bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of coronary collateral circulation in diabetic and nondiabetic patients suffering from coronary artery disease
Authors: Melidonis A. , Tournis S. , Kouvaras G. , Baltaretsou E. , Hadanis S. , Hajissavas I. , Tsatsoulis A. , Foussas S.
Published: February 2009

Background and hypothesis: Although it is well established that diabetes mellitus (DM) induces more severe coronary artery disease (CAD), it is not known whether it contributes to the development of coronary collateral circulation. The present study examines coronary collateral circulation in diabetic and nondiabetic patients with angiographically verified CAD.

Methods: The study group consisted of 463 diabetic patients (382 men, 81 women) with a mean age of 60.3 ± 8.8 years, and 227 nondiabetic subjects (159 men, 68 women) with a mean age of 59.2 ± 9 years. The extension and functional capacity of coronary collateral circulation was assessed according to the Cohen and Rentrop grading system of 0 to III.

Results: We found that diabetic patients had grade III collateral circulation more frequently than nondiabetic subjects (13.2 vs. 8.5%, p<0.01). This finding was even more pronounced in diabetic men aged < 55 years compared with both nondiabetic men (20 vs. 3.4%, p<0.001) and diabetic women (20 vs. 2.2%, p<0.001). Grade III collateral circulation was found to develop mainly at the left anterior descending (LAD) coronary artery and the right coronary artery (RCA), where complete occlusions of coronary arteries usually occur.

Conclusions: Diabetic patients with CAD develop more extensive coronary collateral circulation than nondiabetic subjects, especially men aged <55 years. The collateral circulation mainly develops at the LAD and RCA.
Pocket infection complicating inadvertent transarterial permanent pacing. successful percutaneous explantation
Authors: Trigano J.‐A. , Paganelli F. , Fekhar S. , Gelisse R. , Alimi Y.
Published: February 2009

This report describes a patient admitted for the treatment of a pocket infection occurring 5 months after a dual chamber pacemaker implantation. The ventricular lead had been inadvertently placed into the left ventricle through the arterial system. After careful examination using transesophageal echocardiography and left heart angiogram, successful percutaneous extraction was performed without complication.
The association between the on‐site availability of cardiac procedures and the utilization of those services for acute myocardial infarction by payer group
Authors: Canto John G. , Rogers William J. , Roseman Jeffrey M. , Zhang Yuan , French William J. , Gore Joel M. , Chandra Nisha C.
Published: February 2009

Background: Prior studies have suggested that in‐hospital availability may be an important determinant for the use of invasive cardiac services; however, whether this association is influenced by payer status remains unclear.

Hypothesis: The interaction of payer status and the on‐site availability of coronary arteriography is associated with increased utilization of this procedure.

Methods: In‐hospital availability and utilization of coronary arteriography was ascertained in 275,046 patients with acute myocardial infarction (AMI) enrolled in the National Registry of Myocardial Infarction 2 from June 1994 to April 1996. Logistic regression analyses were performed to determine the association between the on‐site availability of cardiac catheterization at the initial hospital and subsequent utilization of coronary arteriography. Similar analyses were performed within Medicare, Medicaid, Commercial, Health Maintenance Organization (HMO), and Uninsured payer groups.

Results: Patients initially admitted to hospitals having on‐site cardiac catheterization facilities were almost twice as likely to receive coronary arteriography as patients admitted to hospitals without such facilities and later transferred out [un‐adjusted odds ratio (OR) = 1.69,95% confidence interval (CI) 1.66–1.73, p < 0.0001; adjusted OR = 2.08,95% CI 2.01–2.15, p < 0.0001]. Furthermore, this relationship of increased utilization with greater availability was evident within each payer group, but was highest among those with Commercial insurance and lowest among Medicaid recipients: [Commercial insurance (OR = 2.19,95% CI 2.07–2.31, p < 0.0001); Uninsured (OR = 1.74,95% CI 1.57–1.92, p < 0.0001); HMO (OR = 1.67,95% CI 1.54–1.82, p < 0.0001); Medicare 1.60,95% CI 1.55–1.64, p < 0.0001); Medicaid (1.46,95% CI 1.29–1.65, p < 0.0001)].

Conclusions: Our results show a strong association between in‐hospital availability and subsequent utilization of invasive cardiac procedures following AMI among all patients, but the strength of these associations varied among payer status.
Management strategies in unstable coronary artery disease—Current problems and future directions
Authors: Verheugt F. W. A. , Becker R. C. , Bertrand M. E. , Bode C. , Chesebro J. H. , Cleland J. G. F. , Conti R. , Hillis W. S. , Klein W. , Maseri A. , Turpie A. G. G. , Wallentin L. , Waters D. D.
Published: February 2009

Unstable coronary artery disease continues to pose a major challenge to clinicians. The advent of new therapies, such as percutaneous transluminal coronary angioplasty, low‐molecular‐weight heparins, and glycoprotein IIb/IIIa inhibitors, provides new management options for this indication but also raises new questions with regard to optimal management. Prospective randomized trials with well‐defined, long‐term outcome measures and a means of identifying which patients will derive most benefit from each treatment, together with a means of rapid and clear dissemination of study results and implications, are required in order to advance the management of unstable coronary artery disease.
Effect of amlodipine on exercise‐induced platelet activation in patients affected by chronic stable angina
Authors: Sanguigni Valerio , Gallù Mariacarla , Sciarra Luigi , Cannata Dario , Strano Antonio , Principe Domenico Del , Menichelli Adriana , Palumbo Giovanni
Published: February 2009

Background: Literature concerning exercise‐induced platelet activation in chronic stable angina is somewhat confusing. The reason lies in the type of exercise as well as in methodological problems. A powerful, recently introduced procedure to detect platelet activation is flow cytometry. Platelet response to activating factors is mediated by calcium uptake; however, calcium antagonist effect on platelet activity is still unclear.

Hypothesis: The study was undertaken to investigate exercise‐induced platelet activation before and after treatment with amlodipine in chronic stable angina.

Methods: Twenty patients with chronic stable angina were entered into the study. Each subject underwent a symptom‐limited cycloergometer stress test following a washout period of 2 weeks. Blood samples were collected before and immediately after exercise. All subjects were then randomized into two groups of 10 patients each, with Group 1 and Group 2 taking amlodipine 10 mg/day, and placebo for 4 weeks, respectively. They subsequently underwent a second exercise stress test, and blood samples were obtained before and immediately after exercise. Flow‐cytometric evaluation of platelet activity was performed in order to recognize GMP‐140 expression on platelet membrane.

Results: Strenuous exercise induced a significant increase in platelet activation in all subjects prior to therapy. No significant differences were observed in platelet activity at rest between Groups 1 and 2, whereas a significant decrease in exercise‐induced platelet activation was demonstrated in Group 1 compared with Group 2.

Conclusion: Our data provide evidence of the favorable effect of amlodipine on exercise‐induced platelet activation in patients affected by chronic stable angina.
Transvenous atrial defibrillation—techniques and clinical applications
Authors: Tse Hung‐Fat , Lau Chu‐Pak , John Camm A.
Published: February 2009

Atrial fibrillation (AF) is the most common arrhythmia requiring treatment. The most desirable therapy may be restoration and maintenance of sinus rhythm. Limitations of the current methods for cardioversion of AF have prompted the development of transvenous atrial defibrillation (TADF) as an alternative and more effective technique for converting AF. Recent advances in the technique of TADF, particularly in the design and configuration of the electrodes, and the use of an optimal biphasic shock waveform have dramatically improved the efficacy of TADF for the termination of all types of AF. The reduction in voltage and energy requirements for cardioversion by TADF may allow the procedure to be performed with little or no sedation and the risk of general anesthesia may be avoided. Both experimental and clinical studies have demonstrated the feasibility, safety, and efficacy of using TADF as a new temporary or “permanent” mode of electrical therapy for AF. It has several potential applications, from acute termination of AF in the electrophysiology laboratory and in patients who have failed to respond to external cardioversion, to its use as an implantable device for treating recurrent AF. This article reviews the current technique and clinical applications of TADF for treatment of AF.
Effects of isosorbide dinitrate on electrocardiography, hemodynamics, and ventilation in patients with exercise‐induced elevation of pulmonary artery wedge pressure
Authors: Josrgensen Lars H. , Thaulow Erik , Refsum Harald E.
Published: February 2009

Background: The mechanisms underlying exertional hyperpnea in patients with coronary artery disease and transient left ventricular dysfunction are still not fully understood.

Hypothesis: The study was undertaken to investigate whether the ventilatory response to exercise reflects the effects of acute medical treatment of exercise‐induced left ventricular dysfunction, and to evaluate mechanisms relevant to excessive exertional ventilation.

Methods: In 11 male patients, aged 65.2 pL 6.0 years, all with pulmonary artery wedge pressure (PAWP) < 25 mmHg and ST depression < 2 mm during moderate supine exercise, ventilation ( ), oxygen uptake (Vo2), hemodynamics, electrocardiogram (ECG), and arterial and mixed venous blood gases were examined during supine rest and exercise, before and at hourly intervals after peroral intake of 30 mg isosorbide dinitrate (ISDN). Six similar patients were examined with the same protocol without ISDN administration and comprised a control group.

Results: Before administration of ISDN, exercise PAWP was 35.3 pL 5.9 mmHg, ECG showed 2.77 pL 1.06 mm ST depression, and V/Vo2was 31.8 pL 4.8 l/l. One h after ISDN administration, exercise mean PAWP was 11.0 pL 2.5 mmHg (p < 0.001), ST depression 0.59 pL 0.8 mm (p < 0.001), whereas V/Vo2was unchanged, 30.1 ± 5.3 l/l. Two h later, PAWP remained reduced and there were only minor ST depressions, while V/Vo2remained high. Exercise cardiac index (CI) and mixed venous oxygen tension (Pvo2), initially 4.7 pL 0.67 l/min/m2and 3.54 pL 0.35 kPa, respectively, remained at the same low level throughout the study. In the six nontreated patients, there were no significant changes in ST depression, exercise PAWP, or exertional ventilation.

Conclusion: Isosorbide dinitrate treatment markedly improved exercise‐induced left heart dysfunction, whereas excessive ventilatory response was unaffected, even after 3 h. Thus, measurements of the exercise hyperpnea did not properly reflect effective reduction of myocardial ischemia.
The role of flumazenil in outpatient transesophageal echocardiography
Authors: Tsang Teresa S. M. , Martin Marjorie L. , Bailey Kent R. , Seward James B.
Published: February 2009

Background: Benzodiazepines used for transesophageal echocardiography (TEE) sedation may be associated with postprocedural psychomotor effects that are undesirable.

Hypothesis: We hypothesize that flumazenil can reverse cognitive and motor effects from benzodiazepine, promoting earlier return to baseline function.

Methods: We prospectively evaluated the cognitive and motor function of patients who did or did not receive flumazenil following TEE. Patients' gait, level of drowsiness, and recall of items learned before and after benzodiazepine administration were evaluated before TEE, as well as immediately and 30 min after the procedure.

Results: Of 207 patients (123 men and 84 women), 93 (45%) were given flumazenil 0.2 or 0.4 mg intravenously, and 113 (55%) were not. The baseline characteristics of the patients who received flumazenil were not significantly different from those who did not receive flumazenil, with the exception of a higher mean dosage of midazolam administered to the flumazenil group. In addition, patients in the flumazenil group appeared more drowsy immediately following TEE. When adjusted for age and midazolam dosage, there were no differences, at any time, between the two groups in gait or recall of items learned prior to sedation. However, at 30 min following TEE, the flumazenil group was able to recall a larger number of new items learned immediately after the procedure (1.92/3 vs. 1.61/3, p = 0.02) than did patients in the group not receiving flumazenil. No adverse effects were encountered in any patient.

Conclusion: Flumazenil appears safe and effective in reversing anterograde amnesic effects of benzodiazepine following TEE, but has no effects on retrograde amnesia and does not promote earlier return of motor function to baseline. It is useful in clinical situations where high dosages of benzodiazepine have been used and/or excessive drowsiness is evident following TEE. Routine use of the drug, however, is not necessary.
The clinical utility of adenosine in difficult to diagnose tachyarrhythmias
Authors: O'Rourke Daniel J. , Palac Robert T. , Schindler John T. , Keim Stephen G.
Published: February 2009

Background: The use of intravenous adenosine to help differentiate the origin of tachyarrhythmias has been suggested to be beneficial. However, the benefit of this intervention to physicians with different levels of training in electrocardiographic (ECG) interpretation is unknown.

Hypothesis: The purpose of the study was to determine whether intravenous adenosine improved the diagnostic accuracy of difficult to diagnose tachyarrhythmias when used by physicians with different levels of training in ECG interpretation.

Methods: We studied 28 consecutive patients presenting with wide and narrow complex tachyarrhythmias, in whom adenosine was given specifically for diagnostic purposes. Two groups of physicians, attending (n = 14) and housestaff (n = 10), reviewed each ECG before and after the administration of adenosine.

Results: For narrow complex tachyarrhythmias, neither physician group derived diagnostic benefit from the use of adenosine. However, for wide complex tachyarrhythmias, the diagnostic accuracy of the housestaff group significantly improved with the use of adenosine (pre = 54%, post = 70%, p < 0.01), while the attending physician group had no significant improvement (pre = 61%, post = 71%, p = NS).

Conclusion: This study suggests that adenosine provides useful diagnostic information to physicians less experienced in ECG interpretation when presented with patients having wide complex tachyarrhythmias of uncertain origin.
Prolongation of the QT interval in children with liver failure
Authors: Fishberger Steven B. , Rossi Anthony F. , Pittman Nanci S.
Published: February 2009

Background: Alcoholic liver disease has been associated with QT prolongation and sudden cardiac death.

Hypothesis: We evaluated children with hepatic failure to determine whether they have abnormalities of ventricular repolarization.

Methods: Between October 1990 and January 1996, 38 pediatric patients (mean age 6.5 ± 7.2 years) underwent evaluation for liver transplantation, including a 12‐lead electrocardiogram and an echocardiogram. All patients had normal serum electrolytes, calcium, and magnesium at the time of cardiac evaluation and were not on any medications known to prolong repolarization. Follow‐up electrocardiograms were performed on all survivors with QT prolongation following liver transplantation.

Results: Among those evaluated, seven (18%) were noted to have a prolonged QT interval corrected for rate (QTc> 450 ms; range 460–560 ms). All had a structurally normal heart, except one with an atrial and ventricular septal defect. When compared with patients with a normal QT interval, there was no significant difference in serum indices of liver function or indication for liver transplantation. None of the patients developed a ventricular arrhythmia. Two patients with a prolonged QTc died prior to transplant and another died immediately after surgery. All four survivors had normalization of the QTc following liver transplantation.

Conclusion: QTc prolongation can be seen in a significant number of children with hepatic failure. While the mechanism is not known, it appears to be reversible following liver transplantation.
Spontaneous multivessel coronary artery dissection: Repeated presentation in a healthy postmenopausal woman
Authors: Judkins David A. , Capone Robert J. , Houghton Jan L. , Miller Stuart J.
Published: February 2009

Spontaneous coronary artery dissection is a rare cause of acute myocardial infarction which is infrequently diagnosed antemortem. Most previously reported cases were found in women of whom a significant proportion presented during pregnancy or the postpartum period. We describe the first antemortem case of spontaneous coronary artery dissection, unrelated to pregnancy or the postpartum state, which ultimately resulted in diffuse involvement of both the left and right coronary arteries over a period of 4 months. Pathophysiology and case management of this disorder are discussed.
Clinical relevance of chest pain during dobutamine stress echocardiography in women
Authors: Sizemore Clay , Lewis Jannet F.
Published: February 2009

Background: Dobutamine stress echocardiography (DSE) is commonly used for diagnosis and management of patients with known or suspected coronary artery disease. Chest pain occurring during DSE potentially provides additional diagnostic accuracy. Our experience suggests that chest pain occurs frequently in women undergoing DSE.

Hypothesis: It was the purpose of this study to determine the frequency with which chest pain occurs in women undergoing DSE and the relation to inducible ischemia or coronary artery stenosis.

Methods: To determine the prevalence and clinical significance of chest pain during DSE, we reviewed the records of 154 consecutive women undergoing DSE in our laboratory. Of these, 59 patients (37.5%) also underwent coronary angiography. The presence or absence of chest pain was correlated with ECG changes, left ventricular wall motion abnormalities during DSE, and coronary stenosis by angiography.

Results: Forty‐one women (26%) developed chest pain during DSE. Patients experiencing chest pain were older (58.5 ± 9.3 vs. 54.9 ± 12.6; p = 0.05), and had lower resting heart rates (71 ± 12.2 vs. 77.9 ± 14.9; p = 0.008), but received similar maximum doses of dobutamine and reached comparable peak heart rates (131.1 ± 17.4 vs. 133.5 ± 21.7; p = NS). Patients with chest pain more commonly exhibited ST‐segment depression ≥ 1 mm during dobutamine infusion (13/41, 32%, vs. 17/113, 15%; p = 0.02), but chest pain showed no statistically significant correlation with abnormal DSE or with coronary stenosis.

Conclusions: In women undergoing DSE, chest pain occurs in 26% and does not appear to be related to inducible myocardial ischemia. Electrocardiographic changes occur more frequently in patients who experience chest pain, but are also often unrelated to inducible myocardial ischemia.
Stress long‐axis function in coronary artery spasm
Authors: Cooke Fiona J. , Clague Jonathan , Henein Michael Y.
Published: February 2009

In a patient with prior myocardial infarction who had complained of frequent angina repeat arteriograms proved normal coronary arteries. Both ECG exercise testing and thallium scanning excluded ischemia. Resting echocardiogram showed increased distal septal and right ventricular apical myocardial echo intensity. Dobutamine stress echo demonstrated right ventricular and posteroseptal abnormalities consistent with ischemia. Repeat angiogram with ergonovine confirmed distal right coronary spasm.
Treatment of a coronary artery aneurysm with a novel stent
Authors: Kolettis Theofilos M. , Kyriakides Zenon S. , Kremastinos Dimitrios T.
Published: February 2009

We report a case of a prominent aneurysm of the right coronary artery secondary to atherosclerotic coronary artery disease. The aneurysm was complicated by recurrent myocardial infarction despite optimal medical treatment. It was successfully treated with coronary artery stenting, using a novel device, consisting of two stents with a layer of expandable graft material placed between them. Follow‐up angiography 6 months after the procedure showed a sustained excellent result.
Long‐term prognosis of late spontaneous reperfusion after failed thrombolysis for acute myocardial infarction
Authors: Ishihara Masaharu , Sato Hikaru , Tateism Hironobu , Kawagoe Takuji , Shimatani Yuji , Ueda Kentarou , Noma Kensuke , Yumoto Akihisa , Nishioka Kenji
Published: February 2009

Background: Early reperfusion improves left ventricular (LV) function and survival after acute myocardial infarction (MI). Thrombolytic therapy achieves early patency of the infarct artery in about two‐thirds of patients. In nearly half of the remaining patients, in whom early reperfusion was not achieved with thrombolytic therapy, the infarct artery might reopen by the time of predischarge angiography. However, the impact of such late spontaneous reperfusion after failed thrombolytic therapy on LV function and long‐term survival remained unclear.

Hypothesis: This study was undertaken to assess implication of late spontaneous reperfusion after failed thrombolytic therapy on LV function and long‐term survival after acute MI.

Methods: The study consisted of 198 patients with anterior acute MI who underwent thrombolytic therapy and predischarge angiography: 160 patients with infarct artery patent early and late after therapy (persistent patency), 17 patients with infarct artery occluded early after therapy but patent at predischarge angiography (late spontaneous reperfusion), and 21 patients with infarct artery occluded early and late after therapy (persistent occlusion).

Results: Persistent patency was associated with enhanced improvement in LV ejection fraction (7.7 ± 11.8%) compared with late spontaneous reperfusion (0.0 ± 9.6%, p = 0.03) and persistent occlusion (‐1.4 ± 9.7%, p = 0.003). Persistent patency was associated with better long‐term survival than with late spontaneous reperfusion (p < 0.001) and persistent occlusion (p < 0.001). Multivariate analysis comparing persistent patency and late spontaneous reperfusion showed that early reperfusion was an independent predictor of long‐term survival.

Conclusion: Late spontaneous reperfusion after failed thrombolytic therapy was associated with poor LV function and long‐term survival, emphasizing the importance of early reperfusion.
Serial circulating concentrations of c‐reactive protein, interleukin (il)‐4, and il‐6 in patients with acute left heart decompensation
Authors: Sato Yukihito , Takatsu Yoshiki , Kataoka Kazuaki , Yamada Tasuku , Taniguchi Ryoji , Sasayama Shigetake , Matsumori Akira
Published: February 2009

Background: Interleukin (IL)‐6 has recently been shown to have negative inotropic effects, and several studies have reported increases in circulating concentrations of this cytokine in patients with depressed left ventricular ejection fraction and chronic left heart failure. However, most previous clinical studies have measured cytokines in compensated chronic heart failure.

Hypothesis: The purpose of this study was to examine the temporal evolution of circulating concentrations of C‐reactive protein (CRP) and cytokines in patients with cardiomyopathy and acute cardiac decompensation, free of infection and unstable angina.

Methods: The time course of circulating concentrations of CRP, an anti‐inflammatory cytokine interleukin (IL)‐4, and a proinflammatory cytokine IL‐6 were studied in eight patients with cardiomyopathy and acute cardiac decompensation in the absence of infection or unstable angina. Control samples were obtained from eight age‐matched asymptomatic subjects.

Results: Increased circulating concentrations of CRP (2.6 ± 0.8 mg/dl), IL‐4 (164.6 ± 36.5 pg/ml), and EL‐6 (17.1 ± 5.1 pg/ml) were found in all eight patients during acute cardiac decompensation; these values decreased significantly with the resolution of symptoms of cardiac decompensation (0.5 ±0.1 mg/dl, 77.8 ± 23.6 pg/ml, 2.3 ± 0.1 pg/ml, respectively, p< 0.05 for both). There was a significant correlation between peak CRP and peak IL‐6 (p<0.05).

Conclusions: In patients with acute left heart decompensation in the absence of infection or coronary events, CRP, IL‐4, and IL‐6 increased and returned toward normal levels as the symptoms of heart failure resolved. Since the changes in concentrations of CRP, IL‐4, and IL‐6 in patients with heart failure are dynamic, the distinction between compensated and decompensated state is important when discussing the significance of acute reactive proteins or cytokines in the pathogenesis of heart failure.
Rest and exercise hemodynamics before and after valve replacement‐A combined doppler/catheter study
Authors: Inselmann G. , Jahns R. , Capell A. J. , Eigel P. , Nellessen U. , Ludwig J.
Published: February 2009

Background: Hemodynamic improvement is a common finding following valve replacement. However, despite a normally functioning prosthesis and normal left ventricular ejection fraction, some patients may show an abnormal hemodynamic response to exercise.

Methods: In a combined catheter/Doppler study, rest and exercise hemodynamics were evaluated in 23 patients following aortic (n = 12) (Group 1) or mitral valve (n = 11) (Group 2) replacement and compared with preoperative findings. Patient selection was based on absence of coronary artery disease and left ventricular failure as shown by preoperative angiography. Cardiac output, pulmonary artery pressure, pulmonary capillary pressure, and pulmonary resistance were measured by right heart catheterization, whereas the gradient across the valve prosthesis was determined by Doppler echocardiography. Postoperative evaluation was done at rest and during exercise. The mean follow‐up was 8.2 ± 2.2 years in Group 1 and 4.2 ± 1 years in Group 2.

Results: With exercise, there was a significant rise in cardiac output in both groups. In Group 1, mean pulmonary pressure/capillary pressure decreased from 24 ± 9/18 ± 9 mmHg preoperatively to 18 ± 2/12 ± 4 mmHg postoperatively (p < 0.05), and increased to 43 ± 12/30 ± 8 mmHg with exercise (p < 0.05). The corresponding values for Group 2 were 36 ± 12/24 ± 6 mmHg preoperatively, 24 ± 7/17 ± 6 mmHg postoperatively (p < 0.05), and 51 ± 2/38 ± 4 mmHg with exercise (p < 0.05). Pulmonary vascular resistance was 109 ± 56 dyne·s·cm‐5 preoperatively, 70 ± 39 dyne·s·cm‐5 postoperatively (p < 0.05), and 70 ± 36 dyne·s·cm‐5 with exercise in Group 1. The corresponding values for Group 2 were 241 ± 155 dyne·s·cm‐5, 116 ± 39 dyne·s·cm‐5 (p < 0.05), and 104 ± 47 dyne·s·cm‐5. There was a significant increase in the gradients across the valve prosthesis in both groups, showing a significant correlation between the gradient at rest and exercise. No correlation was found between valve prosthesis gradient and pulmonary pressures.

Conclusion: Exercise‐induced pulmonary hypertension and abnormal left ventricular filling pressures seem to be a frequent finding following aortic or mitral valve replacement. Both hemodynamic abnormalities seem not to be determined by obstruction to flow across the valve prosthesis and may be concealed, showing nearly normal values at rest but a pathologic response to physical stress.
John B. Barlow: Master clinician and compleat cardiologist
Authors: Cheng Tsung O.
Published: February 2009

This paper reports the case of a 76‐year‐old man in whom atrial flutter with varying atrioventricular block and intermittent right bundle‐branch block was found. This is the first report on tachycardia‐dependent right bundle‐branch block associated with supernormal conduction in a case of atrial flutter. When an impulse is conducted to the ventricles beyond 0.72 s after a QRS complex of right bundle‐branch block configuration, the impulse falls after the abnormally long effective refractory period of the right bundle branch and passes through the right bundle branch. When the conducted impulse occurs within 0.72 s after a QRS complex of right bundle‐branch block configuration, the impulse usually falls in the refractory period and is blocked in the right bundle branch; however, only when the impulse occurs 0.48 or 0.49 s after that does it fall in the supernormal period and passes through the right bundle branch. The findings in the present report strengthen our previous suggestion that the presence of supernormal conduction plays an important role in the initiation of reentrant ventricular tachycardia.
Amiodarone: What have we learned from clinical trials?
Authors: Naccarelli Gerald V. , Wolbrette Deborah L. , Dell'Orfano Joseph T. , Patel Hemantkumar M. , Luck Jerry C.
Published: February 2009

Amiodarone is an antiarrhythmic agent commonly used in the treatment of supraventricular and ventricular tachyarrhythmias. This paper reviews clinical trials in which amiodarone was used in one of the treatment arms. Key post‐myocardial infarction trials include EMIAT and CAMIAT, both of which demonstrated that amiodarone reduced arrhythmic but not overall mortality. In patients with congestive heart failure (CHF), amiodarone was associated with a neutral survival in CHF/STAT and improvement in survival in GESICA. In patients with nonsustained ventricular tachycardia, the MADIT trial demonstrated that therapy with an implantable cardioverter‐defibrillator (ICD) improved survival compared with the antiarrhythmic drug arm in such patients, most of whom were taking amiodarone. In sustained VT/VF patients, the CASCADE trial demonstrated that empiric amiodarone lowered arrhythmic recurrence rates compared with other drugs guided by serial Holter or electrophysiologic studies. Several trials including AVID, CIDS, and CASH have demonstrated the superiority of ICD therapy compared with empiric amiodarone in improving overall survival. Clinical implications of these trials are discussed.
Intravenous optison® (FS069) enhances pulmonary vein flow velocity signals: A multicenter study
Authors: Ellahham Samer , Hausnerova Eva , Gottdiener John
Published: February 2009

Background: Pulmonary vein spectral Doppler signals to characterize ventricular diastolic and systolic function, though often difficult to obtain, can be enhanced using contrast agents.

Hypothesis: The objective of this study was to determine the efficacy of the intravenous contrast agent Optison® for enhancement of Doppler signals in patients with poor signals on two‐dimensional echocardiographic examinations.

Methods: Enhancement of pulmonary venous flow was evaluated in 191 patients at 0.2, 0.5, 3.0, and 5.0 ml per injection.

Results: Greatest contrast enhancement for right and left pulmonary veins was observed at the highest doses. At 0.5 ml, conversion from inadequate to adequate was observed in right and left pulmonary veins in 48.0 and 79.3% of patients, respectively, while any degree of improvement was 54.4 and 65.8%, respectively. The adverse event rate (6.5%) was similar to a first‐generation agent.

Conclusion: The results demonstrate that Optison is a safe and effective contrast agent for improving visualization of pulmonary Doppler signals, especially the left pulmonary vein.
The effect of amlodipine and enalapril on blood pressure and neurohumoral activation in hypertensive patients with ribbing's disease (multiple epiphysal dystrophy)
Authors: Cocco Giuseppe , Ettlin Thierry , Baumeler Hans Ruedi
Published: February 2009

Background: In patients with Ribbing's disease (RD)—a form of multiple epiphysal dystrophy—hypertension is frequent, often severe, and accompanied by a relevant cardiac dysfunction.

Hypothesis: This study was undertaken to evaluate the contribution of the calcium antagonist amlodipine and of the angiotensin‐converting‐enzyme inhibitor enalapril to blood pressure regulation by studying their effect on neurohormonal activation.

Methods: Fifty hypertensive patients with RD were studied. After a placebo run‐in period of 4 to 6 weeks, patients were randomly assigned to receive either amlodipine (10 mg once daily) or enalapril (20 mg once daily) for 6 months.

Results: Both drugs significantly lowered blood pressure. Enalapril did not result in activation of the sympathetic system (as determined by measurement of the plasma norepinephrine level). On the other hand, the hypotensive effect of amlodipine occurred with an increase in heart rate and in the levels of plasma norepinephrine and angiotensin II.

Conclusion: It is unclear whether amlodipine may reduce cardiac dysfunction in patients with RD.
Comparison of left ventricular diastolic filling with myocyte bulk modulus using doppler echocardiography and acoustic microscopy in pressure‐overload left ventricular hypertrophy and cardiac amyloidosis
Authors: Masugata Hisashi , Mizushige Katsufumi , Kinoshita Aki , Sakamoto Seiji , Matsuo Hirohide , Senda Shoichi , Sakamoto Haruhiko
Published: February 2009

Background: The myocardial bulk modulus has been described as the constitutive properties of the left ventricular (LV) wall and is measured as ρV2 (ρH = density, V = sound speed) using acoustic microscopy.

Hypothesis: The study was undertaken to assess the relationship between the myocyte bulk modulus and transmitral inflow patterns in patients with pressure‐overload LV hypertrophy (LVH) and cardiac amyloidosis (AMD).

Methods: In 8 patients with LVH, 8 with AMD, and 10 controls without heart disease, the transmitral inflow pattern was recorded by Doppler echocardiography before death, and myocardial tissue specimens were obtained at autopsy. The tissue density and sound speed in the myocytes were measured by microgravimetry and acoustic microscopy, respectively. The diameters of the myocytes were measured on histopathologic specimens stained by the elastica Van Gieson method.

Results: In the subendocardium, the myocyte bulk modulus was larger in LVH (2.98 X 109N/m2,p<0.001) and smaller in AMD (2.61 X 109N/m2,p<0.001) than in the controls (2.87 X 109N/m2). The myocyte diameter in LVH (26±1 m̈m) was larger than that in the control (21±1 m̈m, p<0.001) and AMD (20±1 m̈m, p<0.001). The bulk modulus in the subendocardial myocyte significantly correlated with the deceleration time (DT) of the early transmitral inflow (r=0.689, p=0.028 in control, r=0.774, p=0.024 in LVH, and r=0.786, p=0.021 in AMD).

Conclusion: The changes in the myocyte elasticity as represented by the bulk modulus were limited to the subendocardial layers and may be related to relaxation abnormalities in LVH and a reduction in LV compliance in AMD.
Aortic valve replacement for patients with mild to moderate aortic stenosis undergoing coronary artery bypass surgery
Authors: Hilton Thomas C.
Published: February 2009

Aortic valve replacement (AVR) is not normally recommended in asymptomatic patients, even if aortic stenosis is severe. However, as the population ages, an increasing number of patients with mild or moderate aortic stenosis will require coronary artery bypass grafting (CABG). In these cases, risk of “prophylactic” AVR needs to be weighed against risks of subsequent worsening of the mildly or moderately diseased aortic valve. If unoperated, aortic stenosis will worsen at an average of 6–8 mmHg per year (‐0.1 cm2/year valve area), and one‐quarter of such patients will require late AVR with a high operative mortality (14–24%). If AVR is performed at the time of CABG, operative risk is increased only slightly (from 1–3% to 2–6%), as are late mortality (1–2% per year) and morbidity (1–2% per year), mainly from hemorrhagic complications. Intrinsic gradients of most prosthetic valves are sufficiently low that even patients with low aortic valve gradients are likely to derive hemodynamic benefit from AVR. Thus, if there is a measurable (> 20–25 mmHg) gradient across the aortic valve in a patient who requires CABG, the patient is at considerable risk for developing symptomatic aortic stenosis prior to reaching the end of expected benefit from CABG; in this case AVR should be considered. It may be reasonable in patients with very mild gradients (< 25 mmHg) to defer aortic valve surgery; however, it should be noted that aortic stenosis progression is generally more rapid when the initial gradient is small.
The role of strict metabolic control by insulin infusion on fibrinolytic profile during an acute coronary event in diabetic patients
Authors: Melidonis Andreas , Tournis Simeon , Stefanidis Alexander , Manoussakis Stavros , Handanis Stilianos , Zairis Michael , Foussas Stefanos , Dadiotis Loukas
Published: February 2009

Background: Many clinical and laboratory observations give support to the hypothesis that strict metabolic control by insulin infusion during acute coronary events may improve the ischemic damage and prognosis.

Hypothesis: We investigated the impact of intensive insulin treatment on fibrinolytic parameters during an acute ischemic myocardial event (unstable angina or acute myocardial infarction) in patients with type 2 diabetes mellitus.

Methods: The study group consisted of 48 type 2 diabetic patients, of whom 24 were randomized to conventional therapy plus intensive insulin treatment (Group 1) and 24 to conventional therapy only (Group 2). The two groups were comparable according to gender, age, body mass index, waist:hip ratio, duration of diabetes, previous antidiabetic treatment, type of ischemic events, concomitant therapy, and the classic risk factors for coronary disease. Insulin‐treated patients were excluded from the study. Plasma levels of fibrinogen, tissue plasminogen activator (t‐PA), and plasminogen activator inhibitor‐1 (PAI‐1) were measured on admission and discharge. Fibrinogen (fibr) was measured using the photometric method. PAI‐1 and t‐PA were measured by enzyme‐linked immunosorbent assays.

Results: T‐PA increased in both groups during hospitalization (t‐PAadmission VS. t‐PAdischarge: Group 1: 15.42 ± 4.4 ng·ml−1 vs. 21.2 ± 5.74 ng·ml−1, p = 0.000037; Group 2: 14.47 ± 6.31 ng·ml−1 vs. 19.18 ± 6.88 ng·ml−1, p = 0,001). On the other hand, fibr and PAI‐1 levels increased remarkably in controls (Group 2, fibradmission vs. fibrdischarge: 2.98 ± 1.04 g·l−1 vs. 3.59 ± 1.01 g·l−1, p = 0.002, and PAI‐1admission vs. PAI‐1discharge: 30.6 ± 17.34 ng·ml−1 vs. 40.62 ± 23.48 ng·ml−1, p = 0.003). This finding was not observed in the intensive insulin treatment group (Group 1, fibradmission vs. fibrdischarge: 2.87 ± 0.73 g·l−1 vs. 2.67 ± 0.72 g·l−1, p = 0.101, and PAI‐1admission vs. PAI‐1discharge: 30.75 ± 15.81 ng·ml−1 vs. 27.75 ± 6.43 ng·ml−1, p = 0.484).

Conclusion: Intensive insulin treatment during an acute coronary event improves fibrinolytic profile in patients with diabetes mellitus. This is a possible mechanism for the reduced short‐ and long‐term mortality in diabetic patients treated with intensive insulin treatment protocol.
Electropharmacologic effect of a standard dose of intravenous procainamide in patients with sustained ventricular tachycardia
Authors: Rials Seth J. , Britchkow David , Marinchak Roger A. , Kowey Peter R.
Published: February 2009

Background: Patients with inducible sustained ventricular tachycardia (VT) sometimes receive intravenous procainamide during electrophysiologic testing. Unfortunately, the responses to intravenous and subsequent oral drug therapy are variable and may be discordant.

Hypothesis: It was the aim of this study to determine whether this variability might be explained by heterogeneity in the electropharmacologic response, even in a homogeneous population.

Methods: We studied 42 patients who had spontaneous malignant ventricular arrhythmia and were inducible to sustained monomorphous VT during electrophysiologic testing. Each received 15 mg/kg of intravenous procainamide followed by a 2 mg/min infusion. Serum levels were drawn immediately following programmed stimulation. The mean procainamide level was 6.7 ± 1.4 mcg/ml with an N‐acetyl procainamide level of 1.0 ± 0.5 mcg/ml. The 14 procainamide responders (5 of whom were noninducible and 9 whose VT cycle length increased > 100 ms) and the 28 nonresponders had similar procainamide and NAPA levels (6.5 ± 1.4 vs. 6.7 ± 1.4 mcg/ml).

Results: There was no significant difference in baseline clinical parameters, His to ventricular electrogram (HV) interval, effective refractory period, or VT cycle length. Prolongation of the effective refractory period and infra His conduction time occurred to a similar extent in responders and nonresponders.

Conclusion: We conclude that procainamide has a consistent dose‐response relationship with respect to refractoriness and conduction in patients with malignant arrhythmias. However, acute antiarrhythmic efficacy of procainamide cannot be predicted by clinical factors, drug levels, or drug‐induced changes in common electrophysiologic parameters.
Changes of QT dispersion in patients with coronary artery disease dependent on different methods of stress induction
Authors: Hailer B. , Leeuwen P. , Sallner D. , Wehr M. , Lange S.
Published: February 2009

Background: Episodes of stress‐induced myocardial ischemia in patients with coronary artery disease (CAD) may cause increases of QT dispersion (QTd).

Hypothesis: Aim of this study was to analyze the effect of increasing heart rates on QTd and to compare the effect of different methods of stress induction in patients with varying degrees of CAD when estimating QTd.

Methods: We studied 58 patients, 22 with prior myocardial infarction (MI), 25 without MI or wall motion disturbances at rest, and 11 patients without evidence of CAD. Prior to coronary angiography, standard 12‐lead ECGs were obtained at rest as well as during dynamic exercise and pharmacologic stress using arbutamine simultaneously with echocardiography. QTd was determined at each stress level by subtracting minimal from maximal QT interval duration.

Results: QTd values at rest were not consistently higher in the patients with CAD. At maximal heart rate, QTd was statistically significantly higher in patients with CAD with a better discrimination between groups for pharmacologic stress (p < 0.005 for exercise, p < 0.0001 for arbutamine). Patients after MI had higher QTd values under all conditions than did the groups without MI. As in patients with CAD, the values of this group changed more radically as a result of pharmacologic stress.

Conclusion: Patients with CAD can be identified on the basis of QTd under stress. These changes were not as marked in patients with MI as their rest values were already increased. Overall, drug‐induced stress produced greater differences than dynamic exercise, suggesting that the ischemic threshold might be lower in the former.
Implantable cardioverter defibrillator discharge rates in patients with unexplained syncope, structural heart disease, and inducible ventricular tachycardia at electrophysiologic study
Authors: Menon Vend , Steinberg Jonathan S. , Carillo Luis , Akiyama Toshio , Beckman Karen , Kutalek Steven
Published: February 2009

Background and hypothesis: The implantable cardioverter defibrillator (ICD) is the best available strategy to protect patients from life‐threatening ventricular arrhythmia. Although unproven, it is commonly utilized to treat subjects with syncope, a negative clinical workup, structural heart disease, and inducible sustained monomorphic ventricular tachycardia (VT) on programmed electrophysiologic stimulation (EPS). The purpose of this paper was to validate this approach.

Methods: We retrospectively identified 36 subjects who received primary ICD therapy for syncope in the setting of structural heart disease with inducible sustained monomorphic VT on EPS. The cohort was predominantly male (32/36) with underlying coronary artery disease (29/36). The mean left ventricular ejection fraction was 31 ± 12%, and a third of the patients (12/36) had undergone bypass surgery.

Results: The study group was followed for a mean of 23 ± 15 months (range 3–81 months) and experienced an ICD event rate of 22% at 3 months, which increased to 55% at 36 months. This event rate was comparable with the 66% event rate seen in a group of patients with primary ICD therapy for spontaneous life‐threatening VT treated during the same time period. No future predictors of ICD events in the study group could be identified.

Conclusion: Syncope patients with negative workup, structural heart disease, and sustained monomorphic VT at EPS are at high risk for future tachyarrhythmic events. Based on present evidence, primary ICD therapy in this group appears warranted and justified.
Paroxysmal atrial fibrillation and insidious neck pain
Authors: Nastri Marcio V. , Taricco Mario A. , Alves Venancio A. F. , Mansur Alfredo J.
Published: February 2009

Paroxysmal atrial fibrillation (AF) is an arrhythmia usually secondary to autonomic imbalance, and it may occur in the absence of any structural heart disease. The case of a patient with paroxysmal AF, in whom the arrhythmia may have been a presenting symptom of a later diagnosed cervical schwannoma, is reported.
Acetylcholine‐ and ergonovine‐induced coronary microvascular spasm reflected by increased coronary vascular resistance and myocardial lactate production
Authors: Horimoto Masashi , Igarashi Keiich , Takenaka Takashi , Inoue Hitoki , Yamazaki Kohko , Sakuragi Hitoshi
Published: February 2009

Diagnosis of coronary microvascular spasm remains largely speculative because it has been mostly based on chest pain and electrocardiographic ST‐segment shift with slow filling of contrast medium into the coronary artery. A patient with resting chest pain and normal coronary angiograms underwent provocative tests with intracoronary acetylcholine (ACh) and ergonovine. During the tests, coronary diameter and flow velocity in the left anterior descending (LAD) coronary artery were measured with quantitative coronary angiography and intracoronary Doppler guide wire, respectively. Vascular resistance of the LAD and lactate production were determined separately. With injections of 100 μg of ACh and 20 μg of ergonovine, chest pain occurred with ST‐segment elevation in the precordial leads in the absence of epicardial coronary spasm. Coronary vascular resistance increased by 2.2‐ and 1.6‐fold of the baseline value with ACh and ergonovine, respectively. Myocardial lactate production was noted during the ST‐segment elevation. Coronary microvascular spasm was verified by the increment in coronary vascular resistance and myocardial lactate production with concomitant ST‐segment elevation in the presence of normal coronary angiograms.