bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surgically Induced Right Bundle-Branch Block with Left Anterior Hemiblock
Authors: WOLFF GRACE S. , ROWLAND THOMAS W. , ELLISON R. CURTIS 
Published: June 2012

A review of the electrocardiograms of 291 patients who survived more than 1 month after complete repair of tetralogy of Fallot disclosed that 24 (8.2%) developed a pattern of right bundle-branch block and left anterior hemiblock (RBBB-LAH) following surgery. When the course of these 24 patients was compared with a control group of 100 additional patients who did not develop this pattern following surgery, a significant increase in morbidity and mortality was noted.
Complete heart block developed at some time in the follow-up period in 41.7% of the RBBB-LAH group and in 4% of the control group. The incidence of serious ventricular arrhythmias was 16.7% for the RBBB-LAH group and 1% for the control group. Sudden death occurred in 12.5% of the patients with RBBB-LAH and in 2% of the controls. At the time of this review (1-12 years following surgery) overall late mortality was 25% for the RBBB-LAH group and 2% for the control group.
The study indicates that serious complications are much more frequent in tetralogy of Fallot patients who acquire the RBBB-LAH pattern during surgical repair. Prophylactic or therapeutic pacing may be indicated in many of these patients.
Quantitative Assessment of Left Ventricular Diastolic Stiffness in Man
Authors: GROSSMAN WILLIAM , STEFADOUROS MILTIADIS A. , MCLAURIN LAMBERT P. , ROLETT ELLIS L. , YOUNG DANIEL T. 
Published: June 2012

An approach to the quantitative assessment of left ventricular (LV) diastolic stiffness in man has been developed utilizing strip-chart recordings of simultaneous ultrasonic LV dimensions, LV pressure, and electrocardiogram (ECG). In 23 patients without regional abnormalities of contraction, LV pressure, and LV internal diameter (D = distance between endocardial surfaces of LV posterior wall and septum at the plane of the mitral valve) were determined at the onset (P
1
, D
1
) and peak (P
2
, D
2
) of left atrial mechanical systole. In addition, left ventricular volumes, V
1
and V
2
, were calculated from D
1
and D
2
using a regression formula for end-diastolic volume previously determined from biplane angiographic studies. This allowed calculation of ΔP/ΔD and ΔP/ΔV associated with the "a" wave of the LV pressure trace, and these ratios were utilized as measures of LV stiffness late in diastole.

Patients with LV hypertrophy by standard ECG criteria had much greater late diastolic stiffness (11 patients, ΔP/ΔD = 6.1 ± 1.1 mm Hg/mm, ΔP/ΔV = 1.0 ± 0.2 mm Hg/cc) than those without LV hypertrophy (12 patients, ΔP/ΔD = 1.8 ± 0.2 mm Hg/mm, ΔP/ΔV = 0.29 ± 0.04 mm Hg/cc,
P
< 0.001 for each ratio).

Comparison of the stiffness ratios showed significant variation among patients with different disease states. Thus, late diastolic stiffness was highest in patients with aortic stenosis (three patients, ΔP/ΔD = 8.9 ± 2.9 mm Hg/mm, ΔP/ΔV = 1.5 ± 0.5 mm Hg/cc), lowest in mitral stenosis (four patients, ΔP/ΔD = 1.5 ± 0.5 mm Hg/mm, ΔP/ΔV = 0.23 ± 0.06 mm Hg/cc), and intermediate in patients with aortic regurgitation (three patients, ΔP/ΔD = 4.8 ± 0.7 mm Hg/mm, ΔP/ΔV = 0.83 ± 0.12 mm Hg/cc) and mitral regurgitation (three patients, ΔP/ΔD = 3.2 ± 0.7 mm Hg/mm, ΔP/ΔV = 0.5 ± 0.1 mm Hg/cc).
It is concluded that the quantitative evaluation of LV diastolic stiffness obtained by this approach correlates well with the presence or absence of LV hypertrophy and with the underlying pathophysiology.
Coronary Artery Bypass
Authors: HALL ROBERT J. , DAWSON JOHN T. , COOLEY DENTON A. , HALLMAN GRADY L. , WUKASCH DON C. , GARCIA EFRAIN 
Published: June 2012

From October 1969 through March 1972, 1,276 patients underwent coronary artery bypass at the Texas Heart Institute. Associated conditions included simultaneous valve replacement and resection or repair of ventricular aneurysms or ascending aortic aneurysms. Among the series were 1,105 patients who underwent bypass surgery alone, with or without endarterectomy.
Factors affecting outcome were analyzed and revealed adverse influences including concomitant endarterectomy, female sex, age, evidence of left ventricular failure or serious ventricular dysfunction, and previous myocardial infarction within the month before surgery, but more importantly within the week prior to surgery. Functional class III and IV angina was significantly decreased or totally relieved in a high percentage of patients after bypass surgery, and remains the major indication at this time for myocardial revascularization. Progressive reduction in surgical risk and improvement in patient selection allow coronary artery bypass to be performed currently with an early mortality risk of only 3.7%.
Rate-Dependency of Functional Block in the Human His Bundle and Bundle Branch-Purkinje System
Authors: SCHUILENBURG REINIER M. , DURRER DIRK 
Published: June 2012

In eleven patients in whom atrial premature stimulation elicited functional block in the conduction system distal to the atrioventricular (A-V) node, the influence of atrial driving rate was studied. Functional conduction disturbances in the left bundle branch-Purkinje system were produced by driving the atria at a rate just above the spontaneous sinus rate and by introducing premature atrial stimuli. In five patients this was associated with block or delay of conduction in the right bundle branch-Purkinje system and in one with block within the His bundle. In these patients it was shown that the ultimate QRS configuration of the premature beat was determined by different conduction delays in the three parts of the bundle branch system. In three patients complete block of impulse conduction could be produced below the level of the His bundle, in one within the His bundle. In these four patients conduction delay of earlier atrial premature beats within the A-V node with resumption of conduction in the more peripheral pathways, gave rise to the phenomenon of the A-V gap. In two patients functional conduction delay in the contralateral bundle branch caused pseudo-normalization of a pre-existent complete right bundle branch block pattern, indicating that this pattern may not be caused by complete block, but by delayed conduction in the right bundle branch.
In ten of the eleven patients functional block or delay of atrial premature beats in the peripheral conduction system became less pronounced as the driving rate was increased. In nine of these ten the phenomenon disappeared completely at higher rates; in six this occurred with an increase in rate of only 20 beats/min. The A-V gap phenomenon present in four cases at the lowest rate disappeared at higher rates in all four. It was concluded that functional conduction disturbances in the peripheral conduction system are favored by a low basic heart rate and that this rate dependency is caused by a differential influence of heart rate upon the functional properties of the A-V node and of the more peripheral parts of the conduction system.
Rate Dependent Aberrancy
Authors: FISCH CHARLES , ZIPES DOUGLAS P. , McHENRY PAUL L. 
Published: June 2012

Forty patients with "rate dependent aberrancy" (RDA) were studied. This large group of patients permitted a clear definition of the syndrome and recognition of a number of features not previously described. These proved to have a significant bearing on the recognition and differential diagnosis of RDA and non-rate dependent aberrancy.
It was found that a small change in cycle length, perhaps too small to be recognized in the surface ECG, can result in RDA. Consequently, if a critical shortening of cycle length is to be recognized, it is necessary to record not only the onset of aberrant rhythm but also sufficiently long strips with normal intraventricular conduction preceding and following the RDA. In some patients there was no recognizable sudden change in cycle length and the onset of aberrancy was a function of the duration of the accelerated rate. In others only the first cycle of the rhythm with RDA was shortened and the remaining R-R intervals were paradoxically longer than the R-R cycle which initiated the RDA.
The aberrancy in RDA occurred at relatively slow heart rates (in 26 of the 40 patients the rate was below 80), and was frequently independent of any significant changes in the duration of the immediately preceding cycle length. There was a striking prevalence of left bundle branch block, and in 35 of the 40 patients obvious organic heart disease was documented.
Intermittent Parasystole—Mechanism of Protection
Authors: COHEN HOWARD , LANGENDORF RICHARD , PICK ALFRED 
Published: June 2012

Analysis of ten cases of intermittent ventricular parasystole suggested temporary loss of protection of the parasystolic focus resulting in discharge and "resetting" of the parasystole by sinus or other supraventricular beats. Parasystolic centers appear to be protected from supraventricular and other ventricular ectopic impulses early in their cycle by their refractory periods, and late in the cycle by diastolic depolarization. Between these two areas of protection is a period of "susceptibility" during which supraventricular beats can discharge the parasystolic focus. This phenomenon accounted for fixed coupling of the first parasystolic beat of a series to a preceding sinus beat. Under certain conditions all parasystolic beats may have such fixed coupling, a new and previously unconsidered mechanism for parasystole with fixed coupling.
In one case of intermittent ventricular parasystole, the parasystole was shown to originate in the posterior fascicle of the left bundle branch on the basis of the shape of the standard electrocardiogram and by His bundle recordings. These parasystolic impulses produced a compensatory pause regardless of whether their discharge was manifest or concealed, and thus imitated a second degree (Type II) atrioventricular (A-V) block. This represents the first description of completely blocked atrial impulses resulting from concealed parasystolic beats arising within the ventricular conduction system.
Ischemic Response to Sudden Strenuous Exercise in Healthy Men
Authors: BARNARD R. JAMES , MACALPIN REX , KATTUS ALBERT A. , BUCKBERG GERALD D. 
Published: June 2012

In ten healthy, asymptomatic men, intra-arterial pressure and electrocardiograms were recorded during various types of exercise. Potential subendocardial blood flow was estimated from a diastolic pressure time index (DPTI) and myocardial oxygen requirements estimated from the tension time index (TTI). The ratio DPTI/TTI provided an estimate of the supply/demand relationship With sudden vigorous exercise without warm-up, the DPTI/TTI was below 0.35 in three men who had ischemic electrocardiograms, below 0.44 in three men with minor ST abnormalities, and above 0.44 in four men with normal ST segments. With a prior warm-up exercise, sudden exercise caused no ischemic changes, but DPTI/TTI was below 0.44 in two subjects who had minor ST abnormalities. Maximum treadmill testing produced higher heart rates and TTI than did sudden exercise, but DPTI/TTI was above 0.44 in all cases and no ST abnormalities occurred.
Abnormal electrocardiographic responses produced by sudden, vigorous exercise in normal men may represent subendocardial ischemia caused by a transient, unfavorable alteration in the subendocardial oxygen supply/demand relationship which is predictable from arterial pressure measurements.
Unusual Properties of Accessory Pathways
Authors: ZIPES DOUGLAS P. , DEJOSEPH ROBERT L. , ROTHBAUM DONALD A. 
Published: June 2012

Electrophysiologic evaluation in five patients who exhibited manifestations of the pre-excitation syndrome and/or supraventricular tachycardia provided functional evidence that the properties of the accessory fibers may be quite variable. The unusual responses to electrical stimulation in these patients included: 1) failure to depolarize the His bundle from the site of ventricular pre-excitation; 2) supraventricular tachycardia with two types of re-entry; 3) anterograde block in the accessory pathway with intact retrograde conduction; and 4) retrograde delay or block in the accessory pathway and atrioventricular (A-V) node with intact anterograde conduction. Understanding these variations may provide important therapeutic implications regarding drug and surgical management.
In addition to these anomalies in conduction over accessory pathways we demonstrated in these patients the occurrence of retrograde functional right bundle branch block and retrograde "gap" phenomenon, and ventricular reciprocation without recording intervening atrial discharge.
Ultrasound Evaluation of Systolic Anterior Septal Motion in Patients With and Without Right Ventricular Volume Overload
Authors: HAGAN ARTHUR D. , FRANCIS GARY S. , SAHN DAVID J. , KARLINER JOEL S. , FRIEDMAN WILLIAM F. , O'ROURKE ROBERT A. 
Published: June 2012

Little information is available concerning the normal systolic pattern of movement of the interventricular septum in man. Accordingly, we studied 242 patients without clinical or catheterization evidence of right ventricular volume overload (RVVO) employing the ultrasound continuous recording technique. In the plane of the mitral valve, systolic anterior septal motion (SASM) was present in 111 patients; in 38 patients the septum did not move during systole while in 74 patients, septal motion was variably anterior and posterior during the same recording. Normal posterior septal motion occurred in only 19 patients. However, at or below the level of the chordae tendineae, 226 of the 242 patients (93%) had normal posterior septal motion. The other 16 patients had severely impaired left ventricular function.
In 56 patients with RVVO, 34 had abnormal septal motion at the level of the chordae tendineae (24 with SASM, 7 with variable motion and 3 with no movement).
To evaluate septal motion further, 100 normal subjects were studied using a phased multicrystal ultrasound system designed by Bom which provided a sagittal plane image of the cardiac structures. In all 100 subjects the superior septum moved anteriorly in systole with the aortic root, and the upper one-third of the septum acted as a "hinge" for the lower two-thirds which moved posteriorly. In 8 of 21 patients with RVVO studied by the multicrystal method, the entire septum moved anteriorly during systole; variable patterns occurred in 7 patients, while normal septal motion was present in 6 patients.
We conclude that 1) normal septal motion consists of anterior movement of the superior segment of the septum during systole; 2) below a pivot point, the inferior two-thirds of the septum moves posteriorly during systole; 3) the normal pivot point of the septum frequently results in SASM when recordings are made in the plane of the mitral valve in patients with and without RVVO; and 4) paradoxical septal motion is not always present in patients with RVVO even when echocardiographic recordings are obtained at or below the level of the chordae tendineae.
Echocardiographic Criteria in the Diagnosis of Idiopathic Hypertrophic Subaortic Stenosis
Authors: ROSSEN RONALD M. , GOODMAN DANIEL J. , INGHAM ROBERT E. , POPP RICHARD L. 
Published: June 2012

Echocardiography has proven to be a useful technique in the diagnosis and assessment of therapy in idiopathic hypertrophic subaortic stenosis (IHSS). Asymmetric septal hypertrophy has been described as the pathognomonic anatomic marker of the disease. A characteristic systolic anterior motion of the anterior mitral valve leaflet has been detected in the presence of hemodynamically significant subaortic left ventricular outflow obstruction. An echocardiographic quantification of the outflow gradient (the obstruction index) has been derived previously.
Four patients were studied by ultrasound at the time of cardiac catheterization. All four demonstrated systolic anterior motion of the anterior mitral leaflet in the absence of a resting gradient. In three of the four, the calculated obstruction index predicted hemodynamically significant resting gradients. All four patients were shown to have labile gradients with provocative maneuvers. A fifth patient with abnormal systolic anterior motion demonstrated a close correlation between the obstruction index and resting gradient; however, symmetric hypertrophy of the septum and left ventricular posterior wall was detected by ultrasound. Therefore, the abnormal mitral valve pattern may be seen in the absence of a resting gradient and symmetric left ventricular hypertrophy may exist in the presence of IHSS.
Surface Markers of Heterogeneous Peripheral Blood–Derived Smooth Muscle Progenitor Cells
Authors: Wang Chao-Hung , Lee Yun-Shien , Lin Shing-Jong , Mei Hsiu-Fu , Lin Sheng-Yuan , Liu Min-Hui , Chen Jim-Ray , Cherng Wen-Jin 
Published: June 2012

Objective—
Smooth muscle progenitor cells (SMPCs) were intriguingly shown to act as a double-edged sword in the pathogenesis of atherosclerosis. To fully clarify the roles of SMPCs in atherosclerosis, a distinct panel of SMPC surface markers is mandatory to be developed.

Methods and Results—

Microarray gene expression analyses were used to discover potential surface markers of SMPCs. In vitro and in vivo experiments documented that platelet-derived growth factor receptor-β, carboxypeptidase M, carbonic anhydrase 12, receptor activity-modifying protein 1, and low-density lipoprotein receptor–related protein were the 5 specific surface markers regulating various SMPC functions, including migration, extracellular matrix formation, resistance to hypoxia, and anti-inflammation. In s
evere combined immunodeficiency
/nonobese diabetic mice after femoral arterial wire injury, injected human peripheral blood mononuclear cells contributed to substantial amount of neointimal α-smooth muscle actin-positive cells, coexpressing platelet-derived growth factor receptor-β, carboxypeptidase M, carbonic anhydrase 12, receptor activity-modifying protein 1, and low-density lipoprotein receptor–related protein. Based on these markers, a novel quantification assay was developed to enumerate circulating early SMPC. Early SMPC numbers were higher in patients with unstable angina compared with those with normal coronary angiograms. In patients with acute ST-elevation myocardial infarction, different patterns of serial early SMPC changes were noted, related to different clinical presentations.

Conclusion—
Surface markers of heterogeneous SMPCs exhibit various functions associated with atherosclerotic pathophysiology. Quantification of surface marker–defined SMPCs provides a platform for studying SMPCs in cardiovascular diseases.
Effects of Estrogen on Vascular Inflammation
Authors: Novella Susana , Heras Magda , Hermenegildo Carlos , Dantas Ana Paula 
Published: June 2012

Objective—
Our study aims to determine the role of time of menopause on vascular inflammation biomarkers and how it affects their modulation by estrogen and raloxifene in postmenopausal women.

Methods and Results—
Uterine arteries from 68 postmenopausal women were divided into 3 segments and cultured for 24 hours in tissue culture media containing 17β-estradiol (100 nmol/L), raloxifene (100 nmol/L), or vehicle. Assessment of arterial concentration of 13 inflammatory biomarkers was performed by multiplex immunobead-based assay. Aging per se has a positive correlation with the generation of several proinflammatory markers. Although short-term estradiol exposure correlates with lower expression of tumor necrosis factor-α, vascular endothelial growth factor, and interleukin-1β in all age groups, for most biomarkers aging was associated with a switch from a beneficial anti-inflammatory action by estrogen, at earlier stages of menopause, to a proinflammatory profile after 5 years past its onset. Raloxifene has no significant effect on the expression of all proinflammatory markers. Western blot analysis of estrogen receptor expression (estrogen receptor-α and estrogen receptor-β) showed that estrogen receptor-β increases with aging, and this increase has a positive correlation with the generation of several proinflammatory markers.

Conclusion—
Aging alters estrogen-mediated effects on the modulation of inflammatory biomarkers in women. How aging affects estrogen responses on vascular inflammation is not clear, but our data show a positive association between increased estrogen receptor-β expression with aging and proinflammatory effects by estrogen.
Differing Relationship of Nocturnal Fluid Shifts to Sleep Apnea in Men and Women With Heart Failure
Authors: Kasai Takatoshi , Motwani Shveta S. , Yumino Dai , Mak Susanna , Newton Gary E. , Bradley T. Douglas 
Published: June 2012

Background—
In men with heart failure, nocturnal rostral fluid shift is associated with an overnight increase in the neck circumference (NC) and with severity of obstructive sleep apnea. Because the prevalence of obstructive sleep apnea is lower in women than in men with heart failure, we hypothesized that less fluid would shift into the neck in association with less severe obstructive sleep apnea in women than in men with heart failure.

Methods and Results—

In 35 men and 30 women with heart failure, we assessed overnight changes in NC (ΔNC) and leg fluid volume before and after polysomnography. The severity of obstructive sleep apnea was assessed by the apnea–hypopnea index. Although the changes in leg fluid volume did not differ significantly between men and women (−131 ± 90 versus −180 ± 132 mL,
P
=0.081), in women, ΔNC was smaller (
P
<0.001) than in men. Furthermore, although in men, changes in leg fluid volume correlated inversely with ΔNC (
r
=−0.755,
P
<0.001) and apnea–hypopnea index (
r
=−0.765,
P
<0.001), it did not in women.

Conclusions—
Despite no difference in overnight displacement of fluid from the legs compared with in men, in women, less of this fluid reached the neck, and unlike men, there was no relationship between changes in leg fluid volume and either ΔNC or apnea–hypopnea index. These findings suggest a differing relationship between overnight fluid shift from the legs and severity of obstructive sleep apnea in women than in men with heart failure.
Cardiac Micro–Computed Tomography Imaging of the Aging Coronary Vasculature
Authors: Sangaralingham S. Jeson , Ritman Erik L. , McKie Paul M. , Ichiki Tomoko , Lerman Amir , Scott Christopher G. , Martin Fernando L. , Harders Gerald E. , Bellavia Diego , Burnett John C. 
Published: June 2012

Background—
Alterations at the level of the coronary circulation with aging may play an important role in the evolution of age-associated changes in left ventricular (LV) fibrosis and function. However these age-associated changes in the coronary vasculature remain poorly defined primarily due to the lack of high resolution imaging technologies. The current study was designed to utilize cardiac micro–computed tomography (micro-CT) technology as a novel imaging strategy, to define the 3-dimensional coronary circulation in the young and aged heart and its relationship to LV fibrosis and function.

Methods and Results—
Young (2 months old; n=10) and aged (20 months old; n=10) Fischer rats underwent cardiac micro-CT imaging as well as echocardiography, blood pressure, and fibrosis analysis. Importantly, when indexed to LV mass, which increased with age, the total and intramyocardial vessel volumes were lower, whereas the epicardial vessel volume, with and without indexing to LV mass, was significantly higher in the aged hearts compared with the young hearts. Moreover, the aged hearts had a significantly lower percentage of intramyocardial vessel volume and a significantly higher percentage of epicardial vessel volume, when normalized to the total vessel volume, compared with the young hearts. Further, the aged hearts had significant LV fibrosis and mild LV dysfunction compared with the young hearts.

Conclusions—
This micro-CT imaging study reports the reduction in normalized intramyocardial vessel volume within the aged heart, in association with increased epicardial vessel volume, in the setting of increased LV fibrosis, and mild LV dysfunction.