Biomedical subjects

J L Delcán

Publications and source records attributed to J L Delcán.

At least 19 recordsLinked to original sources

PubMed2001

Quantification of myocardial perfusion using contrast echocardiography: methodological basis of image postprocessing.

Intravenous contrast agents have provided the opportunity to clinically assess myocardial perfusion using ultrasound. In perfusion echocardiography, obtaining maximal diagnostic information requires the use of digital image postprocessing techniques, since subjective visual interpretation can be frequently inaccurate. Prior research using other intravascular tracers such as radioactive microspheres provides the theoretical basis for perfusion analysis that can be readily implemented to contrast echocardiography. Aspects of digital videodensitometric quantification, fitting to gamma-variable mathematical wash-in/wash-out functions and parameter analysis have been well validated for other tracers and have demonstrated excellent applicability in contrast echo. Currently available scanner technologies provide with a number of image-acquisition modalities, from standard continuous to intermittent-triggered images that require specific postprocessing algorithms. The present paper reviews the basis of temporal and spatial contrast postprocessing. The issues of image registration, background subtraction, videointensity measurement and mathematical function fitting are also discussed. This theoretical background should be helpful to understand the general aspects of currently available and future systems of perfusion densitometric systems.

Coronary Circulation↗

PubMed2000

Predictors of left atrial spontaneous echo contrast and thrombi in patients with mitral stenosis and atrial fibrillation.

The purpose of this study was to investigate the independent factors associated with the presence of left atrial (LA) spontaneous echo contrast (SEC) and thromboembolic events in patients with mitral stenosis (MS) in chronic atrial fibrillation (AF). Factors independently associated with LASEC, thrombi, and embolic events have been mainly investigated in patients with nonvalvular AF or inhomogeneous populations with rheumatic heart disease. Transesophageal and transthoracic echo studies were performed in 129 patients with MS in chronic AF. Previous embolic events were documented in 45 patients, 20 of them within 6 months, and 65 patients were receiving long-term anticoagulation. The intensity of LASEC and mitral regurgitation, the presence of thrombi and active LA appendage flow (peak velocities > or = 20 cm/s), and LA volume as well as other conventional echo-Doppler determinations were investigated in every patient. The prevalences of significant LASEC (degrees 3+ and 4+), thrombus, active LA appendage flow, and significant mitral regurgitation (>2+) were: 52% (67 patients), 29.5% (38 patients), 32% (41 patients), and 36% (47 patients), respectively. Multivariate analysis showed that decreasing mitral regurgitation severity, absence of active LA appendage flow, and mitral valve area were the independent correlates of LASEC (odds ratio [OR] 3.7, 5.4, and 0.17, respectively; all p <0.02). Active LA appendage flow and anticoagulant therapy were associated negatively, whereas the severity of LASEC was associated positively with the finding of LA thrombus (OR 9.6, 3.9, and 1.6, respectively; all p <0.05). The intensity of LASEC and previous anticoagulant therapy (OR 1.74 and 4.5, respectively; p <0.005) were the independent covariates of thrombi and/or recent embolic events. In conclusion, the severity of mitral regurgitation and lack of active LA appendage flow were, respectively, the strongest independent correlates of significant LASEC and thrombus in patients with MS in chronic AF. LASEC remains the cardiac factor most strongly associated with thrombus and/or recent embolic events in these patients.

Atrial Appendage↗

PubMed2000

Frequency of left ventricular free-wall rupture in patients with acute myocardial infarction treated with primary angioplasty.

A total of 590 patients with myocardial infarction treated with primary angioplasty were studied, to assess the incidence and related factors of free-wall rupture in patients with acute myocardial infarction when treated with primary angioplasty. The incidence of free-wall rupture was 2.2% (13 patients); this incidence was higher in patients >65 years old, women, nonsmokers, as well as in those with anterior location and an initial TIMI grade 0 flow, but it was similar in patients with a successful or unsuccessful angiographic result.

Angioplasty, Balloon, Coronary↗

PubMed2000

Flow dynamics of stenotic aortic valves assessed by signal processing of Doppler spectrograms.

Clinical assessment of aortic stenosis (AS) is sometimes challenging, because all hemodynamic indexes of severity are modified by flow rate. However, the mechanisms underlying flow dependence remain controversial. Analysis of instantaneous flow dynamics has provided crucial information in a number of cardiovascular disorders and may add new insight into this phenomenon. This study was designed to analyze in vivo the effects of flow interventions on instantaneous valvular dynamics of stenotic valves. For this purpose, a custom algorithm for signal processing of Doppler spectrograms was developed and validated against a control population. Digital Doppler recordings at the aortic valve and left ventricular outflow tract were obtained in 15 patients with AS, at baseline and during low-dose dobutamine infusion; 10 normal subjects were studied as controls. Spectrograms were processed by signal averaging, time alignment, modal-velocity enhancement, envelope tracing, and numerical interpolation. Instantaneous relative aortic valve area (rAVA) was obtained by the continuity equation and plotted against normalized ejection time. Curves were classified as either type A (rapid, early-systolic opening) or type B (slow, end-systolic opening). Curves from controls closely matched prior knowledge of normal valve dynamics, but curves from patients were clearly different: all controls except 2 (80%) had type A, whereas all patients except 3 (80%) had a type B pattern (p = 0.03). Dobutamine infusion in patients increased and slightly anticipated peak rAVA by accelerating valve opening. Despite similar values of area and pressure difference, type B dynamics were associated with lower blood pressure (p = 0.01) and worse long-term outcome (>3 years) than type A flow dynamics (p = 0.02). Signal processing of Doppler spectrograms allows a comprehensive assessment of aortic flow dynamics. Differences in timing of valve aperture and in maximal leaflet excursion account for flow-mediated changes in valve area, suggesting complementary effects of inertia and elasticity on the kinetics of stenotic aortic valves. Flow-dynamic analysis provides novel clinical information regarding physiology of AS unavailable to conventional indexes.

Aged↗

PubMed2000

[Results of coronary stenting in acute myocardial infarction].

OBJECTIVE: To describe the angiographic results and the in-hospital clinical outcome of patients with an acute phase of myocardial infarction treated with coronary angioplasty and stent placement. METHODS: 268 patients with myocardial infarction were treated with angioplasty and coronary stenting within in our center 12 hours after the onset of symptoms from January in 1992 to March 1998. 366 stents were placed (1.4 +/- 0.7 per patient), 35% being Palmaz-Schatz, 26% Wiktor, 21% Multi-Link and 18% others. Stenting was elective in 171 patients (64%), and the majority of patients (91%) were treated with aspirin plus ticlopidine. RESULTS: A successful angiographic result was achieved in 258 patients (96%). Minimum lumen diameter was increased from 0.2 +/- 0.3 to 2.7 +/- 0.7 mm (p < 0.001), and stenosis decreased from 94 +/- 8% to 13 +/- 11% (p < 0.001). Mortality was 15.3% (3.2%, 24.4% and 67.7% in patients in Killip class I, II-III and IV, respectively). Nonfatal reinfarction and recurrent ischemia rates were 2.6% and 9%, respectively. Stent thrombosis occurred in 8 patients (3.0%), and new target vessel revascularization was needed in 12 (4.5%). CONCLUSIONS: Stent placement in acute myocardial infarction is associated with high angiographic success rate, as well as a good in-hospital outcome. Mortality is localized, especially in patients with cardiac failure at the beginning of the procedure.

Aged↗

PubMed2000

[Coronary angioplasty in the acute myocardial infarction: in which patients is it less likely to obtain an adequate coronary reperfusion?].

INTRODUCTION: In patients with acute myocardial infarction treated with primary angioplasty, the inability to achieve successful coronary reperfusion is associated with higher mortality. The objective of the study was to identify which characteristics may predict a lower angiographic success rate in patients with acute myocardial infarction treated with coronary angioplasty. PATIENTS AND METHODS: The study population is constituted by the 790 patients with acute myocardial infarction that were treated with angioplasty within the 12 hours after the onset of symptoms from 1991 to 1999 at our institution. A successful angiographic result was considered in presence of a residual stenosis < 50% and a TIMI flow 2 or 3 after the procedure. RESULTS: A successful angiographic result and a final TIMI 3 flow were achieved in 736 (93.2%) and 652 (82.5%) patients, respectively. In-hospital mortality was higher in patients with angiographic failure than in those with angiographic successful result (48 vs. 10%; p < 0.01). Age under 65 (91 vs. 95%; p = 0.02), non smoking (90 vs. 96%; p < 0,01), previous infarction (87 vs. 94%; p < 0.01), angioplasty after failed thrombolysis (83 vs. 94%; p = 0. 02), cardiogenic shock (80 vs. 95%; p < 0.01), undetermined location (67 vs. 93%; p < 0.01), non-inferior location (92 vs. 96%; p = 0.04), left bundle branch block (64 vs. 94%; p < 0.01), multivessel disease (91 vs. 95%; p = 0.02), left ventricular ejection fraction < 0.40 (89 vs. 97%; p < 0.01), no utilization of coronary stenting (90 vs. 96%; p < 0.01), and use of intraaortic balloon counterpulsation pump (82 vs. 95%; p < 0.01) were associated with a lower angiographic success rate. In the multivariable analysis, the following were independent predictors for angiographic failure: left bundle branch block (odds ratio [OR], 12.95; CI 95%, 3.00-53.90), cardiogenic shock (OR, 4.20; CI 95%, 1.95-8.75), no utilization of coronary stent (OR, 3.44; CI 95%, 1.71-7.37), and previous infarction (OR, 2.82; CI 95%, 1.29-5.90). CONCLUSIONS: Coronary angioplasty allows a successful coronary recanalization in most patients with acute myocardial infarction. Some basic characteristics, however, may identify some subsets in which a successful angiographic result may be more difficult to obtain.

Acute Disease↗

PubMed2000

[Usefulness of the new imaging techniques, second harmonic and contrast in endocardial border visualization. Reliability analysis in segmental contraction assessment].

AIM: This study sought to determine if newer techniques significantly improve endocardial border definition in suboptimal acoustic windows, and the reproducibility of the evaluation of wall motion abnormalities according to the different techniques and degrees of expertise. METHODS: We studied a total of 20 consecutive patients with poor ultrasound window, to assess, if the use of tissue harmonic imaging (2H) or contrast with second harmonic (Levovist ; 4 g i.v.), (2HC) improves endocardial border visualization. In order to analyze inter and intraobserver reliability with the different techniques, four observers with different degrees of expertise were each asked to assess the segmental wall motion score of 31 consecutive echocardiograms. RESULTS: The quality of the image was clearly superior with 2H and 2HC compared with 2D. This difference was larger in apex and lateral endocardial border from 0.9 and 1 to 1.5 and 1.64 (p < 0.001) with 2H. 2HC was found to slightly but significantly improve the endocardial definition in apex compared with 2H (1.64 vs 1.81; p = 0.016). The percentage of segments assessed for interobserver variability significantly improve with 2H and 2HC (2D = 50%, 2H = 75% and 2HC = 95%). Interobserver agreement with the different techniques between the experienced observers did not statistically differ. The less experienced observer presented a significantly lower interobserver reliability than those with experience, and did not improve with 2H and 2HC. CONCLUSIONS: a) Native tissue harmonic imaging and second harmonic imaging with contrast (Levovist ) significantly improves endocardial border visualization; b) the newer imaging techniques significantly improve performance (percentage of evaluated segments) without decreasing reliability, and c) experience in assessing wall motion is the main factor in interobserver agreement.

Echocardiography↗

PubMed2000

Echocardiographic features of left atrial dissection.

AIMS: To study left atrial dissection, a rare complication of mitral valve replacement. METHODS AND RESULTS: From our hospital database of 5497 transoesophageal echocardiograms, we analysed 524 echocardiograms performed on 478 patients with mitral valve prosthesis. We found four patients (0.84%) with left atrial dissection diagnosed by transoesophageal echocardiography that visualized the left atrial dissection: in three patients the diagnosis was confirmed intraoperatively. Three patients had previously had replacements of the mitral valve. Left atrial dissection was a severe complication: one patient died and the two patients successfully operated on had paraprosthetic regurgitation. CONCLUSION: Transoesophageal echocardiography is the first choice for diagnosis of left atrial dissection, a rare complication of mitral valve replacement with an acute/subacute clinical course. Previous mitral valve replacement seems to be the main risk factor to develop left atrial dissection.

Aged↗

PubMed2000

[Percutaneous closure of atrial septal defects: midterm results of a new therapeutic strategy].

OBJECTIVE: To evaluate the midterm results of percutaneous closure of the atrial septal defect using two new devices. PATIENTS AND METHODS: Nine children (weight 19.7 +/- 7 kg, age 5.1 +/- 1.9 years) underwent percutaneous type II atrial septal defect closure through the antegrade pathway under general anaesthesia, and monitored by transesophageal echocardiography. The closing devices used were DAS-Angel Wings and Ampaltzer. RESULTS: The hemodynamic results were: mean diameter of the defects was 11.4 +/- 2 mm by TEE measurement and 12.3 +/- 2.6 mm using balloon occlusion reference. Mean pulmonary artery pressure was 12.7 +/- 2 mmHg and mean pulmonary vascular resistance 1.5 +/- 0.5 U/m2. A total of 13 devices were used: 9 Amplatzer and 4 DAS-Angel Wings. Four Amplatzer through the introducer were retrieved without complications. Two of which because of lack of sufficient stability in the atrial septum because they were too small inappropriate and the other two because of inappropriate expansion of distal disk of the device. Finally in all patients the device was a successfully deployed. The angiographic evaluation immediate post-procedure showed a minimal shunt in five patients that was no longer present by color Doppler echocardiography 24 hours later. The children were discharged 38 +/- 12 hours after the procedure and at a mean follow up of 9.6 +/- 2.2 months they remain asymptomatic without any clinical or technical problems. CONCLUSION: With the right selection of patients percutaneous closure of atrial septal defects can obtain a very high success rate without complications.

Cardiac Catheterization↗

PubMed2000

[Management of unstable angina: advanced age is still an independent predictive factor of more conservative management after prognostic stratification with stress test].

BACKGROUND AND OBJECTIVE: In the management of ischemic heart disease, elderly patients constitute a subgroup that, despite having a worse prognosis, are usually managed more conservatively. The objective of this study was to evaluate if, in the management of unstable angina, a more conservative attitude in elderly patients is maintained after stratification by exercise test. PATIENTS AND METHODS: The study population is constitude by 859 patients admitted to hospital due to suspected unstable angina that were referred to exercise test after medical stabilization. The management (invasive versus conservative, according to submission to cardiac catheterization or not) of patients was retrospectively studied, comparing patients < or = 70 versus > 70 years-of age. RESULTS: Out of the 859 patients, 156 (18%) were > 70 years old, and the exercise test was positive in 281 (33%). Cardiac catheterization was performed in 494 (57%): 62% in older and 38% in younger patients (p < 0.0001). Other characteristics associated with a more conservative management were: a negative exercise test, > 85% of the maximum heart rate, duration of exercise test more than 6 minutes, female gender, smoking and absence of episodes of rest angina. In the multivariate analysis, the statistically significant characteristics associated with an invasive management were the result of the exercise test (OR for positive result: 4.50; IC 95% = 2.73-7.63; p < 0.0001), the duration of exercise (OR for > or = 6 minutes: 0.51; IC 95% = 0.29-0.88; p = 0.0177), the percentage of the maximum heart rate (OR for > or = 85%: 0.65; IC 95% = 0.42-0.98; p = 0.0391) and age (OR for > 70 years 0.36; IC 95% = 0.20-0.62; p = 0.0004). CONCLUSIONS: In the management of unstable angina, elderly patients constitute a more conservatively managed subgroup even after risk stratification with exercise test.

Age Factors↗

PubMed1999

Rate-dependent conduction block of the crista terminalis in patients with typical atrial flutter: influence on evaluation of cavotricuspid isthmus conduction block.

BACKGROUND: The crista terminalis (CT) has been identified as the posterior boundary of typical atrial flutter (AFL) in the lateral wall (LW) of the right atrium (RA). To study conduction properties across the CT, rapid pacing was performed at both sides of the CT after bidirectional conduction block was achieved in the cavotricuspid isthmus by radiofrequency catheter ablation. METHODS AND RESULTS: In 22 patients (aged 61+/-7 years) with AFL (cycle length, 234+/-23 ms), CT was identified during AFL by double electrograms recorded between the LW and posterior wall (PW). After the ablation procedure, decremental pacing trains were delivered from 600 ms to 2-to-1 local capture at the LW and PW or coronary sinus ostium (CSO). At least 5 bipolar electrograms were recorded along the CT from the high to the low atrium next to the inferior vena cava. No double electrograms were recorded during sinus rhythm in that area. Complete transversal conduction block all along the CT (detected by the appearance of double electrograms at all recording sites and craniocaudal activation sequence on the side opposite to the pacing site) was observed in all patients during pacing from the PW or CSO (cycle length, 334+/-136 ms), but it was fixed in only 4 patients. During pacing from the LW, complete block appeared at a shorter pacing cycle length (281+/-125 ms; P<0.01) and was fixed in 2 patients. In 3 patients, complete block was not achieved. CONCLUSIONS: These data suggest the presence of rate-dependent transversal conduction block at the crista terminalis in patients with typical AFL. Block is usually observed at longer pacing cycle lengths with PW pacing than with LW pacing. This difference may be a critical determinant of the counterclockwise rotation of typical AFL.

Aged↗

PubMed1999

Efficacy of invasive strategy for the management of acute myocardial infarction complicated by cardiogenic shock.

This retrospective study evaluates the influence of an invasive strategy of urgent coronary revascularization on the in-hospital mortality of patients with acute myocardial infarction (AMI) complicated early by cardiogenic shock. Among 1,981 patients with AMI admitted to our institution from 1994 to 1997, 162 patients (8.2%) developed cardiogenic shock unrelated to mechanical complications. The strategy of management was considered invasive if an urgent coronary angiography was indicated within 24 hours of symptom onset. Every other strategy was considered conservative. Fifty-seven patients who developed the shock late or after a revascularization procedure, or who died on admission, were excluded. The strategy was invasive in 73 patients (70%). Five of them died before angiography could be performed and 65 underwent angioplasty (success rate 72%). By univariate analysis the invasive strategy was associated with a lower mortality than conservative strategy (71% vs 91%, p = 0.03), but this association disappeared after adjustment for baseline characteristics. Older age, nonsmoking, and previous ischemic heart disease were independent predictors of mortality. In conclusion, we have failed to demonstrate that a strategy of urgent coronary revascularization within 24 hours of symptom onset for patients with AMI complicated by cardiogenic shock is independently associated with a lower in-hospital mortality. This strategy was limited by the high mortality within 1 hour of admission in patients with cardiogenic shock, the modest success rate of angioplasty in this setting, and the powerful influence of some adverse baseline characteristics on prognosis.

Aged↗

PubMed1999

Coronary stenting during rescue angioplasty after failed thrombolysis.

Compared with primary angioplasty [percutaneous transluminal coronary angioplasty (PTCA)], rescue PTCA is associated with lower angiographic success and higher reocclusion rates, especially after thrombolysis with tissue-type plasminogen activator (tPA). Although stent placement during primary PTCA has been demonstrated to be safe and even to improve the angiographic results achieved by balloon-alone PTCA, there are few data on stent placement during rescue PTCA after failed thrombolysis. This study sought to assess the feasibility and safety of stent implantation during rescue angioplasty in myocardial infarction after failed thrombolysis. The study population consisted of 20 patients with acute myocardial infarction referred for rescue PTCA after failed thrombolysis consecutively treated with coronary stenting. The thrombolytic agent was tPA in 15 patients (75%), streptokinase in 1 (5%), and anisoylated streptokinase plasminogen activator complex (APSAC) in 1 (5%); 3 patients (15%) were included in the INTIME II study (tPA vs. lanoteplase). After stenting, aspirin 200 mg daily plus ticlopidine 250 mg b.i.d. were administered. Thirty stents (1.5+/-1.0 per patient) were implanted. Angiographic success was achieved in 19 patients (95%). Two patients (10%) died, both because of severe bleeding complications. One patient (5%) suffered a reinfarction, but no patients suffered postinfarction angina or needed new target vessel revascularization. Eighteen patients (90%) were discharged alive and free of events. All these patients remained asymptomatic and free of target vessel revascularization at 6-month follow-up. Stent placement during rescue PTCA after failed thrombolysis is feasible and safe and is associated with a good angiographic result and clinical outcome. Bleeding complications seem to be, however, the main limitation of this reperfusion strategy.

Aged↗

PubMed1999

[Internal cardioversion with low-energy shocks in atrial fibrillation resistant to external electric cardioversion].

BACKGROUND AND OBJECTIVE: Although external electrical cardioversion is effective in most patients with atrial fibrillation, there are cases refractory to external cardioversion. This study is aimed at showing our initial experience with an internal cardioversion system in patients with previous unsuccessful external cardioversion. PATIENTS AND METHODS: Between February, 1997 and September, 1998 nine consecutive patients with spontaneous chronic or persistent atrial fibrillation that failed external cardioversion, were included. Internal cardioversion was performed under sedation with two electrodes that had a 5.5 cm coil placed in the lateral right atrium and coronary sinus. Both electrodes were connected to an external defibrillator capable of delivering R-wave synchronized low-energy biphasic shocks following a minimum RR interval of 500 ms. Energy between 2 J and 10 J was applied until the restoration of sinus rhythm or a maximum of 2 shocks of 10 J. RESULTS: Sinus rhythm was achieved in the nine patients, but in two of them atrial fibrillation recurred after a few beats. Both had underlying structural heart disease. The other 7 patients, 5 of them without structural heart disease, were in sinus rhythm at discharge. No mechanic complications or ventricular arrhythmias were observed. Six patients are in sinus rhythm after 4 +/- 3 months of follow-up. CONCLUSIONS: Low-energy intracardiac cardioversion is useful in some patients with atrial fibrillation that had failed external cardioversion and can be performed without general anesthesia.

Adult↗

PubMed1999

[Radiofrequency ablation of ventricular tachycardia in patients with ischemic cardiopathy].

PURPOSE: We analyze the efficacy of radiofrequency catheter ablation and the clinical significance of inducible ventricular tachycardia that had never been documented before (non clinical ventricular tachycardia) in patients with ventricular tachycardia and coronary artery disease. METHODS: Thirty-four patients (30 men, aged 61 +/- 10 years, left ventricular ejection fraction 31 +/- 10%) with coronary artery disease and documented clinical ventricular tachycardia underwent radiofrequency ablation. Thirty-four clinical ventricular tachycardia and 11 non clinical ventricular tachycardia were treated with radiofrequency. Initial therapeutic success was considered when none of the ventricular tachycardia treated with radiofrequency could no longer be induced at the last stimulation protocol before discharge. RESULTS: Clinical ventricular tachycardia was successfully ablated in 23 patients (68%). Initial therapeutic success was obtained in 21 patients (62%). In 6 of them, 7 non clinical ventricular tachycardia poor tolerated were also induced. During a mean follow-up of 26 +/- 15 months ventricular tachycardia recurred in 6 patients (29%). Five of the 6 patients who recurred were discharged with no inducible non clinical ventricular tachycardia. Three patients died during the follow-up. Two of them from heart failure (one with previous recurrence) and the other suddenly with documented asystole after loss of consciousness without previous recurrence. CONCLUSIONS: In our series of patients with ventricular tachycardia and coronary artery disease selected for radiofrequency ablation, acute success was obtained in 62%. After a mean follow-up of 2 years, 44% of all the patients were free from ventricular tachycardia. Although the possibility of ventricular tachycardia recurrence is high (29%), the recurrence rate is not increased by the inducibility of non clinical ventricular tachycardia.

Aged↗

PubMed1999

[The Doppler color detection of internal mammary artery anastomoses and a functional assessment of their patency].

BACKGROUND: Left internal mammary artery coronary graft patency is usually evaluated invasively by cardiac catheterization. The objective of this study was to assess the ability of a high-frequency transthoracic Doppler echocardiographic system in the evaluation of patency and flow velocities changes in left internal mammary artery. METHODS: Twenty-two patients (63 +/- 9 years, 17 male) who had previously undergone left internal mammary artery to left anterior descending artery were evaluated by transthoracic echocardiography, with an Acuson Sequoia C256 equipment (Acuson, Mountain view, USA), placing the transducer (5 MHz) in the second-third left intercostal space. Left internal mammary artery flow was considered to be found in the presence of one systolic/diastolic biphasic blood flow. Dipiridamol 0.5 mg/kg was administered in absence of contraindications in order to evaluate the flow reserve. RESULTS: In 16 patients (73%), a biphasic systolic-diastolic flow was visualized. Peak velocity of systolic and diastolic waves was 38 +/- 13 and 37 +/- 15 cm/s, respectively. Eleven patients received i.v. dipiridamol 0.5 mg/kg. After dipiridamol, systolic and diastolic velocities rose from 32 +/- 8 to 43 +/- 14 cm/s (p = 0.0429) and from 25 +/- 8 to 50 +/- 17 cm/s (p = 0.0002), respectively (an increasing of 33 +/- 22% and 103 +/- 46% over the baseline, respectively). CONCLUSION: This descriptive study shows that a non-invasive functional evaluation of left internal mammary artery grafts by a transthoracic approach with a high-frequency echocardiographic equipment is possible.

Aged↗

PubMed1999

[Feasibility and safety of intracoronary ultrasound. Experience of a single center].

BACKGROUND AND OBJECTIVES: Intracoronary ultrasound provides a number of advantages in the quantification and characterization of coronary stenoses with regard to contrast angiography. However, previous studies have reported a 3.5 to 11% complication rate, and a 10-30% failure rate in performing this technique. The purpose of the study is to analyze the feasibility of performing intracoronary ultrasound and the incidence of complications associated with the use of contemporary, state of the art equipment. MATERIAL AND METHODS: The feasibility of performing intracoronary ultrasound, analyzed as the percentage of successes and failures in performing the examination was reviewed, as well as the complication rate associated with the technique in all the procedures carried out between July 1, 1994 and February 29, 1996 in which intravascular ultrasound was attempted. Complications were categorized as related, non-related and uncertainly related to the ultrasound study. RESULTS: 239 vessels were studied with intravascular ultrasound in 209 procedures (74% interventional) performed on 139 patients. Ultrasound examination was feasible in all the diagnostic studies and in 96% of the interventional procedures. The major and minor procedural complication rate was 2.4 and 10.5% respectively. No major complication was related to the ultrasound examination. Three patients experienced minor complications (1.4%) related to the ultrasound study. All three complications occurred in baseline studies during interventional procedures. CONCLUSIONS: Intracoronary ultrasound is feasible and safe in the vast majority of the procedures. Improvements in smaller catheter size and design and larger operator expertise have significantly reduced the complication rate, particularly the most frequent coronary spasm so far. Complications are associated with baseline studies during interventional procedures and with less operator expertise.

Aged↗

PubMed1999

Primary angioplasty versus systemic thrombolysis in anterior myocardial infarction.

OBJECTIVES: This study compares the efficacy of primary angioplasty and systemic thrombolysis with t-PA in reducing the in-hospital mortality of patients with anterior AMI. BACKGROUND: Controversy still exists about the relative benefit of primary angioplasty over thrombolysis as treatment for AMI. METHODS: Two-hundred and twenty patients with anterior AMI were randomly assigned in our institution to primary angioplasty (109 patients) or systemic thrombolysis with accelerated t-PA (111 patients) within the first five hours from the onset of symptoms. RESULTS: Baseline characteristics were similar in both groups. Primary angioplasty was independently associated with a lower in-hospital mortality (2.8% vs. 10.8%, p = 0.02, adjusted odds ratio 0.23, 95% confidence interval 0.06 to 0.85). During hospitalization, patients treated by angioplasty had a lower frequency of postinfarction angina or positive stress test (11.9% vs. 25.2%, p = 0.01) and less frequently underwent percutaneous or surgical revascularization after the initial treatment (22.0% vs. 47.7%, p < 0.001) than did patients treated by t-PA. At six month follow-up, patients treated by angioplasty had a lower cumulative rate of death (4.6% vs. 11.7%, p = 0.05) and revascularization (31.2% vs. 55.9%, p < 0.001) than those treated by t-PA. CONCLUSIONS: In centers with an experienced and readily available interventional team, primary angioplasty is superior to t-PA for the treatment of anterior AMI.

Aged↗