bluuebunny/crossref_metadata_2025 huggingface dataset:
Aneurysm of the left aortic sinus causing acute myocardial infarction.
Authors: Hiyamuta K , Ohtsuki T , Shimamatsu M , Ohkita Y , Terasawa M , Bekki H , Toshima H , Utsu F , Ohishi K , Koga M , Nagayama K
Published: June 2011

A 30-year-old female had an acute myocardial infarction complicated by congestive heart failure. Angiography demonstrated an aneurysm in the area of the left aortic sinus. The aneurysm compressed and displaced the main trunk of the left coronary artery and the proximal portion of the left anterior descending artery. This aneurysm was considered to be the cause of the infarction. Aortic valve replacement and removal of the aneurysm were performed. Postoperative studies revealed good function of the replaced valve, good antegrade filling of the left coronary artery, and improved left ventricular function.
The heart is in good hands.
Authors: Butler J
Published: June 2011

A review of mechanical cardiopulmonary interactions is presented and some extrapolations are made concerning cardiopulmonary resuscitation, with the following conclusions: (1) The cardiac fossa of the lungs provides a soft heart bed at normal lung volumes, but tenses at higher volumes to improve the support of the heart during postural changes. (2) The cardiac fossa is a physiologic constraint at normal heart volumes. It acts to restrict ventricular expansion before there is pericardial restriction. The physiologically useful interventricular interdependence is thereby promoted. (3) The effect of lung inflation in tensing the walls of the fossa may also sometimes embarrass both ventricles. Together with the raised intrathoracic pressure, it is responsible for the fall in left and right ventricular volumes and output during positive pressure ventilation. (4) New techniques of cardiopulmonary resuscitation depend on repeated, abrupt increases in pressure in both chest and abdomen, as in coughing.
Alpha-adrenergic blockade for variant angina: a long-term, double-blind, randomized trial.
Authors: Winniford M D , Filipchuk N , Hillis L D
Published: June 2011

Recent reports have shown that beta-adrenergic blockade may exacerbate variant angina. On theoretical grounds, alpha-adrenergic blockade may be beneficial in these patients. To test this hypothesis, we assessed the efficacy of prazosin, an alpha-adrenergic blocking agent, in six men, mean age 49 years, with variant angina. Prazosin, 14.0 +/- 2.4 mg/day (mean +/- SD) in three equal doses, was compared with placebo in a double-blind, randomized, double-crossover trial lasting 4 1/2 months: 2 weeks of open-label prazosin followed by four 1-month periods of blinded alternating therapy. No other vasoactive medications were administered during the study. Prazosin reduced sitting systolic arterial pressure from 145 +/- 18 to 127 +/- 16 mm Hg (p = 0.02), but exerted no effect on diastolic arterial pressure or heart rate. Prazosin did not change the weekly number of episodes of chest pain (2.5 +/- 2.3 with placebo vs 3.1 +/- 3.0 with prazosin, NS), nitroglycerin tablets used (3.9 +/- 3.7 with placebo vs 4.6 +/- 4.2 with prazosin, NS), or transient ST-segment deviations (by calibrated two-channel Holter monitoring for 24 hours/week throughout the study) (6.5 +/- 10.1 with placebo vs 11.8 +/- 17.4 with prazosin, NS). During prazosin therapy, three patients had orthostatic dizziness and one patient had headache. Thus, in a long-term, randomized, double-blind trial, prazosin exerted no obvious beneficial effect in patients with variant angina.
Comparative effect of verapamil and nitroglycerin on collateral blood flow.
Authors: Forman R , Eng C , Kirk E S
Published: June 2011

The effects of intracoronary verapamil and nitroglycerin on collateral blood flow were compared under conditions where coronary perfusion pressure was held constant with a servopump and the systemic effects of the drugs were minimal. Both drugs were infused into 12 anesthetized dogs after occlusion of the left anterior descending coronary artery (LAD) and regional myocardial blood flow (MBF) was measured using microspheres. Before the LAD occlusion, the myocardium not perfused by the LAD was labeled to permit calculation of the fraction of tissue normally perfused in the LAD samples and corrections for collateral flow. The central ischemic zone contained 2.5 +/- 0.3% normally perfused myocardium and a 4-mm border zone contained 26.8 +/- 4.3% normal myocardium. This border zone contained 10% of the total tissue supplied by the LAD. The MBF in the central ischemic zone increased from 0.101 +/- 0.019 to 0.113 +/- 0.022 ml/min/g after verapamil infusion (NS) and to 0.149 +/- 0.024 ml/min/g after nitroglycerin (p less than 0.01). Uncorrected MBF in the border zone increased significantly after infusion of both verapamil (0.469 +/- 0.085 ml/min/g, p less than 0.01) and nitroglycerin (0.398 +/- 0.056, p less than 0.05). When corrections were made for interdigitating normal tissue in the border zone, only the MBF after nitroglycerin was significantly increased. Thus, nitroglycerin significantly increased the collateral blood flow to ischemic tissue in the central ischemic and border zones, but verapamil did not.
Comparison of rest and exercise radionuclide angiocardiography and exercise treadmill testing for diagnosis of anatomically extensive coronary artery disease.
Authors: Campos C T , Chu H W , D'Agostino H J , Jones R H
Published: June 2011

The accuracy of rest and exercise radionuclide angiocardiography (RNA) and exercise treadmill testing (ETT) for diagnosis of three-vessel or left main coronary artery disease (extensive CAD) was determined in 544 patients. ETT and RNA sensitivities were similar (88% vs 92%, NS), but ETT was more specific than RNA (46% vs 34%, p less than 0.01). The prevalence of extensive CAD in patients with a positive treadmill (41%) increased only 3% when the RNA was also positive. However, in the 292 patients with a negative or indeterminate ETT, a positive RNA increased this prevalence from 16% to 23%, while a negative RNA decreased this prevalence to 5%. These results support the initial use of ETT followed by RNA if the treadmill is negative or indeterminate for diagnosis in a population with a high prevalence of extensive CAD. This approach separates patients into subgroups with a high or low probability of extensive CAD.
Value of two-dimensional echocardiography in endomyocardial disease with and without eosinophilia. A clinical and pathologic study.
Authors: Acquatella H , Schiller N B , Puigbó J J , Gómez-Mancebo J R , Suarez C , Acquatella G
Published: June 2011

Ten patients (six women and four men) with endomyocardial disease, four with and six without hypereosinophilia, were studied by two-dimensional echocardiography (2-D echo). Eight had biventricular congestive heart failure and two had atypical chest pain with ischemic electrocardiographic changes. The patients were 15-50 years old (mean 40 years) and duration of illness was 2-9 years (mean 4.4 years). Nine had cardiac catheterization and three pathologic examination. Characteristic 2-D echo findings included apical obliteration of one or both ventricles by echogenic material suggestive of fibrosis or thrombosis; bright, specular echoes at the cavity surface of the apical obliteration suggesting patchy calcification; preserved left apical systolic inward motion, which differed significantly from the dyskinetic motion of thrombotic apical obliteration of ischemic or Chagasic origin (p less than 0.001); involvement of the papillary muscles and posterior atrioventricular valve; preserved ventricular contractile function in most patients; and the combination of normal-to-small ventricles with large atria. None of 14 subjects with secondary hypereosinophilia followed for 15.4 months developed similar 2-D echo findings. We conclude that both forms of endomyocardial disease had a 2-D echo pattern useful for noninvasive recognition and differentiation from patients who have valvular heart disease, constrictive pericarditis and cardiomyopathies of other origins.
In vivo assessment of left ventricular wall and chamber dynamics during transient myocardial ischemia using prospectively ECG-gated computerized transmission tomography.
Authors: Mattrey R F , Slutsky R A , Long S A , Higgins C B
Published: June 2011

Seven dogs were evaluated with prospective ECG-gated computerized transmission tomography (CTT) to analyze left ventricular (LV) wall thickness and cross-sectional chamber area after acute occlusion of the left anterior descending coronary artery (LAD). ECG-gated CTT scanning during i.v. administration of contrast material was performed over the mid-left ventricle at rest, after acute occlusion of the LAD and 30 minutes after release. The extent of systolic wall thickening (EWTh) of the anterior (potentially ischemic) segment was 39.8 +/- 8.8% (SEM) in the control state and -26.0 +/- 4.7% during LAD occlusion (p less than 0.01). The nonischemic septum demonstrated a compensatory increase in EWTh, from 28.6 +/- 3.5% to 46.4 +/- 6.1% during LAD occlusion (p less than 0.05). The end-diastolic LV luminal area (LVA) increased from 17.4 +/- 0.8 cm2 in the control state to 21.0 +/- 1.1 cm2 during LAD occlusion (p less than 0.01). End-systolic LVA also increased, from 11.0 +/- 0.9 to 15.2 +/- 1.1 cm2 (p less than 0.01). In addition, the percent change in LVA from end-diastole to end-systole declined from 37.4 +/- 3.8% during control to 28.0 +/- 2.6% during LAD occlusion (p less than 0.02). In conclusion, gated CTT demonstrates that the alterations in acute ischemia are characterized by changes in regional wall thickening dynamics, consisting of wall thinning during systole in the jeopardized segment and compensatory increase in the extent of systolic thickening in the normal segment, and changes in global LV function, consisting of an increase in the LVA and a decrease in the percent change of LVA during systole. Gated CTT may be useful for monitoring regional and global effects of ischemia when subjects can be studied in the supine position and with respiration suspended for 45 seconds.
Influence of age on wall thickness, cavity dimensions and myocardial contractility of the left ventricle in simple transposition of the great arteries.
Authors: Maroto E , Fouron J C , Douste-Blazy M Y , Carceller A M , van Doesburg N , Kratz C , Davignon A
Published: June 2011

This study was carried out to establish a reference table of echocardiographic values for the left ventricle of simple d-transposition of the great arteries (d-TGA) and to determine at what age left ventricular dimensions in these patients become different from those of a normal population. Fifty-three patients with d-TGA and normal pulmonary pressure and 395 normal children ages 1 day to 10 years were studied by M-mode echocardiography. Results show that in d-TGA, left ventricular systolic and diastolic internal diameters are normal at birth. After 1 month, however, both diameters were below normal and despite a progressive increase with age, the mean values were always below normal. The mean posterior wall thickness of patients with d-TGA was also normal at birth but did not increase with age (2.3 mm in diastole and 4.3 mm in systole) and became significantly thinner than normal at 10 months of age in diastole and 7 months in systole. Septal thickness of patients with d-TGA did not differ from that of the control group. The shortening fraction and mean velocity of circumferential fiber shortening were significantly greater in d-TGA at all ages. Left ventricular measurements related to age are presented and should be of help in interpreting M-mode echocardiograms of patients with d-TGA.
Evaluation and surgical treatment of pulmonary atresia and intact ventricular septum in infancy.
Authors: Lewis A B , Wells W , Lindesmith G G
Published: June 2011

The initial surgical approach to the infant with pulmonary atresia and intact ventricular (PA-IVS) is to establish an adequate source of pulmonary blood flow and, when possible, relieve right ventricular (RV) outflow obstruction. The selection of patients for pulmonary valvotomy, alone or in combination with a systemic-pulmonary arterial shunt, depends on the presence of an RV outflow tract and the adequacy of the RV chamber. To evaluate the size of the RV cavity in PA-IVS, an RV index (RVI) was developed using biplane angiographic measurements of the sum of the tricuspid valve annulus and the RV inflow and the RV outflow tracts. The RVI was normalized by relating it to the aortic diameter (Ao) at the diaphragm (RVI/Ao). The RVI/Ao was 13.5 +/- 1.4 in 20 control subjects and only 7.3 +/- 2.6 in 26 PA-IVS patients (p less than 0.001), and was within the normal range in only two of the 26. Since 1976, pulmonary valvotomy plus a Blalock-Taussig shunt has been performed in 10 infants, with one death. Serial cardiac catheterizations in five of nine survivors demonstrated substantial RV growth in all, with the RVI/Ao increasing from an average of 8.0 to 12.5. In contrast, patients who underwent a shunt alone had no change in RV cavity size. We conclude that pulmonary valvotomy may be performed successfully in most PA-IVS patients, but usually must be combined with a systemic-pulmonary shunt. In a small minority of patients, a normal RV cavity, as evidenced by an RVI/Ao greater than or equal to 11, appears to be sufficient to sustain adequate pulmonary blood flow after valvotomy alone. The RVI/Ao ratio is a simple method of quantitatively evaluating RV cavity size and is helpful in planning the initial surgical approach for these infants.
Complete atrioventricular block in patients with atrioventricular discordance.
Authors: Huhta J C , Maloney J D , Ritter D G , Ilstrup D M , Feldt R H
Published: June 2011

Although patients with atrioventricular (AV) discordance (corrected transposition) have abnormal conduction pathways and may spontaneously develop high-grade AV block, no quantitative assessment of the risk of this happening is available. We reviewed the data on 107 patients with AV discordance ages 2-76 years (mean 22 years) at follow-up. Eighty-two patients (77%) had a ventricular septal defect, 57 (53%) had pulmonary stenosis, 35 (34%) had tricuspid insufficiency and 24 (23%) had dextrocardia. Twenty-three patients (22%) had complete AV block. This condition was present in four patients at birth and developed in 19 patients at ages 4 months to 53 years (mean 18.1 years). Nine of these patients had permanent pacemaker implantation, four at the onset of complete block and five an average of 11 years later. Nine patients have AV block but no pacemaker. One patient died suddenly. Detailed data analysis showed that with increasing follow-up the risk of natural onset AV block continued at a rate of approximately 2% per year after diagnosis. The presence of an intact ventricular septum made AV block more likely. We conclude that patients with AV discordance are at risk of developing complete AV block throughout their lives. With increasing age, this risk is approximately constant and is probably not significantly increased by corrective or palliative surgery if acute surgical AV block does not occur. Pacemaker implantation is not necessary in some children with spontaneous AV block.
Functional characteristics of sinoatrial and subsidiary pacemaker activity in the canine right atrium.
Authors: Rozanski G J , Lipsius S L , Randall W C
Published: June 2011

A canine in vitro right atrial preparation was developed to study the functional characteristics of subsidiary atrial pacemaker (SAP) activity and to compare them with those of sinoatrial node (SAN) activity. Extracellular bipolar electrodes were used to estimate the site of earliest activation and monitor spontaneous rate. Ligation of the SAN artery at the midportion of the sulcus terminalis suppressed SAN activity and usually (73.5%) elicited SAP activity in a well-defined region of the inferior atrium. SAP activity in this region required a "threshold" concentration of norepinephrine (10(-8) M) in the Tyrode's perfusate. In response to all concentrations of norepinephrine tested, SAN activity attained a greater maximum spontaneous rate than SAP activity. Cholinergic stimulation with acetylcholine or eserine elicited a greater negative chronotropic response from SAP than SAN activity. Overdrive pacing suppressed SAP activity to a significantly greater extent than SAN activity. We conclude that this in vitro preparation can be useful for studying the pharmacology and electrophysiology of subsidiary atrial pacemakers that emerge after suppression of SAN activity. In contrast to SAN activity, SAP activity requires norepinephrine and is more sensitive than SAN activity to acetylcholine and overdrive pacing. Consequently, after loss of SAN function, autonomic modulation of SAP activity may result in atrial dysrhythmias and prolonged periods of overdrive suppression.
Balloon dilation angioplasty of aortic coarctations in infants and children.
Authors: Lock J E , Bass J L , Amplatz K , Fuhrman B P , Castaneda-Zuniga W
Published: June 2011

Balloon dilation angioplasty (BDA) was attempted nine times in eight infants and children with aortic coarctation. In three infants (all with associated ventricular septal defect or atrioventricular canal and marked hemodynamic instability) dilation was attempted at a site of aortic narrowing that had not been operated on previously. Although the coarctation gradient fell 40% or more over the short term in two of the three, there was no angiographic or late gradient evidence of improvement. All three underwent subsequent coarctation surgery. Five dilations were performed in four infants and children who had previously undergone coarctation surgery (end-to-end anastomosis, attempted jump graft, and subclavian flap) and had residual gradients. Dilation was successful in all five cases, resulting in an increase in the diameter at the coarctation site (4.7 +/- 2.6 to 7.7 +/- 4.0 mm, p less than .05) and a decrease in the gradient measured 24 hr after dilation (42.0 +/- 15.5 to 11.8 +/- 11.2 mm Hg, p less than .05). In one child with a long area of hypoplasia of the thoracic aorta and similar lesions of the brachiocephalic vessels, a preliminary attempt to dilate a severely narrowed subclavian artery was unsuccessful. Postdilation angiography demonstrated evidence of intimal tears in three of five successful dilations. Follow-up (1 to 6 months) has demonstrated continued gradient relief in four of five children. BDA is frequently, but not always, a successful treatment for human aortic coarctation. The chief determinant of success appears to be the nature of the lesion; short-term changes in coarctation gradient are unreliable indicators of success of failure. Although BDA was not associated with mortality or significant morbidity in this group of patients, its role in the management of children with coarctation is yet to be determined.
Should coronary arteries with less than 60% diameter stenosis be treated by angioplasty?
Authors: Ischinger T , Gruentzig A R , Hollman J , King S , Douglas J , Meier B , Bradford J , Tankersley R
Published: June 2011

We evaluated all patients receiving percutaneous transluminal coronary angioplasty (PTCA) in the past year for mild stenosis (60% or less diameter narrowing, n = 64, group 1) and compared them with a random sample of 330 patients with greater than 60% stenosis (n = 66, group 2) treated during the same year. The degree of coronary stenosis before PTCA was 52 +/- 7% (mean +/- SD) in group 1 and 79 +/- 11% in group 2. The primary success rate was 90% (58 of 64 patients) in group 1 vs 86% (57 of 66 patients) in group 2. The incidence of complications requiring coronary surgery after PTCA failed was similar in both groups (3 of 64 in group 1, 4 of 66 in group 2), but there were four occurrences of myocardial infarction in group 1 and none in group 2 (p less than .05). Recurrence of stenosis was judged on the basis of objective data, 76% of which were angiographic data, in 97% of the patients with primary success. At a mean interval of 5 months with a mean follow-up period of 7 months, 17 of 58 patients (29%) with primary success in group 1 and 24 of 57 patients (42%) in group 2 developed restenosis. In group 1, restenosis was markedly more severe (73 +/- 15%) than initial stenosis (p less than .005), which was not the case in group 2. In conclusion, PTCA in mild stenosis has favorable primary and long-term results, yet carries the risk of myocardial infarction and emergency operation and may, in some cases, even accelerate the disease process.
Quantitative texture analysis in two-dimensional echocardiography: application to the diagnosis of experimental myocardial contusion.
Authors: Skorton D J , Collins S M , Nichols J , Pandian N G , Bean J A , Kerber R E
Published: June 2011

We postulated that the analysis of regional image texture in two-dimensional (2D) echocardiograms would be an accurate method to differentiate normal from abnormal myocardial structure. We tested this hypothesis with quantitative texture measures to study the regional, spatial distribution of echo amplitudes in 2D echocardiograms performed before and immediately after blunt left chest trauma was induced in six anesthetized dogs. After trauma the contused region of myocardium appeared brighter and exhibited an altered myocardial texture. By use of a set quantitative texture measures, we found no significant differences in pretrauma images when normal regions were compared with regions to be contused. Also, we found no difference when we compared the normal regions in each animal in pretrauma vs posttrauma images. Twelve measures, however, differentiated normal from contused regions within the posttrauma images (p values ranged from .0057 to .0001 by multivariate analysis of variance). These texture measures were capable of differentiating normal from abnormal tissue only when texture along the azimuthal (lateral) direction was calculated. We conclude that regions of myocardial contusion exhibit visibly altered local echo-amplitude patterns (altered image texture) and that these image texture alterations may be quantified with digital image analysis techniques. These findings suggest that quantitative texture calculations may be a useful approach to ultrasound tissue characterization.
Dynamics of left ventricular filling at rest and during exercise.
Authors: Carroll J D , Hess O M , Hirzel H O , Krayenbuehl H P
Published: June 2011

Left ventricular filling dynamics were examined at rest and during supine bicycle exercise in 33 patients at cardiac catheterization; 23 had coronary artery disease (ischemia group), five with prior infarction had an akinetic area at rest (scar group), and five had minimal cardiovascular disease (control). Peak filling rate and mean filling rate during the first half and second half of diastole were assessed by biplane angiography. Simultaneous micromanometer pressures were used to compute the time constant of isovolumic pressure decay (T). Peak filling rate and mean filling rate during the first half of diastole increased with exercise in all groups (from 615 to 1050 and 358 to 681 ml/sec in controls and comparably in the scar group and from 697 to 1035 and 347 to 768 ml/sec in the ischemia group). However, T was greater (reduced rate of pressure decay) with exercise in the ischemia group (38 vs 26 msec in controls; p less than .05). Changes in the atrial driving pressure for filling appeared to counterbalance the difference in T. Mean filling rate during the second half of diastole increased with exercise in controls and in the scar group but only modestly in the ischemia group (from 202 to 349 ml/sec). The reduction in late diastolic filling during exercise-induced ischemia was associated with increased filling in early diastole, with a middiastolic volume increase from 160 to 186 ml and an upward shift in the diastolic pressure-volume relation. Thus left ventricular filling is not impaired at rest in patients with coronary artery disease who have normal ejection fractions. Furthermore, the augmentation of early filling induced by exercise is not blunted but is maintained during ischemia, apparently at the expense of elevated left atrial pressure. However, late filling is restricted with ischemia by an increase in impedance.
Interventricular septal configuration as a predictor of right ventricular systolic hypertension in children: a cross-sectional echocardiographic study.
Authors: King M E , Braun H , Goldblatt A , Liberthson R , Weyman A E
Published: June 2011

Abnormal interventricular septal position and motion have been noted in patients with right ventricular pressure overload. The quantitative relationship between this alteration in septal configuration and the severity of right ventricular systolic hypertension has not been previously reported. We used cross-sectional echocardiography to assess the radius of septal curvature at end-diastole, midsystole, and end-systole in 20 normal children and 29 children (ages 2 weeks to 20 years) undergoing cardiac catheterization for a variety of congenital cardiac disorders. The measured septal radius of curvature (r) was normalized by the ideal radius (ri) for the left ventricular cavity area and then expressed as normalized septal curvature [l/(r/ri)]. A slight leftward shift and flattening of the interventricular septum occurred in the course of normal systolic contraction (mean +/- SEM normalized curvature at end-diastole 0.92 +/- 0.03 and at end-systole 0.85 +/- 0.02; p less than .05). Marked exaggeration of this configurational change occurred in patients with right ventricular systolic hypertension (right ventricular systolic pressure greater than 50% systemic pressure), with progressive loss of curvature from end-diastole (0.45 +/- 0.05) to end-systole (0.19 +/- 0.06). Normalized septal curvature correlated well with relative right ventricular systolic pressure at all three sampling periods, with the best correlation at end-systole (r = .86). End-systolic flattening of the interventricular septum thus proved to be a sensitive marker for right ventricular systolic hypertension.
Arterial baroreflex sensitivity, plasma catecholamines, and pressor responsiveness in essential hypertension.
Authors: Goldstein D S
Published: June 2011

Arterial baroreflex sensitivity, plasma norepinephrine (NE) and epinephrine (E), and pressor and depressor responses were assessed in 25 patients with essential hypertension and 29 normotensive control subjects. Sensitivity of the cardiac limb of the baroreflex was determined by blood pressure and interbeat interval responses associated with the Valsalva maneuver, externally applied neck suction and pressure, and injection of phenylephrine and nitroglycerin. By all these techniques, patients with essential hypertension had significantly decreased baroreflex sensitivity, even after adjustment for age mismatching between the hypertensive and normotensive groups. Hypertensive patients also had significantly higher mean levels of plasma NE and E in both brachial arterial and antecubital venous blood (246 vs 154 pg/ml arterial NE, 286 vs 184 pg/ml venous NE, 99 vs 55 pg/ml arterial E, and 65 vs 35 pg/ml venous E) and significantly larger pressor responses to injected phenylephrine (30.9 mm Hg/100 micrograms vs 16.7 mm Hg/100 micrograms). When baroreflex-cardiac sensitivity values measured by the various techniques were averaged, there was a significant inverse relationship between sensitivity and venous NE and between sensitivity and pressor responsiveness. The results indicate that decreased baroreflex-cardiac sensitivity, increased sympathetic outflow, and pressor hyperresponsiveness tend to occur together in some patients with essential hypertension. Decreased arterial distensibility and altered central neural integration can account for these findings.
Factors influencing the long-term prognosis of treated patients with variant angina.
Authors: Waters D D , Miller D D , Szlachcic J , Bouchard A , Méthé M , Kreeft J , Théroux P
Published: June 2011

To determine the prognosis of variant angina and the factors influencing it, 169 consecutive patients hospitalized in our coronary unit were followed for a mean of 15.3 months (range 1 to 68). Survival at 1, 2, and 3 years was 95%, 90%, and 87%, respectively; survival without myocardial infarction was 80%, 78%, and 75%. Twenty of the 22 myocardial infarctions and eight of the 14 deaths occurred within the first 3 months. Mantel-Haenszel log-rank analysis demonstrated that coronary disease, ventricular function, and the degree of disease activity were significant interdependent variables that influenced both survival and survival without infarction. At 1, 2, and 3 years, survival for patients with multivessel disease was 81%, 76%, and 66%; for patients with one-vessel disease, 97%, 92%, and 92%; and for patients without stenoses greater than or equal to 70%, 98% at each year (p = .0003). Survival without infarction at 1 year was 88% in patients with no stenoses greater than or equal to 70% and 82% in patients with single-vessel disease; it did not change thereafter in either group, but was 62%, 58%, and 50% at 1, 2, and 3 years in patients with multivessel disease (p = .001). Treatment did not influence survival in any subgroup (only 14 patients died overall) or survival without infarction in patients with multivessel disease. However, in patients without multivessel disease, treatment with nifedipine, diltiazem, and verapamil improved survival without infarction compared to treatment with perhexiline maleate or long-acting nitrates alone (92% vs 67% at 1, 2, and 3 years; p less than .005). Thus in addition to preventing angina, nifedipine, diltiazem, and verapamil appear to reduce complications in patients with variant angina without multivessel disease.
Noninvasive evaluation of pulmonary hypertension by a pulsed Doppler technique.
Authors: Kitabatake A , Inoue M , Asao M , Masuyama T , Tanouchi J , Morita T , Mishima M , Uematsu M , Shimazu T , Hori M , Abe H
Published: June 2011

We used a pulsed Doppler technique to examine the flow velocity pattern in the right ventricular outflow tract in 33 adults. In the patients with normal pulmonary artery pressure (mean pressure less than 20 mm Hg, 16 patients), ejection flow reached a peak level at midsystole (137 +/- 24 msec, mean +/- SD), producing a domelike contour of the flow velocity pattern during systole. In contrast, the flow velocity pattern in patients with pulmonary hypertension (mean pressure greater than or equal to 20 mm Hg, 17 patients) was demonstrated to accelerate rapidly and to reach a peak level sooner (97 +/- 20 msec, p less than .01); in 10 of the pulmonary hypertensive patients a secondary slower rise in flow velocity was observed during a deceleration, resulting in the midsystolic notching. The time to peak flow (acceleration time, AcT) and right ventricular ejection time (RVET) were measured from the flow velocity pattern. Either AcT or AcT/RVET decreased with increase in mean pulmonary artery pressure, and a very high correlation (r = -.90) was found between AcT/RVET and log10 (mean pulmonary artery pressure). The use of this technique permitted the noninvasive estimation of the pulmonary artery pressure.
Relationship between segmental thallium-201 uptake and regional myocardial blood flow in patients with coronary artery disease.
Authors: Nichols A B , Weiss M B , Sciacca R R , Cannon P J , Blood D K
Published: June 2011

The relationship between the spatial distribution of thallium-201 in myocardial perfusion scintigrams and the distribution of left ventricular regional myocardial blood flow was examined in 25 patients undergoing coronary arteriography. Thallium-201 myocardial scintigrams were obtained after symptom-limited exercise and after a 4 hr delay. Regional myocardial blood flow was measured by the xenon-133 clearance method in patients at rest and during rapid atrial pacing to a double product comparable with that achieved during exercise stress testing. Patterns of regional thallium-201 activity and regional myocardial blood flow, recorded in similar left anterior oblique projections, were compared for left ventricular segments supplied by the left anterior descending (LAD) and left circumflex (CIRC) arteries. In 11 patients without significant lesions of the left coronary artery (group 1), thallium-201 was homogeneously distributed in the LAD and CIRC distributions in scintigrams taken during peak exercise; these scintigrams correspond to homogeneous regional myocardial blood flow in the LAD and CIRC regions during pacing-induced stress. In 14 patients with significant lesions of the left coronary artery (group 2), ratios of regional thallium-201 activity in the LAD and CIRC distributions of exercise scintigrams correlated well (r = .84) with ratios of regional myocardial blood flow measured during rapid pacing. Background subtraction altered the relationship between relative thallium-201 uptake and regional myocardial blood flow, causing overestimation of the magnitude of flow reduction on exercise scintigrams. These data indicate that: (1) in patients with normal left coronary arteries, thallium-201 is homogeneously distributed to the left ventricle, reflecting the homogeneous distribution of regional myocardial blood flow over a wide range of mean left ventricular flow rates and (2) in patients with significant lesions of the left coronary artery, the relative spatial distribution of thallium-201 activity in exercise perfusion scintigrams reflects the distribution of regional myocardial blood flow.
Prediction of cardiac events after uncomplicated myocardial infarction: a prospective study comparing predischarge exercise thallium-201 scintigraphy and coronary angiography.
Authors: Gibson R S , Watson D D , Craddock G B , Crampton R S , Kaiser D L , Denny M J , Beller G A
Published: June 2011

The ability of predischarge quantitative exercise thallium-201 (201T1) scintigraphy to predict future cardiac events was evaluated prospectively in 140 consecutive patients with uncomplicated acute myocardial infarction; the results were compared with those of submaximal exercise treadmill testing and coronary angiography. High risk was assigned if scintigraphy detected 201T1 defects in more than one discrete vascular region, redistribution, or increased lung uptake, if exercise testing caused ST segment depression greater than or equal to 1 mm or angina or if angiography revealed multivessel disease. Low risk was designated if scintigraphy detected a single-region defect, no redistribution, or no increase in lung uptake, if exercise testing caused no ST segment depression or angina, or if angiography revealed single-vessel disease or no disease. By 15 +/- 12 months, 50 patients had experienced a cardiac event; seven died (five suddenly), nine suffered recurrent myocardial infarction, and 34 developed severe class III or IV angina pectoris. Compared with that of patients at low risk, the cumulative probability of a cardiac event was greater in high-risk patients identified by scintigraphy (p less than .001), exercise testing (p = .011), or angiography (p = .007). Scintigraphy predicted low-risk status better than exercise testing (p = .01) or angiography (p = .05). Each predicted mortality with equal accuracy. However, scintigraphy was more sensitive in detecting patients who experienced reinfarction or who developed class III or IV angina. When all 50 patients with events were combined, scintigraphy identified 47 high-risk patients (94%), whereas exercise-induced ST segment depression or angina detected only 28 (56%) (p less than .001). The presence of multivessel disease as assessed by angiography identified nine more patients with events than exercise testing (p = .06). However, the overall sensitivity of angiography was lower than that of scintigraphy (71% vs 94%; p less than .01) because three patients who experienced reinfarction and 10 who developed class III or IV angina had single-vessel disease. Importantly, 12 (92%) of these 13 patients with single-vessel disease who had an event exhibited redistribution on scintigraphy. These results indicate that (1) submaximal exercise 201T1 scintigraphy can distinguish high- and low-risk groups after uncomplicated acute myocardial infarction before hospital discharge; (2) 201T1 defects in more than one discrete vascular region, presence of delayed redistribution, or increased lung thallium uptake are more sensitive predictors of subsequent cardiac events than ST segment depression, angina, or extent of angiographic disease; and (3) low-risk patients are best identified by a single-region 201T1 defect without redistribution and no increased lung uptake.
Assessment of the opening angle of implanted Björk-Shiley prosthetic valves.
Authors: Verdel G , Heethaar R M , Jambroes G , van der Werf T
Published: June 2011

A method has been developed in which cineradiography is used for the assessment of the opening angle of implanted Bjork-Shiley prosthetic valves. The method is based on the fact that the ring and the disc, which are known to be circular, appear to be elliptical on x-ray films. The spatial position of the valve can be retrieved from the characteristics of these ellipses when vectoranalysis is applied. The method's accuracy does not depend on the position of the patient with respect to the direction of the x-ray beam. The accuracy of the method was demonstrated with the use of a phantom valve. The difference between the measured and the real opening angle was -0.7 +/- 1.8 degrees (mean +/- SD). Results were reproducible in patients to within -0.1 +/- 1.8 degrees. In 18 patients with normally functioning valves it could be demonstrated with frame-by-frame analysis (interval between frames 20 msec) that the valves opened very rapidly up to about 60 degrees. Closing patterns varied. In one of our patients with valvular thrombosis insufficient valvular opening could be demonstrated by our method before the patient's complaints drew attention to the valvular dysfunction.
Determination of anaerobic threshold for assessment of functional state in patients with chronic heart failure.
Authors: Matsumura N , Nishijima H , Kojima S , Hashimoto F , Minami M , Yasuda H
Published: June 2011

The use of anaerobic threshold in assessment of aerobic capacity was evaluated in 34 normal subjects and 47 patients with various kinds of chronic heart disease. Anaerobic threshold was determined as the oxygen consumption (VO2) at which a linear relationship between pulmonary ventilation (VE) and VO2 was lost during progressive treadmill exercise. Anaerobic threshold determined in this manner was validated with that determined by blood lactate measurements in eight normal subjects and nine cardiac patients (r = .962, p less than .001). Thereafter, anaerobic threshold was determined only by respiratory measurements. In symptom-limited, maximal exercise, anaerobic threshold was reached well before maximal effort and corresponded to 70% of maximal VO2 both in normal subjects and cardiac patients. Anaerobic threshold decreased as age progressed in normal subjects (r = - .70, p less than .001). Anaerobic threshold in cardiac patients was lower than that in the normal subjects and decreased progressively as New York Heart Association functional classification advanced (normal, 32.95 +/- 6.17 ml/min/kg; class I, 22.78 +/- 3.74; class II, 16.99 +/- 3.66; class III, 12.97 +/- 2.76; p less than .01 between each group other than between class II and class III). Anaerobic threshold in cardiac patients correlated poorly with other objective indices, e.g., cardiomegaly (r = -.54, p less than .001) and rise in pulmonary wedge pressure (r = -.64, p less than .001). At anaerobic threshold, cardiac patients subjectively graded the work load as light (13%), light-to-moderate (27%), moderate (30%), and moderate-to-heavy (28%). Thus determination of anaerobic threshold by respiratory measurements is a safe, accurate, and objective method to measure aerobic capacity in cardiac patients and in normal subjects.
Digital angiography in the pediatric patient with congenital heart disease: comparison with standard methods.
Authors: Levin A R , Goldberg H L , Borer J S , Rothenberg L N , Nolan F A , Engle M A , Cohen B , Skelly N T , Carter J
Published: June 2011

Digital subtraction angiography (DSA) permits high-resolution cardiac imaging with relatively low doses of contrast medium and reduced radiation exposure. These are potential advantages in children with congenital heart disease. Computer-based DSA (30 frames/sec) and conventional cutfilm angiography (6 frames/sec) or cineangiography (60 frames/sec) were compared in 42 patients, ages 2 months to 18 years (mean 7.8 years) and weighing 3.4 to 78.5 kg (mean 28.2 kg). There were 29 diagnoses that included valvular regurgitant lesions, obstructive lesions, various shunt abnormalities, and a group of miscellaneous anomalies. For injections made at a site distant from the lesion and on the right side of the circulation, the mean dose of contrast medium was 60% to 100% of the conventional dose given during standard angiography. With injections made close to the lesion and on the left side of the circulation, the mean dose of contrast medium was 27.5% to 42% of the conventional dose. Radiation exposure for each technique was markedly reduced in all age groups. A total of 92 digital subtraction angiograms were performed. Five studies were suboptimal because too little contrast medium was injected; in the remaining 87 injections, DSA and conventional studies resulted in identical diagnoses in 81 instances (p less than .001 vs chance). The remaining six injections made during DSA failed to confirm diagnoses made angiographically by standard cutfilm angiography or cineangiography. We conclude that DSA usually provides diagnostic information equivalent to that available from cutfilm angiography and cineangiography, but DSA requires considerably lower doses of contrast medium and less radiation exposure than standard conventional methods.
False suspicion of coronary heart disease: a 7 year follow-up study of 36 apparently healthy middle-aged men.
Authors: Erikssen J , Dale J , Rootwelt K , Myhre E
Published: June 2011

Latent coronary heart disease was suspected in 115 of 2014 apparently healthy middle-aged men after a baseline cardiovascular survey. One hundred five of these men underwent angiography and 36 were found to have normal coronary arteries (group 1). A 7 year follow-up survey revealed that: (1) three had died of sudden cardiac death, (2) four had received a diagnosis of cardiomyopathy, (3) one had developed aortic dilatation/aortic regurgitation since the baseline survey, (4) they all had a significantly more rapid decline in their physical performance and maximal heart rate levels from the time of the baseline survey to follow-up than did randomly selected normal controls (group 2), and (5) thallium study results were normal in both groups (27 and 26 patients), but technetium ventriculography revealed a subnormal increase in ejection fraction during exercise (less than 5% units) in 14 of 27 group 1 subjects and in 4 of 26 group 2 subjects. Thus, incipient heart disease may be present in subjects in whom coronary angiographic examination has removed a previous suspicion of coronary heart disease.
Recurrent sustained ventricular tachycardia: structure and ultrastructure of subendocardial regions in which tachycardia originates.
Authors: Fenoglio J J , Pham T D , Harken A H , Horowitz L N , Josephson M E , Wit A L
Published: June 2011

Surgical resection of the endocardium and subendocardium often abolishes chronic recurrent sustained ventricular tachycardia in patients with healed myocardial infarcts or ventricular aneurysms, presumably by interrupting the reentrant pathway. To define the morphologic characteristics of cells in the reentrant pathway, we studied the histology and ultrastructure of the endocardial resections of 23 patients who underwent this procedure. Bundles of apparently viable myocardial fibers embedded in dense fibrous tissue were identified throughout the endocardial resections from all patients. These bundles of cells were separated from one another by fibrous tissue but extended uninterrupted to the margins of the surgical resection. In 14 patients Purkinje fibers were identified beneath the thickened endocardium whereas the remaining bundles were composed of ventricular muscle. The Purkinje fibers appeared to have normal ultrastructure and ventricular cells with both normal and abnormal ultrastructures were present. The abnormal muscle cells were characterized by loss of contractile elements, aggregates of dilated sarcoplasmic reticulum, and osmiophilic dense bodies. The sarcolemma was intact and the nuclear chromatin was evenly dispersed suggesting that these cells were still viable. The abnormal structure and arrangement of the surviving cardiac fibers in the endocardium may cause the abnormal electrophysiologic function that results in ventricular tachycardia.
Patency of the ductus arteriosus after balloon dilatation: an experimental study.
Authors: Lund G , Cragg A , Rysavy J , Castaneda F , Salomonowitz E , Vlodaver Z , Casteneda-Zuniga W , Amplatz K
Published: June 2011

Balloon dilatation of the ductus arteriosus was carried out in vivo in newborn pigs and on postmortem specimens from humans and piglets. The ductus was functionally closed in all newborn animals but patency resulted in all animals after balloon dilatation. Left-to-right shunts of 50% to 70% were found with anatomic lumen sizes of 3 to 5 mm. Patency was demonstrated up to 6 weeks after dilatation. Histologic examination showed splitting of the internal elastic layer and media, areas of hemorrhage confined to the media, and preservation of the adventitia. Mediastinal hemorrhage did not occur. This new technique is useful as an animal model of patent ductus arteriosus and could theoretically be used for palliative treatment of ductus-dependent congenital heart disease.
Effects of calcium antagonists on the electrical alternans of the ST segment and on associated mechanical alternans during acute coronary occlusion in dogs.
Authors: Hashimoto H , Suzuki K , Miyake S , Nakashima M
Published: June 2011

Effects of calcium antagonists on the ST alternans and associated mechanical alternans during acute coronary occlusion were examined in anesthetized dogs. The heart rate was fixed by atrial pacing. The intravenous administration of 0.2 mg/kg verapamil attenuated the ST alternans as did 0.5 mg/kg diltiazem. Although these drugs significantly attenuated TQ depression during occlusion, the attenuation was observed after a longer period of occlusion and when the degree of TQ depression was comparable to that during the control occlusion. Nifedipine, 0.03 mg/kg, slightly attenuated the ST alternans, but 0.5 mg/kg dipyridamole had no effect. These results support the idea that slow inward currents are involved in the ST alternans. On the other hand, the mechanical alternans was attenuated in six of 11 dogs. It is probable that factors other than the electrical alternans may also contribute to the mechanical alternans.
Acute occlusion after percutaneous transluminal coronary angioplasty--a new approach.
Authors: Hollman J , Gruentzig A R , Douglas J S , King S B , Ischinger T , Meier B
Published: June 2011

Between July 1980 and November 1982, there were 935 coronary angioplasties attempted at Emory University Hospital. Of these patients, 20 developed acute occlusion. Of these 20, 19 presented within 3 hr of surgery or within 3 hr after stopping a continuous heparin infusion. Five patients required emergency surgery, but in 15 nitrates, nifedipine, and/or repeat angioplasty reopened the artery and the patient could be stabilized on continuous infusions of heparin and nitroglycerin. In only one case was an occluding thrombus evident on angiographic examination. The mechanism of acute occlusion is unknown, but coronary artery spasm may play a role.