bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation of platelet survival time with occlusion of saphenous vein aorto-coronary bypass grafts.
Authors: Steele P , Battock D , Pappas G , Genton E
Published: June 2012

Platelet survival time is frequently shortened in patients with coronary artery disease, and it is one of several factors that might contribute to graft occlusion after saphenous vein coronary artery bypass (CAB). In 35 patients with CAB, average platelet survival (autologous labeling with 51Chromium) was shortened in 20 with one or more saphenous vein grafts occluded and normal in 15 with all grafts open. Of 15 with all grafts open, individual levels of platelet survival were normal in 10 while in 20 with one or more grafts occluded platelet survival was normal in only one. Platelet survival was not altered by coronary surgery and nine of ten with shortened platelet survival pre-operatively had graft occlusion. Platelet survival did not correlate with either parent artery occlusion or serum lipoproteins. These findings suggest a relationship between shortened platelet survival and saphenous vein graft occlusion and suggest that platelet suppressant therapy might be useful in preventing graft occlusion.
Heparin kinetics in venous thrombosis and pulmonary embolism.
Authors: Hirsh J , van Aken W G , Gallus A S , Dollery C T , Cade J F , Yung W L
Published: June 2012

The response to a standard dose of heparin was studied in 20 patients with venous thromboembolism. The heparin regimen consisted of intravenous injection of 70 units per kg, followed after 90 minutes by a maintenance dose of 400 units per kg per 24 hours given by continuous infusion. Plasma heparin activity and the activated partial thromboplastin time (APTT) were measured at intervals to determine clearance of the initial injection and the response to maintenance dose. Large inter-individual variations were found in the anticoagulant effect and these were due in part to differences in heparin clearance and in part to differences in the APTT response to given amounts of heparin (heparin effect index). The heparin half-life was 63 +/- 15 minutes when plasma heparin activities were used for this calculation and 84 +/- 71.5 minutes when the APTT was used. These results are similar to values previously reported in normal volunteers. Four of the 20 patients had pulmonary embolism and in these heparin half-life was significantly shortened (P less than 0.005).
Incidence and significance of left anterior hemiblock complicating acute inferior wall myocardial infarction.
Authors: Kourtesis P , Lichstein E , Chadda K D , Gupta P K
Published: June 2012

The hospital course and serial vectorcardiograms of 56 consecutive patients with acute inferior wall myocardial infarction were reviewed. Left anterior hemiblock (LAH) complicating inferior wall myocardial infarction was diagnosed by vectorcardiographic criteria. Seven patients (12.5%) developed LAH between the first and third hospital day, while 49 patients did not. There was no significant difference between these two groups when compared for age, sex, incidence of congestive heart failure, atrial and ventricular arrhythmias, atrioventricular (A-V) block, hospital mortality, and previous hypertension, diabetes mellitus, and myocardial infarction. We conclude that LAH is a relatively common complication of acute inferior wall myocardial infarction, with no apparent effect on the clinical course.
Echocardiographic assessment of left ventricular function in mitral valve disease.
Authors: McDonald I G
Published: June 2012

Echocardiography was used to study left ventricular size and contraction in 90 patients with isolated mitral valve disease--47 patients with mitral stenosis, 26 with mixed mitral valve disease and 89 with mitral regurgitation. Left ventricular measurements included the end-diastolic internal dimension (LVIDd), mural thickness (PWTd), an index of circumferential myocardial contraction--fractional shortening (see article)--and stroke volume (LVSV). The left ventricle was abnormally small only when mitral stenosis was severe. Reduced myocardial contraction was common in patients with rheumatic valvular heart disease but was rarely severe. In mitral regurgitation without left ventricular failure, measurements were characteristic of volume overload with increases in LVIDd, LVSV and PWTd which were related to the severity of regurgitation. In other diseases, left ventricular failure is usually associated with reduced myocardial contraction (FS) but in mitral regurgitation with failure, myocardial contraction (FS 32%) did not differ significantly from normal (34%). The reduction in afterload caused by mitral regurgitation probably increases myocardial contraction and may lead to underestimation of the severity of myocardial impairment. Also potentially misleading was severe mitral regurgitation with normal values for LVIDd and LVSV (three patients). When the distinction between cardiomyopathy with secondary mitral regurgitation and primary mitral regurgitation was difficult clinically, echocardiography could usually make the distinction by demonstrating severe reduction of myocardial contraction with a slight or moderate increase in LVSV.
The determinants of onset of mitral valve prolapse in the systolic click-late systolic murmur syndrome.
Authors: Mathey D G , Decoodt P R , Allen H N , Swan H J
Published: June 2012

The onset of mitral valve prolapse and its close correlate, the time of systolic click, vary considerably with different physiologic and pharmacologic interventions. In order to explain the mechanism responsible for these alterations, the effects of tilt and amyl nitrite inhalation on left ventricular dynamics and the time of the systolic click were studied by analyzing echocardiograms and simultaneously recorded phonocardiograms in 14 patients with mitral valve prolapse and mid-systolic click. The patients were studied in the supine position, with 40-60 degrees head-up tilt and after amyl nitrite inhalation. Computer analysis of the recordings was used to measure the left ventricular end-diastolic diameter, the click diameter (left ventricular diameter at the time of mid-systolic click), the maximal velocity of circumferential fiber shortening (max VCF), and the time interval between the first heart sound and systolic click (S1-X). With tilt and amyl nitrite, shortening of the S1-X interval b y an average of 44 and 87 msec, respectively, was observed. The click diameter, however, remained virtually constant with both maneuvers. Earlier prolapse after tilt was due to a decrease in the end-diastolic diameter from 5.03 +/- 0.74 to 4.50 +/- 0.68 cm (P less than 0.001) with no change in max VCF. Immediately after amyl nitrite, earlier prolapse was due to an increase of VCF in the preprolapse period, with max VCF increasing from 2.15 +/- 0.27 to 3.06 +/- 0.40 circ/sec (P less than 0.001), there being no change in the end-diastolic diameter up to this time. The constant click diameter indicates that the abnormal valve motion in this syndrome occurs at a critical left ventricular chamber size. Variations in the onset of prolapse are caused by changes in left ventricular end-diastolic dimensions and the velocity of circumferential fiber shortening in the preprolapse period.
The frontal chest film as a method of suspecting transposition complexes.
Authors: Tonkin I L , Kelley M J , Bream P R , Elliott L P
Published: June 2012

The frontal chest film as a means of suspecting transposition complexes is discussed. The first step is recognizing the normal relationships formed by the ascending aorta, an aortic knob-descending aorta, and pulmonary trunk. The concept of which ventricle is connected to which atrium is developed--the terms ventricular noninversion and inversion being utilized. Frontal chest film signs of transposition are summarized as follows: 1) in the majority of transposition complexes, absence of the pulmonary trunk is the premier sign; 2) patients with ventricular noninversion tend to show the ascending aorta and aortic knob-descending aorta in normal position. Patients with ventricular inversion usually show absence of all three great artery relationships. 3) In ventricular inversion, the left heart border shows a septal notch or a diffuse convex bulge (two ventricles), or a discrete bulge high up on the left border (single ventricle).
Echocardiography in Wolff-Parkinson-White syndrome.
Authors: Chandra M S , Kerber R E , Brown D D , Funk D C
Published: June 2012

Twenty-six patients with Wolff-Parkinson-White (WPW) syndrome were studied by echocardiography. They were classified into the following WPW types: anterior right ventricular pre-excitation (Type I) - six patients; posterior right ventricular pre-excitation (Type II) - six patients; posterior left ventricular pre-excitation (Type III) - fourteen patients. Twenty-three patients were in WPW at the time of study. Four patients with Type I WPW had abnormal systolic motion of the interventricular septum: three paradoxical and one flat. Patients with Type II and Type III WPW had no septal motion abnormalities related to pre-excitation. Three patients had intermittent WPW, Type III; in all three only minor changes in normal septal motion were apparent on WPW beats. Associated cardiac abnormalities were evident in six patients: two mitral prolapse (one Type II WPS and one Tpe III); one idiopathic hypertrophic subaortic stenosis (Type III); one congestive cardiomyopathy (Type III); one hypertrophic nonobstructive cardiomyopathy (Type I); and one atrial septal defect (Type II). We conclude that abnormal interventricular septal motion may occur with Type I WPW abnormality. Other abnormalities are detectable by echocardiography in a high proportion of WPW patients, but do not appear to be associated with any single Wolff-Parkinson-White type.
Effects of perhexiline maleate on coronary flow distribution in the ischemic canine myocardium.
Authors: Klassen G A , Sestier F , L'Abbate A , Mildenberger R R , Zborowska-Sluis D T
Published: June 2012

Intravenous perhexiline maleate in a canine preparation with fixed coronary flow increases coronary diastolic pressure. It also redistributes coronary flow so as to preserve endocardial flow. Myocardial oxygen consumption was reduced and lactate uptake enhanced by the drug. It had no effect upon the threshold for ischemic-induced left ventricular failure.
The cortisol response during heart-lung bypass.
Authors: Taylor K M , Jones J V , Walker M S , Rao S , Bain W H
Published: June 2012

The response patterns of plasma cortisol and plasma free cortisol have been studied in 20 consecutive patients undergoing cardiac surgery involving the use of heart-lung bypass. Sixteen consecutive patients undergoing closed mitral valvotomy have been used as controls. Total plasma cortisol levels fell at the onset of extracorporeal circulation (ECC) and did not rise significantly throughout the period of ECC. The peak cortisol level in the bypass patients occurred at 24 hours postoperatively with elevated levels still present at 48 hours. This pattern was significantly different from the control patients (P less than 0.001) who exhibited the typical cortisol stress response pattern. Synthetic ACTH stimulation of the adrenal cortex during heart-lung bypass produced a positive response (i.e., a rise in plasma cortisol greater than 7.5 mug/100 ml) in all six patients studied while the six mitral valvotomy patients had no response to synthetic ACTH administration during operation (P less than 0.01). Plasma free cortisol estimations indicate that a rapid and significant rise in % free cortisol occurred at the onset of ECC, but that despite the rise in percentage free, the overall plasma free cortisol concentration (i.e., total plasma cortisol X % free) was significantly lower during ECC in the bypass patients when compared with control (P less than 0.01). Twenty-four hours postoperatively these concentrations were significantly higher in the bypass patients (P less than 0.001).
The early posthospital phase of myocardial infarction. Prognostic stratification.
Authors: Moss A J , DeCamilla J , Davis H , Bayer L
Published: June 2012

Prognostic stratification was carried out on 518 patients less than or equal to 65 years of age who were discharged from the hospital following a definite or probable acute myocardial infarction and followed for four months. The total population was made up of 272 patients hospitalzed in 1973 and 246 patients hospitalized in 1974; one hundred and forty-two variables were collected on each patient. The clinical characteristics of the 1973 and 1974 populations were remarkably similar, and both groups had a four-month posthospital cardiac mortality rate of 4%. Two prognostic stratification schemes were developed on the 1973 population which identified low and high risk groups with meaningfully different four-month cardiac death rates. Both stratification schemes were tested on the 1974 population, and one of the two schemes was validated as identifying a significantly increased cardiac mortality rate in the high as opposed to the low risk group. The four-month posthospital cardiac mortality rate was 3% in the low and 14% in the high risk group (Z = 2.70, P less than 0.003). The high risk group was characterized by two or more of the following characteristics: 1) history of angina at ordinary levels of activity or at rest; 2) CCU hypotension and/or congestive heart failure; 3) ventricular premature beat frequency greater than or equal to 20/hr on a six-hour electrocardiographic tape recording. The low risk group had none or only one of the above characteristcis. The prognostic power of this stratification scheme is such that sixteen percent of the posthospital population can be identified as high risk, and this subgroup contains forty-six percent of the patients who die of cardiac cause in the four-month posthospital interval.
Echocardiographic evaluation of the stent mounted aortic bioprosthetic valve in the mitral position. In vitro and in vivo studies.
Authors: Horowitz M S , Tecklenberg P L , Goodman D J , Harrison D C , Popp R L
Published: June 2012

Echocardiograms were performed on 20 clinically stable patients following mitral valve replacement with glutaraldehyde-preserved porcine aortic heterografts and three patients with antibiotic sterilized aortic homografts mounted in the mitral position. Such valves were evaluated in a test chamber at varied flow rates resulting in improved understanding of movements seen with the echocardiogram in vivo. The technique for recording the valvular stent and leaflets is described and a method for measuring several parameters is demonstrated. Initial diastolic slope averaged 2.4 +/- 0.5 cm/sec (range 1.9 to 3.3 cm/sec). Left ventricular outflow tract measured from the anterior portion of the stent to the interventricular septum averaged 1.5 +/- 0.5 cm at end-diastole and 1.3 +/- 0.6 cm at end-systole. Leaflet excursion averaged 1.5 +/- 0.3 cm (with a range from 1.0 to 2.1 cm). The ratio of internal to external stent diameters averaged 0.66 +/- 0.05 (with a range from 0.56 to 0.74).
An echocardiographic study of interventricular septal motion in the Wolff-Parkinson-White syndrome.
Authors: Francis G S , Theroux P , O'Rourke R A , Hagan A D , Johnson A D
Published: June 2012

Echocardiographic studies of interventricular septal motion were performed in 26 consecutive patients with the Wolff-Parkinson-White (WPW) syndrome and in ten normal subjects. All patients with types A or B pre-excitation were subclassified into groups I to IV on the basis of their electrocardiogram utilizing the method of Boineau and associates. In all 14 patients with type A (Group III or IV) pre-excitation, the motion of the interventricular septum and posterior left ventricular wall motion were normal. However, in 11 patients with type B (Group I) WPW an abnormal septal movement was noted. This was characterized in ten patients by an early systolic posterior motion, a subsequent anterior movement in mid systole, and the usual posterior septal motion beginning in late systole. In eight patients, including the one without early systolic posterior movement of the septum, the late systolic posterior movement was interrupted by a prominent septal notch. On e patient with type B (Group II) WPW was studied and exhibited normal septal and posterior wall motion. In one patient with a spontaneous change in the QRS complex from normal to a type B (Group I) WPW pattern, the septal motion was initially normal and abruptly changed following the first WPW beat. The onset of abnormal interventricular septal motion with type B pre-excitation QRS complexes strongly suggests that abnormal septal movement may be related to an altered sequence of ventricular depolarization during right ventricular pre-excitation.
Continuous rapid atrial pacing to control recurrent or sustained supraventricular tachycardias following open heart surgery.
Authors: Waldo A L , MacLean W A , Karp R B , Kouchoukos N T , James T N
Published: June 2012

A technique is described to control recurrent or sustained supraventricular tachycardia associated with rapid ventricular rates following open heart surgery. The technique utilizes a pair of temporarily implanted atrial epicardial wire electrodes to pace the heart. In one group of patients with recurrent atrial flutter and 2:1 A-V conduction, continuous rapid atrial pacing at 450 beats/min produced and sustained atrial fibrillation. The ventricular response rate immediately slowed when compared to that during atrial flutter, and if further slowing was required, it was easily accomplished by the administration of digitalis. Another group of patients with different arrhythmias (recurrent paroxysmal atrial tachycardia, sustained ectopic atrial tachycardia, or sinus rhythm with premature atrial beats which precipitated runs of atrial fibrillation) was treated with continuous rapid atrial pacing to produce 2:1 A-V block. In all instances, the continuous rapid atrial pacing suppressed the supraventricular tachycardia and maintained the ventricular response rate in a therapeutically desirable range. It was demonstrated that the technique is safe, effective, and reliable.
Serum cholesterol and triglyceride levels in 3,446 children from a biracial community: the Bogalusa Heart Study.
Authors: Frerichs R R , Srinivasan S R , Webber L S , Berenson G R
Published: June 2012

Serum lipid profiles of 3,446 (91% of population) children, ages 5-14 years, were determined in a biracial community (Bogalusa, Louisiana) as part of a program investigating the early natural history of atherosclerosis. Black children had significantly higher mean levels of serum cholesterol than white children (170 mg/dl vs 162 mg/dl, P less than 0.0001). On the other hand, significantly lower levels of triglycerides were found in blacks than in whites (61 mg/dl vs 73 mg/dl, P less than 0.0001). Girls had higher levels of triglycerides than boys in both races (blacks, 64 mg/dl vs 59 mg/dl, P less than 0.001; whites, 77 mg/dl vs 69 mg/dl, P less than 0.001). The racial differences in serum cholesterol and triglyceride levels were even more apparent at the 95th percentile. The serum cholesterol level remained relatively constant in all children until ages 11 and 12 years, after which a slight reduction occurred. This reduction was more pronounced in boys than in girls. In contrast, a significant increase in the level of triglycerides with age was observed in all children except black girls, the increasing slope being most pronounced in white girls.
The effects of morphine on venous tone in patients with acute pulmonary edema.
Authors: Vismara L A , Leaman D M , Zelis R
Published: June 2012

In order to compare the venodilation effect of morphine in normal individuals (22) with that in patients (13) with heart failure morphine sulfate (0.1 mg/kg) was administered to 13 patients with mild pulmonary edema. After morphine congestive symptoms improved and venodilation was induced as determined by two independent techniques: venous pressure fell 10.2 mm Hg by the isolated hand technique and the venous volume of the forearm increased by 0.48 cc/100 ml, measured by equilibration technique. Neither finding differed from those in normal individuals. Reflex venoconstriction noted on the taking of a single deep breath was unaffected by morphine administration and was similar to that observed in normal subjects. Since the drug morphine sulfate does not cause a major pooling of blood in the limbs, the favorable effect of narcotics in patients with pulmonary edema must be caused by other mechanisms such as splanchnic pooling, afterload reduction or reduced breathing effort.
False positive diagnostic tests and coronary angiographic findings in 105 presumably healthy males.
Authors: Erikssen J , Enge I , Forfang K , Storstein O
Published: June 2012

Among 2014 presumably healthy males aged 40-59 years coronary heart disease (CHD) was suggested in 115 in the presence of one or more of the following criteria: 1) a WHO-questionnaire on angina pectoris positive on interview, 2) typical angina during a near maximal bicycle exercise test, 3) a positive exercise ECG during and/or post exercise, 4) a Minnesota Code 1.1 on a resting ECG. Diagnostic coronary angiography was offered to all 115 CHD-suspect cases. Six refused angiography and four others were excluded. Of the remaining 105, thirty-six had less than 50% obstruction of any major coronary artery (34.3%). Eighteen (17.1%) had single, 25 (23.8%) had double and 26 (24.8%) had triple vessel disease. In 62 of the 69 with pathologic angiograms at least one obstruction greater than or equal to 75% was found. Eighty percent of the cases with proven CHD were greater than or equal to 50 years. All CHD-suggestive criteria had approximately the same diagnostic performance regardless of age, i.e., approximately one false positive/two true positives. Except for one retroperitoneal hematoma no complications to angiography occurred.
Pathogenesis of paradoxical hypertension after coarctation resection.
Authors: Rocchini A P , Rosenthal A , Barger A C , Castaneda A R , Nadas A S
Published: June 2012

The pathogenesis of paradoxical hypertension after resection of coarctation of the aorta was investigated by comparing the course of seven children undergoing repair of coarctation with five acyanotic children undergoing elective cardiovascular surgery. During the first 24 hours after surgery, all coarctation patients demonstrated a rise in systolic blood pressure (35 +/- 15.5 mm Hg; P less than 0.001), a significant depression in cold pressor test response, and only a slight elevation in plasma renin activity. In the next 24-72 hours, coarctation patients developed a rise in diastolic blood pressure (26.8 +/- 10.6 mm Hg; P less than 0.001), plasma renin activity (22.9 +/- 10.2/ml/hr; P less than 0.001) and fluid retention. By contrast, control patients had no significant postoperative changes. Abdominal pain occurred in five coarctation patients during the period of maximal plasma renin activity. The data suggest that the sympathetic nervous system may be responsible for the initial phase of hypertension after coarctation resection and that the renin angiotension system plays a major role in the second phase of hypertension and in the pathogenesis of mesenteric arteritis.
Tunnel subaortic stenosis: left ventricular outflow tract obstruction produced by fibromuscular tubular narrowing.
Authors: Maron B J , Redwood D R , Roberts W C , Henry W L , Morrow A G , Epstein S E
Published: June 2012

The clinical and morphologic features of tunnel subaortic stenosis, an unusual form of obstruction to left ventricular outflow, are described in 11 patients. Although patients with tunnel subaortic stenosis demonstrate a variety of cardiovascular malformations, the most characteristic anatomic feature is fibromuscular tubular narrowing of the outflow tract that remains relatively unchanged during the cardiac cycle. The aortic anulus was abnormally small in six of the 11 patients, including one who also had a hypoplastic ascending aorta. Evidence of a small mitral orifice was present in two patients, and two other patients had asymmetric septal hypertrophy. Although operation was successful in significantly reducing the outflow gradient in two of the seven operated patients, all seven patients had gradients of 50 mm Hg or more at the most recent postoperative evaluation. Three patients (two with previous operation) died suddenly; each of these patients had mild or no symptoms. Because of the apparent ineffectiveness of current operative methods in patients with tunnel subaortic stenosis, it is important to differentiate this condition from obstructions to left ventricular outflow.
Echocardiographic patterns of ventricular contraction in the Wolff-Parkinson-White Syndrome.
Authors: Hishida H , Sotobata I , Koike Y , Okumura M , Mizuno Y
Published: June 2012

Echocardiograms of 52 patients with the Wolff-Parkinson-White (WPW) syndrome were investigated. Abnormal patterns of motion were observed in the left ventricular posterior wall (LVPW) and the interventricular septum (IVS). The abnormal LVPW motion was presumably specific for the syndrome and included early onset of the anterior motion which preceded the first heart sound (S1) and a premature peak formation of the anterior displacement which occurred before the second heart sound. The latter was usually followed by a second lower peak. These findings seem to suggest that both contraction and relaxation of LVPW begin earlier than normal due to ventricular pre-excitation initiated at or near the LVPW. The IVS abnormality characteristic of the syndrome was a posterior protrusion, the onset of which preceded S1. Subsequent motion of IVS was either paradoxical or hypokinetic during ejection. These IVS abnormalities were quite similar to those observed in left bundle branch block. The abnormal LVPW motion was observed in all 20 Type A patients and 10 of the 32 Type B patients. The abnormal IVS motion was observed in 10 Type B patients. We feel that echocardiography could be used as an auxiliary noninvasive means of locating the pre-excitation site in patients with WPW.
Limitations of thallium-201 myocardial perfusion scintigrams.
Authors: Mueller T M , Marcus M L , Ehrhardt J C , Chaudhuri T , Abboud F M
Published: June 2012

The reliability of myocardial perfusion scintigrams with thallium-201 (201Tl) for detecting areas of hypoperfusion was assessed in 16 closed-chest dogs. Variable areas of ischemia were produced either by occluding or stenosing the left anterior descending coronary artery. Cardiac scintigrams taken in four projections were compared with regional myocardial perfusion maps. Segmental concentrations and segmental perfusions were quantitated by counting the emissions from 201Tl and the microspheres in each of 96 segments of the left ventricle. In addition, studies with a phantom were performed. The results indicate: 1) The emissions from 201Tl and from microspheres correlated well in ischemic segments (r = 0.93 +/- SE 0.02). 2) Seven of twelve ischemic hearts had definitely abnormal scintigrams and in each of these the hypoperfused zone was greater than 4.9 grams and perfusion was decreased by more than 45%. 3) In the phantom, abnormal scintigrams could be detected in the presence of lesser deficits than in the dogs. The limitation of the thallium perfusion scintigrams will be the inconsistent detection of small perfusion deficits.
Hemodynamic correlates of the normal aortic valve echogram. A study of sound, flow, and motion.
Authors: Laniado S , Yellin E , Terdiman R , Meytes I , Stadler J
Published: June 2012

The aortic valve echogram was recorded in open chest dogs simultaneously with aortic flow, acceleration of flow, aortic and left ventricular pressures, and intracardiac phonocardiograms. Comparison of echographic with hemodynamic data showed the following: The aortic valve started its opening with the onset of flow, at the same point that left ventricular pressure exceeded aortic pressure. Complete valve opening preceded peak aortic flow by an average of 43 msec and the cusps started to move toward closure while flow was still accelerating. Final closure of the valve was achieved at the time of zero flow and preceded the aortic second sound by 4-10 msec. The echographically determined "valve orifice area" correlated well with aortic stroke volume (r = 0.94). The intensity of the aortic first sound was related to peak acceleration of aortic flow. The intensity of the second sound was not related to the amplitude of cusp motion but correlated well with the aortic pressure at the time of closure and with peak flow deceleration.
ST-segment variations after acute myocardial infarction. Relationship to clinical status.
Authors: Kronenberg M W , Hodges M , Akiyama T , Roberts D L , Ehrich D A , Biddle T L , Yu P N
Published: June 2012

The degree of vectorcardiographic ST-segment elevation was employed as an index of myocardial ischemic injury in a study of 27 patients after acute myocardial infarction (AMI). The ST-segment vector magnitude (STVM) was derived from the continuously recorded modified Frank vectorcardiogram and was plotted serially by hours after onset of AMI. The STVM in normal subjects was 51.1 +/- 7.1 muV (mean +/- SE). A standard deviation of the pooled variance of 15.2 muV was obtained in a group of control patients and a change of more than 2 SD (greater than 30 muV) in an individual STVM was considered to be significant. The STVM progressively decreased in patients who survived without clinical complications while it remained elevated in those with congestive heart failure. A modest, sustained re-elevation of STVM was observed in patients who developed pericarditis, and a significant late average increase of 64 muV occurred in survivors with infarct extension. In contrast, STVM underwent a major increase in patients who died. In five of these six patients without associated pericarditis a mean increase of 164 muV was recorded in the last 5-12 hours of life. While death was clinically predictable in two patients with cardiogenic shock, it was not so for the four other patients who died. Thus, major increases in STVM frequently suggested significant new ischemic injury and were often premonitory to sudden death after AMI. The increases preceding death implied that not only ventricular extopy but also lethal conduction abnormalities after AMI might be ischemia-related.
Quantitative analysis of pulmonary vascular disease in complete transposition of the great arteries.
Authors: Yamaki S , Tezuka F
Published: June 2012

Forty autopsy cases of complete transposition of the great arteries (TGA) and 22 autopsy cases of ventricular septal defect (VSD) were analyzed histologically for evidence of vascular damage due to pulmonary vascular disease (PVD). Positive correlations were generally observed between an index of pulmonary vascular disease (IPVD) and blood pressure of pulmonary circulation. No significant difference in IPVD was found between TGA and VSD in the first five months of life, when cases of each disease were compared at similar blood pressure levels. After that age, however, IPVD was much higher in TGA, and particularly severe PVD in this disease was demonstrated histologically. Morphometrical analysis of the pulmonary artery revealed hypertrophy of the muscular cost in response to elevated blood pressure. However, the progress of medial hypertrophy was retarded in TGA in the first five months, and medial thickness in arteries of cases of TGA older than five months was only 70% of that in VSD at the same blood pressure levels. Suppression of this process of reinforcement of the arterial wall in response to the stress of high pulmonary pressure was regarded as one of the important factors precipitating severe pulmonary vascular disease in transposition of the great arteries.
Bilateral ductal origin of the pulmonary arteries. Systemic-pulmonary arterial anastomosis as first stage in planned total correction.
Authors: Todd E P , Lindsay W G , Edwards J E
Published: June 2012

Absence of continuity between the heart and the pulmonary arteries has the potential for total correction. When the pulmonary arteries are narrow, a palliative first stage systemic-pulmonary arterial anastomosis serves to enlarge the pulmonary arteries so that, with time, they become of adequate caliber for total correction. In a case with bilateral ductal origin of pulmonary arteries, palliative anastomosis between the aorta and right pulmonary artery was performed as the first stage in a program planned for ultimate total correction.
Clinical efficacy and pharmacokinetics of a new orally effective antiarrhythmic, tocainide.
Authors: Winkle R A , Meffin P J , Fitzgerald J W , Harrison D C
Published: June 2012

Tocainide, a new oral antiarrhythmic agent, was studied in man in a short-term protocol designed to evaluate the efficacy, kinetics, and toxicity of this compound. Premature ventricular contractions (PVCs) were suppressed by less than 70% in 11 of 15 patients compared with pre-drug placebo controls. For these 11 responders, there was an average PVC reduction of 91% +/- 10 (range 70 to 100%) at tocainide doses not associated with side effects. Mild transient central nervous system toxicity was observed in some patients near the time of peak concentrations during the highest dose administered. The drug was found to have linear kinetics over the dose range studied and a plasma half-life of 13.5 +/- 2 hours. Plasma concentration-response curves indicate antiarrhythmic activity over all plasma concentrations, with 70% PVC reduction above 6.0 mug/ml. This study suggests that tocainide is a safe and effective antiarrhythmic agent during short-term administration and is worthy of further clinical trials.
Multilevel atrioventricular block.
Authors: Kosowsky B D , Latif P , Radoff A M
Published: June 2012

Arrhythmias displaying conduction disturbances consistent with block at more than one level within the atrioventricular conduction system were seen in 36 patients during a two year period in a community hospital. Two levels of block were postulated in each patient; one patient also demonstrated a third level of block. In 24 patients (Type A), there was an integral conduction ratio at the upper level of block. This pattern was most frequently seen in atrial flutter (mean atrial rate 284 +/- 35 beats/min) with 2:1 block at the upper level and Wenckebach at the lower level. Progression to 2:1 block at the lower level resulted in 4:1 block. Twelve patients (Type B) had a nonintegral conduction ratio of their block at the upper level with a mean atrial rate of 162 +/- 62 beats/min. Their conduction patterns consisted of Wenckebach block at the upper level with either integral (2:1) or nonintegral (Wenckebach) block at the lower level. The presence of multilevel block was not related to specific etiological diagnoses, medications, or electrolyte patterns. It is suggested that multilevel block is a common, frequently transient, conduction pattern seen in a variety of clinical conditions. It is readily recognized from a standard electrocardiogram and, of itself, has no short-term detrimental prognostic implications.
Echocardiographic evaluation of the Valsalva Maneuver in healthy subjects and patients with and without heart failure.
Authors: Parisi A F , Harrington J J , Askenazi J , Pratt R C , McIntyre K M
Published: June 2012

The Valsalva maneuver was evaluated by echocardiography in three groups: A) 10 normal volunteers, B) 10 patients with no history of heart failure and normal ejection fractions, and C) 10 patients with heart failure and depressed ejection fractions. Groups A and B had a significant fall in left ventricular internal dimensions and calculated stroke volume by end strain which returned rapidly to baseline in recovery without significant overshoot. Arterial pressure showed a signoidal strain pattern with a normal overshoot in early recovery in all group B patients. In group C ventricular dimensions did not diminish during strain; arterial pressures showed a "square wave" pressure elevation during strain without an overshoot in recovery. Echocardiography allows a new approach to evaluate further the left ventricular response to the Valsalva maneuver. Patients with severely depressed ejection fractions, unlike those with normal ventricular function, are unable to alter stroke output in response to acutely increased intrathoracic pressure. A square wave pressure response is a likely consequence of a fixed stroke output during the strain maneuver.
Detection of left ventricular aneurysms by cross-sectional echocardiography.
Authors: Weyman A E , Peskoe S M , Williams E S , Dillon J C , Feigenbaum H
Published: June 2012

Real-time cross-sectional echocardiographic studies of the left ventricle were performed in 31 consecutive patients with angiographically proven left ventricular aneurysms (group I). In each of these patients the presence and location of the aneurysm was visualized by the cross-sectional echocardiography. In four patients discrepancy in the extent of the aneurysm was noted due either to failure of the cross-sectional technique to visualize the entire anterior wall of the ventricle (3) or failure of the single plane angiogram to adequately define the lateral extent of the aneurysm (1). Ventricular shape and contraction sequence in patients with aneurysms were compared with similar patterns in 20 patients with normal left ventricles (group II), and 20 patients with ischemic heart disease and localized ventricular dysfunction without aneurysm formation (group III). Other noninvasive methods for detecting aneurysms (including physical examination, chest roentgenography, electrocardiography, and M-mode echocardiography) were also evaluated in the aneurysm group. This report suggests that cross-sectional echocardiography is a useful method for detecting ventricular aneurysms noninvasively.
A comparison of real-time, two dimensional echocardiography and cineangiography in detecting left ventricular asynergy.
Authors: Kisslo J A , Robertson D , Gilbert B W , von Ramm O , Behar V S
Published: June 2012

Left ventricular wall motion was assessed in 105 consecutive patients both invasively, using biplane cineangiography, and noninvasively, by a real-time, phased-array, two-dimensional echocardiography system. Ventricular wall motion in five anatomic areas of the ventricle (anterolateral, posterolateral, apical, septal, and inferior) was analyzed by both methods in a double-blind manner. Two-dimensional echocardiographic images were deemed adequate for analysis in 82% of the regions (430 of 525). Fifty-five discrepancies were noted in the comparison of the remaining 430 regions. The reasons for discrepancies in interpretation between the two methods were established for 54 during retrospective review: 33 were due to echocardiography (inadequate target visualization, observer error, or tangential echo views). Fifteen were related to angiography (overlay of silhouettes or observer error), and six were due to other reasons including definition problems or spatial orientation difficulties. Both real-time, two-dimensional echocardiography and cineangiography have advantages and disadvantages. The techniques used together could provide more complete information concerning ventricular wall movement than is now currently available.
Clinical significance of prolonged sinoatrial conduction time.
Authors: Dhingra R C , Amat-y-Leon F , Wyndham C , Deedwania P C , Wu D , Denes P , Rosen K M
Published: June 2012

Prolonged (greater than 152 msec) calculated sinoatrial conduction times (SACT) were found in 24 of 470 patients studied by the atrial extrastimulus technique, ranging from 155 to 220 msec (180+/-4.4; mean+/-SEM). There were 18 males and six females with ages of 29 to 85 (mean 65+/-2.6). Electrocardiographic monitoring revealed significant sinus or atrial dysrhythmias in 19 (79%) patients. Of these 19, 15 had persistent sinus bradycardia and/or sinoatrial block, three had sinus bradyarrhythmia with paroxysmal atrial tachycardia, and one had isolated atrial tachycardia. Additional electrophysiological evidence of sinus node or atrial dysfunction was present in 11 patients. Four patients needed permanent pacing during follow-up (mean follow-up period of 427+/-39 days) because of symptomatic bradyarrhythmia. Three patients died, none suddenly. In conclusion, prolonged calculated SACT was associated with a high incidence of electrocardiographic and electrophysiologic abnormalities of sinus node and/or atrium. Despite this, bradyarrhythmic morbidity was relatively low, suggesting that prolonged sinoatrial conduction time in the absence of symptoms is not an indication for prophylactic pacing.
Variability in the analysis of coronary arteriograms.
Authors: DeRouen T A , Murray J A , Owen W
Published: June 2012

Variability in coronary arteriogram readings was studied by having cine films from ten patients read by eleven readers. Three of the eleven subsequently met as an expert panel to provide a joint evaluation which could serve as a standard. Considerable variability was found between individual readers and between readers and the panel. The average standard deviation for estimation of any segmental stenosis by any single reader was 18%. Disagreement about the number of major vessels with a 70% stenosis occurred 31% of the time. Discrepancies were most likely to occur in analyzing distal arterial segments, in reading nonopacified segments, and during analysis of films showing more severe disease or having poorer technical quality. Recent experience in reading arteriograms seemed to be the most important characteristic in determining the accuracy of a reader. A protocol for the use of three readers is suggested.
Quantitation of left ventricular myocardial fiber hypertrophy and interstitial tissue in human hearts with chronically increased volume and pressure overload.
Authors: Fuster V , Danielson M A , Robb R A , Broadbent J C , Brown A L , Elveback L R
Published: June 2012

Using new techniques, we quantitated left ventricular myocardial fiber hypertrophy and interstitial tissue in four groups of autopsied hearts free of coronary disease: 1) 22 normal hearts, 2) 20 hearts from patients with mitral incompetence (NYHA Class II-III) who died early after mitral valve replacement from causes other than cardiac failure, 3) 22 hearts from patients with mitral incompetence (NYHA Class III-IV) who died early after mitral valve replacement from cardiac failure with low cardiac output syndrome, and 4) 22 hearts from patients with hypertensive heart disease (NYHA Class II-III). Myocardial fiber hypertrophy was quantitated by measuring cross-sectional myocardial fiber diameter; the proportion of interstitial tissue was quantitated by using a computerized, high-resolution video image-digitizing system. Myocardial fiber average diameter in groups 2, 3 and 4 was significantly higher than group 1. The proportion of interstitial tissue was significantly increased in group 3. In chronic mitral incompetence an increase in left ventricular interstitial tissue may play a role in the development of severe cardiac failure.
Physiologic evaluation of a new antihypertensive agent: prazosin HCl.
Authors: Koshy M C , Mickley D , Bourgiognie J , Blaufox M D
Published: June 2012

The mechanism of action of prazosin hydrochloride, a new antihypertensive agent was studied in 14 patients with essential hypertension. Mean supine blood pressure for the group fell from 148/102 +/- 3/2 (SE) mm Hg at baseline to 139/91 +/- 5/4 after eight weeks of therapy (P less than 0.05). No significant postural hypotension was noted in the patients who responded to therapy. Glomerular filtration rate (endogenous creatinine or inulin clearance) and effective renal plasma flow (PAH clearance) remained unchanged during therapy as did supine and stimulated peripheral plasma renin activity. Cardiac output did not change significantly although plasma volume increased in ten out of 12 patients in whom it was measured (P less than 0.025). Among the patients whose mean blood pressure fell 10 mm Hg or more, peripheral vascular resistance fell significantly (P less than 0.025), and the change in plasma volume was not statistically significant. Among the patients whose mean blood pressure changed less than 10 mm Hg with therapy, there was no significant change in peripheral vascular resistance and plasma volume increased significantly (P less than 0.025). Prazosin hydrochloride appears to be an effective antihypertensive agent which acts by peripheral vasodilatation. It may cause fluid retention. The drug does not appear to affect renal function or renin secretion.
Inability of methylprednisolone sodium succinate to decrease infarct size or preserve enzyme activity measured 24 hours after coronary occlusion in the dog.
Authors: Vogel W M , Zannoni V G , Abrams G D , Lucchesi B R
Published: June 2012

Methylprednisolone sodium succinate (50 mg/kg) was given 30 minutes before or after the start of a 90 minute occlusion of the left circumflex coronary artery (LCX) in one group of dogs. In a second group, methylprednisolone sodium succinate was given 15 minutes after permanent occlusion of the left anterior descending artery (LAD). Infarct size was determined by dehydrogenase staining after 24 or 96 hours. Heart slices were incubated with nitro-blue tetrazolium and nonstaining infarcted tissue was dissected and weighed. Myocardial depletion of creatine phosphokinase activity (CPK) and lactate dehydrogenase activity (LDH) were determined 24 hours after temporary LCX occlusion. When measured after 24 hours, methylprednisolone sodium succinate treatment did not reduce infarct size or decrease enzyme loss. After temporary LCX occlusion infarct size was 30.4 +/- 3.6% of left ventricular weight in control dogs and 30.0 +/- 2.3% in treated dogs. No significant difference in infarct size was observed in hearts examined 24 or 96 hours after myocardial infarction. After permanent LAD occlusion, infarct size in control dogs was 39.2 +/- 1.6% of left ventricular weight and 33.7 +/- 3.5% in treated dogs. CPK activity in the LCX area decreased by 26.5 +/- 7% in controls and by 28.1% +/- 7% in treated dogs. Treated dogs sustained a significantly greater fall in arterial blood pressure after LCX occlusion than did controls. During LCX occlusion and upon reperfusion, methylprednisolone sodium succinate treated dogs exhibited a significantly greater number of premature ventricular beats. Since infarct size and enzyme depletion were not reduced when measured after 24 hours, methylprednisolone sodium succinate treatment does not appear to have enhanced myocardial cell viability.
Echocardiographic determination of left ventricular mass in man. Anatomic validation of the method.
Authors: Devereux R B , Reichek N
Published: June 2012

An accurte echocardiographic (E) method for determination of left ventricular mass (LVM) was derived from systematic analysis of the relationship between the antemortem left ventricular echogram and postmortem anatomic LVM in 34 adults with a wide range of anatomic LVM (101-505 g). No subject had massive myocardial infarction, ventricular aneurysm, severe right ventricular volume overload or hypertrophic cardiography. The best method for LVM-E identified combined cube function geometry with a modified convention for determination of left ventricular internal dimension (LVID), posterior wall thickness (PWT), and interventricular septal thickness (IVST), which excluded the thickness of endocardial echo lines from wall thicknesses and included the thickness of left septal and posterior wall endocardial echo lines in LVID (Penn Convention, P). By this method, anatomic LVM = 1.04 ([LVIDp + PWTp + IVSTp]3--[LVIDp]3) -- 14 g; r = 0.96, SD= 29 g, N= 34. Standard echo measurements gave less accurate results, as did previously reported methods for LVM-E. LVM-Dp is an accurate, widely applicable method for the study of left ventricular hypertrophy.