bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of coronary subclavian steal syndrome using sestamibi imaging and duplex scanning with observed vertebral subclavian steal
Authors: Rossum Alfred C. , Steel Susan R. , Hartshorne Michael F.
Published: February 2009

Coronary subclavian steal is defined as retrograde blood flow from the myocardium through the internal mammary artery graft, secondary to a proximal subclavian artery stenosis. The incidence of this syndrome in patients undergoing internal mammary artery grafts for coronary artery bypass is estimated to be 0.44%. Angiography remains the definitive diagnostic test for confirming this condition. We describe a noninvasive method for evaluating coronary subclavian steal syndrome in a 57‐year‐old man, with a 50–55% subclavian stenosis confirmed by angiography. Noninvasive evaluation using duplex scanning demonstrated normal vertebral artery blood flow. Technetium 99m‐sestamibi (99mTc) imaging confirmed a fixed anterolateral defect. When left‐arm isometric exercise was employed, retrograde vertebral artery blood flow was observed by Doppler imaging. A repeat 99mTc‐sestamibi study documented an increase in tracer distribution in the anterolateral defect confirming reperfusion of the myocardium through the left internal mammary artery graft. The use of duplex scanning and 99mTc‐sestamibi may serve as an adjunct in evaluating coronary subclavian steal syndrome as well as documenting transient vertebral subclavian steal in this patient population.
Current status of stress echocardiography
Authors: Lewis Jannet F.
Published: February 2009

Stress echocardiography is a widely applied technique for the evaluation of individuals with known or suspected coronary artery disease. The technique combines echocardiographic imaging with exercise testing or pharmacologic stress. Advances in digital image acquisition and harmonic imaging have substantially improved the quality of echocardiographic images, and have therefore increased general applicability of stress echocardiography.
Seropositivity against chlamydia pneumoniae in patients with coronary atherosclerosis
Authors: Romeo Francesco , Cerabino Luigia Maria , Martuscelli Eugenio , Chirieolo Gaetano , Ericson Katharina , Saldeen Tom G. P. , Mehta Jawahar L.
Published: February 2009

Background: Results of therapy in patients with unstable coronary syndromes with antibiotics directed against Chlamydia pneumoniae have been variable, perhaps due to the heterogeneity of patients in these trials.

Hypothesis: The aim of the present study was to correlate the severity of coronary artery disease (CAD) with seropositivity against C. pneumoniae prospectively.

Methods: We measured the frequency of seropositivity (IgG levels ≥ 1/64 and IgA levels ≥ 1/16 against Chlamydia pneumoniae) in 110 patients with CAD and in 49 controls.

Results: As expected, traditional CAD risk factors were seen more often in patients with CAD than in controls. Mean values of total cholesterol (184 ± 52 and 166 ± 44 mg/dl, respectively) and triglyceride (143 ± 60 and 112 ± 63 mg/dl, respectively) in serum were significantly higher in patients with CAD than in controls (both p < 0.04). There were no significant differences between the two groups in serum high‐density lipoprotein cholesterol (34 ± 13 and 32 ± 14 mg/dl, respectively) and lipoprotein (a) (Lp(a):241 ± 247 and 223 ± 263 mg/l, respectively) levels. The rate of IgG seropositivity was 52% (28/54) in patients with stable CAD, 41% (23/56) in patients with unstable CAD, and 35% in controls (p = NS). The rate of IgA seropositivity was 25% (14/54) in patients with stable CAD, 12% (6/49) in patients with unstable angina, and 12% (6/49) in controls (all p = NS).

Conclusions: Only a small percentage of patients with CAD demonstrate seropositivity against Chlamydia pneumoniae. Antibiotic therapy in these selected patients, but not in the remaining patients, may be considered rational. These considerations may underlie the failure to see consistent benefits of antibiotic therapy in patients with CAD.
Angiotensin‐converting enzyme and apolipoproteins genes polymorphism in coronary artery disease
Authors: Mansur Antonio P. , Favarato Desidério , Avakian Solange D. , César Lufz A. M. , Ramires José A. F. , Annicchino‐Bizzacchi Joyce
Published: February 2009

Background: Association between angiotensin‐converting enzyme (ACE) as well as apolipoprotein (apo) AI, B, and E polymorphisms and dyslipidemia and coronary artery disease (CAD) is controversial.

Hypothesis: This study assessed the distribution of ACE insertion/deletion, apo AI A/G mutation, apo B signal peptide insertion/deletion, apo B XbaI restriction fragment length, and apo E polymorphisms in 388 nondiabetic patients.

Methods: The study population included 112 patients with stable CAD, 139 patients with acute myocardial infarction (AMI), and 137 age‐matched control subjects.

Results: Univariate analysis showed higher prevalence of XbaI X+/X+ genotype in patients with CAD (p = 0.02). Angiotensin‐converting enzyme and apo polymorphisms were not associated with lipid levels or severity of CAD. When all genotypes known to be related to CAD, such as ACE DD, apo AI GG, apo B del/del, and XbaI X+X+, and E4 allele of apo E, were pooled, again no significant differences among groups were seen. Multivariate regression analysis disclosed traditional risk factors and elevated levels of apo B for men and reduced levels of apo AI for women as independent variables for CAD.

Conclusions: In addition to traditional coronary risk factors, apo B and AI could be considered predictors of CAD. No association between either form of CAD and polymorphisms was noted.
Ethnicity does not affect outcomes of coronary angioplasty
Authors: Mastoor Momina , Iqbal Uzma , Pinnow Ellen , Lindsay Joseph
Published: February 2009

Background: Access to high quality medical care and especially to complex procedures may be adversely affected in members of a minority ethnic group or a lower socioeconomic class. For example, Caucasians undergo coronary artery bypass grafting (CABG) or percutaneous transluminal coronary interventions (PTCI) twice as frequently as African‐Americans. Data exist to suggest that African‐Americans derive less benefit than Caucasians from CABG.

Hypothesis: We investigated the possibility that outcomes of catheter‐based coronary angioplasty might also be less favorable in minority populations.

Methods: We analyzed in‐hospital outcomes in 6,559 consecutive patients who underwent PTCI in our laboratory. In 37 ethnicity was classified as “other,” 5,203 (79.8%) were identified as Caucasians, 863 (13.2%), as African‐Americans, and 456 (7.0%), as Hispanics. Twelve baseline clinical, angiographic, and procedural characteristics were entered into a computerized data base. Hospital complications were identified by trained quality assurance nurses.

Results: Substantial differences in baseline characteristics existed between the populations. Despite these differences, on univariate comparison of ethnicity and outcome, no differences between ethnic groups were found with a single exception. Mortality in Hispanics was higher than in the other two populations. (2.0 vs. 0.7 and 0.8%, respectively, p=0.008). However, when this was adjusted for baseline characteristics, the difference was not significant.

Conclusions: In contrast to previous studies suggesting less favorable outcomes of CABG in African‐American patients, this analysis demonstrates an equal frequency of procedural success and rate of hospital complications for PTCI in that population, in Hispanics, and in Caucasians.
Fungal endocarditis at the aortotomy site after aortic valve replacement
Authors: Sorrell Vincent L. , Koutlas Theodore C. , Ohl Christopher
Published: February 2009

This brief report presents a patient with fungal endocarditis involving the suture location in the ascending aorta after aortotomy to replace a stenotic aortic valve. It emphasizes the importance of expanding the diagnostic investigation for endocarditis beyond the prosthesis, which was normal in this case. It also reiterates the value of transesophageal echocardiography during the evaluation of prosthetic valves and reminds the echocardiographer to visualize the aortotomy site carefully.
Mortality, risk indicators for death, and mode of death in younger and elderly patients during five years after coronary artery bypass graft
Authors: Herlitz Johan , Brandrup‐Wognsen Gunnar , Karlson Björn W. , Sjöland Helén , Karlsson Thomas , Caidahl Kenneth , Hartford Marianne , Haglid Maria
Published: February 2009

Background: The number of elderly patients who may be candidates for coronary artery bypass graft (CABG) for severe coronary artery disease has increased. Cardiac surgery in the elderly is a high‐risk procedure because many of these patients have concomitant systemic disease and other disabilities.

Hypothesis: The study was undertaken to evaluate mortality, risk indicators for death, and mode of death in younger and elderly patients during 5 years after CABG.

Methods: The study included all patients in western Sweden who underwent CABG without concomitant valve surgery and without previously performed CABG between June 1988 and June 1991. In all, 2,000 patients, of whom 953 (48%) were ≥ 65 years, were divided into two age groups (< 65 years and ≥ 65 years).

Results: Compared with the younger patients, the elderly had a relative risk of death of 2.3 (95% confidence interval 1.8–3.0). The increased risk of death in the elderly was significantly more marked in men, in patients with more severe angina pectoris, and in patients without a history of cerebrovascular diseases. The mode and place of death appeared similar regardless of age; neither was there marked difference in symptoms of angina pectoris among survivors 5 years after CABG.

Conclusion: Compared with patients < 65 years, the elderly have more than twice as high a risk of death during the subsequent 5 years, and this risk is higher in men, in patients with severe symptoms of angina pectoris, and in those with no history of cerebrovascular disease.
Response to changing plasma concentrations of isosorbide‐bound no2 during acute and sustained treatment with isosorbide dinitrate in patients with coronary artery disease
Authors: Jørgensen Lars H. , Thaulow Erik , Refsum Harald E. , Bredesen Jan
Published: February 2009

Background: The mechanisms behind development of tolerance to nitrate effects during sustained, asymmetric isosorbide dinitrate (ISDN) therapy are not fully understood.

Hypothesis: The study was undertaken to investigate the changes of the relationships between left ventricular (LV) function and plasma concentrations of ISDN and its vasoactive metabolites (2‐ and 5‐ISMO) during acute and sustained, asymmetric ISDN therapy.

Methods: Left ventricular function and plasma concentrations of ISDN, 2‐ and 5‐isosorbide mononitrates (P‐ISDN, P‐2‐and 5‐ISMO) were measured at rest and at supine exercise before and for 4 h after peroral 30 mg ISDN in 15 patients with coronary artery disease, all with initial exercise pulmonary artery wedge pressure (PAWP) > 25 mmHg. Seven patients were untreated (acute group), while eight received 30 mg ISDN b.i.d. for 2 weeks before the invasive study. P‐ISDN and the concentration of available isosorbide‐bound nitrate (NO2) in plasma (P‐ISDN‐2 + P‐2‐ISMO + P‐5‐ISMO) (P‐NO2) were used as measures of the nitric oxide (NO) offer to the tissues.

Results: Throughout the study, after administration of medication, all plasma concentrations, in particular P‐ISDN, were higher in the chronic than in the acute group. Peak P‐ISDN was reached after 15 min in the chronic group and after 25 min in the acute group, while P‐2‐ and 5‐ISMO reached maximum only after 40 min in both groups. At rest, the full effect on PAWP was observed after 10 min in both groups, but at markedly higher levels of P‐ISDN and P‐NO2 in the chronic group. Afterward, no further changes in PAWP were observed. During exercise, 1 h after medication, PAWP and stroke index to PAWP ratio (SI/PAWP) were normal in both groups. Thereafter, at slowly declining P‐NO2, PAWP rose and SI/PAWP declined toward the initial level in the chronic group, but remained unchanged in the acute group, in spite of higher P‐NO2 and greater NO release in the former.

Conclusions: Patients receiving sustained, asymmetric 30 mg ISDN b.i.d. dosing had the same immediate beneficial effects on LV function during exercise after a morning dose as did untreated patients. However, in spite of higher P‐NO2 and higher rate of NO release during sustained treatment, the effects deteriorated gradually 2 to 3 h after medication. The changes in metabolism and/or distribution of isosorbide‐bound NO2 may possibly be part of the tolerance induced by long‐term treatment, even with asymmetric dosing.
Normalization of left ventricular dysfunction in systemic hypertension
Authors: Frimm Clovis De Carvalho , De Moraes Álvaro Villela , Medeiros Caio César Jorge , Filho Antǒnio Esteves , Marino Júlio César
Published: February 2009

Background: In hypertensive heart disease, it is uncertain whether the impairment of left ventricular (LV) systolic function might be reverted by antihypertensive treatment.

Hypothesis: This study was undertaken to address the likelihood of recovery of LV dysfunction and to identify factors potentially related.

Methods: Twenty‐six patients with primary (n = 16) and renovascular (n = 10) hypertension participated in the study and were classified into Groups A (n = 12) and B (n = 14) according to normalization or persistent left ventricular dysfunction (fractional shortening <0.30) after 36 weeks of follow‐up. All patients received standard medical therapy and appropriate procedures for renovascular disease correction. Logistic regression analysis was used to identify variables associated with recovery.

Results: Patients in Group A compared with those in Group B were younger (41±14 vs. 52 ± 10 years; p<0.05), had a greater frequency of renovascular hypertension (8 vs. 2; p<0.05), showed shorter LV end‐diastolic (54±5 vs. 61±8 mm; p<0.05) and end‐systolic dimensions (41±6 vs. 49±9 mm; p<0.05), and lower mass index (215±64 vs. 261±47 g.m‐2; p<0.05) before treatment, whereas fractional shortening (0.24±0.4 vs. 0.20±0.5;p>0.05) and diastolic blood pressure (116±12 vs. 122±19 mmHg; p>0.05) were similar. On follow‐up, Group A patients showed lower diastolic blood pressure (89±15 vs. 105±20 mmHg; p<0.05) and mass index (142±34 vs. 222±40 g.m2; p<0.05). Logistic regression analysis identified systolic dimension and renovascular hypertension as factors associated with fractional shortening normalization.

Conclusion: The recovery of LV dysfunction is expected to occur most likely in patients with renovascular hypertension and the shortest systolic dimensions.
Angiographic and scintigraphic (perfusion and electrocardiogram‐gated spect) correlates of clinical presentation in unstable angina
Authors: Emre Ayşe , Ersek Birsen , Gürsürer METIN , Aksoy Mehmet , Siber Turgut , Engin Öuner , Yeşslilçlhvien Kemal
Published: February 2009

Background: Braunwald classification can be used as a measure of the acuteness or severity of clinical presentation of unstable angina. Gating perfusion images might provide additional information to that obtained from angiography, allowing correlations between the coronary anatomy and extent of myocardium at risk via simultaneous perfusion/function assessment.

Hypothesis: The aim of this study was to determine the relation between the highest levels of the Braunwald classification (class III = rest angina within 48 h of presentation; class C = postinfarction angina; class c = refractory angina) and the angiographic findings, and the extent of perfusion and segmental wall motion abnormalities using technetium—99m ( 99m Tc) sestamibi‐gated single‐photon emission computed tomography (SPECT) imaging.

Methods: The study group consisted of 86 patients with unstable angina who underwent rest gated 99mTc sestamibi SPECT imaging and coronary angiography. Perfusion was graded on a 5—point scale (0 = normal; 4 = absent uptake) and wall motion on a 4—point scale (0 = akinesia/dyskinesia; 3 = normal) using the 20 segment model. Perfusion (PI) and wall motion indices (WMI) were calculated by adding the score of all segments and dividing this by 20. The localization, the degree of stenosis, and the morphology of the culprit lesion were assessed. Multivariate analysis was performed to identify the independent predictors of class III, C, and c angina.

Results: Perfusion index was higher and WMI was lower in classes HI, C, and c than in classes < III, < C, and < c, respectively (all p < 0.001). Class III angina was associated with PI (p < 0.0001), WMI (p < 0.0001), complex morphology (p = 0.01), and decreased Thrombolysis in Myocardial Infarction (TIMI) flow (p = 0.002); class C angina with PI (p< 0.0001), WMI (p<0.0001), intracoronary thrombus (p = 0.007), and decreased TIMI flow (p = 0.003); and class c angina with PI (p = 0.005) and WMI (p = 0.006).

Conclusion: The highest levels of the Braunwald classification are associated with a greater size and intensity of myocardial perfusion and wall motion abnormalities and with the angiographic findings of complex morphology, intracoronary thrombus, and decreased TIMI flow.
Intravascular ultrasound predictors of major adverse cardiac events in patients with unstable angina
Authors: Gyongyosi Mariann , Yang Paul , Hassan Ali , Domanovits Hans , Laggner Anton , Weidinger Franz , Glogar Dietmar
Published: February 2009

Background: Intravascular ultrasound (IVUS) predictors of native culprit lesion morphology for occurrence of major adverse cardiac events (MACE) have not been reported. Moreover, the published data on IVUS predictors of restenosis include patients with stable and unstable angina, although the development and progression of atherosclerosis related to unstable coronary syndrome is different from that of stable angina.

Hypothesis: This study investigated whether IVUS‐de‐rived qualitative and quantitative parameters of native (prean‐gioplastic) plaque morphologic features can predict major adverse cardiac events in patients with unstable angina.

Methods: Clinical (age, gender, coronary risk factors), qualitative and quantitative angiographic (lesion localization, morphology, pre‐ and postangioplastic minimal lumen diameter, reference diameter, and percent diameter stenosis), and IVUS variables (soft/fibrocalcific plaque, calcification, presence of thrombus or plaque disruption, different types of arterial remodeling, pre‐ or postangioplastic minimal lumen, external elastic membrane and plaque cross‐sectional area, and plaque burden of the target lesion and reference segments) were analyzed by regression analyses using the Cox model, assuming proportional hazards.

Results: Of 60 consecutively enrolled patients, 21 suffered from MACE, while 39 remained event‐free during the follow‐up period. Multivariate regression analyses revealed that the presence of adaptive remodeling [p = 0.0177, risk ratio (RR) = 3.108, with 95% confidence interval (CI) = 1.371—8.289] and the preangioplastic lumen cross‐sectional area (p = 0.0130, RR = 0.869, with 95% CI = 0.667—0.913) are independent predictors of MACE during follow‐up, as is postangioplastic angiographic minimal lumen diameter (p = 0.0330, RR = 0.715 with 95% CI = 0.678—0.812).

Conclusions: Adaptive remodeling and preangioplastic lumen cross‐sectional area determined by IVUS and postangioplastic minimal lumen diameter calculated by quantitative angiography are significant independent predictors of time‐dependent MACE in patients with unstable angina.
Circadian heart rate response to chronotherapy versus conventional therapy in patients with hypertension and myocardial ischemia
Authors: Glasser Stephen P. , Frishman William , White William B. , Stone Peter , Johnson Mary F.
Published: February 2009

Background: Changes in heart rate (HR) may contribute to the higher incidence of cardiovascular events in the morning.

Hypothesis: The objectives of this analysis were to assess HR patterns in two populations (patients with chronic stable angina or stage I to HI hypertension) and to compare the effects of various antianginal and antihypertensive treatments on HR.

Methods: This was a retrospective analysis of HR data from two clinical trials evaluating the efficacy of controlled‐onset, extended‐release (COER)‐verapamil. The effects of COER‐verapamil were compared with placebo, nifedipine gastrointestinal therapeutic system (GITS), amlodipine, and the combination of amlodipine and atenolol.

Results: In patients with angina (n = 498), the change from baseline in HR following 4 weeks of treatment was —6.7 ± 10.5 beats/min in the COER‐verapamil group, —10.8 ± 10.8 beats/min in the amlodipine/atenolol group, + 2.5 ± 9.1 beats/min in the amlodipine monotherapy group, and —1.3 ± 10.5 beats/min in the placebo group (p < 0.001). Data were stratified based on whether patients experienced asymptomatic ischemia during baseline ambulatory electrocardiographic monitoring. The circadian HR pattern was morphologically similar in all groups; however, differences in the magnitude of HR response were evident. In the subset of patients with asymptomatic ischemia (n = 101), treatment with amlodipine monotherapy increased HR compared with placebo. In this same subset of patients, HR reductions were achieved with COER‐verapamil and amlodipine/atenolol. In patients with hypertension (n = 557), the change in HR following 10 weeks of treatment was —3.3 beats/min for patients treated with COER‐verapamil compared with + 2.0 beats/min for patients treated with nifedipine GITS (p < 0.0001, between‐group differences).

Conclusion: This analysis demonstrates that morphologically similar circadian patterns of HR occur in both hypertensive patients and those with angina. In addition, significant variation exists among antianginal and antihypertensive agents regarding HR effects.
Effects of glibenclamide, a k atp channel blocker, on warm‐up phenomenon in type 11 diabetic patients with chronic stable angina pectoris
Authors: Öuvoünç KENAN
Published: February 2009

Background: Warm‐up phenomenon, one of the clinical models of ischemic preconditioning, refers to an increased tolerance to myocardial ischemia during the second of two consecutive exercise tests.

Hypothesis: Blockers of K ATP channels, such as the sulfonylurea drugs, can induce loss of ischemic preconditioning. This study aimed to investigate the effects of glibenclamide, a sulfonylurea with a high affinity for myocardial K ATP channels, on the results of two consecutive exercise tests in diabetic patients with coronary artery disease.

Methods: Eighteen type II diabetic patients with chronic stable angina pectoris participated in this study. All patients underwent two consecutive treadmill exercise tests with a recovery period of 15 min in fasting state. On the day after these exercise tests, 10 mg oral glibenclamide was given to the same patients and 30 min later 200 ml of 30% glucose solution was given orally. Half an hour later, which is the time of peak plasma levels of glibenclamide, two exercise tests were repeated consecutively with a 15 min recovery period.

Results: There was no difference in blood glucose levels before and after exercise tests on each day (p > 0.05). Without glibenclamide, heart rate, rate‐pressure product at 1.5 mm ST depression, and peak exercise increased significantly (p < 0.05). Time to 1.5 mm ST‐segment depression and onset of pain, as well as duration of exercise also increased, but ST‐segment depression and ST‐recovery time significantly decreased (p < 0.05). In contrast, these values did not significantly change after glibenclamide (p > 0.05), with a significant drug—test interaction (p < 0.05, at two‐way ANOVA).

Conclusions: Glibenclamide, an oral hypoglycemic agent with a KATP channel‐blocker activity, with a 10 mg oral dose, abolished the warm‐up phenomenon which is a clinical finding of ischemic preconditioning on two consecutive exercise tests. Therefore, glibenclamide should be used carefully in patients with coronary heart disease and diabetes mellitus since this agent leads to a decrease in ischemic threshold and exercise capacity.
Right ventricular infarction—diagnosis and treatment
Authors: Haji Showkat A. , Movahed Assad
Published: February 2009

Right ventricular infarction (RVI) as assessed by various diagnostic methods accompanies inferior‐posterior wall myocardial infarction (MI) in 30 to 50% of patients. Recognition of the syndrome of RVI is important as it defines a significant clinical entity, which is associated with considerable immediate morbidity and mortality and has a well—delineated set of priorities for its management. Patients may clinically present with hypotension, elevated jugular venous pulse (JVP), and occasionally shock, all in the presence of clear lung fields. The ST—segment elevation of ⩾ 0.1 mV in the right precordial leads V 4 R is a readily available electrocardiographic sign used for diagnosis of RVI. Other diagnostic approaches for assessing RVI include echocardiography, radionuclide ventriculography, technetium pyrophosphate scanning, and hemodynamic measurements. The proper management of RVI includes volume loading to maintain adequate right ventricular preload, ionotropic support, and maintenance of atrioventricular synchrony. Reperfusion therapy should be initiated at the earliest signs of right ventricular dysfunction. Finally, complete recovery over a period of weeks to months is a rule in a majority of patients, suggesting right ventricular “stunning” rather than irreversible necrosis has occurred.
Low—molecular—weight heparins in acute myocardial infarction: RationaLe and results of a pilot study
Authors: Ross Allan M. , Coyne Karin , Hammond Melissa , Lundergan Conor F.
Published: February 2009

Background: Antithrombotic adjuncts to fibrinolytic drugs for acute myocardial infarction increase the rate and speed of infarct artery recanalization.

Hypothesis: A low—molecular—weight heparin might be preferable to unfractionated heparin for this indication, as it has been shown to be in several other thrombus‐related vascular disorders.

Methods: We performed a pilot study in 20 patients, all receiving aspirin and recombinant tissue plasminogen activator. Randomization was to standard dose intravenous unfractionated heparin or enoxaparin (the first dose given intravenously and followed by a subcutaneous administration). The endpoint was stability of anticoagulant effect.

Results: Enoxaparin produced stable therapeutic anti—Xa levels with minimal effect on activated partial thromboplastin times. Unfractionated heparin produced wide swings of these parameters, often outside desired levels.

Conclusions: Enoxaparin may be a better antithrombotic agent than conventional unfractionated heparin when used in conjunction with fibrinolytics.
Recent advances in dobutamine stress echocardiography
Authors: Usher Bruce W. , O'Brien Terrence X.
Published: February 2009

Dobutamine stress echocardiography (DSE) is a reliable cardiac risk stratifier that has widespread applicability because of its clinical accuracy and cost effectiveness. Dobutamine has positive inotropic and chronotropic effects and is commonly used in patients who cannot exercise or achieve an adequate heart rate response with exercise. Recently available long‐term results from several independent clinical trials, combined with enhancements in image quality, have improved the ability to detect significant coronary artery disease and determine myocardial viability. Dobutamine stress echocardiography has an excellent safety profile with clinical results superior to regular exercise electrocardiography and comparable with exercise echocardiography and radionucleotide perfusion stress imaging. Low‐dose dobutamine response can accurately predict dysfunctional yet viable myocardial regions that may improve with revascularization. Clinical studies are now available refining the common use of DSE preoperatively in female patients with valvular disease, as well as in the emergency department. Dobutamine stress echocardiography does have some limitations in discriminating particular regions of ischemia when multiple ventricular segments are involved and when the imaging is suboptimal. It can be applied using minimal additional resources in an otherwise functioning echocardiography laboratory and, with appropriate training, can result in clinical results comparable with those of large‐scale multi‐center trials. Ongoing improvements in technology and the development of new reagents such as myocardial contrast agents hold promise for further advancement in the near future.
High variability of retrograde fast pathway sensitivity to adenosine
Authors: Mewis Christian , Kühlkamp Volker , Mermi Johann , Bosch Ralph F. , Seipel Ludger
Published: February 2009

Background: Adenosine is widely used as a tool to assess the effectiveness of radiofrequency ablation of concealed accessory pathways.

Hypothesis: The goal of this study was to determine the reliability of this test by studying the retrograde fast pathway sensibility in a large patient population with typical atrioventricular (AV) nodal reentry tachycardias. We sought also to determine whether AV nodal properties were predictive of a retrograde fast pathway sensitivity to adenosine.

Methods: In all, 124 patients with inducible AV nodal reentrant tachycardia were included in this study. All patients received a clinically used standard dose of 12 mg adenosine during ventricular pacing, with 500 ms and a constant ventriculoatrial (VA) conduction via the fast pathway. Electrophysiologic parameters of the AV node were determined in all patients in order to correlate them with the adenosine sensitivity of the retrograde pathway.

Results: In 74 patients, the injection of 12 mg adenosine resulted in a transient VA block, whereas no VA block occurred in the remaining 50 patients. In two patients, concealed accessory pathways were unmasked after the injection of adenosine. The adenosine sensitivity of the retrograde fast pathway was associated with longer retrograde conduction times and cycle lengths during AV nodal reentrant tachycardias.

Conclusion: This study shows a high variability of retrograde fast pathway sensitivity to adenosine. Thus, in 40% of patients the lack of VA block after adenosine injection is not specific for persistent accessory pathway function after radiofrequency ablation. Electrophysiologic properties of patients with AV nodal reentrant tachycardias were different in patients with and without adenosine‐sensitive retrograde fast pathways, possibly indicating differential patterns of penetration of the retrograde fast pathway into the compact AV node.
Pulmonary embolus after coronary artery bypass surgery: A review of the literature
Authors: Shammas Nicolas W.
Published: February 2009

Pulmonary embolus (PE) after cardiac bypass surgery is an uncommon complication but carries with it high morbidity and mortality. The incidence of deep vein thrombosis (DVT) and PE after cardiac bypass varies depending on postoperative thromboprophylaxis, the presence of indwelling central venous catheters in the lower extremities, and early ambulation. The clinical diagnosis of DVT remains difficult and challenging. Pulmonary embolus is often the first occurring clinical event. The safety and effectiveness of preventative pharmacologic agents, such as subcutaneous unfraction‐ated or fractionated heparin or oral Coumadin, remain largely unknown. Heparin‐induced thrombocytopenia, generally associated with a high incidence of DVT and PE, occurs in approximately 3.8% of patients who have undergone cardiac surgery and are placed postoperatively on high‐dose intravenous unfractionated heparin. Sequential compression devices (SCD) have not been effective in reducing the incidence of DVT in an ambulating cardiac bypass patient when added to routine elastic graded compression stockings (GCS). Very large clinical trials are necessary to prove the effectiveness of pharmacologic or mechanical preventative measures in reducing the incidence of PE after cardiac surgery above the commonly used GCS, early ambulation, and aspirin. In a nonam‐bulating, higher‐risk cardiac bypass patient with slow recovery, a more aggressive prophylaxis regimen might be necessary for optimal prevention, although further data are needed to support this hypothesis.
Susceptibility of apolipoprotein B‐containing lipoproteins to oxidation and antioxidant status in acute coronary syndromes
Authors: Yesilbursa Dilek , Serdar Akin , Güllülü Sümeyye , Cordan Jale , Serdar Zehra , Dirican Melahat
Published: February 2009

Background: Oxidized lipoproteins may play an important role in the pathogenesis of atherosclerosis, and it has been shown that antioxidants have a protective effect against the progression of atherosclerosis.

Hypothesis: The aim of this study was to investigate the oxidative susceptibility of apolipoprotein B‐containing lipoproteins and antioxidant status in patients with acute coronary syndromes and chronic stable angina pectoris.

Methods: The study population included 70 patients with acute coronary syndromes (14 with recent acute myocardial infarction and 56 with unstable angina pectoris), 105 patients with stable angina pectoris, and 75 control subjects. In addition to conventional lipid and lipoprotein analysis, the susceptibility of apolipoprotein B‐containing lipoproteins to in vitro oxidation (lag phase) and plasma vitamin E and total carotene levels was measured.

Results: The lag phase was significantly shorter in patients with acute coronary syndromes (45 ± 12 min) than in patients with stable angina pectoris (51 ± 10 min) and in control subjects (58 ± 9 min) (p < 0.0001). Both plasma vitamin E and total carotene levels were lowest in patients with acute coronary syndromes (1.11 ± 0.32 mg/dl and 119 ± 32 μg/dl, respectively), followed by patients with stable angina pectoris (1.25 ± 0.37 mg/dl and 132 ± 37 μg/dl) and then controls (1.52 ± 0.31 mg/dl and 167 ± 41 μg/dl).

Conclusions: These data suggest that there is an intense oxidative process and a lower antioxidant status in acute coronary syndromes. This may lead to plaque instability due to the activation of the inflammatory response in coronary atherosclerotic lesions.
The assessment of myocardial viability and hibernation using resting thallium imaging
Authors: Perrone‐Filardi Pasquale , Chiariello Massimo , Underwood Richard
Published: February 2009

Rest‐redistribution thallium‐201 imaging is widely used to assess recovery of regional systolic dysfunction in patients with chronic coronary artery disease. In several studies, this technique has demonstrated very high sensitivity but reduced specificity, as reported in general for radionuclide imaging. In clinical terms, this implicates that many dysfunctional territories will not recover after revascularization despite a substantial amount of tracer uptake. Yet, the amount of tracer uptake in a given myocardial segment, although not perfect, remains the best indicator for predicting reversible dysfunction. In fact, the occurrence of redistribution after rest injection is not very common and it does not substantially contribute to the accuracy of the test. However, it is still undetermined whether the presence of redistribution is relevant for prognostic implications.
Aortic atherosclerotic lesions in the thoracic aorta detected by multiplane transesophageal echocardiography as a predictor of coronary artery disease in elderly patients
Authors: Parthenakis Fragiskos I. , Kochiadakis George E. , Skalidis Emmanuel I. , Kanakaraki Marina K. , Mezilis Nikos E. , Kanoupakis Emmanuel M. , Vardas Panos E. , Nihoyannopoulos Petros
Published: February 2009

Background: The presence of atherosclerotic lesions in the thoracic aorta by transesophageal echocardiography (TEE) appears to be a marker for the presence of significant coronary artery disease (CAD) in the general population.

Hypothesis: We investigated whether atherosclerotic lesions in the thoracic aorta, by multiplane TEE, could be a marker for CAD in elderly patients.

Methods: In all, 127 patients (67 men, 60 women, aged 68 ± 13 years), underwent a TEE study with imaging of the thoracic aorta and cardiac catheterization with coronary angiography. The presence of a distinct, linear, or focal, highly echogenic mass protruding into the vessel lumen was the criterion for the diagnosis of atherosclerotic plaque.

Results: Atherosclerotic lesions were found in 30 of 36 patients (83.3%) with and in 20 of 91 (22%) without CAD. Of the 41 patients ≥ 70 years, atherosclerotic lesions were detected in 14 of 17 (82.3%) with and in 13 of 24 patients (54%) without CAD. The sensitivity, specificity, and positive and negative predictive values in this group were 82.3, 46, 52, and 78.6%, respectively. Multivariate logistic regression analysis revealed that in patients aged ≥ 70 years only advanced atherosclerotic lesions were independent predictors of significant CAD. However, the high negative predictive value of the method indicates that the absence of aortic plaque is a strong predictor of the absence of CAD.

Conclusions: The presence of atherosclerotic lesions in the thoracic aorta is a strong predictor of CAD only in patients < 70 years old. However, the negative predictive value of the method is high for all patients regardless of age.
Improved survival after acute myocardial infarction in patients with advanced killip class
Authors: Miller Wayne L. , Scott Wright R. , Grill Joseph P. , Kopecky Stephen L.
Published: February 2009

Background: The continuing applicability of the Killip classification system to the effective stratification of long‐term and short‐term outcome in patients with acute myocardial infarction (MI) and its influence on treatment strategy calls for reanalysis in the setting of today's primary reperfusion treatments.

Hypothesis: Our study sought to test the hypothesis that Killip classification, established on admission in patients with acute Ml, is an effective tool for early prediction of in‐hospital mortality and long‐term survival.

Methods: A series of 909 consecutive Olmsted County patients admitted with acute MI to St. Marys Hospital, Mayo Clinic, between January 1988 and March 1998 was analyzed. Killip classification was the primary variable. Endpoints were in‐hospital death, major in‐hospital complications, and post‐hospital death.

Results: Patients analyzed included 714 classified as Killip 1,170 classified as Killip II/III, and 25 classified as Killip IV. Increases in in‐hospital mortality and prevalence of in‐hospital complications correspond significantly with advanced Killip class (p < 0.01), with in‐hospital mortality 7% in class I, 17.6% in classes II/III, and 36% in class IV patients (p < 0.001). Killip classification was strongly associated with mode of therapy administered within 24 h of admission (p < 0.01). Killip IV patients underwent primary angioplasty most commonly and were less likely to receive medical therapy.

Conclusions: Killip classification remains a strong independent predictor of in‐hospital mortality and complications, and of long‐term survival. Early primary angioplasty has contributed to a decrease in mortality in Killip IV patients, but effective adjunctive medical therapy is underutilized.
Transient increase in plasma brain (b‐type) natriuretic peptide after percutaneous transluminal coronary angioplasty
Authors: Tateishi Jun , Masutani Motomaru , Ohyanagi Mitsumasa , Iwasaki Tadaaki
Published: February 2009

Background: Brain (B‐type) natriuretic peptide (BNP) is known to be secreted predominantly from the myocardium. Brain natriuretic peptide plasma concentrations have been shown to be markedly increased in patients with acute myocardial infarction; however, plasma BNP response during episodes of myocardial ischemia has not been established.

Hypothesis: This study was designed to examine plasma BNP in patients with transient myocardial ischemia induced by inflation of a percutaneous transluminal coronary angioplasty (PTCA) balloon.

Methods: Thirty consecutive patients (26 men and 4 women; mean age 61 years) who underwent PTCA, and another 49 patients (39 men and 10 women; mean age 63 years) who underwent diagnostic coronary angiography were enrolled in this study. Serum BNP concentrations were assayed in all patients.

Results: Plasma BNP was increased significantly with a peak concentration of 66.1 ± 65.2 pg/ml 24 h after PTCA. Coronary angiography did not cause plasma BNP increase (immediately before 30.4 ± 29.0 pg/ml, 24 h after 33.7 ± 30.6 pg/ml). No significant differences were present in hemodynamic parameters measured immediately before and 24 h after PTCA.

Conclusion: Plasma BNP is increased by transient myocardial ischemia induced by PTCA.
Transcatheter closure of a patent ductus arteriosus in an elderly patient with the gianturco‐grifka vascular occlusion device
Authors: Befeler Benjamin , Justiniano Alberto , Zahn Evan
Published: February 2009

This paper reports the unusual case of a 76‐year‐old woman who was discovered to have a hemodynamically significant patent ductus arteriosus following uneventful mitral valve replacement, utilizing cardiopulmonary bypass. The shunt was successfully eliminated using a new transcatheter device, thereby obviating the need for further surgery. The patient did not have calcification within the ductus, making diagnosis prior to surgery more difficult.
Lack of compensatory enlargement at sites of coronary vasospasm: Identification by ultrasound and successful treatment with stenting
Authors: Kinlay Scott , Selwyn Andrew P. , Ganz Peter , O'gara Patrick T.
Published: February 2009

The case of a young man with spontaneous vasospasm at two sites in his left anterior descending coronary artery is described. Intravascular ultrasound demonstrated mild eccentric atherosclerosis with smaller total artery cross‐sectional area (defined as the external elastic membrane) compared with reference segments. Impaired compensatory enlargement (remodeling) in response to mild atherosclerosis may derive from one or more biologic mechanisms that are also responsible for vasospasm. This characteristic is easily identified by intravascular ultrasound. In this case, coronary stenting of the vasospastic sites led to excellent long‐term control of symptoms more than 1 year after intervention.
Bosentan and the endothelin system in congestive heart failure
Authors: Ellahham Samer H. , Choucair Wassim K. , Charlon Vincent , Abassi Zaid , Calis Karim A.
Published: February 2009

The endothelin system appears to play an important role in the pathophysiology of congestive heart failure (CHF). Endothelin receptor antagonists represent a novel class of agents that are being evaluated for their potential benefits in treating various cardiovascular disorders. Bosentan is an orally active endothelin receptor antagonist that has been studied for the treatment of CHF. Early clinical experience with bosentan has confirmed some benefits on hemodynamic parameters in patients with CHF. Its role in slowing the progression of the disease and improving survival remains to be elucidated.
Does left ventricular shape influence clinical outcome in heart failure?
Authors: Harjai Kishore J. , Edupuganti Ravindra , Nunez Eduardo , Turgut Tansel , Scott Luis , Pandian Natesa G.
Published: February 2009

Background: Left ventricular (LV) shape tends to become spherical in patients with dilated cardiomyopathy of diverse etiology. Clinical and echocardiographic factors which affect the degree of LV spherical distortion and the impact of altered LV shape on prognosis have not been studied adequately.

Hypothesis: This study was undertaken to investigate the prognostic implications of altered LV shape on clinical outcome in dilated cardiomyopathy.

Methods: In 112 patients with depressed LV ejection fraction (19 ± 9%) and symptomatic heart failure, and in 10 age‐and gender‐matched normal controls, we performed 2‐dimensional echocardiography to assess LV shape using the eccentricity index. Eccentricity index was defined as the ratio of the LV long axis to the LV transverse diameter, measured at end systole and end diastole in the apical four‐chamber view. We sought univariate and multivariate clinical and echocardiographic correlates of LV shape. Further, we sought correlations between eccentricity index and clinical outcomes (death and composite outcome of death or emergent heart transplant).

Results: Compared with controls, patients with cardiomyopathy had significantly lower systolic (2.04 vs. 1.56; p = 0.001) and diastolic (1.75 vs. 1.53; p = 0.003) eccentricity index, implying a more spherical LV shape. Of all clinical and echocardiographic variables tested, mitral regurgitation, right ventricular dysfunction, and increased LV mass were independently associated with spherical LV shape. At a follow‐up period of 17 ± 12 months, no correlation was found between eccentricity index and the occurrence of death or the combined endpoint of death or emergent heart transplant, in univariate or multivariate analysis.

Conclusions: In patients with dilated cardiomyopathy, the degree of spherical distortion of the LV does not correlate with prognosis.
Lipoprotein(a) Is Related to the Extent of Lesions in the Coronary Vasculature and to Unstable Coronary Syndromes
Authors: Zampoulakis John D. , Kyriakousi Areti A. , Poralis Kostas A. , Karaminas Naoum T. , Palermos Ioannis D. , Chimonas Elias T. , Cokkinos Dennis V.
Published: February 2009

Background: Lp(a) is a highly atherogenic particle with a prothrombotic effect. Until now its relation to the extent and severity of the atheromatic lesions had not been established by standard procedures.

Hypothesis: This study examined the correlation of Lp(a) to the extent and severity of coronary artery disease (CAD) and its relation to unstable clinical events (not including sudden death).

Methods: In 202 patients undergoing coronary angiography, plasma lipids were measured with the usual procedures and Lp(a) with the enzyme‐linked immunosorbent assay. The extent of CAD was expressed in the number of diseased vessels and its severity in terms of the severity coefficient and the obstruction coefficient.

Results: A very strong relationship between LP(a) and the number of diseased vessels (p = 0.0007) signifying diffuse atherosclerosis, but no relation with the severity of the lesions, was found. However, it was the only lipid that correlated significantly with the number of totally occluded vessels (p = 0.0003). The thrombogenic ability of Lp(a) was manifested by increased incidence of myocardial infarction and unstable angina episodes in patients with elevated Lp(a) (p = 0.0157).

Conclusion: Elevated Lp(a) predisposes to the extent of CAD and total occlusions but not to the severity of lesions. Patients with increased Lp(a) levels and unstable angina are at increased danger of suffering myocardial infarction. Thus, Lp(a) may predispose to plaque destabilization and thrombosis of noncritical lesions.