bluuebunny/crossref_metadata_2025 huggingface dataset:
Two-dimensional echocardiography and B-mode ultrasonography for the diagnosis of loculated pericardial effusion.
Authors: Friedman M J , Sahn D J , Haber K
Published: June 2012

Two cases of loculated pericardial effusion resulting in cardiac tamponade are presented. The loculated nature and extent of the effusion was best defined by two-dimensional echocardiography or B- mode ultrasonography. Cross-sectional images should probably be obtained in all cases of suspected loculated pericardial effusion and in patients in whom the interpretation of the M-mode echocardiogram is equivocal as to the presence or absence of pericardial effusion.
Accuracy and reproducibility of new M-mode echocardiographic recommendations for measuring left ventricular dimensions.
Authors: Crawford M H , Grant D , O'Rourke R A , Starling M R , Groves B M
Published: June 2012

In order to assess the accuracy and reproducibility of the proposed American Society of Echocardiography (ASE) method for measuring left ventricular dimensions on M-mode echocardiograms, we measured the end-diastolic (Dd) and end-systolic (Ds) dimensions by the ASE method and our current technique in 50 normal subjects and 24 patients without coronary artery disease who had symmetrically contracting ventricles on cineangiography. Dd and Ds were significantly greater by the proposed ASE method than by our current technique (p less than 0.001), but the correlation between the two was good (r = 0.93 and 0.83, respectively). In 10 of the normal subjects, the interobserver variability of both methods was excellent. In the 24 patients, the proposed method consistently overestimated the angiographic left ventricular volumes compared with our current technique and occasionally the discrepancies were quite large. Therefore, the proposed ASE method for measuring left ventricular dimensions is not clearly superior to other currently available techniques.
Constrasts and similarities of acute hemodynamic responses to specific antagonism of angiotensin II ([Sar1, Thr8] A II) and to inhibition of converting enzyme (captopril).
Authors: Fouad F M , Ceimo J M , Tarazi R C , Bravo E L
Published: June 2012

The early blood pressure and hemodynamic effects of the converting enzyme inhibitor (CEI), captopril, were compared in 23 hypertensive patients with those of a specific angiotensin II antagonist (AA), [Sar1, Thr8] A II. AA reduced mean arterial pressure (MAP) greater than 10 mm Hg only in seven of 23 patients vs 15 of 23 who responded to CEI (p less than 0.02). With both drugs, changes in MAP were not associated with significant changes in cardiac output (p greater than 0.10 for both drugs), but correlated with changes in systemic resistance (TPR); r = 0.84, p less than 0.001 for AA and r = 0.71, p less than 0.001 for CEI. Changes in TPR and MAP correlated significantly and inversely with log plasma renin activity in both instances; for AA, r = 0.829 and for CEI, r = -0.737; p less than 0.001 for both. The slopes of the two regression lines were not significantly different but the intercepts were +8.47 mm Hg for AA vs -10.17 mm Hg for CEI (p less than 0.001). This quantitative difference in response could be attributed either to an agonistic effect of [Sar1, Thr8] A II or to an additional vasodilator effect of captopril.
Distribution and anomalies of coronary arteries in tetralogy of fallot.
Authors: Dabizzi R P , Caprioli G , Aiazzi L , Castelli C , Baldrighi G , Parenzan L , Baldrighi V
Published: June 2012

The surgical management of tetralogy of Fallot (TF) may be complicated by anomalies in the course and distribution of coronary arteries. Selective coronary angiography was performed in 119 cases of TF in order to prevent injury of aberrant vessels. In 11 patients, anomalies in the origin of coronary branches were revealed (five patients with a single coronary ostium, five with the anterior descending coronary artery arising from the right coronary artery or right sinus of Valsalva, and one with the circumflex artery arising from the right coronary artery). Other findings include anastomoses between coronary and bronchial arteries, small fistulas between coronary arteries and the pulmonary artery or right atrium, and hypoplasia of the coronary tree. The onset of left anterior hemiblock after total correction of TF could possibly be explained, in cases with a dominant left pattern, by injury to the coronary system after closure of the interventricular septal defect, rather than by injury to the conduction system.
Effect of non-nicotine cigarettes and carbon monoxide on angina.
Authors: Aronow W S
Published: June 2012

The effect of smoking five non-nicotine cigarettes and of breathing carbon monoxide on exercise-induced angina was evaluated in 12 patients with angina. Smoking increased venous carboxyhemoglobin from 1.71 to 5.35%, decreased exercise duration until angina 45%, increased ischemic ST-segment depression at angina from 1.33 to 1.52 mm, and decreased systolic blood pressure times heart rate at angina. Breathing carbon monoxide increased venous carboxyhemoglobin from 1.73 to 5.37%, decreased exercise duration until angina 35%, increased ischemic ST-segment depression at angina from 1.31 to 1.50 mm, and decreased systolic blood pressure times heart rate at angina. Greater decreases in exercise duration until angina and in systolic blood pressure times heart rate at angina (p less than 0.001) were observed after smoking than after breathing carbon monoxide. Tobacco components other than nicotine or carbon monoxide are responsible for a small decrease in exercise performance until angina.
Comparison of endocardial catheter mapping with intraoperative mapping of ventricular tachycardia.
Authors: Josephson M E , Horowitz L N , Spielman S R , Greenspan A M , VandePol C , Harken A H
Published: June 2012

To validate the accuracy of catheter endocardial mapping to localize the origin of ventricular tachycardia (VT), we compared cathether endocardial mapping with intraoperative epicardial and endocardial mapping of 24 morphologically distinct VTs in 18 patients undergoing surgery. Twelve had VT with left bundle branch block morphology and 12 had VT with right bundle branch block morphology. Catheter endocardial mapping localized 23 VT morphologies to the border of a left ventricular aneurysm or myocardial infarction and one VT to a right ventriculotomy scar. Intraoperative epicardial mapping showed epicardial breakthrough on the right ventricle in 10 VTs with left bundle branch block morphology and on the left ventricle in two. In 12 VTs with right bundle branch block morphology, intraoperative epicardial mapping revealed the earliest site of VT with left bundle branch block morphology (11 patients) and VT with right bundle branch block morphology (12 patients) at the border of a left ventricular aneurysm, and one VT with left bundle branch block morphology in the right ventricle. Catheter endocardial mapping predicted the origin of VT within 4--8 cm2 of that determined by intraoperative endocardial mapping, which always identified the earliest site. These data validate the accuracy of catheter endocardial mapping in localizing the origin of VT.
Quantification of aortic valvular regurgitation in dogs by nuclear imaging.
Authors: Baxter R H , Becker L C , Alderson P O , Rigo P , Wagner H N , Weisfeldt M L
Published: June 2012

Radionuclide gated cardiac blood pool (GBP) imaging was used to quantitatively assess the severity of acute aortic valvular regurgitation produced experimentally in 10 anesthetized dogs. Right ventricular (RV) and left ventricular (LV) stroke counts (end-diastolic minus end-systolic counts in RV and LV regions of interest) were used as indices of the stroke volumes of the two ventricles. Regurgitant fraction (RFGBP) was derived by assuming that an excess of LV stroke counts compared to RV stroke counts was due to regurgitant flow: RFGBP = LV stroke counts - RV stroke counts/LV stroke counts X 100. Regurgitant fraction (RFEMF) was also estimated directly from an electromagnetic flowmeter (EMF) on the ascending aorta. Mean RFEMF was 55.8 +/- 17.9% (+/-SD). Close agreement was found between regurgitant fractions measured by GBP and EMF (RFGBP = 1.09, RFEMF - 4.7%, r = 0.88, p less than 0.001, SEE = 9.98%). The severity of regurgitation from blood pool images also correlated closely with aortic pulse pressure (r = 0.89) and the length of the tear in the aortic valve (r = 0.84). These results suggest that blood pool imaging may be sueful for noninvasive quantification of regurgitant flow in patients with valvular insufficiency.
Surface topography of stenotic aortic valves by scanning electron microscopy.
Authors: Riddle J M , Magilligan D J , Stein P D
Published: June 2012

Surface features of 19 stenotic aortic valves from patients undergoing valve replacement were investigated by scanning electron microscopy. Villi, prominent on five valves, were distributed either singularly or in clusters and differed in shape. Endothelial cells had microvilli and bulbous surface projections. Endothelial disruption with a focal loss of endothelial cells was uniformly observed. Erythrocytes were found scattered over the exposed subendothelial surface or enmeshed within fibrin networks on 11 of the valves. Activated leukocytes were seen on four valves and showed veil-like projections as well as microvilli. Platelets, observed on three valves, displayed pseudopodial formation and hyalomeric spreading, signifying an increased degree of membrane response. Most platelet aggregates were composed entirely of dendritic forms (reversible aggregates), but a few also contained spread forms (irreversible aggreates). Focal deposits of crystalline material, presumably containing calcium, were observed in areas of endocardial disruption.
Effects of oral propranolol on left ventricular size and performance during exercise and acute pressure loading.
Authors: Crawford M H , Lindenfeld J , O'Rourke R A
Published: June 2012

Oral propranolol (160 mg/day) was administered to 19 normal subjects for 2 weeks. Echocardiograms were performed at rest, during graded supine bicycle exercise in 10 subjects and during acute pressure loading with intravenous phenylephrine in the remaining nine subjects. Resting heart rate on propranolol decreased compared with control (52 +/- 8 vs 63 +/- 10 beats/min; p less than 0.001), as did systolic blood pressure (99 +/- 9 vs 107 +/- 9 mm Hg; p less than 0.01). Left ventricular end-diastolic dimension was slightly enlarged (48.3 +/- 4.2 vs 47.1 +/- 3.6 mm, p = 0.05), but percent dimensional shortening was unchanged (37 +/- 4 vs 38 +/- 5%). At each stage during supine bicycle exercise, heart rate was slower, blood pressure lower, left ventricular dimensions were larger and percent dimensional shortening was reduced on propranolol by an analysis of variance. In contrast, during acute pressure loading, while the heart rate response to increased blood pressure was blocked by atropine, there was no significant difference in left ventricle size and performance compared with control. We conclude that prolonged oral propranolol therapy has little, if any, intrinsic effect on myocardial performance in normal subjects. Its major action on the heart is competitive inhibition of beta-adrenergic tone, which is most manifest during conditions associated with increased sympathetic tone, such as exercise.
Intrapericardial abnormalities in patients with pericardial effusion. Findings by two-dimensional echocardiography.
Authors: Martin R P , Bowden R , Filly K , Popp R L
Published: June 2012

Ten patients with pericardial fluid who also had striking band-like intrapericardial echoes by two-dimensional ultrasonic sector scanning are reported. Four patients had prior mediastinal radiation and four patients had severe renal disease. One patient had purulent pericarditis and one patient had traumatic hemopericardium. The two-dimensional images permitted recognition of loculation of fluid and led to the suspicion of thickened pericardial membranes. Three postradiation patients had both tamponade and constriction; tamponade alone was present in four additional patients. These data are preliminary but suggest that such findings by two-dimensional echocardiography should alert us to consider an effusive-constrictive form of pericardial disease.
Noninvasive diagnosis of coronary artery disease: the cardiokymographic stress test.
Authors: Silverberg R A , Diamond G A , Vas R , Tzivoni D , Swan H J , Forrester J S
Published: June 2012

Stress-induced abnormalities of regional left ventricular wall motion were assessed by cardiokymography (CKG) during the course of maximal treadmill exercise tests in 157 patients, of whom 122 subsequently underwent coronary angiography. Seventy patients had significant angiographic coronary artery disease and 52 were normal. Forty-one of the 70 patients developed greater than 0.1 mV ST-segment depression (ECG sensitivity 59%) and 52 of 70 patients developed abnormal systolic outward motion by CKG (CKG sensitivity 74%). Among the 52 normals, 36 had negative ECG stress tests (ECG specificity 69%) and 49 had normally sustained systolic inward motion by CKG (CKG specificity 94%). The stress CKG was normal in 15 of the 16 false-positive stress ECGs; the stress ECG was correctly normal in two of the three false-positive stress CKG tests. Only one normal patient had concordantly false-positive ECG and CKG tests. The predictive accuracy of concordant ECG and CKG interpretations was, therefore, higher than either test alone. These data suggest that regional wall motion abnormalities, which are sensitive and specific markers of myocardial ischemia, may be detected noninvasively by CKG. We concluded that CKG helps identify false-positive and false-negative ECG stress tests and improves the diagnostic accuracy of stress testing for detection of coronary artery disease.
Body surface map patterns of altered depolarization and repolarization in right bundle branch block.
Authors: Sohi G S , Flowers N C
Published: June 2012

Surface maps from 14 patients with right bundle branch block were analyzed throughout depolarization and repolarization. The abnormalities in depolarization found in all the subjects were 1) epicardial breakthrough that was delayed and shifted to the left, and 2) development of right upper anterior positivity during the midportion of depolarization. In eight patients, this positivity manifested as multiple peaks, suggesting a fragmented spread of depolarization. We believe these findings result not only from the delayed engagement of the right ventricle by the conduction process, but also from its nonuniform and dyssynchronous spread. The recovery phase displayed five abnormal patterns: 1) simultaneous negativity on the right and positivity on the left of the midline in six patients; 2) only negativity on the right of the midline in four; 3) only positive potentials in the left upper chest in two; 4) only negative potentials on the left side of the midline in one; and 5) negative potentials spread diffusely over the precordium in one. The different degrees of this altered repolarization, we believe, depend upon the degrees of altered sequence of activation of the heart in addition to the changes produced by the underlying disease process.
Optimal diagnosis in acute myocardial infarction. A cost-effectiveness study.
Authors: Grande P , Christiansen C , Pedersen A , Christensen M S
Published: June 2012

The predictive value of a diagnostic test estimates the likelihood for presence or absence of disease in a patient with a positive or negative test result (PVpos or PVneg). We evaluated the predictive values of serum activities of the heart-specific creatine kinase isoenzyme MB (CK-MB), aspartate aminotransferase, lactate dehydrogenase, CK, and ECG in 401 consecutively admitted patients suspected of acute myocardial infarction (AMI). The study showed that CK-MB (PVpos = 0.98, PVneg = 1.00) was better than the other enzymes (single as well as serial) and ECG, evaluated both separately and in combinations. In all cases of AMI CK-MB was positive within 17 hours from admission. Replacement of the standard enzymes with CK-MB provides a faster and safer diagnosis of AMI and reduces hospitalization time considerably for patients without AMI.
Elevated plasma fibrinopeptide A and thromboxane B2 levels during cardiopulmonary bypass.
Authors: Davies G C , Sobel M , Salzman E W
Published: June 2012

Patients who underwent operations in which cardiopulmonary bypass was used had elevations of plasma fibrinopeptide A which did not return to normal during bypass despite conventional heparin anticoagulation, suggesting inadequate heparin dosage and continued thrombin activity during the operation. Patients who underwent aortocoronary artery grafting had high plasma thromboxane B2 levels and a rapid fall in platelet count at the onset of extracorporeal circulation. Thromboxane elevations were less marked in patients who underwent valve replacement. Platelet aggregation and coronary artery constriction secondary to thromboxane production may contribute to the morbidity of cardiopulmonary bypass.
Comprehensive clinical electrophysiologic studies in the investigation of documented or suspected tachycardias. Time, staff, problems and costs.
Authors: Ross D L , Farre J , Bar F W , Vanagt E J , Dassen W R , Wiener I , Wellens H J
Published: June 2012

To assess time, staff, problems and costs involved in clinical electrophysiologic studies for documented or suspected tachycardia, 33 consecutive cases were analyzed prospectively. At least seven staff members were used for each study. Insertion of catheters required 24--105 minutes (mean 63 +/- 20 minutes). Programmed stimulation required 12--210 minutes (mean 87 +/- 38 minutes). Total fluoroscopy times were 6--67 minutes (mean 22 +/- 15 minutes). Each study used 360--2100 feet (mean 1260 +/- 390 feet) of recording paper. Detailed analysis of tracing took 1--11 hours (mean 5 +/- 2.5 hours). Delays occurred during electrophysiologic study in 25 cases (76%), with multiple causes of delay in 14 cases (42%). These were caused by 1) difficulty in obtaining venous access (five patients); 2) difficult initial catheter placement (15 cases); 3) repositioning of catheters during stimulation (17 cases); 4) sustained atrial fibrillation (four cases). Coronary sinus catheterization was achieved from the groin in 21 of 27 cases (78%) in whom a sustained attempt was made. The approximate cost of each study was greater than $800. Our data show that clinical electrophysiologic studies in the investigation and management of tachycardia are difficult, time-consuming and expensive.
Hypoplastic and fibrotic sinus node associated with intractable tachycardia in a neonate.
Authors: Fox K M , Anderson R H , Hallidie-Smith K A
Published: June 2012

A case of fetal and neonatal persistent atrial tachycardia is described in a child with complete transposition of the great arteries. At autopsy, serial sections of the conducting tissue showed that the sinus node was hypoplastic and markedly fibrotic. The sinus node consisted of a small area of cells clustered around the nodal artery. Although the underlying mechanism of neonatal persistent tachycardia is unclear, it is possible that the hypoplasia and fibrosis of the sinus node was the substrate in the present case. This mechanism should be considered in any newborn infant in whom sinus rhythm cannot be established.
Left ventricular response to isometric exercise in patients with denervated and innervated hearts.
Authors: Savin W M , Alderman E L , Haskell W L , Schroeder J S , Ingels N B , Daughters G T , Stinson E B
Published: June 2012

Patients with cardiac denervation resulting from allograft transplantation have been observed to increase their diastolic and systolic blood pressure during isometric exercise without concomitant cardioacceleration. To determine the mechanism for the blood pressure increase, heart rate, blood pressure, and ventricular volumes (measured using fluoroscopy of tantalum midwall myocardial markers) were recorded before and after a 50% maximal voluntary contraction. Seven cardiac transplant recipients (denervated heart) and seven nontransplant patients (innervated heart) were studied. Innervated and denervated heart patients increased systolic blood pressure by 16% and 21% and total peripheral resistance by 20% and 12%, respectively. The percentage responses were not significantly different between groups, except for heart rate, which increased 17% in innervated heart patients and 2% in denervated heart patients (p less than 0.05). Neither group had enhanced contractility or increases in cardiac output, suggesting that the blood pressure increases resulted in both groups from increased peripheral resistance.
Responses of normal children and young adults to controlled bicycle exercise.
Authors: James F W , Kaplan S , Glueck C J , Tsay J Y , Knight M J , Sarwar C J
Published: June 2012

Exercise responses were obtained from 149 children and young adults (average age 14.5 years) and divided by sex and body surface area (BSA): children with BSA less than 1 m2; children with BSA 1--1.19 m2; males with BSA greater than or equal to 1.2 m2; and females with BSA greater than or equal to 1.2 m2. Total work, mean and maximal power outputs were more affected by body size (height) than age in children with BSA less than 1 m2 and in males and females with BSA greater than or equal to 1.2 m2. Mean systolic pressure increased up to 64% above the preexercise supine value at peak effort, with the level of mean maximal systolic pressure having a positive relationship with body size (height), power output and preexercise sitting systolic pressure in all subgroups except children with BSA 1--1.19 m2. Mean diastolic pressure increased up to 24% above the preexercise supine value at peak effort. ST-segment depression of 1--2 mm was recorded in 12.1% (18 of 149) of the population at peak exercise. These changes occurred in 8.9% of all males and in 16.9% of all females (p greater than 0.1). The data from this study reveal the importance of sex and body size in the clinical interpretation of exercise responses in growing subjects, provide a reference for objective evaluation of subjects with or without cardiac abnormalities and provide a guide for careful monitoring of subjects during an exercise study.
Angiotensin II, plasma renin and sodium depletion as determinants of blood pressure response to saralasin in essential hypertension.
Authors: Thananopavarn C , Golub M S , Eggena P , Barrett J D , Sambhi M P
Published: June 2012

To evaluate the role of the renin-angiotensin system and sodium depletion in the hypotensive response to 1-sarcosine-8-alanine-angiotensin II (saralasin), 15 male patients with essential hypertension were studied on a diet containing 120 mEq of sodium and 100 mEq of potassium per day. After a 5-day control period, all subjects had a mild pressor response to the saralasin infusion (p less than 0.01). After 5 days of the diuretic metolazone (5 mg/day), eight of the 15 patients had a vasodepressor response; these responders had a significantly greater increase in plasma renin activity and angiotensin II concentrations than did the non-responders. Sodium deficit differed markedly (p less than 0.001) between the two groups (361 +/- 121 mEq (SD) vs 52 +/- 26 mEq sodium, respectively). The addition of spironolactone (400 mg/day) for 5 days resulted in saralasin responsiveness in all but two patients, both of whom had small sodium deficits. Thus, variability in the natriuretic response to diuretics may affect saralasin testing and limit its clinical utility.
Immediate and sustained hemodynamic and clinical improvement in chronic heart failure by an oral angiotensin-converting enzyme inhibitor.
Authors: Ader R , Chatterjee K , Ports T , Brundage B , Hiramatsu B , Parmley W
Published: June 2012

The hemodynamic effects of an oral angiotensin-converting enzyme inhibitor, captopril, were evaluated in 10 symptomatic patients with chronic congestive heart failure. In all patients there was a significant increase in cardiac output (average 28%), stroke volume (49%), and stroke work index (26%), along with a decrease in pulmonary capillary wedge pressure (48%), indicating improved left ventricular function. Modest decreases in heart rate and arterial pressure were also observed. In seven patients maintained on captopril therapy, repeat hemodynamic studies at 2 months revealed sustained effects. These beneficial hemodynamic effects were accompanied by clinical improvement and improved exercise tolerance during maintenance therapy. These findings suggest that captopril may be a useful therapeutic adjunct for the long-term management of patients with chronic congestive heart failure.
Evaluation of methods for quantitating left ventricular segmental wall motion in man using myocardial markers as a standard.
Authors: Ingels N B , Daughters G T , Stinson E B , Alderman E L
Published: June 2012

Radiopaque markers were implanted in the left ventricular myocardial midwall in 58 patients and studied in the 30 degrees right anterior oblique projection by computer-aided fluoroscopy. Marker motion was used as a standard of segmental wall motion against which the accuracy of five methods for measuring left ventricular wall motion was assessed: two methods using hemiaxial measurements in rectangular coordinates, two using radial measurements in polar coordinates (all with frame-by-frame axial reindexing) and one using radial measurements in fixed external polar coordinates. The latter method showed significantly less error (25.9%, p less than 10(-6)) in measuring midwall marker motion than the other four methods (range 42.5--47.5%) in the group as a whole and in subgroups that had abnormalities of posterior, apical and anterior wall motion. This method also had the best correlation of marker motion and motion of adjacent endocardial border (of the overall left ventricle and the posterior, apical, and anterior walls separately) as visualized by ventriculography in 29 patients. The bulk of the reduction in error using this method was due to the use of a fixed external reference system, with a small additional increment of error removed by proper selection of the polar origin at a point 69% of the distance from the anterolateral edge of the aortic valve to the ventricular apex at end-systole.
Disruption in the temporal sequence of regional ventricular contraction. I. Characteristics and incidence in coronary artery disease.
Authors: Holman B L , Wynne J , Idoine J , Neill J
Published: June 2012

While spatial asynergy at end-systole has been well characterized in patients with coronary artery disease, assessment of regional asynchrony has been hampered by technical constraints. We developed a computer-assisted method for analyzing regional asynchrony from the equilibrium (ECG-gated) radionuclide ventriculogram. Twenty patients with normal contrast left ventriculograms (nine with a normal coronary arteriogram [group 1] and 11 with coronary artery disease [group 2]) and 20 patients with asynergy during contrast ventriculography (group 3) were studied. The earliest evidence of regional asynchrony occurred in early systole. Regional ejection fraction at one-third systole was 0.32 +/- 0.02 (mean +/- SEM) in group 1, 0.22 +/- 0.01 in group 2 (p less than 0.001) and 0.12 +/- 0.01 in asynergic regions in group 3 patients (p less than 0.001). In group 3, severe forms of regional asynchrony appeared in both early systole and early diastole: five patients (25%) had early systolic paradox, 13 (65%) had regional prolongation of peak ejection fraction and 16 (80%) had reduced percent peak ejection fraction at global end-systole. It appears, therefore, that there is progressively increasing regional asynchrony in patients with increasing severity of coronary artery disease.
Previously undiagnosed variant angina as a cause of chest pain after coronary artery bypass surgery.
Authors: Waters D D , Theroux P , Crittin J , Dauwe F , Mizgala H F
Published: June 2012

Variant angina was diagnosed after coronary artery bypass surgery in six patients over a 22-month period. Although all six patients had at least occasional angina at rest preoperatively, all but one had predominantly exertional angina. After surgery, rest angina with transient ST-segment elevation appeared in all six after an asymptomatic interval of 1 week to 4 years. In two patients the involved artery had not been bypassed, in two patients it was perfused by a patent graft and in two patients the graft to the involved vessel was occluded. Treatment with calcium antagonist drugs (four cases) or isosorbide dinitrate (one case) eliminated symptoms; one patient spontaneously became asymptomatic. The diagnosis of variant angina should be considered when rest angina occurs after bypass surgery, particularly if exertional angina is absent and grafts are patent.
Clinical profile of restrictive cardiomyopathy.
Authors: Benotti J R , Grossman W , Cohn P F
Published: June 2012

The characteristic hemodynamic features of restrictive cardiomyopathy (normal or reduced cardiac index, normal ventricular systolic function, and "dip and plateau" early in diastole) are traditionally associated with pathologic evidence of inflammation, infiltration and fibrosis. Prognosis is usually poor. Nine patients with restrictive hemodynamic features were recently identified in our laboratory; six were males, three were females, and ages ranged from 23-57 years (mean 47 years). Only one was asymptomatic. Chest pain, dyspnea on exertion and fatigue were the most common symptoms. Echocardiography revealed various degrees of left ventricular wall thickening, but no significant pericardial effusion, pericardial thickening or calcification. Mean left ventricular end-diastolic pressure was 25 mm Hg, cardiac index 2.8 l/min/m2 and ejection fraction 0.63. Endomyocardial and pericardial biopsies, obtained in two patients, were normal. Follow-up (mean 22 months, range 16-42 months) revealed no cardiac deaths. These findings support the hypothesis that the restrictive hemodynamic profile does not necessarily indicate the presence of a specific pathologic process in the subendocardium or myocardium and that the prognosis is not necessarily ominous. The common pathophysiologic feature for this syndrome appears to be reduced ventricular diastolic compliance, but the etiology in many cases is unclear.
Histology of the persistent ductus arteriosus in cases of congenital rubella.
Authors: Gittenberger-de Groot A C , Moulaert A J , Hitchcock J F
Published: June 2012

Histologic study of the persistent ductus arteriosus in case of a congenital rubella syndrome revealed that this persistency is probably due to an arrest in the development of the ductus. Histologically, it resembles a very immature ductus and not the most common type of persistent ductus arteriosus. The earlier finding, that in the human ductus arteriosus, the presence of an extensive subendothelial elastic lamina is incompatible with anatomic sealing, still holds.
Effects of amrinone on myocardial energy metabolism and hemodynamics in patients with severe congestive heart failure due to coronary artery disease.
Authors: Benotti J R , Grossman W , Braunwald E , Carabello B A
Published: June 2012

Amrinone has been shown to exhibit a potent inotropic effect in patients with heart failure secondary to congestive cardiomyopathy, but its effects on myocardial oxygen consumption (MVO2) and coronary blood flow (CBF) are unknown. Accordingly, the hemodynamic, myocardial metabolic and ECG responses to amrinone (2.5 mg/kg i.v. over 1 hour) were measured in nine patients with congestive heart failure secondary to coronary artery disease. Increases were observed in cardiac index (1.3 +/- 0.4 to 2.2 +/- 0.7 l/min/m2) and left ventricular stroke work (10.6 +/- 3.0 to 19.2 +/- 6.3 g-m/m2), and decreases in mean pulmonary wedge (31 +/- 5 to 26 +/- 4 mm Hg), mean pulmonary artery (44 +/- 8 to 36 +/- 7 mm Hg) and mean right atrial pressures (18 +/- 4 to 10 +/- 4 mm Hg), myocardial arteriovenous oxygen difference (129 +/- 19 to 109 +/- 17 ml/l), CBF (215 +/- 117 to 178 +/- 84 ml/min) and MVO2 (27 +/- 14 to 19 +/- 9 ml/min). All changes were significant (p less than 0.01). No significant changes occurred in aortic mean pressure, heart rate, myocardial lactate extraction or ECG, and no patient developed angina. In explaining the decline in MVO2, it is possible that the increase in contractility was more than offset by the reductions in preload and afterload. The amrinone-induced hemodynamic improvement in patients with congestive heart failure secondary to coronary artery disease was associated with reductions in MVO2 and CBF and no evidence of myocardial ischemia.
The association between urinary sodium excretion and blood pressure in children.
Authors: Cooper R , Soltero I , Liu K , Berkson D , Levinson S , Stamler J
Published: June 2012

This study explored the association between sodium excretion and blood pressure (BP). A new method was used to minimize the measurement error introduced by the large intrinsic variability of 24-hour sodium excretion. The ratio of intra- to interindividual variation was used to estimate the number of measurements needed to characterize the individual. When seven consecutive 24-hour samples were collected from 73 children, ages 11-14 years, a significant correlation between mean individual sodium excretion and BP was demonstrated. The independent relationship persisted when controlling for height, weight, pulse, age, sex and race (p = 0.045), but was eliminated by simultaneously considering mean creatinine excretion. Although the cross-sectional association described is quantitatively weak, a linear relationship between BP and sodium over the range consumed in this society could be important for prevention.
Risk factors and angiographic coronary artery disease: a report from the coronary artery surgery study (CASS).
Authors: Vlietstra R E , Frye R L , Kronmal R A , Sim D A , Tristani F E , Killip T
Published: June 2012

The findings for 14 risk variables were correlated with the results of coronary arteriography in 8807 patients registered in the interinstitutional Coronary Artery Surgery Study (CASS). Discriminant-function analysis revealed that age, sex, cigarette smoking and the level of blood cholesterol best distinguished between the groups with (6688 patients) and without (2119 patients) coronary artery disease. A family history of coronary artery disease and the presence of hypertension or diabetes were of addition, but less, discriminating value. The relative risk for coronary artery disease in patients with the combination of cigarette smoking and an elevated cholesterol level was high (> 4) in females age 55 years or younger and in males age 35 years or younger. Few females age 45 years or younger (seven of 97) had coronary artery disease when both of these risk factors were absent. In spite of these correlations, only limited gains accrued from the use of discriminant-function analysis in correctly allocating patients into disease and nondisease groups. This indicates that, while certain factors are significantly correlated with coronary arteriographic findings, their value for predicting the presence of coronary artery disease is limited.
QRS mapping in the evaluation of acute anterior myocardial infarction.
Authors: von Essen R , Merx W , Doerr R , Effert S , Silny J , Rau G
Published: June 2012

In 42 patients with acute anterior myocardial infarction (AMI), we studied the course of Q-wave development and R-wave reduction during the first 48 hours after the onset of chest pain. We used precordial mapping in relation to clinical features, hemodynamic measurements and enzyme release. Q waves developed within 6-14 hours (mean 9 hours) after onset of symptoms. R-wave amplitudes demonstrated nearly a reflected image: They reduced abruptly 5-11 hours (mean 9 hours) after onset of chest pain, coinciding with ST-segment elevation. In 14 patients (group A, 33%) after initial QRS alterations, there were no further changes. Twenty patients (group B, 48%) had a distinct new increase of Q waves (delta sigma Q = 3.0 +/- 2.0 mV/hours) and further R-wave reduction (-delta sigma R = 1.0 +/- 0.6 mV/hour) simultaneous with new severe chest pain and a delayed second increase of enzyme release corresponding with extension of infarction. There were no significant differences between the groups in age, hemodynamics and infarct size calculated from creatine kinase release. Eight patients (group C, 19%) had contradictory findings. Our findings are consistent with previous results indicating that the critical period for intervention is very small except in patients with extension of necrosis.
Detecting abnormalities in left ventricular function during exercise before angina and ST-segment depression.
Authors: Upton M T , Rerych S K , Newman G E , Port S , Cobb F R , Jones R H
Published: June 2012

To determine if abnormalities in left ventricular function precede angina pectoris and electrocardiographic evidence of myocardial ischemia, we used radionuclide angiocardiography to measure left ventricular ejection fraction, volumes, cardiac output and wall motion in 10 normal subjects and 25 patients with coronary artery disease at rest and during two levels of upright bicylce exercise. In the patients with coronary artery disease, the first radionuclide study during exercise was performed before and the second after the onset of ST-segment depression. In all normal subjects, the ejection fraction increased more than 5%, the end-diastolic volume increased less than 25% and the end-systolic volume decreased from rest to both levels of exercise. Wall motion was normal at rest and increased with exercise. No patient with coronary artery disease had chest pain or ST-segment depression during the first level of exercise. The ejection fraction either decreased or increased less than 5% in 18 patients, the end-diastolic volume increased more than 25% in nine, the end-systolic volume increased in 19 and a segmental contraction abnormality developed in 14. Hemodynamic and wall motion abnormalities occurred in all patients during the second level of exercise when ST-segment depression was present. During exercise in patients with coronary artery disease, abnormalities in left ventricular function frequently develop before angina pectoris and electrocardiographic evidence of myocardial ischemia.
Experimental myocardial ischemia. IV. Shape and volume changes during "isolvolumetric relaxation" in normal and ischemic ventricles.
Authors: Van Houten F X , Serur J R , Borkenhagen D M , Adams D F , Abrams H L
Published: June 2012

Shape and volume changes were studied in mongrel dogs between end-systole and mitral valve opening (MVO). Biplane left ventricular cineangiograms were performed at 200 frames/sec. The dogs were studied during the control state and during regional myocardial ischemia produced by balloon occlusion of the left anterior descending coronary artery. Outward wall motion, called pre-inflow relaxation (PIR), occurred in all 10 dogs in the control state, most frequently in the apical (seven of 10) and equatorial planes (seven of 10). PIR was seen less frequently during ischemia (13 of 40 measurements vs 19 of 40 measurements during control state), usually in the basal plane (five of 10). The ventricular volume between end-systole and MVO increased in all 10 dogs during the control state (mean increment 4.4 +/- 0.7 ml). Volume increased in eight of 10 dogs during ischemia (mean increment 3.0 +/+ 1.1 ml). The characteristic patterns of wall motion occurring between end-systole and MVO are altered by regional myocardial ischemia. During ischemia PIR occurs in segments of the myocardium with normal perfusion, but usually not in ischemic segments. Biplane ventricular volume between end-systole and MVO increased in 18 of 20 measurements (mean increment 3.6 +/- 0.9 ml).
The effect of lidocaine on reentry within the His-Purkinje system in man.
Authors: Ruskin J N , Akhtar M , Damato A N , Foster J R
Published: June 2012

The effects of intravenous lidocaine were assessed in 11 patients with normal intraventricular conduction in whom reentry within the His-Purkinje system (RE-HPS) occurred consistently over a narrow range of ventricular (S1S2) coupling intervals. RE-HPS was characterized by a spontaneous beat (V3) inducible by critically timed premature stimuli (S2) during constant ventricular drive (S1S1), and was dependent upon critical retrograde conduction delay within the HPS (S2H2 interval). Lidocaine abolished RE-HPS in six of 11 patients (group 1) and shortened the zone of RE-HPS in five of 11 patients (group 2). In group 1 after lidocaine, critical S2H2 intervals for RE-HPS were not attained at any S1S2 in four patients and critical S2H2 intervals were equaled but not exceeded in two patients without resulting in RE-HPS. In group 2 after lidocaine. RE-HPS was present in all patients at S2H2 intervals comparable to control values; however, significantly closer S1S2 intervals were necessary to achieve these requisite S2H2 delays (p < 0.005). The longest S2H2 intervals at comparable S1S2 intervals were significantly shortened by lidocaine in 11 of 11 patients (p < 0.001). Thus, lidocaine causes a significant decrease in retrograde refractoriness within the HPS in patients with normal intraventricular conduction.
Angiographic studies of atrioventricular discordance.
Authors: Attie F , Soni J , Ovseyevitz J , Muñoz-Castellanos L , Testelli M R , Buendia A
Published: June 2012

The results and value of conventional and axial angiocardiography were studied in 26 cases of atrioventricular discordance (AVD). The angiographic anatomy of this malformation was analyzed to determine the precise characteristics of atrioventricular and ventriculoarterial connections. The left and right ventricles in atrial situs solitus and levocardia show angiographic features that differ from those seen in atrial situs solitus and dextrocardia. The same differences are found in atrial situs inversus. Regardless of the type of ventriculoarterial connections, the ventricles maintain the same angiographic characteristics. The ventricular septum in AVD in situs solitus and levocardia and situs inversus and dextrocardia has a peculiar orientation. The use of axial angiocardiography facilitates detection and localization of the ventricular septal defect. In cases of malposition of the heart, the conventional frontal view allows visualization of the ventricular septum in all of its length. The axial projection is useful in diagnosing left ventricular outflow tract obstruction.
A new approach for evaluating risk factors in coronary artery disease: a study of lipid concentrations and severity of disease in 1847 males.
Authors: Scott D W , Gorry G A , Hoffman R G , Barboriak J J , Gotto A M
Published: June 2012

Using recently developed statistical techniques, we estimated joint probability density functions for plasma cholesterol and plasma triglyceride concentrations in 12 subgroups of 1847 males with angiographically demonstrated coronary artery disease. The subjects were grouped by patterns of age, history of hypertension, history of smoking and severity of disease. From the estimated joint probability density functions, we determined the way in which the risk of severe vs moderate coronary artery disease varied with the joint variation of plasma lipids for given combinations of the other risk factors. The patterns of risk that we found are evidence of the complicated way in which the relationship between plasma lipids and the severity of coronary artery disease is affected by other risk factors.
Effect of duration of regional myocardial ischemia and degree of reactive hyperemia on the magnitude of the initial thallium-201 defect.
Authors: Wharton T P , Neill W A , Oxendine J M , Painter L N
Published: June 2012

Thallium-201 and microspheres were injected into the blood simultaneously during left circumflex (LC) occlusion in open chest dogs. The dogs were sacrificed 6-8 minutes later and regional myocardial (201)TI and microsphere concentrations determined. In dogs with permanent LC occlusion the myocardial (201)TI distribution approximated blood flow distribution as judged by the microsphere concentrations. Release of LC occlusion 45 seconds after (201)TI injection almost obliterated the myocardial (201)TI deficit in the area of the LC without changing the microsphere results, presumably a result of deposition of (201)TI during reactive hyperemia. Either delaying the onset of reflow until 3 minutes of attenuating the magnitude of reactive hyperemia by LC stenosis markedly decreased the change in (201)TI distribution due to reflow. We conclude that for a given degree of reversible regional myocardial ischemia at the time of (201)TI injection, the perfusion deficit observed on the initial scintigram will be influenced by the subsequent duration of ischemia and by the magnitude of postischemic reactive hyperemia.
Initial ventricular activation in left-sided intraventricular conduction defects.
Authors: Cannom D S , Wyman M G , Goldreyer B N
Published: June 2012

Nine patients with ECG evidence of rate-related left bundle branch block (LBBB) were studied using His bundle electrograms, electrograms from the right ventricular (RV) apex and vectorcardiograms recorded as heart rate was increased to produce LBBB. In five patients, when LBBB occurred, initially normal septal activation reversed and the HV intervals increased 10-30 msec, while the H-RVA interval did not change (group 1). Four patients had initially normal QRS duration (90-100 msec) but reversed septal activation (group 2). When LBBB developed there was no shift in either the HV interval or H-RVA interval. Only the QRS complex itself widened to distinguish these patients from group 1. These studies defined ventricular septal activation in normal conduction and in complete LBBB (group 1) and incomplete LBBB (group 2). The conduction patterns of group 1 and 2 patients are similar but are both markedly different from normal.
Adrenergic responsiveness after abrupt propranolol withdrawal in normal subjects and in patients with angina pectoris.
Authors: Lindenfeld J , Crawford M H , O'Rourke R A , Levine S P , Montiel M M , Horwitz L D
Published: June 2012

Adrenergic responsiveness after abrupt propranolol withdrawas during exogenous and esdogenous catecholamine stimulation was assessed in 10 normal subjects and 10 patients with angina pectoris. Propranolol, 160 mg/day, was administered for 2 weeks and then stopped. During an epinephrine infusion, period (p < 0.005). There were no differences from control 96 hours after the drug had been stopped in both groups or at 144 hours in the angina patients who were studied for a longer time. At 48 hours of heart rate and the pressure-rate product were significantly less than control level in the angina patient, but not in the normal subjects. Similar results were observed during exercise in both groups. The epinephrine-induced increase in free fatty acids was blocked by propranolol (p < 0.005), was still attenuated at 48 hours of withdrawals (p < 0.05), but returned to control levels thereafter in both groups. Resting serum triiodothyromine levels decreased with propranolol ( < 0.005) and remaind low throughout the withdrawal period. Measurements of dopamine beta-hydroxylase, plasma platelet factor 4, and platelet aggregation at rest and after exercise did not change significantly during or after propranolol administration. Plasma norepinephrine and epinephrine values were not changed from control during the withdrawal period at rest or after exerise. We conclude that there is no evidence of hypersensitivity to beta-adrenergically mediated responses after abrupt propranolol withdrawal.