bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability of the noninvasive baroreflex sensitivity assessment using cross‐spectral analysis of heart rate and arterial blood pressure variabilities
Authors: Wichterle Dan , Melenovsky Vojtech , Necasova Lucie , Kautzner Josef , Malik Marek 
Published: February 2009

AbstractBackground: Depressed baroreflex sensitivity (BRS), usually estimated using the invasive phenylephrine method or the nitroprusside test, is significantly and independently associated with an increased risk of malignant ventricular arrhythmias and sudden cardiac death in patients surviving acute myocardial infarction. Several investigators have compared the standard phenylephrine test and different noninvasive methods.Hypothesis: This study evaluated the influence of different body positions with different breathing regimes on cross‐spectral baroreflex indices (coherence between the spectral densities of blood pressure and cardiac cycle variabilities) in both low‐ and high‐frequency bands.Methods: The data were obtained in 103 patients (73 males, aged 53 ± 12 years) with coronary artery disease and/or hypertension. Simultaneous electrocardiographic and noninvasive blood pressure recordings were obtained in each subject in both supine and sitting positions during both spontaneous and slow and fast controlled respiration (0.1 and 0.33 Hz).Results: The results show a significant bias and disagreement between noninvasive baroreflex sensitivity (BRS) indices. The mean values of the baroreflex in low frequency ranged from 5.0 ± 5.3 to 10.1 ± 7.9 ms/mmHg, while in high frequency, the mean values ranged from 6.6 ± 6.1 to 10.1 ± 7.9 ms/mmHg. The limits of agreement ranged from ± 1.7 to ± 4.1 ms/mmHg with bias from ‐1.0 to + 0.7 ms/mmHg.Conclusion: A comprehensive comparison of different methods shows that BRS estimated in low‐frequency band in sitting position during spontaneous respiration is the most representative part of the global baroreflex gain.
Acute management of atrial fibrillation and atrial flutter in the critical care unit: shouLd it be ibutilide?
Authors: Varriale Philip , Sedighi Abdollah 
Published: February 2009

AbstractBackground:Ibutilide is currently indicated for the rapid conversion of atrial fibrillation (Afb) or atrial flutter (Afl) of recent onset but limited to patients who are hemodynamically stable and without symptomatic cardiovascular conditions.Hypothesis:The study was undertaken to assess the efficacy and safety of ibutilide in patients with Afb or Afl associated with acute cardiovascular‐medical disorders and in patients receiving prior selective antiarrhythmic drug therapy.Methods:The study included 34 patients, mean age 75 ± 16.3 years, with Afb (n = 25) or Afl (n = 9) having a variety of disorders, for example, congestive heart failure, unstable angina, borderline hypotension, respiratory failure, and chronic renal failure. Prior antiarrhythmic drugs consisted of propafenone (n = 5) or amiodarone (n = 3). Eligibility for cardioversion was established with appropriate anticoagulation or transesophageal echocardiography findings. Ibutilide was given as up to two 10 min infusions of 1 mg separated by 10 min.Results:The overall conversion rate after ibutilide was 79.4% (27/34 patients): 80% for Afb and 78% for Afl. More than 90% converted within 1 h of treatment. A high conversion rate of 92% resulted in those with an arrhythmia duration of ≤ 1 week. All eight patients with prior antiarrhythmic therapy converted to sinus rhythm. The average baseline QTc interval for all patients increased 17.1% (397 ± 63.3 to 465 ± 60.2 ms) at 30 min. For eight patients (including four who received prior antiarrhythmic drugs), QTc interval prolongation ≥ 500 ms was associated with nearly half the entire incidence of arrhythmic events. Proarrhythmia, the exclusive adverse effect, consisted of ventricular extrasystoles (n = 10) and nonsustained monomorphic ventricular tachycardia (VT) (n = 2) managed with intravenous MgSO4, and sustained polymorphic VT (n = 1) requiring electrical cardioversion.Conclusion:Ibutilide is an effective and well tolerated drug for the rapid termination of Afb or Afl of recent onset associated with symptomatic and/or hemodynamically unstable disorders, and it is most efficacious (≥ 90%) when the atrial arrhythmia is ≤ 1 week in duration. Proarrhythmic events are readily manageable in a monitored unit with access to appropriate treatment.
Myocardial stunning in hyperthyroidism
Authors: Pereira Naveen , William Dec G. , Choo Joseph , Hajjar Roger , Parisi Alfred , Gordon Paul C. 
Published: February 2009

AbstractThe cases of two patients with hyperthyroidism and acute left ventricular (LV) dysfunction with segmental wall motion abnormalities resulting in heart failure are reported. Both had electrocardiographic changes mimicking ischemic coronary artery disease. Treatment with antithyroid medications, beta blockers, and angiotensin‐converting enzyme inhibitors rapidly restored LV function. The rapid reversibility suggests a role for myocardial stunning, an important entity to recognize in hyperthyroidism since this form of LV dysfunction can be reversed with appropriate treatment.
High‐output heart failure resulting from a remote traumatic aorto‐caval fistula: Diagnosis by echocardiography
Authors: Abreo Gerard , Lenihan Daniel J. , Nguyen Peter , Runge Marschall S. 
Published: February 2009

AbstractCongestive heart failure (CHF) due to high output states is known to occur in a variety of systemic illnesses and in patients with arterial‐venous fistulas. This paper reports the case of a 45‐year‐old man admitted to the emergency room with a diagnosis of new onset atrial fibrillation and CHF, whose past medical history was not significant except for a gunshot wound to his abdomen 22 years previously. The etiology of his CHF together with the cardiomegaly and hyperdynamic left ventricular systolic function was unknown. A subcostal view routinely done during transthoracic echocardiography revealed a severely dilated inferior vena cava and the presence of an aorto‐caval fistula by color doppler. The patient underwent successful corrective repair with dramatic improvement in symptoms and resolution of the atrial fibrillation, and cardiac size returned to normal. This rare case emphasizes that patients with refractory CHF must be closely examined with particular attention to palpation and auscultation over all scars, irrespective of the duration since any traumatic or surgical event.
The implantable cardioverter‐defibrillator
Authors: Leon Greene H. 
Published: February 2009

AbstractVentricular arrhythmias remain a major cause of cardiovascular mortality. Therapy for serious ventricular arrhythmias has evolved over the past decade, from treatment primarily with antiarrhythmic drugs to implanted devices. The implantable cardioverter‐defibrillator (ICD) is the best therapy for patients who have experienced an episode of ventricular fibrillation not accompanied by an acute myocardial infarction or other transient or reversible cause. It is also superior therapy in patients with sustained ventricular tachycardia (VT) causing syncope or hemodynamic compromise. Controlled clinical trials have confirmed the utility of these devices. As primary prevention, the ICD is superior to conventional antiarrhythmic drug therapy in patients who have survived a myocardial infarction and who have spontaneous, nonsustained ventricular tachycardia, a low ejection fraction, inducible VT at electrophysiologic study, and whose VT is not suppressed by procainamide. The effect of the ICD on survival of other patient populations remains to be proven. The device is costly, but its price is generally accepted to be reasonable. The ICD has been a major advance in the treatment of ventricular arrhythmias.
Impact of left ventricular size on pharmacologic reverse remodeling in heart failure
Authors: Barry Levine T. , Levine Arlene B. , Bolenbaug Janet , Stomel Robert J. 
Published: February 2009

AbstractBackground and hypothesis: Although medical therapy may normalize echocardiographic left ventricular (LV) systolic function in selected patients with cardiomyopathy, other patients experience no change or a further deterioration in heart failure remodeling. Our aim was to determine what clinical or echocardiographic parameters predict a beneficial therapeutic response.Methods: We prospectively followed biannual clinical and echocardiographic assessments in 215 patients. Forty‐six of these patients (“Nonresponders”) experienced no change or a decline in LV ejection fraction at 6 months. Of the 148 patients who improved LV function, 21 (“Responders”) normalized LV systolic function at 6 months. Only Responders (n = 21) and Nonresponders (n = 46) were compared.Results: On average, these 67 patients were 54 ± 12 years old with 4.5 ± 3.3 years of heart failure. At 6 months, following uptitration of angiotensin‐converting enzyme inhibitors and nitrates, Responder LV ejection fraction rose from 22 ± 6 to 50 ± 5% with improvement in New York Heart Association classification (2.6 ± 0.8 to 1.5 ± 0.8, p = 0.001). These patients had significantly more favorable clinical and echocardiographic outcomes versus Nonresponders despite comparable medical therapy. All baseline demographic, clinical, and echocardiographic variables were equivalent, except for initial LV end‐diastolic diameter which differentiated Nonresponders (7.1 ± 0.7 cm) from Responders (6.1 ± 0.8 cm), p = 0.007.Conclusion: Thus, although heart failure therapy improves LV systolic function in a majority of patients, with normalization in up to 10% of patients, significant LV enlargement may render remodeling unresponsive to pharmacologic intervention, with a potential future need for alternative mechanical or surgical intervention.
Acute myocardial infarction—A late complication of intracoronary stent placement
Authors: Danenberg Haim D. , Lotan Chaim , Hasin Yonathan , Gotsman Mervyn S. , Rozenman Yoseph 
Published: February 2009

AbstractBackground: Myocardial infarction (MI) as the first indication of postangioplasty restenosis is extremely rare, and it has been speculated that the fibroproliferative restenotic lesion is less likely to undergo plaque rupture than the lipid ‐laden native atherosclerotic lesion.Hypothesis: The present study was designed to examine whether intracoronary stent implantation affects this course.Methods: In all, 994 consecutive patients who underwent angioplasty and intracoronary stent implantation in our hospital were reviewed retrospectively for the occurrence of MI.Results: Eight patients (0.8%), all male and hypertensive, aged 33–83 years, presented with an MI due to stent occlusion more than 30 days following stenting (range: 35–398 days). In two patients, MI occurred 3 and 5 h, respectively, following completion of a maximal high‐level exercise test that was negative for ischemia. Angiography revealed complete occlusion or significant stenosis of the stent in all eight patients, with an obvious intimal dissection in either edge of the stent in six patients. Except for gender and hypertension, no correlation was found with other risk factors, vessel involved, initial angiographic results, or with stent design, diameter, or length.Conclusions: Myocardial infarction as a late complication of successful stent implantation occurred in 0.8% of our patients. This is only the lower bound of the estimated frequency for such an event. We hypothesize that the transition point between the relatively fixed stent and the normal artery is exposed to high deformation stress which makes it vulnerable to rupture and dissection. Strenuous exercise and hypertension may increase the deformation stress and the risk of intimal rupture.
Hyperthyroid heart disease
Authors: Fadel Bahaa M. , Ellahham Samer , Lindsay Joseph , Ringel Matthew D. , Wartofsky Leonard , Burman Kenneth D. 
Published: February 2009

AbstractThe heart is an organ sensitive to the action of thyroid hormone, and measurable changes in cardiac performance are detected with small variations in thyroid hormone serum concentrations. Most patients with hyperthyroidism experience cardiovascular manifestations, and the most serious complications of hyperthyroidism occur as a result of cardiac involvement. Recent studies provide important insights into the molecular pathways that mediate the action of thyroid hormone on the heart and allow a better understanding of the mechanisms that underlie the hemodynamic and clinical manifestations of hyperthyroidism. Several cardiovascular conditions and drugs can interfere with thyroid hormone levels and may pose a difficulty in interpretation of laboratory data in patients with suspected thyroid heart disease. The focus of this report is a review of the current knowledge of thyroid hormone action on the heart and the clinical and hemodynamic laboratory findings as well as therapeutic management of patients with hyperthyroid heart disease.
Low‐dose dobutamine radionuclide ventriculography for prediction of myocardial viability: Quantitative analysis of regional left ventricular function
Authors: Takeyasu Noriyuki , Watanabe Shigeyuki , Yamaguchi Iwao , Eda Kazuhiko , Toyama Masahiro , Sakamoto Kazuhiko , Saito Takumi , Yamanouchi Takayoshi , Masuoka Takeshi , Ajisaka Ryuichi , Takeda Tohru , Itai Yuji , Sugishita Yasuro 
Published: February 2009

AbstractBackground: It is important to distinguish viable myocardium from necrotic tissue in order to decide upon therapy in patients with ischemic heart disease.Hypothesis: We verified the hypothesis that quantitative analysis of regional left ventricular function using low‐dose dobutamine radionuclide ventriculography (RNV) can sensitively predict myocardial viability and compared its usefulness with thallium‐201 (201Tl) single‐photon emission computed tomography (201Tl‐SPECT).Methods: Radionuclide ventriculography at rest and during low‐dose dobutamine infusion (5 m̈g/kg/min), 201Tl‐SPECT, and coronary angiography were performed in 51 subjects with severe ischemia‐related stenosis of coronary arteries and 3 subjects without coronary artery disease. 201Tl uptake was assessed as normal (control), low perfusion (LP), or defect. We compared the response of regional function to dobutamine with the regional 201Tl uptake. The accuracy of both methods for identifying viable myocardium was investigated in 17 patients who underwent successful coronary revascularization, with a resulting improvement in wall motion.Results: The increase in regional ejection fraction (δr‐EF) in response to dobutamine was significantly greater in the control (12 ± 6%) and LP (16 ± 11%) regions than in the defect (5 ± 10%) regions. The increase in one‐third regional ejection fraction (δr‐1/3EF) was also significantly higher in the control (14 ± 7%) and LP (10 ± 8%) regions than in the defect regions (5 ± 6%). We defined myocardial viability as a δr‐EF > 5% or a δr‐1/3EF > 2%. The sensitivity and specificity of the δr‐EF for identification of myocardial viability were 91.4 and 55.5%, respectively. The sensitivity and specificity of the δr‐1/3EF were 91.4 and 66.6%, respectively; the corresponding values for 201TlSPECT were 74.2 and 77.8%.Conclusion: Low‐dose dobutamine RNV with quantitative analysis of regional left ventricular function was more sensitive for identification of viable myocardium than 201Tl‐SPECT.
Metabolic and clinical effects of oral magnesium supplementation in furosemide‐treated patients with severe congestive heart failure
Authors: Cohen Natan , Alon Irena , Almoznino‐Sarafian Dorit , Weissgarten Joshua , Gorelik Oleg , Berman Sylvia , Zaidenstein Ronit , Golik Ahuva , Modai David 
Published: February 2009

AbstractBackground:Magnesium depletion and hypomagnesemia are common among furosemide‐treated patients with chronic congestive heart failure.Hypothesis:This investigation evaluated clinical and metabolic effects of oral magnesium supplementation.Methods:Ten patients with severe congestive heart failure maintained on high dose furosemide (≥ 80 mg/day) received a supplement of oral magnesium citrate 300 mg/daily for 30 days. Clinical parameters were followed, and peripheral blood mononuclear cell magnesium and zinc content, serum and urine magnesium, potassium, zinc, calcium, phosphorus, and creatinine were assessed.Results:Peripheral blood mononuclear cell magnesium content and serum potassium rose significantly at the end of the study (2.09 ± 1.89 to 3.99 ± 2.26 m̈g/mg cell protein, p< 0.05, and 4.17 ± 0.38 to 4.39 ± 0.27 mEq/l, p <0.05, respectively), while the other parameters remained unchanged.Conclusion:In some of these patients, oral magnesium supplementation is effective in achieving substantial increments in intracellular magnesium and serum potassium which, in turn, may have cardioprotective effects.
Treatment of hypertension with perindopril reduces plasma atrial natriuretic peptide levels, left ventricular mass, and improves echocardiographic parameters of diastolic function
Authors: Yalçin Fatih , Garcia Mario J. , Thomas James D. , Aksoy Fatma G. , Muderrisoglu Haldun , Sabah Irfan 
Published: February 2009

AbstractBackground: Hypertension is a major independent risk factor for cardiac deaths, and diastolic dysfunction is a usual finding during the course of this disease.Hypothesis: This study was designed to investigate the effects of chronic therapy with perindopril on left ventricular (LV) mass, left atrial size, diastolic function, and plasma level of atrial natriuretic peptide (ANP) in patients with hypertension.Methods: Twenty four patients who had not been previously taking any antihypertensive medication and without prior history of angina pectoris, myocardial infarction, congestive heart failure, dysrhythmias, valvular heart disease, or systemic illnesses received 4–8 mg/day of perindopril orally. Echocardiographic studies were acquired at baseline and 6 months after the initiation of therapy.Results: Systolic and diastolic blood pressure decreased from 174 ± 19.7 and 107.5 ± 7.8 mmHg to 134±10.6 and 82±6.7 mmHg, respectively (p <0.001). Left ventricular mass decreased from 252.4±8.3 to 205.7±7.08 g and left atrial volume from 20.4±5.1 to 17.6±5.2 ml, respectively (p <0.001). Transmitral Doppler early and atrial filling velocity ratio (E/A) increased from 0.69 ± 0.06 to 0.92 ± 0.05 m/s and plasma ANP level decreased from 71.9 ± 11.7 to 35.3 ± 7.8 pg/ml (p <0.001). Reduction of LV mass correlated positively with a reduction in ANP levels (r = 0.66, p <0.0005).Conclusions: Perindopril caused a significant reduction of LV mass, left atrial volume, and plasma ANP levels, as well as improvement in Doppler parameters of LV filling in this group of patients with hypertension.
A comparison of brachial artery row‐mediated vasodilation using upper and lower arm arterial occlusion in subjects with and without coronary risk factors
Authors: Vogel Robert A. , Corretti Mary C. , Plotnick Gary D. 
Published: February 2009

AbstractBackground: The ultrasound assessment of brachial artery flow‐mediated vasodilation provides a noninvasive means for measuring endothelial function. The test is performed using either upper or lower arm blood pressure cuff arterial occlusion to induce hyperemia. Upper arm occlusion produces a greater hyperemic stimulus. Brachial artery flow‐mediated vasodilation is abnormal in the presence of coronary risk factors.Hypothesis: The study sought to compare the ability of the upper and lower arm occlusion techniques to differentiate endothelial function in subjects with and without risk factors.Methods: We measured brachial artery flow‐mediated vasodilation in 20 subjects, 10 without and 10 with a single risk factor (hypertension, hypercholesterolemia, or cigarette smoking) using both the upper and lower arm occlusion techniques (5 min blood pressure cuff occlusion). Using 11 MHz ultrasound, Doppler blood flow velocities were measured before and immediately after cuff deflation. Brachial artery vasodilation was measured 1 min after cuff deflation, compared with baseline, and expressed as a percent increase.Results: The immediately postocclusion hyperemia (% increase in flow) was significantly greater (p<0.01) using the upper versus the lower arm technique in both the normal (530 ± 152 vs. 383 ± 51 %) and the risk factor (583 ± 153 vs. 409 ± 114%) groups. Row‐mediated vasodilation was significantly greater (p < 0.01) using the upper arm versus the lower arm occlusion technique in both the normal (13.4 ± 5.3 vs. 5.6 ± 3.4%) and risk factor (7.9 ± 3.6 vs. 3.9 ± 2.2%) groups. Vasodilation was significantly greater (p < 0.01) in the normal subjects than in the risk factor subjects (13.4 ± 5.3 vs. 7.9 ± 3.6%) using the upper arm technique, but was not statistically different in the two groups using the lower arm technique.Conclusions: Our study demonstrates that upper arm compared with lower arm cuff occlusion undertaken to induce hyperemia for the assessment of brachial artery flow‐mediated vasodilation results in significantly greater hyperemia and vasodilation. Flow‐mediated vasodilation obtained using the upper arm technique better separates subjects with and without coronary risk factors.
Clinical and nonclinical correlates of racial and ethnic differences in recommendation patterns for coronary revascularization
Authors: Barnhart J. Marie , Wassertheil‐Smoller Sylvia , Monrad E. Scott 
Published: February 2009

AbstractBackground: We sought to determine whether gender or racial differences exist in recommendations for coronary revascularization in a multiracial patient population undergoing their first coronary angiography at an academic institution from 1990–1993 for the evaluation of coronary artery disease (CAD).Hypothesis: For patients with clinically significant CAD, no racial differences exist in the recommendation to revascularization following coronary angiography.Methods: The main outcome measure was a recommendation for coronary revascularization such as percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass graft (CABG) for patients with clinically significant CAD (n = 590). The primary multiple logistic regression analysis focused on only those patients with angiographically severe disease, defined as triple‐vessel or left main CAD (n = 180). Race was trichotomized into Hispanic, black, and white to ascertain whether any differential effects of race/ethnicity existed while controlling for age, gender, ejection fraction, angina, diabetes, hypertension, and peripheral vascular disease. A medical record review for all patients with severe CAD, who were given a recommendation for medical therapy, was conducted to ascertain whether previously unmeasured clinical factors or nonclinical factors may have precluded a PTCA/CABG recommendation.Results: Hispanics with severe disease were significantly less likely than whites to be given a recommendation for PTCA/CABG following angiography [odds ratio (OR) = 0.39; 95% confidence interval (CI) (0.17,0.92)]. Blacks were 67% as likely as whites to be given such a recommendation [OR=0.67; 95% CI (0.17,2.71)]. Medical records, reviewed for 35 of 40 of these patients given a recommendation for medical therapy, revealed that 6 patients eventually had PTCA/CABG within 6 months due to precipitating ischemic events; 9 had such severe or diffuse disease that revascularization did not appear to be an alternative, and 2 patients opted for medical therapy.Conclusions: Racial differences were manifested in the recommendations made following angiography and may be explained by previously unmeasured clinical as well as nonclinical factors.