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Biomedical subjects

G Richichi

Publications and source records attributed to G Richichi.

At least 19 recordsLinked to original sources

[Transportation of patients with acute infarction to the closest center with available emergency angioplastic services: why, when, where, and how?].

The success of acute myocardial infarction therapy depends on the ability to achieve prompt reperfusion of the occluded coronary artery and of the corresponding microcirculation. The significant failure rate of thrombolysis and primary angioplasty, often considered as mutually exclusive therapies, is due, in daily clinical practice, to both pathophysiological factors and to delay in the access to care. The introduction of new fibrinolytic and antithrombotic drugs and the differentiated use of primary angioplasty, pre-hospital thrombolysis and rescue angioplasty according to the different risk profile of the patient will probably lead to the optimization of current therapeutic regimens. However, logistic, technical and organizational problems commonly encountered in everyday practice could cause significant delays in the access to care and thus reduce benefits in spite of such a refined strategy. Therefore, the optimization of in- and out-of-hospital organizational aspects is also required if the benefits of therapeutic regimens for acute myocardial infarction are to be increased. Such a strategy should lead to the earlier administration of the optimal drug regimen and enable quicker assessment of the reperfusion status and more timely admission and/or transfer of high-risk patients directly to the catheterization laboratory. We propose a simple model of patient management in which different patient subgroups could be submitted to different treatment regimens according to their specific risk and to the modality of access to care. Such a model is based on the clinical stratification of risk, on telematic connection among care centers and on the facilitation of hospital admission. In Italy, the use of such a model could reduce the average time to reperfusion by 90-120 min and thus improve survival after acute myocardial infarction.

Angioplasty, Balloon, Coronary↗

Coronary flow reserve of normal left anterior descending artery in patients with ischemic heart disease: A transesophageal Doppler study.

The aim of this study was to investigate the flow reserve of a normal left anterior descending coronary artery (LAD) in patients with coronary artery disease (CAD) of other epicardial vessels by Doppler transesophageal echocardiography (TEE). Thirty-one consecutive patients (age 59 +/- 8 years; 23 men) referred for TEE were considered. Eighteen patients had CAD and a 70% or greater LAD stenosis (group 1); 13 patients had right and/or circumflex CAD (>/=70% stenosis) and normal or minimally diseased LAD (group 2). Ten patients (age 54 +/- 11 years) with normal coronary arteries constituted group 3. Baseline and adenosine (0.160 microg/kg per minute intravenously over 60 minutes) flow velocities in the LAD were measured by pulsed Doppler examination during TEE. Peak and mean systolic and diastolic flow velocities were calculated. Adenosine/baseline peak and mean velocity ratios were used for evaluating blood flow reserve in the LAD. Heart rate and arterial pressure values were similar in the 3 groups at baseline and during adenosine infusion. Baseline and adenosine-related flow velocities were comparable in the 3 groups. Peak and mean diastolic velocity ratios were lower in groups 1 and 2 compared with group 3 (peak velocity ratio 1.68 +/- 0.81 and 1.93 +/- 0.35 vs 2.62 +/- 0.32, P <. 05; mean velocity ratio 1.71 +/- 0.86 and 2.01 +/- 0.41 vs 2.84 +/- 0.74, P <.05), whereas no differences were found between groups 1 and 2. No significant differences were found in systolic flow velocity ratios among the 3 groups. Patients with ischemic heart disease have a reduced diastolic flow velocity reserve in the LAD independent from the presence of significant LAD stenosis. Thus the adenosine TEE-Doppler study should be considered a screening test for CAD rather than for LAD disease.

Aged↗

Usefulness of dipyridamole transesophageal echocardiography in the evaluation of myocardial ischemia and coronary artery flow.

High-dose dipyridamole transesophageal stress echocardiography has recently been proposed as a useful and safe method to assess myocardial ischemia in patients with poor transthoracic acoustic window. It has also been shown that transesophageal echocardiography (TEE) allows the study of coronary blood flow reserve (CBFR) in the left anterior descending artery (LAD). The aim of our study was to assess whether the morphologic information and pathophysiologic data on CBFR and myocardial ischemia can be collected by a single stress TEE without comprimizing its feasibility, safety and accuracy. We studied, 29 patient with known or suspected CAD (previous myocardial infarction or angina) (Group A), and as a control group, we studied 11 patients with mitral disease or mitral prostheses (Group B). All patients underwent the coronary angiography. None of Group B patients showed significant coronary artery stenosis (> 70%). In baseline conditions left ventricular wall motion and LAD coronary blood flow velocity (CBFV) were also evaluated. The following CBFV parameters were measured: maximal diastolic velocity (MaxDV), mean diastolic velocity (MnDV), maximal systolic velocity (MaxSV), mean systolic velocity (MnSV). The ratios of dipyridamole to rest maximal and o mean to diastolic velocities (MaxDV-Dip/Max DV-rest; MnDv-Dip/MnDV-rest) were measured as indexes of CBFR. No side effects were observed and the test could be completed in all patients (feasibility 100%). Wall motion analysis was adequate in all patients (feasibility 100%). Comparison between wall motion analysis was obtained and angiographic findings shown that the overall sensitivity and specificity of TEE were 84% and 93% respectively. Sensitivity for one, two and three vessel disease was 60%, 70% and 100%, respectively. LAD CBFV was adequately recorded in 85% of patients. CBFR parameters showed a significant difference between the two groups (Max DV-Dip/Max DV-rest: 1.67 +/- 0.7 vs. 2.73 +/- 0.6, P < 0.001); comparison between Group B patients and those of Group A with angiographically documented LAD stenosis showed a statistically significant difference in CBFR parameters (MaxDV-Dip/MnDV-rest, 2.73 +/- 0.6 vs. 1.65 +/- 0.7, P < 0.001, MnDV-Dip/MnDV-rest, 2.56 +/- 0.5 vs. 1.69 +/- 0.6 < 0.001). We conclude that transesophageal stress echocardiography is a useful method to study CAD and that it is possible to assess both morphologic and pathophysiologic information during a single examination.

Angina Pectoris↗

[Multiplane transesophageal echocardiography and adenosine in the study of coronary blood reserve].

BACKGROUND: Coronary blood reserve is the capacity of coronary vessels to vasodilate and thereby to increase the blood flow, when the heart needs more energy. However, when a coronary stenosis occurs, the capacity to vasodilate is reduced or completely diminished. It is then necessary to use all the tools useful in evaluating the functional conditions of the coronary vessels. Above all, the intracoronary Doppler technique is used to measure the velocity of blood flow. Our purpose was to evaluate a non-invasive tool "Multiplane Transesophageal Echocardiography" in the study of velocity of the anterior descendent artery before and after adenosine infusion. METHODS: At first, we studied 28 patients (pts), which we divided in two groups: Group A, 18 pts 59.38 +/- 8.23 mean age, 15 M. and 3 F., with anterior descending disease; Group B 10 pts, 59.20 +/- 8.48 mean age, 7 M. and 3 F, without significant stenosis (> 75%). Echocardiography examinations were performed with a 5 MHz multiplane probe, connected to a 1000 Hewlett Parkard echocardiography. Before the test, Diazepam 1 mg i.v. and Lidocaine spray were administered to the patients. We introduced the transesophageal probe and after choosing the best position of the aortic short axis view, we studied the anterior descending artery and measured the maximum and mean diastolic and sistolic velocities (V.MAX D., V.MN.D., V.MAX S., V.MN.S.). RESULTS: Transesophageal echocardiography allowed us to study the anterior descending artery in 95% of pts. There were no side effects, except for one pt affected by severe bradicardia. In Group B there was an increase of the diastolic and sistolic velocity after adenosine infusion, resulting twice greater they the rest values. The adenosine/rest velocities ratios were statistically significant (V.MAX D. p < 0.02) (V.MN.D. p < 0.03). CONCLUSION: Our results demonstrated an higher capacity of the Multiplane Transesophageal Echocardiography in studiing coronary blood reserve. We used adenosine, as a vasodilator drug, because of its short half-life and because it can be replatedly infused. The flow velocity values increased up to more than twice the rest values only in normal subjects.

Adenosine↗

[Transitory transesophageal atrial electric stimulation. Preliminary report on 19 cases and considerations on the method, indications and results (author's transl)].

Literature provides sufficient evidence that transitory electric stimulation via esophagus (SATE) - after the first positive experimental attempts on dogs - can be applied to man with a simple, rapid and harmless method. The study covers 19 patients subjected to high frequency transesophageal atrial stimulation by way of a bipolar electrode inserted through a nasogastric tube and connected to an external generator capable of producing tension impulses. Said impulses are variable up to 150 volts, lasting 2.5 microsec. with a frequency of up to 450/min. The 19 patients can be divided into 2 groups. The first including 15 patients on which SATE was effected for diagnostic purposes: in coronary deficiency (8 patients), in the disease of sinus node (3 patients), and lastly in the research for the A-V-block latent in 4 patients with acute post-infarctual A-V-block which regressed during the immediate clinical course of the illness. The other group includes 4 patients in which the atrial stimulation indication was the treatment of rapid, paroxysmic atrial rhythms, inaffected by drugs. By using impulses of 25-30 volts, the AA. have obtained a stable stimulation.

Adult↗