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Biomedical subjects

A Politi

Publications and source records attributed to A Politi.

At least 19 recordsLinked to original sources
PubMed1999

Intermittent 6-month low-dose dobutamine infusion in severe heart failure: DICE multicenter trial.

BACKGROUND: Patients with end-stage heart failure are often refractory to maximal oral therapy, and they have high mortality rates, poor quality of life, and frequent hospitalizations with elevated health care costs. Intermittent dobutamine therapy has been suggested as an additional option in this clinical setting. METHODS AND RESULTS: Thirty-eight patients clinically stable for at least 48 hours with standard treatment, New York Heart Association (NYHA) functional class III or IV, cardiac index </=2.2 L/min/m(2), and left ventricular ejection fraction </=30% were randomly assigned to ambulatory intermittent dobutamine or optimal standard treatment. Dobutamine was infused at 2.5 microgram/kg/min with a portable pump 48 hours/week for 6 months. The primary study end point was the reduction of hospitalizations for worsening of congestive heart failure (CHF); changes in NYHA functional class, 6-minute walking test, and mortality rates were secondary end points. During the 6-month follow-up, all patients in dobutamine and control groups underwent weekly clinical visits with serum sodium and potassium measurement. Baseline characteristics were age 65 +/- 2 years, NYHA class III/IV 17/21, ejection fraction 22% +/- 1%, and cardiac index 1.89 +/- 0.1 L/min/m(2), without differences between treatment groups. Hospitalizations for all causes over a 6-month period were 17 and 11 in control and dobutamine groups; 11 of 17 and 7 of 11 were for worsening CHF. Four control patients but none in the dobutamine group had 2 or more hospitalizations for worsening of CHF. There were no significant differences in NYHA functional class and in 6-minute walking test. Three patients in the control group died and 5 in the dobutamine group died. Two patients in the dobutamine group underwent heart transplantation. Protocol was discontinued in the dobutamine group for severe ventricular arrhythmias (1 patient), infusion system failure (1 patient), and consent withdrawal (1 patient). In 3 patients in the dobutamine group, drug dose was increased to 5 microgram/kg/min because of CHF. CONCLUSIONS: Six-month intermittent low-dose dobutamine administration was well tolerated by patients with severe CHF; it did not improve the functional status and did not significantly increase the mortality rate as found with higher dobutamine doses in other studies. Hospitalizations for all causes and for worsening of CHF tended to be fewer in the dobutamine group.

Adult↗
PubMed1999

External cardioversion of atrial fibrillation: role of paddle position on technical efficacy and energy requirements.

AIM: To define the effect of defibrillator paddle position on technical success and dc shock energy requirements of external cardioversion of atrial fibrillation. METHODS: 301 patients (mean (SD) age 62 (11) years) with stable atrial fibrillation were randomly assigned to elective external cardioversion using anterolateral paddle position (ventricular apex-right infraclavicular area; group AL (151 patients)) or anteroposterior paddle position (sternal body-angle of the left scapula; group AP (150 patients)). A step up protocol was used, delivering a 3 J/kg body weight dc shock, then a 4 J/kg shock (maximum 360 J), and finally a second 4 J/kg shock using the alternative paddle location. RESULTS: The two groups were comparable for the all clinical variables evaluated. The cumulative percentage of patients successfully converted to sinus rhythm was 58% in group AL and 67% in group AP with low energy dc shock (NS); this rose to 76% in group AL and to 87% in group AP with high energy dc shock (p = 0.013). Thirty seven patients in group AL and 19 in group AP experienced dc shock with the alternative paddle position; atrial fibrillation persisted in 10/37 in group AL and in 10/19 in group AP. Mean dc shock energy requirements were lower for group AP patients than for group AL patients, at 383 (235) v 451 (287) J, p = 0.025. Arrhythmia duration was the only factor that affected the technical success of external cardioversion (successful: 281 patients, 80 (109) days; unsuccessful: 20 patients, 193 (229) days; p < 0.0001). The success rate was lower if atrial fibrillation persisted for > 6 months: 29 of 37 (78%) v 252 of 264 (95%); p = 0.0001. CONCLUSIONS: An anteroposterior defibrillator paddle position is superior to an anterolateral location with regard to technical success in external cardioversion of stable atrial fibrillation, and permits lower dc shock energy requirements. Arrhythmia duration is the only clinical variable that can limit the restoration of sinus rhythm.

Adult↗
PubMed1999

[Tracheal stenosis due to metastatic adenopathic compression from breast carcinoma].

Paratracheal lymph-nodal metastases secondary of breast cancer aren't frequent in this kind of cancer. Here is described the case of a 76-years-old woman come to our note for ingravescent dyspnoea caused by metastatic adenopathy compression of the tracheal lumen. After excluding other treatments, a tracheal stent is put on. The obstruction gets better right away, the initial severe respiratory symptoms are improved and the ventilation is almost normal.

Aged↗
PubMed1999

[Primary angioplasty in acute myocardial infarct with or without a stent implant: the experience and results at 6 months in the first 200 patients].

BACKGROUND: Although it is superior to thrombolysis, primary PTCA does have some limitations, both in hospital (recurrent ischemia and reinfarction due to reocclusion of the infarct-related artery) and at the six-month follow-up (high rate of late restenosis). Coronary stenting is a promising way of solving some of these problems, even if its use in patients with acute myocardial infarction could prove to be controversial because of intracoronary thrombus. In this study, we propose two procedural strategies in the treatment of the infarct-related artery (IRA): the search for optimal angiographic results after PTCA ("stent-like result"--SLR--with residual stenosis < or = 20%--no dissection--TIMI III flow) or intracoronary stenting when SLR was not obtained after a second inflation. METHODS AND RESULTS: From December 1995 to May 1998, 200 patients with AMI underwent direct PTCA or rescue PTCA because of failed thrombolysis. There were 143 men and 57 women, mean age 65 (range 36-84). Nineteen patients were in cardiogenic shock and 25 were in Killip class > II. Recanalization of the IRA was achieved in 196 patients (98%). In four patients, it was not possible to cross total occlusion with the guide-wire. SLR post-PTCA was achieved in 40 patients (20%). Stents were placed in 147 patients (75%), with "elective" implantation in 73 lesions because of suboptimal results after PTCA in 41, and early loss or coronary dissection with threatening occlusion in 33. In nine patients without SLR, stenting was not performed because of diffuse disease of the IRA. In-hospital complications included ten deaths (8 of 19 patients with cardiogenic shock at admission and 2 with multivessel disease and severe left ventricular dysfunction). None of the patients required emergency coronary bypass for procedural complications. One patient had a subacute thrombosis on the third day after bail-out stent implantation (re-PTCA). Five patients required elective bypass surgery to complete revascularization for multivessel disease with ten days after the surgical procedure. At the six-month follow-up, one patient had died of cardiogenic shock. Eleven (5%) patients with bail-out procedures underwent coronary bypass surgery or PTCA. Thirty-one patients (31/168) had recurrence of ischemia: 15 patients in the stent group, 11 in SLR group and 5 in the non-SLR group. Re-PTCA was performed in 20 patients, CABG in five and medical therapy in six. Other patients were angina-free at follow-up. CONCLUSIONS: Based on our experience, seeking optimal angiographic results with or without (SLR) stent implantation is a safe and effective operative approach to achieve the best procedural and clinical outcome and reduce complications in patients undergoing PTCA for AMI.

Aged↗
PubMed1999

Percutaneous transmyocardial revascularization with holmium laser in patients with refractory angina: a pilot feasibility study.

BACKGROUND: Percutaneous transluminal myocardial revascularization (PTMR) is a new procedure to improve perfusion of the ventricular wall for patients with intractable angina that is untreatable by surgery or conventional catheter-based intervention. PTMR allows the creation of myocardial channels through the controlled delivery of holmium laser energy from the ventricular chamber. Preliminary studies in animals and human subject have yielded promising results. We now report the feasibility study of PTMR using a laser delivered through a novel Eclipse system, and we present the results of this sole therapy in patients with severe coronary disease and angina refractory to maximal medical treatment angina (III-IV CCS). METHODS: Percutaneous vascular access for PTMR treatment was obtained via the femoral artery. A 9F directional catheter carrying flexible fiber optics was used with a holmium laser (Eclipse system) and was placed across the aortic valve into the left ventricle cavity to create channels with a depth of 5 mm from the endocardial surface into the myocardial tissue. From April to November 1998, 15 patients underwent PTMR with Eclipse system. Two patients were female; the mean age was 66 +/- 8 (range 59-74). Five patients had a severe LV dysfunction (FE < 30%). Preoperative angina class was III in 10 patients and IV in 5 and previous myocardial procedures had been performed in all patients. RESULTS: The procedure was well tolerated and procedural success was obtained in 14 of 15 patients. There was one myocardial perforation because of guiding-catheter manipulation (pericardial drainage in fourth day). We performed a mean of 13 +/- 4 channels in a mean fluoro time of 23 +/- 11 min. Upon release and during follow-up (5.3 months +/- 4.2, range 2-10), angina class had significantly improved in 14 of 14 patients with complete PTMR treatment, with 4 asymptomatic patients, 6 patients in CCS I, 3 in CCS II, 2 in CCS III and only one patient hospitalized due to angina. CONCLUSION: This pilot study confirmed the safety and technical feasibility of PTMR. Immediate and short-term results confirm that a clinical improvement is obtained in most patients. Although these are early clinical benefits, the true efficacy of this approach will necessarily be defined by a randomized trials with prospectively-defined endpoints and with PTMR compared with medical therapy.

Aged↗
PubMed1998

[Non-cardiac transcatheter intervention: operative possibilities in a hemodynamics laboratory].

INTRODUCTION: New possibilities for transcatheter treatment of the cardiovascular system are guaranteed with the improvement of materials and the availability of new devices. Nevertheless, a rationalization of the potential activity in this sector seems to be necessary, and it could arise through the presence of Catheterization Laboratories "open" to diagnostic procedures and therapy that are not confined to the coronary system. This clinical study reports the experiences and results of our work in this field. MATERIALS AND METHODS: During the period from May 1995 to May 1997, our laboratory performed 205 diagnostic procedures that did not involve the coronary system. Based on this diagnostic work, there emerged 91 cases with an indication for transcatheter intervention, which was subsequently performed at our laboratory. There were 68 peripheral angioplasty procedures on the iliofemoral axis, 2 angioplasties of the subclavian artery, 8 of the renal artery, 2 procedures involving the treatment of A-V fistulas, one case of femoral pseudoaneurysm treatment and 10 cases of transcutaneous pericardiotomy performed with a balloon catheter. All the procedures were performed by our laboratory staff using materials that are normally at our disposal. RESULTS: Successful results were obtained in 65 out of the 68 peripheral angioplasty procedures and in all of the 8 renal and 2 subclavian angioplasties. The positioning of the endoprosthesis for the closure of the A/V fistula was effective in one of the two cases. The transcatheter treatment of the femoral pseudoaneurysm was successful. In all cases where a pericardiotomy was performed with a balloon catheter, there was no reoccurrence of cardiac tamponade during the follow-up period. No complications were noted as a result of any of the procedures. CONCLUSIONS: Our experience documents how it is possible to increase the diagnostic and therapeutic options in a Catheterization Laboratory. However, willingness on the part of the staff to update their skills continually and collaborate with other specialists is necessary in order to maintain optimal operative standards.

Adult↗
PubMed1998

[Massive pulmonary embolism after blunt chest trauma: considerations on pathogenesis and therapy].

A blunt chest trauma may provoke many different kinds of cardiac injury, particularly myocardial contusion, sometimes causing subsequent acute myocardial infarction or cardiac arrest by ventricular tachyarrhythmia in the absence of structural lesions. We describe a case of acute massive pulmonary embolism after a blunt chest impact caused when the patient was kicked by a horse. The patient showed progressive dyspnea three days after the trauma. The diagnosis was reached by non-invasive means and finally confirmed by pulmonary angiography. Because of the contraindication to thrombolytic therapy, we performed percutaneous catheter and guide-wire clot fragmentation with at least partial immediate success and subsequent favorable course. We discuss possible pathophysiological mechanisms to explain this case, which has no precedents in the literature.

Angiography↗
PubMed1998

Transcatheter management of cardiac and pericardial metastatic involvement.

We performed percutaneous balloon pericardiotomy and pulmonary valvuloplasty in a woman affected with cardiac and pericardial involvement from a primary pulmonary adenocarcinoma. Pericardial window was indicated for a recurrent, symptomatic, pericardial effusion. Valvular stenosis was severe and related to metastatic infiltration of cardiac tissue. Open surgery was avoided and the procedures were completed in two steps under local anesthesia in less than 60 min. The patient had no recurrence of pulmonary stenosis or pericardial effusion at 7 months post treatment. Transcatheter techniques are successful in helping to manage malignant diseases with cardiac metastasis, particularly in critically-ill patients. It may become the preferred treatment for avoiding a more invasive procedure for patients with a limited life expectancy.

Adenocarcinoma↗
PubMed1998

Transradial approach for coronary procedures: initial experience and results.

BACKGROUND: Due to the recent miniaturization of angioplasty equipment, the transradial approach has gained favor as an alternative catheterization method for coronary procedures. The purpose of this study was to assess the practical clinical application of this method. METHODS: Between June 1997 and February 1998, one operator (MG) attempted the percutaneous transradial approach in 185 consecutive unselected patients with functional radial arch attested using Allen's test. In this series of patients, 102 interventional procedures, balloon angioplasty including stent implantation, were performed with 6F or 7F guiding catheters. RESULTS: Radial arterial punctures for diagnostic procedures were performed in 179 patients with a success rate of 97%. In the six failed transradial accesses, the procedure was performed via the transfemoral route. Balloon angioplasty was performed in 29 patients, 28% (33 lesions), PTCA and stent implantation were performed in 73 patients, 72% (80 lesions). Procedural success was achieved in 100 (98.2%). Two PTCA failed due to the impossibility of crossing a total occlusion. During hospitalization, one patient died of unstable angina and poor left ventricular function 7 days after stenting without stent occlusion at angiography. No major complications related to entry site were observed, and no patients required vascular surgery or blood transfusions. CONCLUSION: This preliminary experience suggests that coronary procedures can be performed safely using the transradial approach. Access-site complications are virtually eliminated and early ambulation may result in a shortened hospital stay and lower hospital costs.

Adult↗
PubMed1997

[Coronary stenting for treatment of intimal dissection and occlusive thrombosis during primary PTCA in acute myocardial infarction].

Coronary angioplasty during acute coronary syndrome, and particularly in MI, continues to involve a greater risk of acute and subacute occlusion. Stenting for acute or threatened vessel closure has a high initial success rate and reduces the need for emergency bypass surgery. Nevertheless, under these conditions intracoronary thrombus actually appears to be a relative contraindication to stent implantation. We report the successful implantation of two Palmaz Schatz stents to treat a coronary occlusion refractory to multiple ballooning during primary PTCA in myocardial infarction with angiographic evidence of intimal dissection containing thrombus. The good clinical improvement and the results of short- and long-term clinical angiographic follow-up confirm both the feasibility and effectiveness of using this technical approach to manage complications in acute and unstable syndromes.

Acute Disease↗
PubMed1997

"Functional myocardial bridging" and "hyperkinetic state": a rare association as a cause of acute myocardial infarction.

An 82-year-old female was admitted to the catheterization laboratory for investigation of acute antero-lateral myocardial infarction with evidence of severe left ventricular dysfunction. Angiographically, she was found to have normal coronary arteries, with the exception of the presence of myocardial bridging in the left anterior descending coronary artery. This was recognized as a "functional" variation of anatomical bridging, in which a systolic coronary compression is caused by abnormal muscular septal hypertrophy. We describe this condition as an unusual cause of myocardial infarction and outline its treatment with beta-blockade therapy, using only esmolol, an ultra-short-acting drug. The patient recovered successfully, with complete recovery of ventricular function and the disappearance of this "functional condition", as shown in an angiographic check-up done prior to hospital discharge. A subsequent long-term follow-up was favorable.

Aged↗
PubMed1996

Analysis of genomic patchiness of Haemophilus influenzae and Saccharomyces cerevisiae chromosomes.

We have analysed some aspects of the primary structure of the chromosome of the prokaryote Haemophilus influenzae and of the eukaryote Saccharomyces cerevisiae that share the same G + C content. In particular, we have investigated genomic patchiness over the gene size level (10 Kb) and that patchiness due to long homogenous tracts. Long polypurine and polypyrmidine tracts that are largely over-represented in S. cerevisiae chromosomes and under-represented in H. influenzae, are responsible for a large fraction of long correlation signals. Generating mechanisms of long homogenous tracts are DNA replication slippage and duplication events that appear to be linked processes driving chromosome primary structure evolution.

Base Sequence↗
PubMed1996

High statistics block entropy measures of DNA sequences.

We have used an improved block-entropy measure in order to gain some further insights into the short-range correlations present in whole chromosomes of S. cerevisiae, viruses and organelles and very large genomic regions of E. coli. Although DNA sequences are largely inhomogeneous and word frequencies are unevenly distributed, the comparison of entire chromosomes and large genomic regions show a "bulk" composition homogeneity. This property suggests that biases in selection, directional mutational pressure and recombination processes act in homogenizing the base composition of the DNA molecules within a genome but their mode of action, relative impact and direction may vary in different organisms. The most interesting results appear to be the differences between the SW (C,G/A,T) and RY (A,G/C,T) two-letter alphabet entropies. Deviations from randomness in E. coli and S. cerevisiae sequences particularly concern SW dinucleotide frequencies and RY tetranucleotide frequencies.

Base Sequence↗
PubMed1996

[Clinical experience with the use of implantable vascular systems in advanced heart failure].

BACKGROUND: Patients with end-stage cardiomyopathy frequently require acute or chronic infusional treatments and long hospitalization. Availability of a simple and safe vascular access is a true necessity for these patients, especially in case of inotropic or diuretic outpatient treatment. In this study we have evaluated the usefulness and the applicability of implantable vascular access in the management of end-stage cardiomyopathy. Technical problems and both short and long term complications have been analysed. METHODS: Nineteen implantable vascular system (16 Port-A-Cath, Pharmacia; 3 Celsite, Bruneau) have been implanted in a group of 15 patients with end-stage cardiomyopathy. All patients had been previously hospitalized and needed prolonged infusional therapy. Implantation was performed in local anaesthesia with technique derived from pace-maker implantation. RESULTS: All the interventions were well tolerated, average procedural time was 30 min (range 20-60 min). No procedural complications occurred. Re-implantation of the system was required in 2 patients due to catheter thrombosis, In 1 patient due to catheter rupture caused by wrong positioning of infusion needle, and in 1 patient due to inflammatory reaction. In 2 further cases catheter thrombosis was treated with local infusion of urokinase. In 1 patient the catheter was repositioned after dislocation. The average in situ permanence of the systems was 8 months (range 15 day-18 months). CONCLUSIONS: Vascular implantable systems have proved useful and easily applf1p4e in the management of patients with end stage cardiomyopathy. After training some of the implied complications are easily avoidable. The use of this device has concurred to reduce duration and frequency of hospitalizations.

Adult↗
PubMed1996

[The electrotherapy of the arrhythmias in 3 cases of myotonic dystrophy (Steinert's disease)].

Myotonic dystrophy is a progressive multisystem disease with autosomal dominant inheritance. Cardiac involvement is an integral part of the disorder, the most prominent manifestations being various conduction defects and rhythm disturbances sometimes related to syncope or sudden cardiac death. We describe 3 cases admitted to our Centres. Two patients received a permanent pacemaker for atrioventricular block of different degree and in the third case an implantable cardioverter defibrillator with antibradycardia pacing was inserted for malignant ventricular tachyarrhythmias and advanced atrioventricular block during atrial flutter.

Adult↗