bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of stenosis on wall motion. A possible mechanism of stroke and transient ischemic attack.
Authors: Binns R L , Ku D N
Published: June 2011

The mechanism by which atherosclerotic plaque causes stroke and transient ischemic attack is not fully understood. One possibility is that the plaque stenosis may set up hemodynamic conditions causing local arterial wall collapse. Arterial wall collapse may, in turn, affect the integrity of the plaque. This study was designed to define the effects of stenosis on the production of arterial wall collapse using a latex tube model. Stenoses ranging up to 81% by diameter were tested in a Starling resistor chamber under pulsatile pressure conditions upstream of the tube. Increasing the degree of stenosis progressively decreased the external pressure necessary to produce collapse, from 37 mm Hg with the 0% stenosis to 24 mm Hg for the 81% stenosis. The stenoses greater than 70% produced a new phenomenon of "systolic wall collapse" just distal to the stenosis. The maximum diameter decrease was 2.83 mm from the baseline diameter of 6.41 mm. Cyclic wall motion just downstream of the stenosis increased with the increased degree of stenosis from 0.34 mm at 0% stenosis to -1.28 mm at 75% stenosis. The phenomena are discussed in terms of simplified Bernoulli pressure drops. We conclude that local arterial stenosis can produce conditions favorable for wall collapse and increased wall motion at physiologic pressure and flow. This collapse may be important in the development of atherosclerotic plaque fracture and subsequent thrombosis or distal embolization.
Preservation and structural adaptation of endothelium over experimental foam cell lesions. Quantitative ultrastructural study.
Authors: Taylor K E , Glagov S , Zarins C K
Published: June 2011

To assess the extent to which endothelial cell (EC) structure is modified by hyperlipidemia and by the formation of intimal plaques, we undertook a quantitative ultrastructural study of aortic EC of cynomolgus monkeys after 3 or 6 months on an atherogenic diet. We compared EC in lesion-free areas (LFA) with EC overlying focal discrete foam cell accumulations (FDA) or covering multilayered confluent plaques (MCP). There was a 15% increase in cross-sectional lumen surface profile length over FDA or MCP compared to LFA (p less than 0.005) corresponding to the bulging contours of immediately underlying foam cells. There was, however, no increase in the number of EC per unit of surface area (26.2 +/- 4.47 per 10(4) mm2 for LFA and 26.0 +/- 4.22 for FDA) or, on cross-section, per 100 microns length of underlying internal elastic lamina (8.79 +/- 2.42 for LFA, 8.26 +/- 2.01 for MCP). Nor did the number of surrounding cells contacted by each cell over LFA or MCP differ from normolipemic controls (6.56 +/- 0.85 for LFA and 5.58 +/- 0.86 for MCP). Most ECs were markedly attenuated over lesions, and while the extent and complexity of lateral contact regions between adjacent EC was diminished, the number and complexity of basilar projections was greatly increased. These structures extended among the intimal foam cells to insert on the internal elastic lamina or on intimal matrix fibers, resulting in a 2.7-fold increase in the length of the abluminal portion of the EC profile. The perimeter of the transverse EC profiles was thereby increased from 41.4 +/- 2.12 microns in LFA to 82.2 +/- 5.21 microns over MCP (p less than 0.0001). Polarization of EC in the direction of flow diminished as lesions developed. The ratio of length to width, as well as the standard deviation of the ratio, decreased from 3.51 +/- 3.92 in LFA to 2.35 +/- 0.25 over MCP, due mainly to increases in the proportion of the cell perimeter exposed to the lumen. Lesion localization bore no relationship to the orientation of EC in corresponding locations in the normolipemic controls or in LFA immediately adjacent to plaques. Organelles of EC in hyperlipidemic animals showed features suggestive of increased metabolic activity in all regions, and stress filaments were increased in the EC attenuated over lesions. There was no evidence of EC degeneration, necrosis, or sloughing regardless of lesion location, size, or complexity.
Left ventricular ejection fraction calculated from volumes and areas: underestimation by area method.
Authors: Wisneski J A , Pfeil C N , Wyse D G , Mitchell R , Rahimtoola S H , Gertz E W
Published: June 2011

The ejection fraction is one of the most widely used measurements of left ventricular systolic function. Angiographic measurement of ejection fraction is based on determination of roentgenographic magnification and calculation of end-diastolic and end-systolic volumes, assuming a prolated ellipse. Because it is simple and radiographic magnification may not have been determined, some laboratories have obtained an "ejection fraction" by comparison of end-diastolic and end-systolic areas. A comparison of the two methods was made using ventriculograms of 538 patients from three cardiac catheterization laboratories. The area method of ejection fraction calculation consistently underestimates ejection fraction from left ventricular volumes. A regression equation was derived that allows adjustment of the ejection fraction obtained from areas to that from volumes.
Systolic anterior motion in the absence of asymmetric septal hypertrophy. A buckling phenomenon of the chordae tendineae.
Authors: Gardin J M , Talano J V , Stephanides L , Fizzano J , Lesch M
Published: June 2011

Systolic anterior motion (SAM) of the mitral valve in the absence of asymmetric septal hypertrophy or concentric left ventricular hypertrophy has been reported in several conditions. In this report we describe the clinical and echocardiographic findings in 15 patients who demonstrated SAM without associated organic heart disease (group 1, 10 patients) or in association with mitral valve prolapse (group 2, five patients). Cross-sectional echocardiography revealed the etiology of SAM in both groups to be early systolic anterior angular motion ("buckling") of mitral chordal structures, rather than movement of the body of the anterior mitral leaflet into the left ventricular outflow tract. In contrast to normal subjects and group 1, group 2 patients had auscultatory evidence of mitral prolapse, a slightly greater mean left ventricular ejection fraction (p < 0.05) (normals, 69 +/- 5.2%, group 1, 72 +/- 3.8%, group 2, 75+/- 5.6%), and a greater mean diastolic mitral valve (D-E) excursion (p < 0.05) (normals, 1.8 +/- 0.2 cm, group 1, 2.2 +/- 0.3 cm, and group 2, 2.6 +/- 0.4 cm). This spectrum of mitral excursion and left ventricular ejection fraction supports the concept that the mitral valve prolapse syndrome may have as its basis a mitral valve abnormality and/or a hyperdynamic state that predispose to both chordal buckling and mitral leaflet prolapse.
Frequency of the first heart sound in the assessment of stiffening of mitral bioprosthetic valves.
Authors: Stein P D , Sabbah H N , Lakier J B , Magilligan D J , Goldstein D
Published: June 2011

The frequency spectrum of the first heart sound (S1) was measured noninvasively in 54 patients with porcine bioprosthetic valves inserted in the mitral position. Phonocardiograms were recorded on magnetic tape on line with a signal processor with which the frequency spectrum and peak frequency of S1 were determined. In 19 patients with normal natural mitral valves, the apparent peak frequency within the range of measured frequencies of S1 was 46 +/- 2 Hz (mean +/- SEM). In 11 patients with porcine bioprosthetic valves implanted in the mitral position for less than or equal to 11/2 years, the apparent peak frequency of S1 was 43 +/- 3 Hz, which was not significantly different from S1 in patients with normal mitral valves. However, in 33 patients with porcine bioprosthetic valves in place 5-7 years, the apparent peak frequency of S1 was higher, 67 +/- 2 Hz (p < 0.001). In patients in whom the porcine bioprosthetic valve was implanted 5 years or longer, the frequency spectrum of S1 showed a greater proportion of sound energy at frequencies between 50-200 Hz compared with patients in whom the prosthetic valve was implanted 11/2 years or less. changes of the frequency of S1 in these patients may be a manifestation of stiffening of the valve as a result of early degenerative changes.
Hormonal and hemodynamic profile of an anaphylactic reaction in man.
Authors: Moss J , Fahmy N R , Sunder N , Beaven M A
Published: June 2011

A 28-year-old female undergoing elective total hip replacement experienced an anaphylactic reaction to succinylcholine. Hemodynamics, plasma histamine and catecholamines were measured. The tachycardia experienced during the reaction appeared to be secondary to the sympathoadrenal response rather than a direct chronotropic effect of histamine.
Digitalis and baroreceptor reflexes in man.
Authors: Ferrari A , Gregorini L , Ferrari M C , Preti L , Mancia G
Published: June 2011

Data in animals indicate that large amounts of digitalis potentiate arterial baroreflexes and that this factor may be important for the cardiovascular effects of the drug. To determine if arterial baroreflex potentiation also exists after administration of therapeutic doses of digitalis in man, we studied how stimulation and deactivation of arterial baroreceptors by phenylephrine and nitroglycerin injection affect heart rate and how stimulation and deactivation of carotid baroreceptors by neck suction and pressure affects blood pressure and heart rate. The study was performed in 29 normotensive or hypertensive subjects before and after injection of Lanatoside C (0.8 mg i.v.). Baroreceptor stimulation reduced heart rate and blood pressure, while baroreceptor deactivation increased both of these variables. The bradycardic and hypotensive effect of baroreceptor stimulation increased significantly after digitalis both in normotensive and hypertensive subjects. However, the tachycardic and hypertensive responses to baroreceptor deactivation were not affected by digitalis. Thus, therapeutic doses of digitalis in man enhance baroreceptor reflexes, and both the heart rate and the blood pressure reflex effects are involved. However, the enhancement occurs to a marked degree only with baroreceptor stimulation and is not evident with baroreceptor deactivation.
Combined doppler and phased-array echocardiographic estimation of cardiac output.
Authors: Magnin P A , Stewart J A , Myers S , von Ramm O , Kisslo J A
Published: June 2011

The capability of a pulsed Doppler flowmeter combined with a phased-array imaging system to measure volume flow was tested in vitro and in patients undergoing cardiac catheterization. The Doppler-phased-array system (DPA) was used to determine vessel diameter and a superimposed cursor was used to locate the range and angle of the Doppler sample volume. DPA estimates of continuous flow through tubing in a water tank correlated strongly (r = 0.99) with measured flow corresponding to physiologic ranges from 3-12 l/min. For pulsatile flow in a water tank, a correlation of r = 0.86 with measured flow was obtained, whereas DPA estimates of cardiac outputs compared with Fick estimates in the 11 patients produced a correlation of r = 0.83. These data indicate that estimates of cardiac output are possible using the DPA approach.
Computed tomography: a new method for diagnosing tumor of the heart.
Authors: Godwin J D , Axel L , Adams J R , Schiller N B , Simpson P C , Gertz E W
Published: June 2011

An unsuspected metastasis of liposarcoma of the heart was detected on a computed tomographic (CT) examination of the chest. Further CT study with i.v. contrast administration gave excellent delineation of the tumor. Compared with two-dimensional echocardiography and angiocardiography, CT was best at showing the myocardial and intrapericardial extension of the tumor, but did not show movement of the tumor during the cardiac cycle. CT is a useful noninvasive method for evaluating cardiac metastasis. Its advantages and disadvantages with respect to echocardiography and angiocardiography are discussed.
Progression of coronary atherosclerosis.
Authors: Kramer J R , Matsuda Y , Mulligan J C , Aronow M , Proudfit W L
Published: June 2011

Two hundred sixty-two patients with 50% or greater obstruction of at least one coronary artery on the initial study underwent recatheterization 2-182 months later and were evaluated for progressive arterial changes. Progression was considered present if (1) a change from less than total obstruction to total obstruction occurred in any vessel; (2) a change from 70% or less to 90% or more occurred in any vessel; (3) a change from 30% or less to 50% or more occurred in any vessel not initially obstructed by 50%; or (4) a 20% or more increase in obstruction was noted in any vessel already narrowed 50% or more. Of the 262 patients, 116 of 238 men (49%) and 12 of 24 women (50%) met the criteria for progression. Risk factors determined at the time of the initial catheterization in patients who met the criteria for progression were compared with risk factors in patients who did not. No significant difference could be found between the groups in relation to family history, blood pressure, diabetes, smoking habits, weight, cholesterol levels, triglyceride values, initial ECG and initial catheterization findings. The frequency of detecting progressive arterial changes tended to increase as the interval between studies increased (p less than 0.001). The frequency of multiple vessel progression increased as the interval between studies increased. Progression was more frequent in patients younger than 50 years than it was in patients 50 years and older.
Platelet survival and the development of coronary artery disease in the young adult: effects of cigarette smoking, strong family history and medical therapy.
Authors: Fuster V , Chesebro J H , Frye R L , Elveback L R
Published: June 2011

Cigarette smoking or a strong family history of coronary disease was present in 46 of 50 symptomatic patients with coronary artery disease who were younger than 50 years of age. We recorded a shortened platelet survival half-life (less than 92 hours) with 51Cr in 60% of these patients, in 56% of apparently normal persons of the same age who smoked or had a strong family history of coronary disease, and in only 14% of normal persons who did not smoke and had no family history (p less than 0.01). Lengthening of the shortened platelet survival toward normal occurred in coronary patients given dipyridamole plus aspirin and in apparently normal smokers who discontinued smoking (p less than 0.01). The study suggests a possible relationship among cigarette smoking, strong family history of coronary disease and platelet activation in the process of coronary atherogenesis in the young adult.
Reduction of CK and CK-MB indexes of infarct size by intravenous nitroglycerin.
Authors: Bussmann W D , Passek D , Seidel W , Kaltenbach M
Published: June 2011

The effect of i.v. nitroglycerin administration on indexes of infarct size was examined in 31 patients with acute myocardial infarction. Serial creatine kinase (CK) and CK-MB isoenzyme determinations were used to calculate infarct size. Twenty-nine patients served as controls. Two subgroups of the study group were formed to evaluate differences between early and late intervention. In the first group (n = 22), continuous infusion of nitroglycerin over 48 hours was initiated within 8 hours (mean 4.5 hours) after the onset of symptoms. Peak CK activity for the nitroglycerin-treated patients (n = 9) in this subgroup was 544 U/1 vs 871 U/1 for the controls (n = 13) (p less than 0.05). The rate of CK release was reduced from 79 to 33 U/1.hr (58%), as was total CK and CK-MB release (p less than 0.02). Calculated infarct size was 69 gEq in the controls and 48 gEq in patients receiving nitroglycerin (CK-MB: 69 vs 43 gEq, p less than 0.05). In the late intervention subgroup, nitroglycerin therapy was begun more than 8 hours (mean 12.8 hours) after the onset of symptoms. Here, too, use of the agent was associated with lower peak CK and CK-MB levels as well as a reduction in calculated infarct size (p less than 0.05). Hemodynamic measurements, recorded every 4 hours, showed that nitroglycerin also reduced left ventricular filling pressure significantly and cardiac output increased. Blood pressure fell slightly, and systemic vascular resistance declined. The results indicate that i.v. nitroglycerin reduces CK and CK-MB release and thus calculated infarct size in both early and late intervention.
Effects of minoxidil on hemodynamics in patients with congestive heart failure.
Authors: Franciosa J A , Cohn J N
Published: June 2011

Vasodilators used in chronic congestive heart failure are not optimal in that nitrates are predominant venodilators, prazosin is associated with tolerance development, and hydralazine produces chronic toxicity. Therefore, we studied the acute hemodynamic effects of a single dose of minoxidil in 18 patients with chronic left ventricular failure caused by ischemic or primary cardiomyopathy. Peak effects were observed 5 hours after single oral doses of minoxidil, averaging 15.3 +/- 1.4 mg (SEM). Heart rate rose slightly, from 85.4 +/- 2.9 to 90.9 +/- 3.2 beats/min, after minoxidil (p less than 0.02) and mean arterial pressure fell slightly, from 88.0 +/- 2.3 to 84.9 +/- 2.5 mm Hg (p less than 0.05). Cardiac index increased from 2.34 +/- 0.l4 to 2.95 +/- 0.29 l/min/m2 after minoxidil (p less than 0.02) and systemic vascular resistance fell from 19.6 +/- 1.5 to 15.0 +/- 1.3 units (p less than 0.01). Minoxidil did not affect right atrial, pulmonary arterial and pulmonary wedge pressures. Hemodynamic effects of minoxidil persisted for at least 8 hours after a single dose. Minoxidil appears to be an effective arterial dilating agent in patients with heart failure and resembles hydralazine in its actions. Because of its potency, prolonged duration of action and relatively low toxicity, minoxidil may be a useful vasodilator for heart failure. However, its long-term effect must be further evaluated.
Two-dimensional echocardiographic visualization of the left coronary artery in anomalous origin of the left coronary artery from the pulmonary artery. Pre- and postoperative studies.
Authors: Fisher E A , Sepehri B , Lendrum B , Luken J , Levitsky S
Published: June 2011

Three young children with anomalous origin of the left coronary artery (LCA) from the pulmonary artery were studied by two-dimensional echocardiography. The LCA was shown to be in confluence with the left posterior aspect of th pulmonary artery root in the two patients studied preoperatively. In one of these patients, and in another patient 2 years after surgery, studied after direct surgical implantation of the LCA to the aorta, the LCA was shown to be confluent with the left anterior aspect of the aortic root. In all, the LCA could be followed beyond the branching point. This study demonstrates the feasibility of noninvasive diagnosis of anomalous origin of the LCA from the pulmonary artery by direct visualization with two-dimensional echocardiography.
Calcific deposits developing in a bovine pericardial bioprosthetic valve 3 days after implantation.
Authors: Ishihara T , Ferrans V J , Jones M , Cabin H S , Roberts W C
Published: June 2011

Calcific deposits, localized in a thin layer of thrombus covering the cuspal surfaces, were present 3 days after implantation in a valved pulmonic conduit that contained an Ionescu-Shiley bovine pericardial valve and was placed in a 29-year-old man with double outlet right ventricle, valvular and infundibular pulmonic stenosis, and ventricular septal defect. Factors that may have contributed to such a rapid calcification were the relatively young age of the patient, the development of acute renal insufficiency postoperatively, and the administration of large amounts of calcium chloride intravenously during blood transfusions and during episodes of cardiac arrest.
Repetitive responses to single ventricular extrastimuli in patients with serious ventricular arrhythmias: incidence and clinical significance.
Authors: Ruskin J N , DiMarco J P , Garan H
Published: June 2011

Electrophysiologic studies were carried out in 85 patients with serious ventricular arrhythmias: 44 with recurrent sustained ventricular tachycardia (group A), 16 with recurrent nonsustained ventricular tachycardia (group B), and 25 with recent prehospital ventricular fibrillation not associated with acute myocardial infarction (group C). Programmed ventricular stimulation from the right ventricular apex included premature stimulation during normal sinus rhythm, atrial pacing, and ventricular pacing, as well as brief bursts of rapid ventricular pacing (RVP). A repetitive ventricular response (RVR) was defined as one or more non-stimulated premature ventricular depolarizations in response to a single paced premature ventricular depolarization during normal sinus rhythm or atrial pacing. RVRs were observed in seven of 44 (16%) group A patients, one of 16 (6%) group B patients, and three of 25 (12%) group C patients. In contrast, single and double premature ventricular stimuli during ventricular pacing and/or bursts of RVP resulted in the reproducible initiation of ventricular tachycardia in 40 of 44 (91%) group A patients, 10 of 16 (63%) group B patients, and 19 of 25 (76%) group C patients. We conclude that RVRs to single ventricular extrastimuli during normal sinus rhythm or atrial pacing are rare, and therefore are an insensitive index of susceptibility to serious ventricular arrhythmias in these patients.
Frequency and clinical significance of failure to visualize the conus artery during coronary arteriography.
Authors: Levin D C , Beckmann C F , Garnic J D , Carey P , Bettmann M A
Published: June 2011

In patients with occlusion of the left anterior descending coronary artery (LAD) or right coronary artery (RCA), the conus artery, which arises at or near the origin of the RCA, often serves as a principal source of collateral circulation. Coronary arteriograms in 508 adult patients revealed that in 80.5% the conus artery was well visualized on the RCA angiogram, but that in 19.5% it was not adequately visualized due to injection of contrast distal to its origin. In the latter patients, the presence of conus-LAD or conus-RCA collaterals might therefore go undetected. Because the degree of distal filling via collateral circulation affects medical and surgical decisions, it is important to attempt to visualize the conus artery adequately whenever the LAD or RCA is obstructed.
Treatment of variant angina with drugs: a survey of 11 cardiology institutes in Japan.
Authors: Kimura E , Kishida H
Published: June 2011

Data from 11 cardiology institutes in Japan were examined to determine the effectiveness of drug therapy, especially with calcium antagonists, on variant angina. The subjects were 243 males and 43 females, most of whom were 40-59 years old. Coronary artery lesions were found in 92 of 162 patients (56.7%) in whom cinecoronary arteriograms were done. The efficacy rates of nifedipine, diltiazem and verapamil were 94.0%, 90.8% and 85.7%, respectively. Regardless of the presence or absence of organic coronary artery lesions, the drugs were effective in 92.3% of the patients with normal or nearly normal coronary arteries and in 82.6% of those with stenosis of more than 50% of the luminal diameter. These findings suggest that the drugs are effective through their antispasmodic actions.
The effects of large negative intrathoracic pressure on left ventricular function in patients with coronary artery disease.
Authors: Scharf S M , Bianco J A , Tow D E , Brown R
Published: June 2011

Using first-pass radionuclide ventriculography, we evaluated the effects of decreases in intrathoracic pressure (Mueller maneuver [M] to -20 to -30 cm H2O) in 14 patients with five patients without coronary artery disease (CAD) and in 12 normal control subjects. In the patients with CAD, control ejection fraction was 0.53 +/- 0.06 (SEM) and control heart rate was 83 +/- 6 beats/min. These did not change during M. In the patients with CAD, control ejection fraction was 0.37 +/- 0.03 and heart rate was 82 +/- 7 beats/min. During M, heart rate did not change, but ejection fraction decreased to 0.33 +/- 0.33 (p less than 0.01). Examination of regional wall motion abnormalities showed akinesis of at least one myocardial segment in nine of 14 patients with CAD, but in none of the patients without CAD, nor in any of the 12 previously studied normal subjects (retrospectively analyzed). These data are consistent with the hypothesis that the Mueller maneuver acts to increase afterload placed on the left ventricle. Furthermore, in patients with CAD, the Mueller maneuver may have induced localized myocardial ischemia or unmasked areas of preexisting marginal function.
Hemodynamics alterations induced by isoproterenol and pacing after aortic valve replacement with the Björk-Shiley or St. Jude medical prosthesis.
Authors: Thormann J , Gottwik M , Schlepper M , Hehrlein F
Published: June 2011

Stress evaluation was carried out in 26 patients approximately 7 months after aortic valve replacement with Björk-Shiley valves (13 patients) and St. Jude medical valves (13 patients). During isoproterenol infusion (0.3 micrograms/kg/min), cardiac output increased by a factor of 1.5 and aortic valve area decreased by 50% for both valve groups, while transvalvular gradients (rest: 7 +/- 2 vs 10 +/- 5 mm Hg, p greater than 0.05) increased by 42 +/- 18 vs 51 +/- 18 mm Hg (p greater than 0.05), i.e., to levels of moderate aortic stenosis. However, during pacing stress these values progressively decreased with rising heart rates. In other postoperative evaluations that included ergometric stress with isoproterenol and pacing, induced hemodynamic changes after aortic valve replacement were predictable and consistent with regard to both direction and magnitude, and they differed characteristically according to the type of stress used. We conclude that no functional differences between Björk-Shiley and St. Jude medical valves can be claimed. Standardized evaluation with isoproterenol is a sensitive stress test of prosthetic valvular hemodynamics. Because of the apparent magnification of residual obstruction after aortic valve replacement, it has advantages over pacing.
Usefulness of the Valsalva maneuver in management of the long QT syndrome.
Authors: Mitsutake A , Takeshita A , Kuroiwa A , Nakamura M
Published: June 2011

Exercise or isoproterenol infusion may evoke ventricular arrhythmias in patients with the long QT syndrome. We examined the electrocardiographic effects of the Valsalva maneuver in eight patients with the long QT syndrome and nine healthy subjects. The Valsalva maneuver lengthened the QTc interval in both groups, but the lengthening was greater in the patients. In the patients who were having frequent attacks of ventricular tachycardia, the Valsalva-induced prolongation of the QTc interval was particularly remarkable and was associated with the development of T-wave alternans and short runs of ventricular tachycardia. Propranolol effectively suppressed the lengthening of the QTc interval during Valsalva strain and prevented Valsalva-induced ventricular arrhythmia. These results suggest that the Valsalva maneuver may be useful in evaluating the risk of ventricular tachyarrhythmias and the efficacy of drug treatment in patients with the long QT syndrome.
Changes in cardiovascular health knowledge occurring from childhood to adulthood. A cross-sectional study.
Authors: White C W , Albanese M A
Published: June 2011

A standardized test of cardiovascular health knowledge was administered to 1367 students, ages 12-18 years, and 562 adults, ages 20-60 years. Mean scores were: ages 12-14 years, 42.5 +/- 0.7% (SEM); 15-18 years, 49.1 +/- 0.1%; 20-40 years, 68.7 +/- 0.7%; 40-60 years, 68.2 +/- 0.7% correct. Cardiovascular health knowledge increased linearly in the student population, averaging 3.08% per year. Increases continued to occur in adults, but plateaued after age 40 years, despite an increasing incidence of cardiovascular disease in this age group. Health knowledge was highly correlated with the highest educational achievement. At all age levels, knowledge of diagnostic tests was highest and knowledge of pathophysiology lowest. A personal or family history of heart disease or history of an elevated serum cholesterol was not a stimulus for increases in health knowledge.
Left ventricular hypertrophy: relationship of anatomic, echocardiographic and electrocardiographic findings.
Authors: Reichek N , Devereux R B
Published: June 2011

Anatomic, echocardiographic and ECG findings of left ventricular hypertrophy (LVH) were compared in 34 subjects. Echocardiographic LV mass correlated weel with postmortem LV weight (r = 0.96) and accurately diagnosed LVH (sensitivity 93%, specificity 95%). In contrast, Romhilt-Estes (RE) point score and Sokolow-Lyon (SL) voltage criteria for ECG LVH were insensitive (50% and 21%, respectively) but specific (both 95%). RE correlated weakly with LV weight (r = 0.64), but SL did not. Echocardiographic LV mass was then compared with RE and SL in an unselected clinical series of 100 subjects, in 28 subjects with severe aortic stenosis (AS) and in 14 with severe aortic regurgitation (AR). Results in the clinical series were comparable to those in the necropsy series. In the AS and AR groups, with a high prevalence of LVH, the low sensitivity of RE point score and Sl criteria led to poor overall results. Analysis of individual ECG variables showed that most voltage information is contained in leads aVL and V1. Correction of voltage for distance from the left ventricle did not substantially improve results. Individual nonvoltage criteria were each nearly as sensitive as RE point score. We could not devise new ECG criteria that improved diagnostic results. We conclude that the ECG is specific but insensitive in recognition of LVH. Moreover, when true LVH prevalence is less than 10%, more false-positive than true-positive diagnoses will be obtained. M-mode echocardiographic LV mass is superior to ECG criteria for clinical diagnosis of LVH.
The relationship of pulmonary valve motion to the motion of surrounding cardiac structures: a two-dimensional and dual M-mode echocardiographic study.
Authors: Green S E , Popp R L
Published: June 2011

To assess the relationship of late diastolic pulmonary valve motion to motion of adjacent cardiac structures, we performed two-dimensional and dual M-mode echocardiography on 15 pulmonary normotensive (group A) and nine pulmonary hypertensive subjects (group B). Simultaneous pulmonary valve and posterior aortic wall a-waves were less prominent in group B than in group A (p less than 0.001), and their amplitudes were linearly related within each group (r = 0.83). Analysis of two-dimensional studies confirmed a relationship between pulmonary valve and posterior aortic wall late diastolic motion. No subject had independent presystolic motion of the pulmonary valve within the pulmonary artery. Subjects with shallow a-waves had impaired left atrial emptying compared with those with normal a-wave amplitudes (p less than 0.01). We conclude that the pulmonary valve a-wave does not represent independent valvular displacement, but rather, reflects motion of the entire cardiac base. Variations in a-wave morphology may result, at least in part, from the effects of altered ventricular geometry and compliance on left atrial emptying.
Radiation exposure to the pediatric patient during cardiac catheterization and angiocardiography. Emphasis on the thyroid gland.
Authors: Martin E C , Olson A P , Steeg C N , Casarella W J
Published: June 2011

Thermoluminescent dosimetry was used to measure the radiation exposure to the skin, thyroid and gonads in 50 consecutive pediatric patients undergoing cardiac catheterization and angiocardiography using cine photofluorography. Average exposures were 17.1 R to the skin, 2.3 R to the thyroid and 0.1 R to the gonads. Fluoroscopy accounted for approximately 80% of the skin and thyroid exposure and cine photofluorography for 20-25%. Occasional primary-beam irradiation was the major contributor to gonad exposure. Internal scatter of the incident x-ray beam was primarily responsible for thyroid exposure, so that infants received relatively high exposures; one receiving 7.3 R. The thyroid was not frequently in the primary beam. The significance of high radiation exposure to the thyroid, and in particular its relationship to thyroid carcinoma, are discussed. The results are compared with other series in the literature and relative exposures of cine photofluorography and serial filming are contrasted.
Use of postmenopausal hormones and risk of myocardial infarction.
Authors: Bain C , Willett W , Hennekens C H , Rosner B , Belanger C , Speizer F E
Published: June 2011

Information was collected by mail survey about myocardial infarction (MI), use of female hormones after menopause, and coronary risk factors 121,964 registered nurses ages 30-55 years. One hundred twenty-three women with a known type of prior menopause reported hospitalization for MI. Overall, use of female hormones by these women was very similar to that of control women matched for age and type of menopause. Compared with nonusers, the relative risk (RR) for women who had ever taken female hormones was 0.9 (95% confidence limits 0.6-1.2), and for current users the RR was 0.7 (0.5-1.1). For women with bilateral oophorectomy, the RR for current users was 0.4 (0.2-0.8). These data imply that, at present, a decision to prescribe postmenopausal hormones should be based primarily on weighing possible benefits from the relief of menopausal symptoms against unknown or suspected risks of other diseases, particularly uterine cancer in women with an intact uterus.
Detection of residual myocardial function in acute transmural infarction using postextrasystolic potentiation. A computerized angiographic study.
Authors: Azancot I , Beaufils P , Masquet C , Georgiopoulos G , Babalis D , Lorente P , Baudouy Y , Slama R , Bouvrain Y
Published: June 2011

Twelve subjects without clinical or hemodynamic heart failure, admitted for a first untreated anterior transmural myocardial infarction, were evaluated within the first 24 hours after the onset of symptoms. Pulmonary angiography was performed while a right ventricular extrastimulus was delivered every fourth beat at 50% of the RR interval to systematically analyze the basal and the postextrasystolic left ventricular frames. Left ventriculograms were quantitatively processed to determine the ejection fraction (EF) and the percentage of the end-diastolic circumference showing hypokinetic (%HK) or akinetic (%AK) areas. Left ventricular angiography was performed 1 month later in all cases at the same paced atrial heart rate to compare this final angiogram to the basal and the electrically induced postextrasystolic initial beats. During the 1-month period of the study none of these subjects had complications such as recurrent chest pain, heart failure or rhythm disturbances, and no drug administration was necessary. Comparing the basal cycle of the initial angiogram and the final cycle, a poor correlation was found between the corresponding values of EF (r = 0.34), %HK (r = 0.38) and %AK (r = 0.48). The correlations were much better when a comparison was made between the postextrasystolic cycle of the initial angiogram and the final cycle (EF, r = 0.84; %HK, r = 0.96; %AK, r = 0.95). These results indicate that, from the first day after a TMI, the analysis of the postextrasystolic frame allows accurate estimation of the final left ventricular function and regional wall motion abnormalities. Postextrasystolic potentiation may be useful in the acute state of transmural infarction to discriminate potentially reversible ischemic from definitely jeopardized areas.
Use of signals in the terminal QRS complex to identify patients with ventricular tachycardia after myocardial infarction.
Authors: Simson M B
Published: June 2011

Small, high-frequency electrocardiographic signals were recorded from the body surface in 39 patients with and 27 patients without ventricular tachycardia (VT). All patients were in normal sinus rhythm, had a previous myocardial infarction, were not taking antiarrhythmic drugs, and did not have bundle branch block. Bipolar X, Y, Z leads were signal averaged and processed by a bidirectional digital filter that allowed low-amplitude signals to be detected in the terminal QRS complex and ST segment. The high-pass filter frequency was 25 Hz. Patients with VT had a lower amplitude of high-frequency signal in the late QRS complex. In the last 40 msec of the filtered QRS complex, the patients with VT had 14.9 +/- 14.4 microV of high-frequency signal; patients without VT had 73.8 +/- 47.7 microV (p less than 0.0001). Ninety-two percent of the patients with VT had less than 25 microV of high-frequency voltage; only 7% of patients without VT had less than 25 microV (p less than 0.0001). Patients with VT had a longer QRS duration than those without VT, 139 +/- 26 vs 95 +/- 10 msec (p less than 0.0001). The QRS duration was longer than 120 msec in 72% of the patients with VT but in none of the patients without VT (p less than 0.0001). In all patients there was no separate and discrete high-frequency signal in the ST segment. Advanced signal processing of the ECG accurately identified the patients in the study with VT after myocardial infarction.
Noninvasive assessment and differentiation of left ventricular outflow obstruction with Doppler ultrasound.
Authors: Hatle L
Published: June 2011

Blood flow velocities in the left ventricle and the ascending aorta were recorded noninvasively with Doppler ultrasound. The ultrasound beam was aligned as much as possible to the direction of velocity, using the frequency shift in the audio signal as a guide to obtain velocities as close as possible to those present. From the maximal velocity recorded by continuous-wave Doppler, a peak pressure drop was calculated in 24 patients with aortic valve stenosis and nine with fixed subaortic stenosis. Fourteen patients with aortic stenosis and three with fixed subaortic stenosis were catheterized. In these patients, the correlation between calculated pressure drops and those obtained by pressure recording was good (r = 0.85). The pressure drop can be underestimated by underestimating velocity, but cannot be overestimated. With pulsed Doppler, the level of obstruction can be determined.
Ventricular septal rupture: a review of clinical and physiologic features and an analysis of survival.
Authors: Radford M J , Johnson R A , Daggett W M , Fallon J T , Buckley M J , Gold H K , Leinbach R C
Published: June 2011

Forty-one patients with postinfarction ventricular septal rupture were cared for in our hospital during 1971-1975. Cardiogenic shock developed after septal rupture in 55% of these patients. Shock was unrelated to site of infarction, extent of coronary artery disease, left ventricular ejection fraction, or pulmonary-to-systemic flow ratio, but mean pulmonary artery pressure was lower in shock than in nonshock patients. These observations suggest that shock was produced mainly by right ventricular impairment. Perioperative survival was much higher in patients who did not have shock preoperatively (14 of 17 [82+]) than in those who did (three of 11 [27%]). Magnitude of shunt, left ventricular ejection fraction, extent of coronary artery disease, and performance of aortocoronary bypass grafting were not distinctly correlated with perioperative survival. After a minimum 4-year follow-up, 76% of the perioperative survivors are alive, and none suffer more than New York Heart Association functional class II disability. All 13 unoperated patients (11 in shock) died within 3 months.
Clinical validity of a negative venogram in patients with clinically suspected venous thrombosis.
Authors: Hull R , Hirsh J , Sackett D L , Taylor D W , Carter C , Turpie A G , Powers P , Gent M
Published: June 2011

Although it is generally accepted that negative venography excludes deep vein thrombosis (DVT) in patients in whom it is clinically suspected, there is no evidence to support this conclusion. To test the correctness of withholding anticoagulant therapy in these patients, we followed 160 consecutive patients who had clinically suspected DVT and negative venograms to determine the frequency of postvenographic DVT. Anticoagulant therapy was withheld in all patients. No patient died or developed pulmonary embolism during 3 months of follow-up. Two of the 160 patients (1.3%) attended the clinic on an emergency basis during follow-up with new symptoms of DVT and in both patients, DVT was confirmed by objective testing. These events developed within 5 days of venography, which suggests that they were induced by venography. Nevertheless, the findings indicate it is safe to withhold treatment in patients with clinically suspected DVT and negative venograms.
Cardiac tamponade in medical patients.
Authors: Guberman B A , Fowler N O , Engel P J , Gueron M , Allen J M
Published: June 2011

We reviewed the cases of 56 medical patients wih cardiac tamponade who were treated at the University of Cincinnati. A paradoxic arterial pulse was critical in the diagnosis because most patients did not have a small quiet heart, and blood pressure was often well maintained. Fifty-two of 55 patients had enlarged cardiac silhouette by chest radiogram; heart sounds were diminished in 19 patients; arterial systolic pressure was greater than or equal to 100 mm Hg in 35, and arterial pulse pressure was greater than or equal to 40 mm Hg in 27. Echocardiograms in 23 patients showed abnormally increased right ventricular dimensions and decreased left ventricular dimensions during inspiration, except in one patient with left ventricular dysfunction. The causes of cardiac tamponade were metastatic tumor in 18 patients, idiopathic pericarditis in eight and uremia in five; five cases of tamponade occurred after heparin administration in acute cardiac infarction. Myxedema and dissecting aneurysm each caused tamponade in two patients. Pericardiocentesis relieved tamponade initially in 40 of 46 patients; however, two suffered fatal complications. Pericardial resection was done in 18, including 12 of these 46.
Changes in ischemic blood flow distribution and dynamic severity of a coronary stenosis induced by beta blockade in the canine heart.
Authors: Buck J D , Hardman H F , Warltier D C , Gross G J
Published: June 2011

The effects of equipotent beta 1-receptor-blocking doses of propranolol, metoprolol and sotalol on distal coronary pressure, stenosis resistance and regional myocardial blood flow (endo/epi) were studied in anesthetized dogs with a severe noncircumferential stenosis of the left circumflex coronary artery. No significant differences between the three beta blockers were observed for overall hemodynamics and regional myocardial blood flow. After drug treatment, subendocardial blood flow (0.47 +/- 0.05 to 0.78 +/- 0.05 ml/min/g) and endo/epi (0.67 +/-0.04 to 1.18 +/- 0.04) increased significantly (p less than 0.05) in the ischemic region. These changes were associated with a marked increase in distal coronary perfusion pressure and a decrease in heart rate. Resistance across the stenosis decreased significantly (p less than 0.05) after beta-receptor blockade (3.2 +/- 0.3 to 1.4 +/- 0.2 units). Atrial pacing to control heart rate only partially attenuated these changes. These results suggest that a favorable redistribution of ischemic blood flow after beta blockade is the result of an increase in distal diastolic pressure-time index and an autoregulation-induced increase in distal bed vascular resistance due to a decrease in myocardial oxygen demand associated with beta blockade. The latter effect also resulted in a decrease in the dynamic severity of a proximal coronary stenosis.
Cardioprotective effects of lidoflazine during 1-hour normothermic global ischemia.
Authors: Flameng W , Daenen W , Borgers M , Thone F , Xhonneux R , van de Water A , van Belle H
Published: June 2011

The cardioprotective effects of lidoflazine, a drug with calcium homeostatic properties, were investigated in dogs subjected to 1 hour of normothermic global ischemia, followed by reperfusion. None of the eight control dogs could be weaned from the extracorporeal bypass, confirming the severity of the ischemic model. All eight acutely pretreated dogs showed rapid recovery from the prolonged ischemic arrest and could support their own circulation. Recovery of preischemic values was 95% for systolic aortic pressure, 71% for diastolic aortic pressure, 99% for left ventricular dP/dt max and 80% for cardiac output. Light and electron microscopy and calcium cytochemistry were performed on left ventricular biopsies taken before, during and after ischemic arrest. In the control dogs, loss of structural integrity of the sarcolemma and mitochondria was prominent at the end of the ischemic period. Intracellular edema, hypercontraction of sarcomeres and great accumulation of calcium in severely damaged mitochondria occurred after 5 and 30 minutes of reperfusion. In the lidoflazine-treated dogs, such lesions were largely prevented during the ischemic period and completely reversed after reperfusion. These observations suggest that the tolerance of ischemia is markedly augmented by lidoflazine.
Effects of quinidine on atrioventricular nodal reentrant paroxysmal tachycardia.
Authors: Wu D , Hung J S , Kuo C T , Hsu K S , Shieh W B
Published: June 2011

Electrophysiologic studies were performed in 14 patients with atrioventricular nodal reentrant paroxysmal tachycardia (PSVT) before and after oral administration of 1.2-1.6 g quinidine sulfate over a 24-hour period (0.3-0.4 g every 6 hours). Studies were performed after 0.5-1 mg i.v. atropine before and after quinidine. All 14 patients had induction of sustained PSVT before quinidine, with or without atropine. After quinidine, 11 patients lost the ability to induce echoes or sustain PSVT, reflecting depression of the retrograde pathway with either absence of atrial echoes (six patients) or induction of nonsustained PSVT, with termination of echoes or PSVT occurring after QRS (block in retrograde pathway) (five patients). In only one of these 11 patients was sustained PSVT inducible after addition of atropine. All 11 were discharged on the same dose of quinidine. In three patients, quinidine was discontinued because of side effects. Follow-up in the remaining eight patients for 8 +/- 2 months showed no recurrence of sustained PSVT. Three of the 14 patients had induction of sustained PSVT after quinidine. Ventricular paced cycle length producing ventriculoatrial block was 314 +/- 7 msec (mean +/- SEM) before and 392 +/- 13 msec after quinidine (p less than 0.01) in the 14 patients, suggesting depression of the retrograde pathway with quinidine. In summary, quinidine inhibited induction of sustained atrioventricular nodal reentrant tachycardia with depression of the retrograde pathway. It is very effective in preventing recurrence of PSVT in most patients.