oguri H
Published: June 2012

Right bundle branch block (RBBB) was produced in five dogs by incising the main right bundle branch. Body surface isopotential maps of each of these dogs were obtained from 85 thoracic electrocardiograms using a mini-computer technique. In addition, the epicardial activaton process was obtained from the same dog, and were correlated with the map pattern. Following the incision, the following characteristic changes in the map pattern occurred: The ventricular activation was prolonged in RBBB as compared with normal. During the early stage of ventricular excitation, the maximum was shifted leftward due to the activation wavefronts in the left ventricle in contrast to the double septal activation in the control. A localized lower potential area (a concavity) which appears in the middle stage of activation within the anterior positivity as an initial representation of breakthrough was also shifted left-and-downward and delayed in appearance. The sudden change in the potential distribution subsequently observed occurred quite differently. The terminal excitation was characterized by the maximum occurring over the right chest in RBBB in contrast to the left chest in control. These changes in the pattern of the potential distribution were compatible with the changes in the ventricular excitation process. This result may be applied to human RBBB map interpretation.
Quantitative analysis of exercise electrocardiograms and left ventricular angiocardiograms in patients with abnormal QRS complexes at rest.
Authors: Simoons M L , Van Den Brand M , Hugenholtz P G
Published: June 2012

The ECG changes during exercise are described in 71 patients with a previous anteroseptal or anterolateral infarction (ANT-MI) and in 73 patients with an old posterior or inferior wall infarction (INF-MI). Left ventricular angiograms in 95 patients yielded a good correlation between areas of dyssynergy and the QRS pattern at rest. The ST changes in patients with coronary artery disease and a normal ECG at rest, and in normal subjects, were oriented toward the right, posteriorly and superiorly. In patients with INF-MI and inferior wall dyssynergy, the ST changes were more inferiorly oriented. Anteriorly-oriented ST changes were associated with anterior wall or apical dyssynergy and with ANT-MI. Thus the spatial direction of the ST changes during exercise is related to three independent factors: those factors which cause the ST changes in normal subjects, the degree of myocardial ischemia in that particular case, and the extent of dyssynergic areas in the wall of the left ventricle.
Correlation of postmortem anatomic findings with electrocardiographic changes in patients with myocardial infarction: retrospective study of patients with typical anterior and posterior infarcts.
Authors: Savage R M , Wagner G S , Ideker R E , Podolsky S A , Hackel D B
Published: June 2012

This retrospective study correlates electrocardiographic and histopathologic findings in 24 patients with single well-circumscribed infarcts to determine 1) whether ECG terms commonly used to describe the location of myocardial infarcts are significant, and 2) whether the extent of infarct can be determined using QRS characteristics. Transverse sections of the hearts were photographed. Based on histologic sections, the infarct was outlined on the photograph and each section was planimetered via a sonic digitizer into a computer that was programmed to divide the left ventricle into 8 radial sectors and also into basal, mesial, and apical thirds. The percentage of infarct in each of these areas was then calculated. Of the 24 hearts evaluated 12 had posterior infarcts and 12 had anterior infarcts. Posterior infarcts principally involved the basal and mesial levels, whereas the anterior infarcts were more extensive in the apical and mesial thirds, with relative or total sparing of the base. Posterior infarcts were associated with Q waves in leads II, III and aVF in 11 instances. The other posterior infarct was associated with markedly diminished R waves in leads II, III and aVf in the presence of a horizontal axis. All anterior infarcts were associated with Q waves or markedly diminished R waves in the right precordial leads. Eight of the anterior infarcts exhibited circumferential apical involvement and all eight were associated with Q waves or markedly diminished R waves in the left precordial leads. This study documents the electrocardiographic identification of anterior, posterior, and apical infarcts by correlation with pathologic anatomy.
Asymptomatic left ventricular aneurysm: a sequela of blunt chest trauma.
Authors: Berkoff H A , Rowe G G , Crummy A B , Kahn D R
Published: June 2012

A routine chest X-ray taken four months after blunt chest trauma revealed a left ventricular aneurysm in a totally asymptomatic patient. At surgery a thin-walled, clot-filled aneurysm was successfully removed. This case demonstrates the need for careful follow-up of all patients sustaining blunt chest trauma even though the initial cardiac evaluation may be negative. Our feeling that all such aneurysms should be treated surgically is further reinforced by our operative findings.
Status of the grafts and the native coronary arteries proximal and distal to coronary anastomotic sites of aortocoronary bypass grafts.
Authors: Spray T L , Roberts W C
Published: June 2012

The status of the native coronary arteries at necropsy in the vicinity of the coronary anastomoses of saphenous vein aortocoronary bypass grafts in 20 patients with severe coronary heart disease is presented. Of the 37 graft systems (graft plus coronary artery into which graft inserted) analyzed, the lumina of 44% of the native coronary arteries within the first 2 cm distal to the anastomoses were greater than 75% narrowed in cross-sectional area by atherosclerotic plaques, and the native coronary artery at the site of the anastomosis was greater than 50% narrowed in cross-sectional area already by atheroclerotic plaque in 25% of the graft systems. The mean coronary arterial size distal to the site of the coronary graft anastomosis, even after correction for heart weight, was greater in the 13 men than in the seven women. The residual luminal areas squared per gram of heart weight, however, were similar in both men and women. These results suggest that 1) relative coronary vessel size is greater in men than women; 2) the luminal area squared per gram myocardial mass (a relative estimation of flow) is the same in the two groups of patients; and 3) less atherosclerotic plaque is necessary in women then in men to produce similar limitation to coronary flow. Thus, vessel size alone cannot account for the higher reported frequency of unsuccessful aortocoronary bypass procedures in women.
Cryodynamic hand angiography in the diagnosis and management of Raynaud's syndrome.
Authors: Rösch J , Porter J M , Gralino B J
Published: June 2012

Cryodynamic hand angiography (CHA) with angiograms done before, just after, and during rewarming following hand immersion in ice water was performed in 39 patients with Raynaud's syndrome and eight volunteers without it. The normal response to cold stimulus was angiographically evident as mild, transient digital arterial constriction. Most of the patients with Raynaud's syndrome, in addition to organic obstructive disease, exhibited basal vasoconstriction and exaggerated persisting cryogenic vasospasm of the hand arteries. Similar angiographic studies done in 32 cases two days after the selective intra-arterial administration of reserpine revealed no differences in normal subjects but substantially decreased vasospasm in patients with Raynaud's syndrome. CHA with postreserpine studies was found to be diagnostically useful in Raynaud's syndrome, revealing the degree of organic arterial disease and functional vasospasm. In addition, correlation of postreserpine studies with observed clinical responses to long-term vasodilator drug therapy indicated that CHA has a good chance to predict the probable outcome of such therapy in Raynaud's syndrome.
Adipose hypocellularity in cyanotic congenital heart disease.
Authors: Baum D , Stern M P
Published: June 2012

Height, weight, total body fat, adipocyte size (cellular lipid content), total adipocyte number, and lean body mass were studied in two groups of similar aged children with congenital heart disease. One group was comprised of 19 children cyanotic from infancy. The second group was made up of 16 asymptomatic, acyanotic patients and served as the basis for age and sex adjusted comparisons. Cyanotic patients were lighter (P less than 0.001) and had less total body fat (P less than 0.001). Although there was no difference in adipocyte size, total adipocyte number was less in the cyanotic children (P less than 0.001), suggesting that the reduced body fat found with cyanosis is due to adipocyte hypocellularity. The additional observation that cyanotic patients were shorter (P less than 0.003) and had less lean body mass (P less than 0.001) than noncyanotic children implies that early hypoxemia produces widespread abnormalities which impair growth.
The pulsed Doppler coronary artery catheter preliminary report of a new technique for measuring rapid changes in coronary artery flow velocity in man.
Authors: Cole J S , Hartley C J
Published: June 2012

A new catheter which measures instantaneous changes in coronary artery blood flow velocity is described. The linear relationship between flow velocity is described. The linear relationship between flow velocity measured with the catheter and volume flow through small arteries is documented with a correlation coefficient of 4=0.99. Coronary flow velocity has been measured from the proximal right and left coronary arteries and aortic ostia of saphenous vein bypass grafts in patients undergoing diagnostic coronary arteriography. The increase in coronary flow following injection of contrast media in normal coronary arteries is similar to the increase in coronary flow reported following near-maximum exercise. This increased flow response following injection of contrast media is severly limited by coronary artery stenosis and may provide a useful method for assessing hemodynamically significant stenosis in patients with coronary artery disease.
The effect of propranolol on canine myocardial CPK distribution space and rate of disappearance.
Authors: Cairns J A , Klassen G A
Published: June 2012

Canine myocardial CPK was partially purified and injected into 11 conscious mongreal dogs. From serial serum CPK measurements in each dog, mean Kd was calculated as 0.0047 +/- 0.0009 (+/- SD) min-1. Correlation coefficients indicated that CPK disappearance rate was well described by a single exponential expression. Kd measured on consecutive days in four dogs varied minimally. CPK distribution space ranged from 74 to 134% of plasma volume. Propranolol loading with 0.3 mg/kg or 2 mg/kg, followed by hourly maintenance doses, resulted in increased Kd in eight of ten dogs, mean Kd rising from .0048 min-1 to .0059 min-1 (P less than 0.02). Propranolol appeared to increase plasma volume but had no significant effect on the relationship of CPK distribution space to plasma volume. If the serial CPK technique were used to measure infarct size, using an average Kd, propranolol might produce artifactual reduction of infarct size measuremnt by increasing Kd and possibly by increasing plasma volume. The obligation to assess the effect upon CPK Kd and distribution space of an agent designed to limit infarct size is apparent.
Asymmetric septal hypertrophy and myocardial fiber disarray. Features of normal, developing, and malformed hearts.
Authors: Bulkley B H , Weisfeldt M L , Hutchins G M
Published: June 2012

The specificity and significance of the asymmetric septal hypertrophy (ASH) and myocardial fiber disarray of idiopathic hypertrophic subaortic stenosis (IHSS) is uncertain. To examine this we studied 215 hearts, including normal embryos, fetuses, children, and adults; and hearts with congenital and acquired disease. Disproportionate septal thickening was present in all embryos and in some abnormal hearts, particularly those with severe right ventricular hypertrophy due to congenital malformations. Some myocardial fiber disarray was present in all hearts at the junctions of interventricular septum and ventricular free wall. In hearts with semilunar valve atresia with intact ventricular septums, and in the infundibulum of some with tetralogy of Fallot, however, extensive fiber disarray was present. Thus, ASH occurs in the normal developing heart and in some malformed hearts with RVH; marked muscle fiber disarray may occur in certain congenital lesions with abnormal systolic contraction. Neither morphologic finding independently or in combination is pathognomonic of idiopathic hypertrophic subaortic stenosis.
Effect of increased free fatty acids on myocardial oxygen extraction and angina threshold during atrial pacing.
Authors: Dagenais G R , Jalbert B
Published: June 2012

To evaluate whether elevated arterial free fatty acids (FFA) increase myocardial oxygen demand and ischemia, 15 fasting patients with coronary artery disease underwent a standardized atrial pacing test before (PTI) and during (PT2) heparin infusion. The patients were monitored for clinical and electrocardiographic (ECG) manifestations of ischemia. Myocardial extraction of lactate, inorganic phosphate, oxygen and FFA was measured before and during each PT. The control arterial FFA was 0.65 +/- 0.03 micromole/ml and rose to 1.83 +/- 0.16 micromole/ml during heparin influsion. Myocardial oxygen extraction at rest and during PT was not affected by the increase in arterial FFA. Seven patients asymptomatic during PT1 did not develop ischaemic manifestations during PT2. In eight patients with angina during both PTs, increased arterial FFA concentration did not modify the severity of anginal pain, the amount of ST-segment depression and the myocardial balance of lactate or inorganic phosphate. Elevation of arterial FFA by heparin neither increased myocardial oxygen extraction at rest or during pacing nor accentuated ischemic manifestations during PT.
A study of left ventricular function in coronary patients before and after physical training.
Authors: Letac B , Cribier A , Desplanches J F
Published: June 2012

Fifteen subjects recovering from a myocardial infarction or suffering from angina were given a maximum effort test on a bicycle ergometer and hemodynamic and angiographic investigations before and after a period of physical training. The training program consisted of three sessions of 60 to 75 min each week for two months. Maximum effort tests showed that physical capacity had increased by 17% (P less than 0.02) and that for the same amount of effort the heart rate had decreased by 13% and the blood pressure by 7% (P less than 0.01). Hemodynamic and angiographic investigations showed no significant changes after training in the left ventricular end-diastolic pressure, ventricular volume, ejection fraction, VCF, percentage of shortening and segmental contractility, in the total group, in those patients whose contractility was considerably impaired, or in those who had large dyskinetic areas or widespread akinesia. It is concluded that training had no direct influence on the myocardium, either beneficial or detrimental.
The conduction system in tricuspid atresia with and without regular (d-) transposition.
Authors: Bharati S , Lev M
Published: June 2012

This is a serial section examination of conduction system in six hearts with tricuspid atresia. Four had regular (d-) complete transposition and two did not have transposition. The conduction system was more or less the same in all the hearts. The atrioventricular (A-V) node was in the normal position posteriorly and was short. The A-V bundle was situated in the left ventricular aspect of the subendocardium and passed posteriorly to the ventricular septal defect. Even though this type of conduction system is abnormal in some respects, it is not the type one finds in single ventricle with small outlet chamber with regular (d-) transposition. In those hearts an anteriorly located A-V node is present. These findings further substantiate the concept that tricuspid atresia with or without transposition is not a form of single (primitive) ventricle.
Clinical primary pulmonary hypertension: three pathologic types.
Authors: Edwards W D , Edwards J E
Published: June 2012

Clinically, there is a group of patients with elevated pulmonary arterial pressure in whom the underlying cause is not apparent. The pulmonary arterial wedge pressure is not elevated. For such cases, the designation of primary pulmonary hypertension may be made clinically. From the clinical categorization of primary pulmonary hypertension, three distinct pathologic entities emerge, namely 1) plexogenic pulmonary arteriopathy, 2) recurrent pulmonary thromboembolism, and 3) pulmonary veno-occlusive disease. The plexogenic type is characterized initially by pulmonary arterial vasoconstriction with medial hypertrophy. Secondary proliferative intimal lesions, including the plexiform lesion, develop. Recurrent pulmonary thromboembolism is characterized by the presence of arterial thrombi of varying ages involving the microscopic-sized pulmonary arteries. Thrombi may be embolic in nature or may develop in situ. Pulmonary veno-occlusive disease is characterized by obstructive lesions of pulmonary veins and venules. The clinical presentation of the three pathologic types may be so similar that definitive diagnosis depends upon histologic examination of the lung from tissue obtained either by biopsy or at necropsy.
The evolution of peripartal heart failure in Zaria, Nigeria. Some etiologic factors.
Authors: Fillmore S J , Parry E H
Published: June 2012

The subsequent course of 173 women with severe congestive heart failure hospitalized within 6 months of delivery has been analyzed after 4 to 7 year follow-up periods. Forty-seven normotensive women and 50 women hypertensive only during the initial 48 hours have little long term morbidity. Thirty-six women with hypertension initially improved, but many are now showing enlarging cardiac silhouettes. Morbidity is increasing in this group. A similar, less severe pattern is developing in 36 women with intermittent hypertension. The uniquely high incidence of this condition in Zaria is associated with several locale factors. These Hausa-Fulani women eat large quantities of a local lake salt, kanwa, for 40 days postpartum. The syndrome is markedly more common in the hot rainy season, when evaporative water loss is less, than in the dry season. The first postpartum days are spent confined to bed in a small heated room. Once or twice daily the new mother is given hot baths with branches which have been dipped in boiling water. The combination of excessive sodium intake and diminished evaporative water excretion seems to precipitate failure in both normotensive and hypertensive patients.
Myocardial consequences of coronary artery bypass graft surgery. The paradox of necrosis in areas of revascularization.
Authors: Bulkely B H , Hutchins G M
Published: June 2012

Myocardial infarction after coronary artery bypass graft (CABG) surgery has been described clinically in up to 30% of patients but there is little morphologic information about the character and pathogenesis of the myocardial injury. We studied myocardium in the distribution of bypassed and nonbypassed coronary arteries for the presence of contraction band necrosis as compared to coagulation necrosis, in 58 autopsied patients who died less than 1 month after surgery. Operation related necrosis consisting of focal subendocardial contraction band necrosis was present to some degree in 48 (83%) patients. Regional transmural necrosis was present in 22 (38%) patients and was of two types. Contraction band necrosis occurred in 18 patients and was in the distribution of a patent bypassed coronary artery in 15 of them. Coagulation necrosis was found in four patients, and in each was in the distribution of a new graft-releated coronary artery occlusion. The results suggest that coronary artery reflow through widely patent grafts following the period of operative nonperfusion, rather than graft or intrinsic coronary artery occlusion, accounts for the majority of operation-related myocardial "infarcts" associated with CABG surgery. Thus, prevention of intraoperative myocardial injury must also focus on characteristics of the phase of myocardial reperfusion.
Left ventricular function before and following aortic valve replacement.
Authors: Kennedy J W , Doces J , Stewart D K
Published: June 2012

Twenty-four patients with aortic valve disease were studied before and 19+/-12 months following valve replacement with a well functioning prosthesis. Biplane left ventricular angiography and pressures were utilized to determine end-diastolic volume/m2 (EDV), end-systolic volume/m2 (ESV), ejection fraction (EF), left ventricular mass/m2 (LVM) and stroke work (SW). There were nine patients with aortic stenosis (AS), ten patients with combined stenosis and regurgitation (AS-AR), and five patients with aortic regurgitation (AR). Following surgery, patients with regurgitation preoperatively showed marked regression in EDV and ESV. All groups demonstrated regression in LVM. Fifteen patients with a normal EF preoperatively (65+/-11%) had no change after surgery; the nine patients with a low EF before surgery (38+/-8%) had a normal EF after surgery (60+/-16%). We conclude that left ventricular dilatation, hypertrophy, and reduced left ventricular pump function are largely reversible after successful aortic valve replacement.
The utility of contrast echocardiographic techniques in the care of critically ill infants with cardiac and pulmonary disease.
Authors: Sahn D J , Allen H D , George W , Mason M , Goldberg S J
Published: June 2012

In order to assess the utility of contrast M-mode echocardiography in an intensive care nursery population of critically ill newborns with cardiac and pulmonary disease and to validate contrast echo methods, we performed 200 serial contrast echoes on 40 infants via umbilical arterial or venous catheters which had been placed into these infants for clinical indications. The resulting contrast echoes recorded from the precordium or the suprasternal notch allowed the delineation of intra- and extracardiac right-to-left and left-to-right shunting patterns. Patterns identified and validated by cardiac catheterization (in cardiac patients) were: right-to-left atrial shunts, right-to-left ventricular shunts, and left-to-right patent ductus arteriosus shunts. The studies were without complication. Serial application of these echocardiographic techniques was extremely important in assessing changing physiology in these neonates. Contrast echocardiography adds physiologic flow information to the anatomical information available from M-mode echoes and is quite important in the diagnosis and sometimes in the management of critically ill newborns.
Suppression of ventricular ectopic depolarizations by tocainide.
Authors: Woosley R L , McDevitt D G , Nies A S , Smith R F , Wilkinson G R , Oates J A
Published: June 2012

In a previous clinical study we demonstrated that tocainide is effective in the suppression of ventricular ectopic depolarizations (VEDs) after single oral doses. This information provided the basis for evaluating this drug's antiarrhythmic efficacy after multiple dose administration according to a loading-maintenance regimen. Twelve patients with stable VEDs were given loading doses of tocainide (400-600 mg) with maintenance doses every 12 hours. Every 48 hours the dose was increased until either arrhythmia suppression to less than 25% of VED frequency during placebo administration or side effects occurred. Computer analysis of 12-hr telemetric ECGs taken 24-36 hr after each dosage increment documented effective suppression (76-95%) in 8 of 12 patients. Those subjects demonstrating suppression were randomly assigned to a cross-over study of placebo or active drug at the dosage found effective in the dose-ranging phase. Dosages for the cross-over stage ranged from 400 to 1100 mg every 12 hours. Comparison of the two five-day periods documented suppression in these patients (mean +/- SE = 83.3 +/- 4%). No serious side effects or undue drug accumulation occurred during the study. The data indicate that tocainide can effectively suppress VEDs for 8-12 hours in many patients and that continuous suppression could be possible on an 8-12 hr dosage regimen.
Myocardial perfusion scintigraphy in patients with mitral valve prolapse: Its advantage over stress electrocardiography in diagnosing associated coronary artery disease and its implications for the etiology of chest pain.
Authors: Massie B , Botvinick E H , Shames D , Taradash M , Werner J , Schiller N
Published: June 2012

Patients with mitral valve prolapse (MVP) frequently experience chest pain which may, expecially in older subjects and males, be difficult to differentiate from angina pectoris. Electrocardiographic (ECG) changes, ventricular arrhythmias, metabolic abnormalities and rare reports of myocardial infarction and sudden death further suggest the presence of an ischemic process in these patients. The recognition of accompanying coronary artery disease (CAD) and exclusion of other causes of ischemia, therefore, may be important in determining the prognosis and appropriate therapy for such patients.
Systolic anterior motion of the mitral valve in the absence of asymmetric septal hypertrophy.
Authors: Mintz G S , Kotler M N , Segal B L , Parry W R
Published: June 2012

Asymmetric septal hypertrophy (ASH) is considered the unifying link in the spectrum of hypertrophic cardiomyopathies. ASH and mitral valve systolic anterior motion (SAM) are the two most important echocardiographic criteria for the diagnosis of idiopathic hypertrophic subaortic stenosis (IHSS). Ten patients found have SAM without ASH were studied. Septal thickness, thickening, and excursion were normal. Seven patients had left ventricular ejection times (LVET) measured before and after amyl nitrite inhalation. In six of them, corrected LVET increased by more than 40 msec. Four patients underwent diagnostic cardiac catheterization. Resting or provocable left ventricular outflow tract (LVOT) gradients were demonstrable in all four patients. The echocardiographic features in patients with SAM alone, ASH and SAM, and ASH alone were compared. compared. LVOT measurements in patients with SAM alone (2.2 +/- .4 cm) and ASH and SAM (2.1 +/- .5 cm) were similar and narrower than in patients with ASH alone (2.8 +/- .5 cm, P less than 0.001). Ejection fractions in patients with SAM alone (79 +/- 10%) were greater than in patients with ASH and SAM (66 +/- 16%, P less than 0.02) or ASH alone (60 +/- 15%, P less than 0.001). Thus, dynamic left ventricular outflow obstruction can exist in the absence of echocardiographic ASH. LVOT width and abnormal LV ejection dynamics may contribute to the LVOT obstruction with or without the presence of ASH.
Effect of nitroglycerin on exercise-induced abnormalities of left ventricular regional function and ejection fraction in coronary artery disease. Assessment by radionuclide clineagiography in symptomatic and asymptomatic patients.
Authors: Borer J S , Bacharach S L , Green M V , Kent K M , Johnston G S , Epstein S E
Published: June 2012

The effects of nitroglycerin (TNG) on exercise-induced abnormalities of left ventricular wall motion and ejection fraction are unknown in symptomatic and asymptomatic patients with coronary artery disease (CAD). In the present investigation radionuclide cineangiographic studies were performed in 47 patients with CAD (14 without angina during exercise) and in 25 normal subjects. All CAD patients, including those without symptoms, demonstrated regional wall motion abnormalities during exercise. In all patients, ejection fraction (EF) also responded abnormally to exercise: EF decreased from 48% at rest to 36% during exercise (P less than 0.001). EF increased in all normal subjects from an average of 58% at rest to 71% during exercise (P less than 0.001). In all CAD patients TNG reduced exercise-induced regional wall abnormalities and increased EF attained during exercise from an average of 36 to 48% (P less than 0.001). EF in normal subjects was unchanged by TNG. Thus, exercise can cause abnormalities in left ventricular regional function and ejection fraction in patients with or without symptoms; these abnormalities can be mitigated by prophylactic TNG.
Hypertensive crises in quadriplegic patients. Changes in cardiac output, blood volume, serum dopamine-beta-hydroxylase activity, and arterial prostaglandin PGE2.
Authors: Naftchi N E , Demeny M , Lowman E W , Tuckman J
Published: June 2012

The syndrome of autonomic dysreflexia often occurs in quadriplegic subjects and is characterized by paroxysmal hypertension, headache, vasoconstriction below and flushing of the skin above the level of transection, and bradycardia. These attacks may cause hypertnesive encephalopathy, cerebral vascular accidents, and death. In five patients during crises, the mean arterial pressure changed from 95 to 154 mm Hg, heart rate 72 to 45 beats/min, cardiac output 4.76 to 4.70 L/min, and peripheral resistance 1650 to 2660 dynes.sec.cm-5. In eight subjects the control plasma, red cell, and total blood volumes were 19.1, 10.5, and 29.6 ml/cm body height, respectively, and when hypertensive, the plasma protein concentration increased by 9.9% and the hematocrit by 9.5%. Plasma volume was only reduced by an estimated 10-15%. At that time, arterial dopamine-beta-hydroxylase (DbetaH) activity increased 65% and prostaglandin E2 concentration by 68%. Thus, the augmented DbetaH activity presented primarily an elevated sympathetic tone and not hemoconcentration of that protein. The rise in prostaglandin may contribute to the severe headaches during hypertensive episodes.
Effect of dopamine on hemodynamics and myocardial metabolism in shock following acute myocardial infarction in man.
Authors: Mueller H S , Evans R , Ayres S M
Published: June 2012

Eight patients in shock associated with acute myocardial infarctions were treated with dopamine. We titrated the dopamine dose to increase mean arterial pressure to 65-70 mm Hg and urine output to greater than 40 ml/hr. Increase of heart rate to 120-125 beats/min and occurrence of potentially dangerous arrhythmias were limiting end-points. Dopamine administration averaged 17.2 microgram/kg/min. Heart rate increased from 95 to 118 beats/min (P less than 0.001), and mean arterial pressure rose from 60 to 65 mm Hg (P less than 0.05). Dopamine increased myocardial contractility as indicated by increase in cardiac index and systolic ejection rate, with only moderate decrease in systemic vascular resistance. Pulmonary wedge pressure and right atrial pressure decreased from 23 to 18 mm Hg (P less than 0.05) and from 10 to 8 mm Hg (P less than 0.001) respectively. Improvement in hemodynamic status by dopamine was associated with deterioration of myocardial metabolism. Myocardial oxygen extraction ratios and arterial-coronary sinus oxygen differences increased from 73 to 76% (P less than 0.05) and from 13.02 to 14.19 ml/100 ml (P less than 0.02) respectively. Myocardial lactate production increased from -8 to -15% (P = 0.05). We conclude that dopamine improved cardiac performance at the expense of myocardial oxygenation and that dopamine is potentially harmful to acutely ischemic myocardium.
The first decade of aortocoronary bypass grafting, 1967-1977. A review.
Authors: McIntosh H D , Garcia J A
Published: June 2012

Despite a decade of experience with aortocoronary bypass grafting embracing 300,000 or more operations, indications for its use remain controversial. The controversy persists because of a lack of adequate controls with which to compare the clinical course of operated patients; only 1248 have been reported who have been studied in a carefully controlled and random manner. Benefit has been claimed frequently by comparing the course of patients treated surgically with medically treated patients followed the decade before. Such comparisons are not valid in view of the well documented changes in the natural history of coronary artery disease that have been occurring during the last decade. Despite a low operative mortality and rate of graft closure, available data in the literature do not indicate that initial symptomatic improvement necessarily persists, or that myocardial infarctions, arrhythmias, or congestive heart failure will be prevented, or that life will be prolonged in the vast majority of operated patients.
Recurrent sustained ventricular tachycardia. 2. Endocardial mapping.
Authors: Josephson M E , Horowitz L N , Farshidi A , Spear J F , Kastor J A , Moore E N
Published: June 2012

Endocardial ventricular mapping of 21 ventricular tachyardias (VT) in 17 patients was performed using electrode catheters. Activation at multiple left and right ventricular sites was utilized to determine the site of origin of the VT. Eleven VT had a left bundle branch block pattern (VT-LBBB) and 10 VT had right bundle branch block pattern (VT-RBBB). In all VT-RBBB the earliest site of activation was in the LV or septum. In VT-LBBB the earliest site was RV (4/11), LV (5/11) and septum (2/11). All ventricular tachycardias with QRS less than 140 msec arose in the septum. In patients with an aneurysm, the site of origin of ventricular tachycardia was always in the aneursm. All VT-LBBB arising from the left ventricle originated in an aneurysm involving the septum. QRS changes during ventricular tachycardia were associated with alterations in the patterm of ventricular activation without alteration of the site of origin. In three patients the site of origin predicted by endocardial ventricular mapping was confirmed intraoperatively by epi- and/or endocardial mapping. We conclude that endocardial ventricular mapping demonstrates the limitations of the surface electrocardiogram in localizing the site of origin of ventricular tachycardia. The method may provide important data upon which the surgical therapy of ventricular tachycardia is based.
Electrophysiologic effects of lidocaine on sinus node and atrium in patients with and without sinoatrial dysfunction.
Authors: Dhingra R C , Deedwania P C , Cummings J M , Amat-Y-Leon F , Wu D , Denes P , Rosen K M
Published: June 2012

Electrophysiological studies were conducted in 13 patients with normal sinus node function and 14 with sinus node dysfunction before and after intravenous lidocaine. Mean +/- SEM sinus cycle length significantly shortened from 810 +/- 34.3 to 774 +/- 34.3 msec in patients with normal sinus node (P less than 0.001) and from 1061 +/- 67.6 to 1016 +/- 64.5 msec in patients with sinus node dysfunction (P less than 0.025) after lidocaine. Mean sinus recovery time was 1027 +/- 49.4 before and 1026 +/- 52.5 msec after lidocaine in patients with normal sinus node (NS) and 1269 +/- 97.7 before and 1170 +/- 73.8 msec after lidocaine in patients with sinus node dysfunction (P less than 0.05). Mean calculated sinoatrial conduction time was 87 +/- 9.5 before and 90 +/- 9.2 msec after lidocaine in patients with normal sinus node (NS) and 80 +/- 10.3 before and 96 +/- 10.2 msec after lidocaine in patients with sinus node dysfunction (P less than 0.001). Mean atrial effective and functional refractory periods were not significantly changed with lidocaine. Thus lidocaine shortened sinus cycle length in both groups, without affecting atrial refractoriness. Lidocaine appeared to depress perinodal tissue only in patients with sinus node dysfunction. The abbreviation of sinus recovery time in patients with sinus node dysfunction could reflect increased sinus automaticity and/or increased perinodal refractoriness, allowing entrance block to occur. This mechanism may explain why sinus arrest has been noted in some patients during lidocaine administration.
Echocardiographic assessment of left ventricular filling and septal and posterior wall dynamics in idiopathic hypertrophic subaortic stenosis.
Authors: Sutton M G , Tajik A J , Gibson D G , Brown D J , Seward J B , Guiliani E R
Published: June 2012

In order to study left ventricular function in idiopathic hypertrophic subaortic stenosis (IHSS), left ventricular echograms were analyzed by computer and compared with results in normal subjects. Systolic function was consistently normal or above normal even in the presence of severe diastolic abnormalities. Wide variation in diastolic function in IHSS allowed separation of patients into three groups on the basis of the left ventricular peak filling rate. Because of the severe septal hypertrophy and hypokinesia, peak left ventricular filling rate is predominantly determined by the rate of free wall thinning. Patients in group 1 had rapid left ventricular filling rates, those in group 2 had normal filling rates, and those in group 3 had slow filling rates. With reduction in left ventricular peak filling rate caused by impaired free wall thinning, there was progressive increase in 1) duration of the rapid filling phase, 2) delay of mitral valve opening, 3) asynchrony between septum and posterior wall, 4) incidence of angina, and 5) incidence of atrial fibrillation.