bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arm exercise testing for coronary artery disease in patients with peripheral vascular disease
Authors: Hanson P. , Pease M. , Berkoff H. , Turnipseed W. , Detmer D. 
Published: February 2009

AbstractWe evaluated 74 peripheral vascular disease (PVD) patients (54 men, age 61 ± 7 years and 17 women, age 63 ± 7 years) for potential coronary heart disease (CAD) using an arm exercise test (AET) protocol. All patients performed upright two‐arm cranking using discontinuous stages of 2 minutes of exercise separated by 2 minutes of rest. Exercise intensity was increased by + 100 or 200 kpm (kilopond meters) with each stage. ECG was monitored continuously and blood pressure and 12‐lead ECG tracings were obtained at the end of each exercise stage. All patients reached an endpoint of subjective exhaustion. Men achieved 91 ± 14% of age‐predicted heart rate at 597 ± 167 kpm, while women achieved 86 + 14% of age‐predicted heart rate at 335 ± 117 kpm. Ischemic ECG responses (+AET) defined as new or additional ST depression > 1.0 mm × 80 ms, occurred in 35 men (65%) and 7 women (42%). Coronary angiography was performed in a subset of 22 patients (15 males and 7 females). CAD (>70% stenosis) was found in 11 of 12 men and 4 of 5 women who showed positive or strongly positive AET responses (overall predictive value for AET = 88%). We conclude that arm exercise stress testing is safely performed in PVD patients who cannot complete treadmill exercise. In this limited series of PVD patients, the predictive value of a + AET response for diagnosis of CAD is similar to established values for treadmill exercise.
Effect of localized surface cooling of the heart muscle on the high‐frequency content of ecg waveforms in dogs
Authors: Akselrod S. , Mor‐Avi V. , Oz O. , David D. 
Published: February 2009

AbstractHypothermia is known to affect the electrophysiology of the myocardium in various ways. A marked increase in action potential duration, combined with a decrease in rate of depolarization and conduction velocity, has been observed. We studied the effect of localized hypothermia of the ventricular myocardium on the high‐frequency (HF) components of the ECG waveform. Signals were obtained from 6 anesthetized dogs using simultaneous recording of three orthogonal body surface leads before, during, and following surface cooling of different areas of the epicardium. Computer analysis included digital averaging and filtering in a frequency range of 150–250 Hz. For each intervention in each animal, the variance of the average nonfiltered QRS complex was used for a quantitative estimate of the total power, whereas the variance of the derived filtered wave (HF QRS complex) expressed the power content in the HF range. The total power increased during localized cooling of the anterior as well as the inferior epicardial surface, while a clear reduction of power was observed in the HF range. This reduction was shown to be lead dependent and nonuniformly distributed during the course of the QRS. In all cases, hypothermia of either anterior or inferior ventricular epicardium produced a zone of reduced amplitude in the HF QRS complex of at least one lead. Thus, typical changes in the morphology of the HF QRS complex are reliable markers for cooling‐induced localized electrophysiological (EP) variations. Therefore, the HF analysis of the body surface ECG may provide noninvasive insight into the EP properties of the myocardium.
Takayasu's arteritis and mitral stenosis
Authors: Doi Y. L. , Seo H. , Hamashige N. , Jin‐Nouchi Y. , Ozawa T. 
Published: February 2009

AbstractA 44‐year‐old housewife was found to have coarctation of the abdominal aorta secondary to Takayasu's arteritis. Since she also had mitral stenosis, possible etiological relation between Takayasu's arteritis and mitral stenosis is suspected.
Angiographic morphology and response to therapy in unstable angina
Authors: Sansa M. , Cernigliaro C. , Bolognese L. , Bongo S. A. , Rossi L. , Rossi P. 
Published: February 2009

AbstractThe coronary anatomy of 69 patients with unstable angina, subgrouped according to response to medical therapy, was investigated. All patients received oral treatment with nitrates, calcium antagonists, and beta‐blocking agents. When combined oral treatment was not effective, an intravenous infusion of nitrates (10–100 m̈g/min) was subsequently administered. Coronary arteriography was performed within hours (14±9 h) from the last episode of chest pain in 28 patients refractory to medical treatment, while in 41 patients who became asymptomatic during medical therapy, angiography was performed after an observation period of several days (8 ± 6 days). On angiography, the nonresponder group was characterized by a prevalence of eccentric and multiple lesions, and by a 46% incidence of thrombi (p <0.001). Recurrent symptoms requiring emergency bypass operation were common in this group. In patients responsive to medical treatment, a high percentage of concentric lesions (37%) and totally occluded (34%) coronary arteries was found (p <0.05). No infarcts and low rate of recurrent angina were noted in these patients during hospitalization. In conclusion, the finding of intracoro‐nary thrombotic material and eccentric or multiple lesions can be an accurate markers of the active phase of the disease, while “silent” occlusion of the involved vessel may be accompanied by relief of symptoms during medical therapy.
The role of ischemia and ventricular asynergy in the genesis of exercise‐induced ST elevation
Authors: Arora R. , Ioachim L. , Matza D. , Horowitz S. F. 
Published: February 2009

AbstractSixty‐five patients with ST elevation were retrospectively studied in order to evaluate the clinical significance and underlying mechanisms of ST‐segment elevation during exercise. Of these, 50 patients had previous myocardial infarction (Group I) and 15 patients did not (Group II). Exercise thallium‐201 imaging was performed on 30 patients, resting gated blood pool imaging was performed on 33 patients, and 23 underwent cardiac catheterization for clinical indications. When the two groups were compared, patients in Group I had more frequent multivessel disease (9/13 vs. 3/10, p<0.05), anterior infarctions (33/50 vs. 4/10, p<0.02), while Group II patients had more frequent single‐vessel disease (7/10 vs. 4/13, p<0.05). For Group I patients, the most common reason for termination of exercise was fatigue and/or dyspnea (35/50 vs. 0/15, p<0.05), with an irreversible defect noted in both stress and delayed views on thallium imaging (20/24 vs. 1/6, p<0.05). In Group II, the most common reason for termination was angina (15/15 vs. 2/50, p<0.001), with reversible thallium defects noted more frequently (4/6 vs. 3/24, p<0.01). Thus, we conclude that in patients with Q waves, left ventricular dysfunction rather than ischemia is the mechanism for ST elevation. In these patients angina is rare, but fatigue, dyspnea, multivessel disease, and fixed thallium defects are common. In patients with non‐Q‐wave exertional ST elevation, ischemia is the rule, manifested by frequent chest pain and reversible thallium defects.
Evidence of anaerobic metabolism during low‐level exercise testing in high‐risk postmyocardial infarction patients
Authors: Hossack K. F. , Wolfel E. 
Published: February 2009

AbstractLow‐level exercise testing was performed on 31 patients 7.4±2.7 days following an acute myocardial infarction. Measurements of oxygen consumption (VO2) and arterial serum lactate were made at rest and during exercise in these patients and 15 normal subjects. The patients were subdivided into finishers (F) and nonfinishers (NF) of the low‐level protocol. The NF group had 2.5 ±. 6 stenosed vessels and an ejection fraction of 44 ± 11% compared to F subjects, who had 1.4 ± 1 vessels stenosed (p <.001) and an ejection fraction of 54 ± 14% (p <.05). Finishers had significantly higher VO2 than the nonfinishers (14.5±2.5 ml/kg/min vs. 11.2+3.5 ml/kg/min p< .01). At the end of exercise serum lactate level was 1.18±.59 mM in normals, 1.43±.52 mM in finishers, and 2.15±.9 mM in nonfinishers. The change in serum lactate from rest to end exercise divided by the change in VO2 from rest to end exercise was .039±.038 mM/ml kg per min in normals, .075±.045 mM/ml kg per min in finishers (p<.03 vs. normal), and .210±.189 mM/ml kg per min for nonfinishers (p <.001 vs. normal). These results indicate that nonfinishers produce more lactate and use less oxygen during low‐level exercise, suggesting that working muscles are deriving energy by anaerobic metabolism. This may be necessary because these patients have more severe coronary artery disease and worse left ventricular function, and consequently are unable to adequately provide the oxygen requirements for the working muscles because of reduced cardiac output.
Percutaneous pulmonary angioscopy using a guiding balloon catheter
Authors: Uchida Y. , Tomaru T. , Kato S. 
Published: February 2009

AbstractThe applicability of angioscopy for observation of the pulmonary arterial lumen was examined in 7 anesthetized dogs and in 10 patients with various heart diseases during cardiac catheterization. A novel guiding balloon catheter (#11F shaft diameter and 1.5 cm in balloon diameter) was introduced through the right femoral vein into the pulmonary artery by Seldinger's method. Then, a fiberscope (1.3 or 1.8 mm in diameter) was introduced through the guiding catheter into the desired portion of the artery. The balloon was inflated, saline was infused, and the pulmonary arterial lumen was photographed on 16‐mm color cinefilms. In all dogs and patients examined, an increase in diameter of the pulmonary artery during systole and the backflow of blood from the pulmonary vein were clearly demonstrated. Also, pulmonary thrombi or emboli experimentally induced in dogs could be observed. No complications were observed in the patients. The results indicate the experimental and clinical applicability of angioscopy using a guiding balloon catheter for observation of the pulmonary arterial lumen.
Pathomorphological changes in experimentally induced canine myocardial infarction
Authors: Tomaru T. , Uchida Y. , Sugimoto T. 
Published: February 2009

AbstractWe performed a pathological study of experimental canine myocardial infarction (MI) induced by coronary thrombosis which was made by endothelial denudation and induction of luminal stenosis in 20 dogs (Group I). Another model of experimental MI by coronary ligation was also evaluated in Groups II and HI. Thirteen dogs of Group I and 7 of Group II underwent persistent coronary occlusion for 6‐8 h (Group IA and Group IIA), and 7 of Group I and 7 of Group II underwent coronary reper‐fusion with intravenous urokinase (UK) (20,000 IU/kg) in Group IB for 5 h following temporary coronary occlusion for 3 h (Groups IB and IIB). The remaining 5 dogs underwent coronary reperfusion for 5 h following intravenous 20,000 IU/kg UK after 3 h ligation. Microscopically, myocardial hemorrhage was present in 6 (86%) Group IB, 4 (31 %) Group IA and in no Group IIA dogs (p<.025 and p<.005 vs. IB). Four Group IIB and 3 Group III dogs also showed myocardial hemorrhage. Moderate hemorrhage was present only in Group I and slight hemorrhage was frequently observed in reperfused hearts. Contraction band necrosis (CBN) was present in 8 (62%) Group IA, all Group IB, all Group IIB, and 4 (80%) Group III dogs. However, there was no hemorrhage with CBN in Group IIA (p <.005 vs. IIB). Marked CBN was present only in Group I. Thus, CBN and myocardial hemorrhage were prominent in reperfused hearts, especially in those with thrombolysis. However, they were also present in the hearts which had undergone persistent coronary occlusion with thrombi.
Nonischemic changes in right ventricular function on exercise. Do normal volunteers differ from patients with normal coronary arteries?
Authors: Caplin J. L. , Maltz M. B. , Dymond D. S. , Flatman W. D. 
Published: February 2009

AbstractFactors other than ischemia may alter right ventricular function both at rest and on exercise. Normal volunteers differ from cardiac patients with normal coronary arteries with regard to their left ventricular response to exercise. This study examined changes in right ventricular function on exercise in 21 normal volunteers and 13 patients with normal coronary arteries, using first‐pass radionuclide angiography. There were large ranges of right ventricular ejection fraction in the two groups, both at rest and on exercise. Resting right ventricular ejection fraction was 40.2 ± 10.6% (mean ± SD) in the volunteers and 38.6±9.7% in the patients, p = not significant, and on exercise rose significantly in both groups to 46.1 ±9.9% and 45.8 ±9.7%, respectively. The difference between the groups was not significant. In both groups some subjects with high resting values showed large decreases in ejection fraction on exercise, and there were significant negative correlations between resting ejection fraction and the change on exercise, r = ‐0.59 (p<0.01) in volunteers, and r = ‐0.66 (p<0.05) in patients. Older volunteers tended to have lower rest and exercise ejection fractions, but there was no difference between normotensive and hypertensive patients in their rest or exercise values. In conclusion, changes in right ventricular function on exercise are similar in normal volunteers and in patients with normal coronary arteries. Some subjects show decreases in right ventricular ejection fraction on exercise which do not appear to be related to ischemia.
Long‐term follow‐up by exercise radionuclide angiography of patients after valve replacement for aortic regurgitation
Authors: Lumia F. J. , Lamanna M. , ‐LAVIN L. Gonzalez , Maranhao V. 
Published: February 2009

AbstractThe long‐term effects of valve replacement for chronic isolated aortic regurgitation as assessed by first‐pass exercise radionuclide angiography have never been reported. We studied 20 males and 5 females before, 15 months postoperatively, and from 29 to 109 (mean 62±21) months following valve replacement with exercise radionuclide angiography. Mean peak heart rate did not change for the three studies. Peak systolic blood pressure decreased from 201 ± 42 mmHg to 185 ± 24 mmHg at 15 months and further declined to 177 ±32 mmHg by the long‐term study (p >0.03). The mean resting left ventricular ejection fraction improved from 44 ± 15 % preoper‐atively to 57 ± 18% at 15 months (p>0.002) with no further improvement by the long‐term evaluation. The postexercise ejection fraction improved from 42 ± 13% preoperatively to 61 ± 21% at 15 months (p>0.002) also with no change by the long‐term study. The duration of exercise improved from 9.7 ± 4.6 min to 11.9 ± 3.4 min (p>0.03) at 15 months with no additional improvement long term. Improvement in resting and postexercise ejection fraction and in exercise duration is maximal at 15 months. Accuracy and cost containment suggest that assessment of the maximal change in ejection fraction by exercise radionuclide angiography after aortic valve replacement in asymptomatic patients be limited to the 15‐month interval.
The natural history of cardiac involvement in myotonic dystrophy: An eight‐year follow‐up in 17 patients
Authors: Melacini P. , Buja G. , Fasoli G. , Scognamiglio R. , VOLTA S.Dalla , Angelini C. , Armani M. 
Published: February 2009

AbstractWe evaluated the progression of conduction system and myocardial disease in 17 asymptomatic myotonic dystrophy patients by clinical evaluation, electrocardiography, vector cardiography, and echocardiography. An exercise test was done in 10 patients. After 8 years, a follow‐up study of 12 of the 17 original patients was done with a similar protocol. During this period, 2 patients died: one of sudden death while the other had acute left ventricular failure. In our first control study, we found EKG abnormalities in IS of our patients, consisting mostly of conduction defects or pseudonecrotic patterns. In our second control, all patients had conduction system disease and, in addition, 3 of them had premature ventricular beats. One patient developed dilated cardiomyopathy. In 6 patients, structural involvement of the right ventricle was found. We conclude that even in asymptomatic myotonic dystrophy patients a conduction system deficit is present and progresses, and cardiac death may occur in about 12% of these patients.
An electrocardiographic criterion to detect av dissociation in wide qrs tachyarrhythmias
Authors: Curione M. , Fuoco U. , Borgia C. , Putini R. L. , Puletti M. 
Published: February 2009

AbstractA study was carried out on 12 patients with wide QRS tachycardia, 8 of whom presented with atrioventricular (AV) dissociation (Group A) and 4 with 1:1 AV association (Group B). This investigation aimed at assessing whether significant variations occurred in the QRS amplitude between the two groups. Group A showed more marked variations in QRS amplitude (31.7±13%) compared to Group B patients (6.2±1.2%) (p>0.001). The amplitude changes observed in Group A patients are probably related to variations in telediastolic volume resulting from the occasional contribution of the atrial systole. The findings suggest that variability in QRS amplitude during wide QRS tachyarrhythmias is a reliable sign of the presence of an AV dissociation. The possibility of diagnosing an AV dissociation on a surface ECG without visible P waves is an important finding, which though not pathognomonic of ventricular tachycardia, is a valid ECG criterion for assessing the ventricular origin of arrhythmias. This ECG criterion can be usefully applied in clinical practice along with others already used for the differential diagnosis of wide QRS tachyarrhythmias.
Recurrence of myocardial infarction related to different vessels in a patient with diffuse coronary artery spasm without underlying severe organic stenosis
Authors: Takashiba K. , Matsuda Y. , Hamada Y. , Ohno H. , Hyakuna E. , Fujii M. , Ebihara H. 
Published: February 2009

AbstractA 59‐year‐old man had a first myocardial infarction in the right coronary artery, followed by an another infarction in the left anterior descending coronary artery. Coronary thrombolysis for both occasions of acute myocardial infarction was successfully performed without severe residual stenosis. In the chronic phase after the second myocardial infarction, ergonovine test showed diffuse coronary artery spasm. The etiology of myocardial infarction is briefly discussed.
Detection of myocardial reperfusion by analysis of serum creatine kinase isoforms
Authors: Tsukamoto H. , Hashimoto H. , Matsui Y. , Okumura K. , Ito T. , Ogawa K. 
Published: February 2009

AbstractSerum creatine kinase (CK) MM isoforms were determined by chromatofocusing in 22 patients with acute myocardial infarction undergoing intracoronary thrombolysis. In 13 patients with successful coronary recanalization within 3.6±1.0 (SD) h after onset, time to peak CK activity occurred 13±3 h after onset which was significantly shorter (p>0.01) than that in 9 patients without coronary recanalization (20 ±4 h). The proportion of CK MM‐A, the myocardial isoform, in serum in the reperfused group at 6, 10, and 14 h after onset (53 ±9, 38±5, and 27±4%, respectively) was always significantly lower (p>0.01) than that in the nonreperfused group (69±7, 59±8, and43±4%). During the same period, the proportions of CK MM‐B and CK MM‐C, the converted isoforms derived intravascularly from MM‐A by circulating carboxypeptidase, in the reperfused group were always significantly higher (p>0.01) than those in the nonreperfused group. The ratios of MM‐A% to MM‐B% and MM‐A% to MM‐C% amplified the differences between the two groups. At 10 h after onset, these ratios clearly differentiated the reperfused and the nonreperfused group at the values of 1.0 (MM‐A/MM‐B) and 3.0 (MM‐A/MM‐C) with the diagnostic sensitivity of 85% and 92%, respectively. Thus, myocardial reperfusion was detectable noninvasively by analysis of serum CK MM isoforms during the early stage of acute myocardial infarction.
The relationship between hypertrophy and dilatation in the postmortem heart
Authors: Murphy M. L. , White H. J. , Straub K. D. , Meade J. , Meade J. 
Published: February 2009

AbstractConfusion may exist at the time of postmortem examination as to whether the diseased heart is dilated, hypertrophied, or both. Ventricular dilatation and ventricular hypertrophy were therefore evaluated by cardiac partition techniques in 441 subjects at autopsy to determine their relationship. Specific weight and surface area of each ventricle were obtained and patients were divided into categories of disease. Wall thickness measurements, a parameter routinely used in the ordinary autopsy, were found to be unreliable in defining hypertrophy. Ventricular surface area (an index of dilatation) was highly correlated with ventricular weight in most disease categories. Exceptions were cardiomyopathy and aortic stenosis, in which hypertrophy predominated. We conclude from these data that dilatation and hypertrophy occur proportionately in the postmortem heart in most disease categories except in cardiomyopathy and aortic stenosis. These findings clarify the relationship of dilatation and hypertrophy at the time of autopsy in most cases. Therefore, uncertainty as to whether cardiac dilatation or hypertrophy is present or which predominates is usually related to the inability to assess these states critically at the time of autopsy when the ordinary pathological methods are used.
Effect of aging on doppler echocardiography filling parameters in normal subjects and in patients with coronary artery disease
Authors: Kuecherer H. , Ruffmann K. 
Published: February 2009

AbstractThis study was performed investigate and to investigate the influence of age on left ventricular diastolic filling parameters, as assessed by pulsed Doppler echocardiography. The study population consisted of 67 normal healthy subjects (Group I, age 15–66 years) and 117 patients (Group II, age 24–79 years), with angiographically proven coronary artery disease. Transmural flow velocities were obtained by pulsed Doppler measurements at the level of the mitral annulus. Peak early and late diastolic filling velocities as well as integrated velocities during early and late filling phases were investigated for their relation to aging and a possible alteration with coronary artery disease. In normal subjects, a reduction of early filling velocities and a compensatory increase in late filling velocities were found with increasing age. In patients with coronary artery disease, however, there was no significant correlation of filling parameters with age. In addition, a comparison of filling parameters between age‐matched normals and patients with coronary artery disease showed a further reduction of the contribution of early filling in patients with coronary artery disease. Thus, factors other than age may influence left ventricular diastolic filling behavior in patients with coronary artery disease. This can be demonstrated noninvasively using pulsed Doppler technique.