Guidelines on the management of stable angina pectoris.
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Biomedical subjects
Publications and source records attributed to Emmanuel I Skalidis.
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OBJECTIVES: To assess atrial fibrillation (AF) associated differences in proinflammatory cytokines, natriuretic peptide levels and exercise capacity in patients with heart failure (HF) secondary to non-ischemic dilated cardiomyopathy (NIDC). METHODS: We studied 147 NIDC patients, mean age 58.3+/-12.5 years, left ventricular (LV) ejection fraction 27.8+/-10.9% and NYHA class II-III. Neurohumoral activation was assessed by measurement of interleukin IL-1, IL-6, tumor necrosis factor-a (TNF-a), its soluble receptors sTNFR I and II, N-terminal atrial (NT-ANP) and -brain (NT-BNP) natriuretic peptide levels, and functional class was assessed by cardiopulmonary exercise test. RESULTS: Forty patients (27.5%) had chronic AF and they did not differ in age, LV ejection fraction or HF duration compared to patients in sinus rhythm (SR). AF was associated with increased levels of IL-6 (p=0.001), TNF-a (p=0.002), sTNFRI (p=0.023), NT-ANP (p<0.001) and NT-BNP (p=0.003), decreased exercise duration (p<0.001) and slightly reduced maximal oxygen consumption at peak exercise (p=0.07) compared to SR patients. No significant differences in cytokine and natriuretic peptide levels or exercise tolerance were noted when patients in AF were compared to the subgroup of SR with restrictive LV filling pattern. Multivariate analysis showed that NT-ANP (p=0.003) and IL-6 (p=0.006) plasma levels were independently associated with the presence of AF in our patient population. CONCLUSION: AF is associated with increased inflammatory state, natriuretic peptide levels and reduced exercise capacity in patients with HF secondary to NIDC. These findings suggest that the presence of AF in HF represents a more advanced stage of the syndrome.
Stent implantation causes significant injury to the vascular wall, resulting in inflammatory activation. Although sirolimus-eluting stents (SES) have anti-inflammatory properties, their effect on periprocedural systemic inflammatory response has not been sufficiently investigated. Eighty-one patients with stable coronary artery disease involving severe stenosis of one major epicardial coronary artery underwent coronary angioplasty with stent implantation and randomly received either SES or bare metal stents (BMS). Blood samples were taken 24h before, at 24h, 48 h and 1 month after the angioplasty and levels of high sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6), interleukin-1 beta (IL-1 beta), and monocyte chemoattractant protein-1 (MCP-1) were determined. HsCRP after BMS implantation increased over 24h (p<0.001) and then remained steady, as did IL-6 and IL-1 beta similarly. In contrast, their levels in SES patients decreased to below baseline by the end of the month. MCP-1 levels increased by the end of 1 month (p<0.001) in the BMS group, whereas in SES they steadily decreased, becoming significantly lower than baseline from 48 h (p=0.015). In conclusion, patients with SES exhibit an attenuation of the postprocedural systemic inflammatory activation during a 1-month follow-up after stent implantation. This might partially explain the reduced restenosis rate associated with SES.
In 12 patients we assessed the effect of inhaled salbutamol on the coronary circulation. According to our results, large doses of salbutamol increase coronary flow, but not in proportion to the needs of the myocardium (as documented by the increase in coronary oxygen extraction), and decrease coronary flow reserve. These effects may have deleterious consequences in patients with coronary artery disease, causing or worsening myocardial ischemia.
OBJECTIVES: The purpose of this study was to assess regional coronary flow and contractile reserve in patients with idiopathic dilated cardiomyopathy (IDCM). BACKGROUND: Although IDCM has been associated with alterations in coronary blood flow and contractile reserve, little is known about their regional distribution and correlation. METHODS: Fourteen patients with IDCM and 11 control subjects underwent coronary flow velocity (APV) measurements in the left anterior descending (LAD), left circumflex (LCx), and right coronary (RCA) arteries at baseline (b) and at maximal hyperemia (h). Coronary flow reserve (CFR) was defined as h-APV/b-APV. Wall thickening was assessed in 16 segments (7 assigned to LAD, 5 to LCx, and 4 to RCA) both at rest and under peak stress during low-dose dobutamine echocardiography. Regional contractile reserve was defined as the percentage difference in wall motion score index between rest and stress in each vascular territory. RESULTS: Although there were no significant differences in b-APV, patients with IDCM had significantly lower h-APV than controls in all three vascular territories and reduced CFR (LAD: 2.79 +/- 0.43 vs. 3.48 +/- 0.51, p < 0.05; LCx: 2.71 +/- 0.39 vs. 3.36 +/- 0.65, p < 0.05; and RCA: 3.43 +/- 0.55 vs. 4.02 +/- 0.73, p < 0.05). There was also a significant correlation between CFR and the corresponding contractile reserve in the vascular territory of the LAD (r = 0.75, p = 0.002) and the LCx (r = 0.64, p = 0.014). CONCLUSIONS: Patients with IDCM have alterations in regional coronary flow and reduced CFR. Furthermore, the correlation between regional CFR and the corresponding contractile reserve indicates that microvascular dysfunction may have a pathophysiologic role in the evolution of the disease.
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OBJECTIVES: The purpose of this study was to assess rest and stress atrial coronary blood flow (CBF) velocity and flow reserve. BACKGROUND: Because of the limitations of the methods used until now for assessing myocardial perfusion (MP) in the small mass of atrial tissue, data are lacking for human atrial MP. METHODS: Seventeen patients with suitable coronary anatomy underwent CBF velocity measurements with the use of a Doppler guide wire in the proximal left circumflex coronary artery (LCx) and left atrial circumflex branch (LACB), at baseline and after adenosine administration. All measurements were performed at resting heart rate and at 100 and 120 beats/min. RESULTS: Coronary blood flow velocity in the LACB showed a predominant systolic pattern in contrast to the diastolic pattern of the LCx. There was a disproportionate increase in baseline time-averaged peak coronary flow velocity (cm/s) between the LACB and LCx during the two levels of pacing-induced stress (16.8 +/- 5.5 vs. 16.2 +/- 5.1 at rest; 22.9 +/- 7.9 vs. 18.4 +/- 5.2 at 100 beats/min; and 27.1 +/- 8.0 vs. 20.4 +/- 5.1 at 120 beats/min; significant interaction, p < 0.001), but there were no significant differences in coronary flow reserve (CFR). CONCLUSIONS: Coronary blood flow in the left atrium is out of phase with that in the ventricular myocardium, showing a predominant systolic pattern. Although atrial and ventricular CFR show no significant differences at rest and with two levels of stress, the disproportionate increase in atrial blood flow velocity during stress indicates a peculiarity of atrial perfusion regulation.
INTRODUCTION: Patients with persistent atrial fibrillation (AF) have hemodynamic changes, which impair endothelial cell function resulting in decreased nitric oxide (NO) production. The aim of this work was to assess endothelial function in AF patients before and at various time points after cardioversion. METHODS: Forty-two patients with AF and 21 normal and age-adjusted healthy controls were studied. Nitrites and nitrates (NO(x)) and von Willebrand factor (vWf) concentrations were measured on blood samples taken just before cardioversion and over a 30 day period after the procedure. RESULTS: Plasma levels of NO(x) in AF were significantly lower compared to healthy controls (p < 0.001), but after cardioversion gradually increased to approach to those of the healthy controls by the end of the first month of sustained sinus rhythm (p = 0.004). Interestingly plasma levels of NO(x) were negatively correlated to left atrial volume measured by ultrasonography (r = -0.34, p < 0.05). Plasma levels of vWf in AF patients were significantly higher compared to the healthy controls (p < 0.01) but with sustained sinus rhythm decreased (p = 0.02). CONCLUSION: The parallel normalization of the NO(x) titers and vWf levels suggests that vascular endothelial function improves after 30 days of normal sinus rhythm.
This study evaluated the possibility of diagnosing chronic myocardial infarction in the presence of the pacing electrocardiogram. Forty-five patients with known myocardial infarction (anterior 23, inferior 22) and 26 healthy controls were studied. After coronary angiography, pacing was applied from the right ventricular apex, and the sensitivity, specificity, and average diagnostic accuracy of five criteria on the paced electrocardiogram were assessed: (1) Notching 0.04 second in duration in the ascending limb of the S wave of leads V3, V4, or V5 (Cabrera's sign); (2) Notching of the upstroke of the R wave in leads I, aVL, or V6 (Chapman's sign); (3) Q waves > 0.03 second in duration in leads I, aVL, or V6; (4) Notching of the first 0.04 second of the QRS complex in leads II, III, and aVF; (5) Q wave > 0.03 second in duration in leads II, III, and aVF. The most sensitive criteria, for anterior and inferior myocardial infarctions were Cabrera's and Chapman's (91.1 and 86.6%, respectively). All criteria had low specificity (range 42.3-69.2%). The combination of Cabrera's and Chapman's sign decreased the sensitivity to 77.7%, but increased specificity to 82.2%. The sensitivity and specificity of all the criteria were independent of the myocardial infarction site. In paced patients, the application of electrocardiographic criteria, and especially the combination of Cabrera and Chapman, provides useful clinical information in recognizing prior myocardial infarction but not in assigning the specific infarct site.
STUDY OBJECTIVE: Doppler-derived myocardial performance index (MPI), a measure of combined systolic and diastolic myocardial performance, was assessed at rest and after low-dose dobutamine administration in patients with idiopathic or ischemic dilated cardiomyopathy. MPI also was correlated with other conventional echocardiographic indexes of left ventricular (LV) function, and its ability to assess cardiopulmonary exercise capacity in those patients was investigated. SETTINGS: A tertiary-care, university heart failure clinic. PATIENTS: Forty-two consecutive patients (27 men; mean [+/- SD] age, 57 +/- 10 years) with heart failure (New York Heart Association [NYHA] class, II to IV) who had received echocardiographic diagnoses of dilated cardiomyopathy. Coronary angiography distinguished the cause of dilated cardiomyopathy. INTERVENTIONS: Low-dose IV dobutamine was infused after patients underwent a baseline echocardiographic study. All patients also underwent a cardiopulmonary exercise test using a modified Naughton protocol. RESULTS: Advanced NYHA class and restrictive LV filling pattern were associated with higher index values. A negative correlation was found between MPI and LV stroke volume, cardiac output, early filling/late filling velocity ratio, and late LV filling velocity, as well as oxygen uptake at peak exercise (r = -0.550; p < 0.001) and at the anaerobic threshold (r = -0.490; p = 0.002). Dobutamine administration produced an improvement in MPI, reducing its value and decreasing the isovolumic relaxation and contraction times. Stepwise regression analysis revealed that the rest index and the late LV filling velocity were the only independent predictors of cardiopulmonary exercise capacity. CONCLUSION: MPI correlates inversely with LV performance, reflects disease severity, and is a useful complimentary variable in the assessment of cardiopulmonary exercise performance in patients with heart failure.
A case of congenital absence of the left pulmonary artery, in which perfusion of the affected lung was accomplished via an arterial shunt from the circumflex coronary artery, is discussed. Data from myocardial perfusion scintigraphy showed that myocardial perfusion was unaffected by the existence of the shunt, largely because the flow through the shunt occurred mainly during systole.
The case is described of a man aged 51 years who, one hour after a coronary angiographic examination that showed coronary arteries without lesions, suffered an acute inferior myocardial infarction as the result of an acute allergic reaction, probably to the iodinated contrast agent that was used. Acute myocardial infarction following an allergy is an extremely rare clinical entity that, according to existing data, is due to the local release of vasoconstrictive substances as a result of the allergic reaction.
We describe the case of a male patient, aged 62 years, with acute myocardial infarction, who underwent primary angioplasty using a new thrombus aspiration catheter in conjunction with the conventional technique. This catheter is easier to use than similar devices available to date and is extremely effective in the removal of large intracoronary thrombi, thus providing protection against distal embolism during angioplasty procedures.
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