bluuebunny/crossref_metadata_2025 huggingface dataset:
Echocardiographic assessment of left ventricular function in aortic valve disease.
Authors: McDonald I G
Published: June 2012

Echocardiography was used to study left ventricular size and contraction in 128 patients with isolated aortic valve disease -45 patients with aortic stenosis, 25 with mixed aortic valve disease and 58 with aortic regurgitation. Left ventricular measurements included the end-diastolic internal dimension (LVIDd), mural thickness (PWTd), an index of circumferential myocardial contraction-fractional shortening (FS=[(LVIDd-LVIDs)/LVIDd] X 100)--and stroke volume (LVSV). In the absence of left ventricular failure, measurements in aortic stenosis were characteristic of pressure overload with normal LVIDd and FS and an increase in PWTd related to the severity of stenosis; in aortic regurgitation, there was volume overload with increases in LVIDd and PWTd which were related to the severity of regurgitation, while FS was slightly reduced. In mixed aortic valve disease there was evidence of both pressure and volume overload. When left ventricular failure was associated with aortic stenosis, mixed aortic valve disease and chronic aortic regurgitation, FS was usually reduced. By contrast, in a recent patient with acute severe aortic regurgitation, FS was normal despite left ventricular failure, suggesting pump rather than myocardial failure.
Hemodynamic consequences of afterload reduction in patients with chronic aortic regurgitation.
Authors: Bolen J L , Alderman E L
Published: June 2012

Nitroprusside was used to reduce afterload in 13 patients with isolated, severe aortic regurgitation. The drug significantly lowered mean aortic pressure, pulse pressure, left ventricular end-diastolic pressure and left ventricular volume. Total ventricular, or angiographic, cardiac index was generally unaffected, but forward cardiac index was improved significantly in 8 of 13 patients. Augmentation of forward cardiac index was seen in patients with subnormal resting forward cardiac index, in patients with decidedly elevated end-diastolic pressure, and in those with depressed resting ejection fractions. Regurgitant fraction fell with nitroprusside in six patients and remained unchanged in seven. Total stroke work index was diminished in all patients. These data show that afterload reduction in patients with severe aortic regurgitation may improve hemodynamics by reducing aortic regurgitation or by improving ventricular pump function. The lowered total stroke work, reduced ventricular size and improved forward cardiac index imply that afterload reduction may benefit left ventricular failure and delay progressive ventricular dysfunction in patients with aortic regurgitation.
Mitral atresia with normal aortic valve: a study of eighteen cases and a review of the literature.
Authors: Moreno F , Quero M , Diaz L P
Published: June 2012

Eighteen cases of mitral atresia with normal aortic valve plus 68 cases from the literature are analyzed. A new classification based on anatomical findings is proposed. Pulmonary stenosis or atresia is frequent in the type with transposition of the great arteries. The rare instances of normal or large left ventricle are due to a large ventricular septal defect, or to straddling or displaced tricuspid valve. The clinical, radiologic and electrocardiographic findings have been summarized and correlated with the different physiopathological situations. In our catheterized cases an oxygen saturation step-up was found in the right atrium together with left atrial hypertension. In seven cases mitral atresia was demonstrated by selective left atrial contrast injection. The average age at death was six months. Among the cases surviving one year or more, the association of atrial septal defects or pulmonary stenosis was frequent. Enlargement of the interatrial communication, accompanied by other palliative measures, is the only available surgical procedure.
XVIII. Persistent fetal dispersion of the atrioventricular node and His bundle within the central fibrous body.
Authors: James T N , Marshall T K
Published: June 2012

In the hearts of two victims of sudden unexpected death (one age 20 years and the other 11 years) there was abnormally delayed persistence of the pattern of fetal dispersion of the A-V (atrioventricular) node and His bundle within the central fibrous body. This pattern is characterized by a splayed or excessively fragmented histological appearance of these structures viewed in cross-section. Some of the fronds of A-V nodal tissue formed loops connecting one portion of the node to another. Other fragments of nodal tissue appeared isolated within the central fibrous body, occasionally connecting directly to the crest of the interventricular septum. A number of the A-V nodal fragments were undergoing resorptive degeneration. Directly adjacent to the A-V node of the 11-year-old subject there was an island of cartilage within the central fibrous body. Since these anatomically separated fragments of A-V nodal tissue were so numerous and varied widely in size and thickness, in length, in histological organization, and in their apparent state of preservation probably extant during life, it is suggested that they form potential routes for abnormal conduction or impulse formation within the A-V junctional region and that some of these electrophysiological disturbances might be quickly lethal.
Echocardiographic studies of abnormalities associated with coarctation of the aorta.
Authors: Scovil J A , Nanda N C , Gross C M , Lombardi A C , Gramiak R , Lipchick E O , Manning J A
Published: June 2012

Echocardiograms were performed in thirty-six patients (aged 4 to 36 years) with proven coarctation of the aorta. Nineteen patients (53%) were found to have marked diastolic eccentricities of their aortic valves (Eccentricity Index greater 1.5), indicating the presence of bicuspid aortic valves. One of these patients also had multilayered aortic root echoes in diastole. Five patients had angiographic proof of their aortic valve morphologies which corroborated the echo findings. Five patients with bicuspid aortic valves showed mitral valve diastolic flutter indicative of aortic regurgitation. Idiopathic hypertrophic subaortic stenosis (IHSS) was suspected in four patients (11%) with abnormal systolic anterior motion of the mitral valve; three of these patients also had asymmetric septal hypertrophy. There was catheterization proof of IHSS in one patient. Two patients (5.6%) demonstrated mitral valve proplapse.
Quantitative ultrasonographic studies of lower extremity flow velocities in health and disease.
Authors: Fronek A , Coel M , Berstein E F
Published: June 2012

Quantitative Doppler ultrasonographic flow velocity determinations are reported from 39 normal control subjects and 80 patients with angiographically documented peripheral arterial disease, in whom femoral, posterior tibial and dorsalis pedis arteries were studied. The mean control values of the most useful parameters were: femoral artery: peak forward velocity (PFV) cm/sec: 40.7 +/- 10.9, deceleration (Dec.) cm/sec2:250.9 +/- 60.0, peak/mean velocity (P/MV): 4.8 +/- 1.6; posterior tibial artery: PFV: 16.0 +/- 10.0, Dec.: 129.8 +/- 75.7, P/MV: 4.8 +/- 2.5; dorsalis pedis artery: PFV: 168 +/- 5.7, Dec.: 137.9 +/- 54.5, P/MV: 6.0 +/- 4.1. The values of these measurements in the patients with arterial occlusive disease were all significantly lower, and also permitted distinguishing those with multilevel disease from those with a single site of occlusion. Quantitative evaluation of the Doppler ultrasonogram permits obtaining detailed functional information on the degree of arterial flow impairment in patients with peripheral arterial occlusive disease.
Experimental myocardial infarction. XIII. Sequential changes in left ventricular pressure-length relationships in the acute phase.
Authors: Pirzada F A , Ekong E A , Vokonas P S , Apstein C S , Hood W B
Published: June 2012

Diastolic pressure-length relationships of an ischemic region of the canine left ventricle were measured over a six-hour period following left anterior descending coronary artery ligation, and their evolution was compared with the extent of systolic aneurysmal bulging. Normalized ischemic segment length excursion, which after coronary artery ligation may be taken as a measure of systolic aneurysmal bulging, increased during the first hour after ligation but thereafter declined toward control values. Concurrently, reciprocal changes were demonstrated in the slope of the end-diastolic pressure-length curves obtained during transient pressure loading of the left ventricle. These data show that the magnitude of acute systolic aneurysmal bulging followed experimental coronary artery ligation is determined not only by loss of contractile function, but also by changes in passive pressure-length relationships of the myocardium. Moreover, the results indicate that development of akinesis in experimental ischemia, heretofore demonstrated only in the chronic phase of infarction, may begin within hours of the onset of myocardial ischemia.
Radionuclide assessment of nitroglycerin influence on abnormal left ventricular segmental contraction in patients with coronary heart disease.
Authors: Salel A F , Berman D S , DeNardo G L , Mason D T
Published: June 2012

Noninvasive gated cardiac blood pool imaging with technetium-99m autologous erythrocytes was employed to differentiate reversible verus irreversible abnormal ventricular segmental contraction by regional wall and pump responses to sublingual nitroglycerin in 25 patients with chronic coronary heart disease. In 12 patients without ECG infarctions compared to 13 with infarctions, radioisotopic images demonstrated significantly greater percent decreases in end-systolic volumes (33.8 +/- 6.7 SEM vs 187 +/- 4.4; P less than 0.05) without differences in percent reductions in end-diastolicvolumes (13.7 +/- 3.9 vs 11.6 +/- 6.1; NS) and thereby significantly greater percent increases in ejection fractions (9.3 +/- 1.6 vs 4.1 +/- 2.0; P less than 0.05). In the 22 patients with regional dyssynergy, improvement in disordered pattern and extent of localized dyssynergy following antianginal action of nitroglycerin was related to ECG absence of prior infarction. These obsevations demonstrate the clinical accuracy of atraumatic scintigraphy in the detection of reversible localized dyssynergy due to myocardial ischemia in coronary heart disease.
Vasodilator administration in the presence of beta-adrenergic blockade.
Authors: Mroczek W J , Lee W R , Davidov M E , Finnerty F A
Published: June 2012

To explore the possibility that the presence of propranolol-induced beta-adrenergic blockade might have an adverse effect upon homeostatic circulatory reflexes activated by the administration of a potent vasodilator agent, arterial blood pressure and pulse rate response to rapid intravenous diazoxide injection was monitored before and after pretreatment with propranolol in ten hypertensive patients. It appeared that beta-adrenergic blockade had no clinically significant effect on the magnitude of hypotension or the degree of heart rate acceleration induced by the administration of the potent vasodilator diazoxide. This reflex vasodilator-induced cardio-acceleration after propranolol adminstration could be the result of incomplete blockade of endogenously released neurotransmitter, inhibition of the parasympathetic nervous system, or a direct pharmacologic action of diazoxide. Diazoxide administration to hypertensive patients in the presence of beta-adrenergic blockade was not associated with any clinically significant hemodynamic consequences.
Scanning electron microscopy of surface irregularities and thrombogenesis of polyurethane and polyethylene coronary catheters.
Authors: Bourassa M G , Cantin M , Sandborn E B , Pederson E
Published: June 2012

Following routine coronary arteriography, surface irregularities and thrombogenesis of the inner and outer wall of six Ducor polyurethane and six RPX polyethylene coronary catheters were studied by scanning electron microscopy. Polyurethane catheters had rough and highly irregular external and internal surfaces. All catheters showed adherent thrombi on their external surface. The internal surface of three catheters showed evidence of thrombosis. Polyethylene differed from polyurethane in several respects. Although the external surface had an irregular and wavelike appearance, the internal surface was smooth and regular. Two polyethylene catheters showed thrombi on their external surface. The internal surface of one catheter showed single platelets in one area. These results confirm recent reports showing that internal and external surface irregularities play a major role in the initiation of thrombosis in and on intravascular catheters. They stress the need for high quality catheter materials with smooth and regular surfaces in the prevention of thromboembolic complications from coronary arteriography.
The natural history of truncus arteriosus.
Authors: Marcelletti C , McGoon D C , Mair D D
Published: June 2012

The cases of 23 patients whose condition was diagnosed as truncus arteriosus, type I or II, and who were seen at the Mayo Clinic during the decade preceding 1967, that is, before corrective operation became feasible, were reviewed. Ten were infants (through one year of age), and all ten have died. Eight ranged in age from more than one year through seven years of age, and all are living, except one, who diet 11 years after diagnosis. Five were older than seven years, and all had severe pulmonary vascular obstructive disease; three have died. Thus, 14 of the 23 have died, and all but one surviving patient have mild to moderate disability. The generally grave prognosis for patients with truncus arteriosus warrants continued use of corrective operation, but suggests that the greatest benefit can be realized by successful correction in the infant with congestive heart failure and in early childhood before the development of severe pulmonary vascular obstructive disease.
Valve ring abscess in active infective endocarditis. Frequency, location, and clues to clinical diagnosis from the study of 95 necropsy patients.
Authors: Arnett E N , Roberts W C
Published: June 2012

Analysis of 95 necropsy patients with active infective endocarditis (AIE) involving 128 native cardiac valves (aortic = 59, mitral = 48, tricuspid = 20, and pulmomic = 1) disclosed 27 patients with ring abscesses involving 30 valves: the aortic valve ring was infected in 24 patients and only an atrioventricular valve ring (mitral in two, and tricuspid in one) in three patients. Comparison of the following parameters showed no significant differences between the 27 patients with and the 68 patients without ring abscess: age, sex, antibiotic treatment or length of treatment, status of the cardiac valve(s) before infection, and the kind of infecting organism. Comparison of the following parameters, however, showed significant (P less than 0.05) differences between the 27 patients with and the 68 patients without valve ring abscess: 1) infection of the aortic valve; 2) occurrence of valvular regurgitation of recent origin; 3) presence of pericarditis; 4) presence of high degree of atrioventricular block; and 5) short duration of symptoms leading to severe debility or death. These five features, therefore, serve as a clinical clues to the presence of valve ring abscess in patients with AIE.
Mitral valve prolapse.
Authors: Devereux R B , Perloff J K , Reichek N , Josephson M E
Published: June 2012

For half a century the systolic click and late systolic murmur lay dormant as innocent auscultatory curiosities. The thirteen years since Barlow related these phenomena to mitral leaflet prolapse have witnessed an astonishing information explosion. We have sought to bring together the accumulated data in this review. An Historical Perspective traces the evolution from the now abandoned "pericardial" or "extracardiac" phases, through the leafletchordal phase (redundancy), the myocardial phase (segmental left ventricular contraction abnormalities), to the anular phase (dilatation and faulty systolic contraction). Functional Anatomy is dealt with in terms of pathology, pathophysiology, hemodynamics, angiocardiography, echocardiography, and physical and pharmacological interventions. Clinical Manifestations are concerned with prevalence, natural history, symptoms, physical signs, electrocardiographic abnormalities and roentgen fingings. The four Major Complications- sudden death, infective endocarditis, spontaneous rupture of chordae tendineae, and progressive mitral regurgitation- are examined. Associated Cardiac Diseases, i.e., Marfan's syndrome, ostium secundum atrial septal defect and atherosclerotic coronary artery disease, are discussed, and a section on Treatment deals chiefly with prophylaxis for infective endocarditis and the management of arrhythmias and chest pain. A final section on Evolving Information considers etiologic concepts, the nature of left ventricular contration abnormalities, the cause of chest pain, the relationship to Marfan's syndrome and ostium secundum atrial septal defect, and the effect of aging and sex differences on leaflet chordal redundancy.
Effect of timolol versus propranolol on hypertension and hemodynamics.
Authors: Aronow W S , Ferlinz J , Del Vicario M , Moorthy K , King J , Cassidy J
Published: June 2012

The effect of timolol versus propranolol on hypertension, hemodynamics, and plasms renin activity was evaluated in 20 men. After two weeks of placebo, 11 men received timolol 30 to 60 mg daily, and nine men received propranolol, 240 to 480 mg daily, for five weeks in a double-blind randomized study. The 20 men then received placebo again for two weeks. Right heart catheterization was performed in all 20 patients after two weeks of the first placebo and after five weeks of timolol or propranolol. Equipotent doses of timolol and propranolol were equally effective in significantly lowering supine and upright systolic and diastolic blood pressure and heart rate recorded on an outpatient basis. Equipotent doses of timolol and propranolol caused similar hemodynamic effects including similar significant depression of cardiac index. Equipotent doses of timolol and propranolol caused similar marked depression of plasma renin activity. The hypotensive action of timolol and of propranolol was unrelated to their effect on plasma renin activity.
Functional significance of regional ischemic contraction abnormalities.
Authors: Forrester J S , Wyatt H L , Da Luz P L , Tyberg J V , Diamond G A , Swan H J
Published: June 2012

To evaluate the progression of segment function following induction of ischemia, the left anterior descending coronary artery was ligated (eight dogs) or cannulated and perfused at various pressures via a bypass-oxygenator (six dogs). Mercury-in-silastic length gauges were sutured to the anterior left ventricle, and pressure was recorded by a catheter-tipped transducer. Segment function was determined from the area of the pressure-length loop by plotting instantaneous left ventricular pressure against segment length and by evaluation of the degree of systolic shortening. Segment function decreased linearly as flow in the left anterior descending artery was decreased in a stepwise fashion by reduction in perfusion pressures from 100 to 20 mm Hg. With both left anterior descending coronary artery ligation and stepwise flow reduction, the pressure-length loop invariably showed four clearly identifiable morphologic patterns which relate conceptually to the specific left ventricular contraction patterns: dyssynchrony, hypokinesis, akinesis, and paradoxic systolic expansion. Re-oxygenation following occlusion invariably revealed return to a normal pattern in reverse order. This study demonstrates that a consistent and predictable progression of segmental contraction abnormalities occurs with ischemia.
Evaluation of 99mtechnetium stannous pyrophosphate as an imaging agent in acute myocardial infarction.
Authors: Bruno F P , Cobb F R , Rivas F , Goodrich J K
Published: June 2012

Serial 99mTc pyrophosphate scintigrams were obtained 7 hr to 15 days after experimental acute myocardial infarction produced by permanent or transient coronary occlusion. Scintigrams were interpreted visually and the increased radioactivity in the precordial image was quantitated and compared to extent of infarction found histologically. Results of these studies indicate: 1) 99mTc pyrophosphate imaging is an extremely sensitive for detection of acute myocardial infarction, i.e., infarction in excess of 1% of the left ventricular mass was detected. 2) Early detection of acute infarction is a function of blood flow since 7 hr after infarction scans were negative after permanent occlusion but were strongly positive after transient occlusion. 3) Radioactivity in the precordial image was inversely related to extent of infarction after permanent occlusion and directly related to extent of infarction after transient occlusion. 4) 99mTc pyrophosphate localized in areas with significant histologic infarction but the distribution of radioactivity was not proportional to extent of infarction.
Noninvasive visualization of the left main coronary artery by cross-sectional echocardiography.
Authors: Weyman A E , Feigenbaum H , Dillon J C , Johnston K W , Eggleton R C
Published: June 2012

Real time cross-sectional echocardiographic studies of the left main coronary artery (LMCA) were performed in 15 normal patients, 15 patients with angiographically proven coronary artery disease but normal left main coronary segments, three patients with greater than 75% obstruction of the left main coronary artery, and one patient with a larger aneurysm of the left main coronary artery. In normal subjects the LMCA evaginates from in inferolateral wall of the aorta. The artery appears as two dominant parallel linear echoes separated by a clear space representing the lumen of the vessel. The LMCA courses beneath the right ventricular outflow tract and can generally be followed to its expected point of bifurcation. Confirmation that this structure was in fact the LMCA was obtained by injection of cardiogreen dye directly into the LMCA in two cases and by visualization of dye in this structure following aortic flush in one case. In the three cases with obstructive lesions of the LMCA, there was an area of inward bending of the parallel vessel wall echoes resulting in varying degrees of narrowing of the arterial lumen. In the case with the aneurysmal dilatation of the LMCA, an echo-free circular bulge in the distal portion of the LMCA was recorded. This study demonstrates the fesibility of recording the left main coronary artery using the cross-sectional echocardiographic technique.
The clinical significance of exercise-induced ST-segment elevation.
Authors: Chahine R A , Raizner A E , Ishimori T
Published: June 2012

The significance of exercise-induced ST-segment elevation remains unsettled. We reviewed the treadmill tests of 840 consecutive patients and exercise-induced ST-segment elevation was noted in 29 (3.5%). Only eight of these (28%) stopped because of angina. Anterior myocardial infarction (AMI) was found on the resting electrocardiogram in 25 (85%). Angiographic studies performed on 21 showed critical lesions of the left anterior descending (LAD) in 19 (90%) and left ventricular aneurysm in 18 (86%). When all the patiens who had AMI or critical LAD obstruction during the study period were reviewed, only 22% and 18% respectively showed exercise-induced ST-segment elevation, while 64% of the cases with left ventricular aneurysm displayed this phenomenon. Thus, exercise-induced ST elevation seems to reflect the presence of severe coronary artery disease most commonly with an associated left ventricular aneurysm and may relate more to the abnormal wall motion than to the myocardial ischemia per se.
Observations on mechanisms of ventricular tachycardia in man.
Authors: Wellens H J , Düren D R , Lie K I
Published: June 2012

Fifty patients with sustained ventricular tachycardia were studied by endocavitary recordings and programmed electrical stimulation. Of 29 patients in whom tachycardia could be initiated, 18 had chronic coronary artery disease and eight had no detectable heart disease. Of 35 patients in whom the tachycardia could be terminated by premature ventricular stimuli, 21 had chronic coronary artery disease and eight had no detectable heart disease. Initiation of tachycardia was facilitated in 18 of 21 patients by pacing the ventricle at the slowest possible pacing rate. An inverse relation was found between the prematurity of the tachycardia-initiating premature beat and the interval between the premature beat and the first beat of tachycardia, a finding suggestive of a re-entry mechanism. The role of the specific conduction system in initiation and during tachycardia remains unknown. Stimulation site was found to affect initiation and termination of tachycardia and width of tachycardia zone.
Noninvasive evaluation of regional myocardial perfusion in 112 patients using a mobile scintillation camera and intravenous nitrogen-13 labeled ammonia.
Authors: Walsh W F , Harper P V , Resnekov L , Fill H
Published: June 2012

The short half-life positron emitter 13N, as labeled ammonia (13NH4+), was evaluated as a myocardial imaging agent. Regional myocardial uptake of 13NH4 correlated with the distribution of labeled microspheres in experimental myocardial infarction. Using intravenous 13NH4+, myocardial scintigraphy was performed in 85 cardiac patients and 27 normal subjects. Ninety-five scintigrams were suitable for analysis. Eighteen of 24 normal subjects had homogeneous myocardial images; six had inhomogeneous images attributable to early technical problems. Perfusion defects were observed in the scintigrams of 82% (57/65) of patients with coronary artery disease, being most common in patients with myocardial infarction (27/28). Six sequential studies showed changes in perfusion consistent with the clinical course of each patient. Scintigraphic abnormalities were also observed in 4/6 patients with valvular heart disease. 13NH4+ myocardial scintigraphy is a valid and sensitive method of assessing regional myocardial perfusion and is especially useful for sequential imaging at short intervals.
Sudden death among postoperative patients with tetralogy of Fallot: a follow-up study of 243 patients for an average of twelve years.
Authors: Quattlebaum T G , Varghese J , Neill C A , Donahoo J S
Published: June 2012

Two hundred and forty-three patients were evaluated following total correction of tetralogy of Fallot with special emphasis on postoperative conduction disturbances and on the occurrence of sudden death. The average follow-up period was 12 years with a range of 6 1/2 to 16 1/2 years. Sudden death occurred in seven patients. Four deaths were among those with right bundle branch block pattern (RBBB) and three of the four had premature ventricular contractions (PVC) for more than one month postoperatively. PVCs were documented in ten of the 158 patients with RBBB; sudden death occurred in three (30%). Three of the ten (30%) patients with trifascicular block pattern (TB) died suddenly, while no deaths occurred in 24 patients with bifascicular block pattern (BB). Progression of RBBB to BB and TB occurred in 18 patients from one month to seven years postoperatively (58% of BB and 40% of TB). The risk of sudden death in patients with RBBB and PVCs following tetralogy repair is high and warrants consideration of suppressive therapy. TB also carries a high risk. The finding that RBBB may progress to BB or TB mandates long-term careful follow-up of all tetralogy patients with postoperative conduction disturbances.
The normal spectrum of mitral and aortic valve discontinuity.
Authors: Rosenquist G C , Clark E B , Sweeney L J , McAllister H A
Published: June 2012

The relationship of the base of the left and noncoronary sinuses of the aortic valve and the adjacent aortic leaflet of the mitral valve was studied in 106 normal heart specimens and 184 specimens with isolated VSD. The results show a spectrum of persistence of the tissue along the inner curvature of the heart. This may help settle the recent controversy in the interpretation of echocardiograms of this area because the recorded mitral-aortic discontinuity may be due to this spectrum rather than to variations in technique.
Pharmacoangiographic manipulation of renal collateral blood flow.
Authors: Bookstein J J , Walter J F , Stanley J C , Fry W J
Published: June 2012

Vasodilatory or vasoconstrictive renal pharmacoangiography was applied in investigating the significance of 50 renal artery stenoses. The technique involves comparison of selective magnification renal arteriograms before and after intra-arterial injection of epinephrine or acetylcholine, seeking changes in direction of flow in potential collateral routes. The drug injected depended upon the hemodynamic conditions during control arteriography. Final determination of significance depended on response to surgery in most patients, and renin levels in a few. Vasoconstrictive angiography was determinate in 18/26 (69%) of significant stenoses and correctly identified hemodynamic significance in each. Other angiographic signs of collateral circulation were present in seven of the other eight significant stenoses studied with the vasoconstrictive method. Vasodilatory pharmacoangiography was determinate in 20 arteries, and correctly evaluated each of nine significant and 11 insignificant lesions. Pharmacoangiography is a moderately sensitive and completely specific angiographic method for evaluating the hemodynamic significance of renal artery stenoses.
De subitaneis mortibus. XIX. On the cause of sudden death in pheochromocytoma, with special reference to the pulmonary arteries, the cardiac conduction system, and the aggregation of platelets.
Authors: James T N
Published: June 2012

Pheochromocytoma may cause sudden and unexpected death. In this study of three fatal cases of pheochromocytoma the small pulmonary arteries were narrowed by a variety of chronic and acute processes which included medial hypertrophy and fibrosis, endothelial proliferation and fibrosis, and endothelial cellular edema; within the sinus node, atrioventricular (A-V) node and His bundle of all three cases there was focal degeneration and fibrosis similar to that also observed throughout the ventricular myocardium; and in addition to the focal narrowing of many small coronary arteries produced by medial hypertrophy, intimal fibrosis, and fibromuscular dysplasia, there were also focal aggregations of platelets clogging the lumen and occasionally mixed with a varying amount of fibrin. In patients known to have pheochromocytoma it may be necessary to direct new attention to the possibility of abnormal pulmonary vascular resistance, instability of normal cardiac rhythm, and perhaps difficulty in restoring it when disordered and to the effects of platelet aggregations, both causing acute obstruction and possibly contributing to the pathogenesis of chronic vascular disease.
Quantitative measurement of left ventricular volumes in man from radiopaque epicardial markers.
Authors: Vine D L , Dodge H T , Frimer M , Stewart D K , Caldwell J
Published: June 2012

The distances between three or four radiopaque markers located on the left ventricular epicardial surface at the apex and in the region of the minor axes in 22 subjects showed close correlations with left ventricular chamber radii, length, volume and wall thickness determined from biplane angiograms over the range of stroke volume. The markers were previously placed during heart surgery. Regression equations relating the distances between epicardial markers and chamber volumes were used to predict volumes for other beats. There was close agreement of end-diastolic, end-systolic, and stroke volumes as determined by the angiographic and epicardial marker methods for premature atrial contraction beats and post premature contraction beats, and in studies performed during rest and exercise. Time-volume curves determined by the epicardial marker and angiographic methods were similar. It is concluded that epicardial marker measurements can be used to quantitate beat-to-beat left ventricular chamber volume and dimension changes.
Potential role of QT interval prolongation in sudden infant death syndrome.
Authors: Maron B J , Clark C E , Goldstein R E , Epstein S E
Published: June 2012

To investigate the possibility that a genetically transmitted cardiac abnormality is involved in the genesis of the sudden infant death syndrome (SIDS), 42 sets of parents who had at least one infant with SIDS were studied by electrocardiography. Prolongation of the QT interval was present in at least one member of 11 (26%) sets of parents. In families in which QT interval prolongation was found in a parent, prolonged QT interval was also present in 39% of the siblings of infants with SIDS, suggesting an autosomal dominant pattern of inheritance. In addition, an infant with "near-miss" SIDS showed marked prolongation of the QT interval. Thus, our data suggest that prolonged QT interval may play a role in a considerable proportion of sudden and unexpected infant deaths. However, definitive confirmation of the relation between QT interval prolongation and SIDS will require large prospective investigations.
Earlier onset of QRS in anterior precordial ECG leads: precision of time interval measurements.
Authors: Danzig M D , Robertson T L , Webber L S , Day G , Dock D S
Published: June 2012

Onset of QRS was compared between simultaneously recorded conventional ECG leads in 84 subjects with clinically normal hearts from a defined population sample. Mean onset of QRS was 6.4 msec earlier in lead V1 and 7.4 msec earlier in V2 than in lead II. These differences were statistically significant. The measuring system was adapted from drafting techniques and took into account variations in paper speed which occurred during recording. Interobserver differences equivalent to greater than 1 msec occurred in 3.9% of timeline measurements, but in in 38% of QRS onset measurements. The lower precision in measuring QRS onset may be attributed to baseline oscillations and to the relatively slow rate of voltage change at the onset of ventricular depolarization.
The conduction system in double outlet right ventricle with subpulmonic ventricular septal defect and related hearts (the Taussig-Bing group).
Authors: Bharati S , Lev M
Published: June 2012

The Taussig-Bind group of hearts is that group in which the aorta emerges completely from the right ventricle, unrelated to the position of the ventricular septal defect (VSD), while the pulmonary trunk emerges at varying degrees from the right ventricle related to the location of the VSD. Several types of surgical procedures involve the VSD in these hearts. The conduction systems in six of these hearts were therefore studied. The atrioventricular (A-V) bundle lies in the inferior (posterior) wall of the defect on the left side beneath the summit of the ventricular septum. In some cases, the bundle may be proximal to the defect, thus lying intramuscularly, and only the right and left bundle branches are related to the defect. The pattern od development of the atrioventricular (A-V) node, bundle and bundle branches is related primarily to the development of the endocardial cushions and posterior ventricular septum, and not to that of the absorption of the bulbus.
Nitroprusside after open-heart surgery.
Authors: Benzing G , Helmsworth J A , Schrieber J T , Loggie J , Kaplan S
Published: June 2012

The effects of intravenous infusion of sodium nitroprusside were studied in 11 children immediately after open-heart surgery for congenital heart disease. The patients were selected because, following bypass, their cardiac index was below 2,0 L/min/m2 and their systemic vascular resistance exceeded 30 units. In order to eliminate the effects of preload, mean left atrial pressure was maintained at a constant level by blood transfusion. During infusion of nitroprusside the mean decrease of mean arterial pressure was 18.6%, of systemic vascular resistance was 53.7%, and the increase in cardiac index was 76.9%. All children recovered.
Impaired forearm oxygen consumption during static exercise in patients with congestive heart failure.
Authors: Longhurst J , Gifford W , Zelis R
Published: June 2012

In this study, the effects of forearm static exercise were determined on local blood flow and oxygen consumption in 15 normal individuals (NL) and their responses were compared with ten patients in congestive heart failure (CHF). Forearm blood flow was determined by a plethysmographic technique before and during 15% of maximum voluntary contraction of the forearm. Regional arterial and venous oxygen contents were sampled and forearm oxygen consumption calculated by the Fick principle. At rest, forearm blood flow was less in patients with heart failure than in normal individuals; however, this was compensated for by an increased oxygen extraction, thus maintaining forearm oxygen consumption at a normal level. In contrast, during static exercise, forearm blood flow failed to rise normally with heart failure (NL 9.31; CHF 4.35 ml/min-100 ml, P less than 0.001) and the increased oxygen extraction was not sufficient to maintain a normal forearm oxygen consumption (NL .82; CHF .44 ml/min-100 ml, P less than 0.01). Therefore, patients with congestive heart failure demonstrate regional circulatory and metabolic abnormalities during static exercise that are comparable to those present during dynamic exercise. Because of a limited ability of their skeletal muscle resistance vessels to respond to dilator stimuli, they have an attenuation of their exercise hyperemia which leads to an earlier shift to anaerobic metabolism.
Retrograde coronary artery flow in aortic valve disease.
Authors: Carroll R J , Falsetti H L
Published: June 2012

Retrograde coronary artery flow was observed angiographically in 43 patients with aortic stenosis and/or regurgitation. In the 24 patients with pure or predominant aortic stenosis, retrograde flow was seen in all 24 during end-systole. In the eight patients with pure aortic regurgitation, retrograde flow was seen mainly during end-diastole (6/8). Among the 11 patients with stenosis and regurgitation, retrograde flow was both end-systolic and enddiastolic. Dominant left coronary arteries were seen in 13 patients; 13 showed retrograde flow in the dominant arteries. Dominant right coronary arteries were seen in 25 patients: all 25 showed retrograde flow equally in the right and left coronary. Five of the 43 patients could not be evaluated for dominance because of coronary artery occlusions. The severity of retrograde flow did not correlate with usual clinical, hemodynamic or tension-stress parameters: angina, electrocardiographic abnormality, end-diastolic pressure or volume, end-systolic pressure or volume, ejection fraction, severity of aortic regurgitation, peak or mean valve gradient, aortic valve area, myocardial tension and stress calculations, or DPTI:SPTI. In summary, retrograde coronary artery flow was seen in all 43 patients with severe aortic valve disease. The time in the cardiac cycle when retrograde flow occurred was related to the type of valve disease. Retrograde flow was seen mainly in the coronary arteries supplying the left ventricle and may result from increased regional myocardial stresses.
Echocardiography of cardiac valves in pericardial effusion.
Authors: Nanda N C , Gramiak R , Gross C M
Published: June 2012

Nine adult patients with large pericardial effusions (PE) demonstrated echocardiographic motion abnormalites of cardiac valves in systole. In four cases (Group 1), the abnormal findings consisted of prominent systolic anterior movements of the mitral valve resembling those seen in idiopathic hypertrophic subaortic stenosis. In Group 2(five cases), typical mitral valve prolapse patterns with large posterior midsystolic displacements well below the C point were observed. Additional abnormalities in Group 2 included tricuspid valve prolapse patterns (four cases), early systolic movement of the aortic valve toward closure (three cases), midsystolic notching of the pulmonary valve (two cases) and abnormal or attenuated motion of the aortic root in all patients. Marked decrease or resolution of PE resulted in complete disappearance of all the observed abnormalities. These findings appeared to be related to large fluid collections behind the left atrium and abnormal movement of the heart in the pericardial space. In the presence of PE, therefore, the echocardiographic observation of abnormal valve motion may not be clinically significant.
Pseudoejection sound in hypertrophic subaortic stenosis: an echocardiographic correlative study.
Authors: Sze K C , Shah P M
Published: June 2012

Phonoechocardiographic studies were performed in 23 patients with hypertrophic subaortic stenosis. In ten patients a distinct systolic sound was recorded, usually along the lower left sternal border. In eight of these cases the sound was low or medium frequency. Unlike the ejection click of valvular aortic stenosis, the sound began 40-100 msec after the upstroke of the indirect carotid pulse and occurred close to the initial peak of the carotid pulse. This sound, termed pseudoejection sound, was associated with systolic anterior movement (SAM) of the anterior mitral leaflet on the echocardiogram. In all six patients studied with simultaneous phonoechocardiograms, the pseudoejection sound coincided with the sudden halting of SAM of the anterior mitral leaflet. Following provocative maneuvers the sound became louder, and its timing, as well as the sharp halting of SAM of the mitral leaflet, occurred earlier in systole. The pseudoejection sound probably results either from impact of the anterior mitral leaflet against the interventricular septum or more likely from deceleration of blood flow in the left ventricular outflow tract. The echo data support the association of the pseudoejection sound with significant left aventricular outflow obstruction,
Coronary atherosclerosis in subjects with mitral stenosis.
Authors: Tadavarthy S M , Vlodaver Z , Edwards J E
Published: June 2012

The coronary arteries were examined in 60 specimens from patients with mitral stenosis. In three, localized obstruction was nonatherosclerotic in nature (in one, arterial dysplasia; in two, embolic). In 18 of the remaining 57 cases (31.5%), significantly obstructive atherosclerosis in one or more segments of the coronary arterial system was found. This represented 46% of the males and 27% of the females. The incidence of involvement of three or more arteries by significantly obstructive atherosclerosis was 39%, while in a cited series of subjects with angina pectoris three or more vessels were involved in 79% of the cases. It may be concluded that, on the average, the distribution of lesions in patients with mitral stenosis and significant coronary atherosclerosis is less wide than in subjects with clinical coronary disease.
Left atrial enlargement. Echocardiographic assessment of electrocardiographic criteria.
Authors: Waggoner A D , Adyanthaya A V , Quinones M A , Alexander J K
Published: June 2012

A comparison of electrocardiographic manifestations of left atrial enlargement (LAE) and left atrial size by echocardiography was made in 307 patients in sinus rhythm. Electrocardiographic criteria used were L:P wave duration in lead II equal to or greater than 0.12 sec; Va: the ratio of the duration of negative terminal P in V1 to the P-R segment equal to or greater than 1.0; Vb: a negative P terminal force in V1 less than -0.03 mm sec. The echocardiographic diagnosis of left atrial enlargement was based on 1) transverse dimension greater than 4.0 cm; or 2) a ratio of transverse atrial to transverse aortic root dimension greater than 1.17. In the presence of left atrial enlargement, a combination of criteria occurred more often than a single criterion. The overall predictive index of the electrocardiogram for left atrial enlargement was 63% (excluding criterion Vb raised probability to 80%); and that for absence of left atrial enlargement was 78%. The index of coarse versus fine fibrillary waves was unreliable in predicting left atrial enlargement. Changes in P wave morphology may be used as a reasonably specific but less sensitive indicator of left atrial enlargement.
Echocardiographic detection of intracardiac right-to-left shunts following peripheral vein injections.
Authors: Valdes-Cruz L M , Pieroni D R , Roland J M , Varghese P J
Published: June 2012

A contrast echocardiographic technique using peripheral vein injections for the detection and localization of intracardiac right-to-left shunting is described. Fifty children underwent cardiac catheterization and peripheral contrast echocardiographic studies. The site, degree, and direction of shunting were established at catheterization by oximetry, indicator dilution analysis and/or angiography. Peripheral vein injections were performed from the right antecubital vein or the right saphenous vein. Right-to-left shunts were documented at catheterization in 27/50 patients; contrast echocardiographic studies indicated the presence and level of shunting in all 27 patients. The contrast echocardiographic technique using peripheral vein injections detects and localizes right-to-left intracardiac shunting. It is a safe and sensitive method to evaluate systemic desaturation in ambulatory and postoperative patients.
The similarity of changes in segmental contraction patterns induced by postextrasystolic potentiation and nitroglycerin.
Authors: Klausner S C , Ratshin R A , Tyberg J V , Lappin H A , Chatterjee K , Parmley W W
Published: June 2012

Despite a fundamental difference in their underlying mechanisms, both postextrasystolic potentiation (PESP) and administration of nitroglycerin (TNG) have been utilized to predict reversibility of abnormal segmental wall motion in patients with ischemic heart disease. To determine whether these interventions induce the same changes in segmental contraction pattern, we analyzed biplane ventriculograms of 14 patients who had an adequately visualized PESP beat on a basal ventriculogram as well as a post-TNG ventriculogram. Four segments in each plane were defined and the area ejection fraction of each segment was calculated for a basal sinus, PESP, and post-TNG beat. To correct for global differences in the response to PESP and TNG, we normalized each segmental ejection fraction (NSEF) by the ventricular ejection fraction for that beat and then compared the differences in NSEF from the basal value after PESP and TNG. Eleven patients demonstrated similar responses to both interventions. The three patients whose responses were discordant had elevated or unchanged left ventricular systolic or end-diastolic pressures at the time of the TNG ventriculogram. Our data suggest that, provided these pressures are lower than basal values at the time of the TNG ventriculogram, PESP and TNG will induce similar changes in segmental contraction patterns. Seven patients with similar responses had a PESP beat on their post-TNG ventriculogram. Changes in NSEF after PESP+TNG were identical to those after either intervention. This implies that the combination of interventions does not induce further changes in segmental contraction pattern beyond that produced by either intervention alone.