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A Rimondini

Publications and source records attributed to A Rimondini.

At least 19 recordsLinked to original sources
PubMed2002

Usefulness of virtual endoscopic three-dimensional reconstructions of the middle ear.

This work uses a new programme for producing 3D radiological images acquired by means of CT which enables the internal surfaces of the examined structures to be visualized. This new method, which is able to navigate inside organs in a similar way to fibreoptic endoscopy, is known as virtual endoscopy. CT examinations of the temporal bone were carried out using spiral equipment and endoscopic 3D processing was carried out on a separate workstation equipped with a volume-rendering programme. Once the technical parameters necessary for obtaining a representation of the internal surfaces had been defined, a simulation of a virtual otoscopy was conducted by moving the virtual endoscope from the external auditory canal through the annulus to the tympanic cavity. The simulation can be obtained either by moving the endoscope by hand, using the mouse, or by defining a path along which the software automatically creates an endoscopic 3D reconstruction. The images thus obtained are projected sequentially to give a "movie" effect, i.e. a continuous progression of the endoscope. The average time required to conduct the procedure ranges from 20 to 30 min. A virtual endoscopic visualization of the middle ear was obtained which, in particular, generated images of the tympanic cavity with the ossicular chain. In our experience, virtual otoscopy shows the anatomy of the structures of the tympanic cavity in excellent detail and may be considered complementary to CT, providing useful images enabling better visual representation and understanding of this complex structure. Although clinical applications of the technique remain to be defined it may have a role to play in presurgical diagnostic evaluation of the ossicular chain, epitympanum and retrotympanum.

Ear, Middle↗
PubMed2001

Evaluation of image quality and dose in renal colic: comparison of different spiral-CT protocols.

The aim of this study was to test different technical spiral-CT parameters to obtain optimal image quality with reduced X-ray dose. Images were acquired with a spiral-CT system Philips Tomoscan AVE1, using 250 mA, 120 kV, and 1-s rotational time. Three protocols were tested: protocol A with 5-mm thickness, pitch 1.6, slice reconstruction every 2.5 mm; protocol B with 3-mm thickness, pitch 1.6, slice reconstruction every 1.5 mm; and protocol C with 3-mm thickness, pitch 2, slice reconstruction every 1.5 mm. Two phantoms were employed to evaluate the image quality. Axial images were acquired, then sagittal and coronal images were reconstructed. Finally, the absorbed X-ray dose for each protocol was measured. Regarding image quality, 5-mm-thick images (protocol A) showed greater spatial resolution and lower noise compared with 3-mm-thick images (protocols B and C) on the axial plane; 3-mm reconstructed sagittal and coronal images (protocols B and C) showed an improved image quality compared with 5-mm reformatted images (protocol A). Concerning X-ray dose, the mean dose was: protocol A 19.6 +/- 0.8 mGy; protocol B 14.4 +/- 0.6 mGy; protocol C 12.5 +/- 1.0 mGy. Our study supports the use of thin slices (3 mm) combined with pitch of 1.6 or 2 in renal colic for X-ray dose reduction to the patient and good image quality.

Clinical Protocols↗
PubMed2001

[Spiral-CT with multiplanar reconstructions (MPRS) in the evaluation of ureteral neoplasms: preliminary results].

PURPOSE: Urothelial tumors of the upper urinary tract (renal pelvis and ureters) are rare: the most common of these are Transitional Cell Carcinomas (TCC), usually localized in the bladder (75% of cases), whereas only 7-10% arise in the renal pelvis and 2,5-5% in the ureter. Multicentricity is not infrequent and synchronous or metachronous tumors have been reported to develop in 11-13% of patients with upper urinary tract cancer and 2-4% of those with bladder cancer. The presence of additional lesions can change patient management. Clinically these tumors may present with hematuria or flank pain, but sometimes there are no specific clinical findings. Radiological studies play an important role in tumor detection and staging and in follow up. The diagnosis is usually performed by IVU and US, while CT is generally employed in the staging. Our purpose was to verify the role of Spiral CT with Multiplanar Reconstructions (MPRs) in the evaluation of ureteral tumors. MATERIAL AND METHODS: Nine patients with ureteral neoplasms were examined with a single detector spiral-CT, using the following parameters: 120 kV, 200 mA; 5 mm collimation, pitch 1.4, slice reconstruction every 5 mm; image acquisition 2-5 minutes after injection of 120 cc of contrast medium (300 mgI/ml). All the exams were transferred to a separate workstation to obtain curvilinear MPRs. RESULTS: Spiral CT on the axial plane visualized 4 urothelial tumors as concentric ureteral wall thickening; 3 as intraluminal soft tissue masses, with involvement of almost the entire urinary tract, as far as the bladder in 1 case. In other 2 patients there were synchronous lesions which presented both patterns (wall thickening and intraluminal mass). In all cases the lesions exhibited moderate enhancement after c.m. injection. Medium- to high-grade hydronephrosis above the tumors was always present. On MPRs both ureteral involvement and dilated, urine-filled upper urinary tract were clearly represented on coronal and sagittal oblique planes; these images allowed to visualize the craniocaudal extension of short or long lesions, and to detect multicentricity. DISCUSSION: The radiological diagnosis of ureteral tumors is usually performed by IVU, US and CT. IVU allows to visualize the tumors as filling defects or irregular narrowing of the ureteral lumen. IVU however is unable to show the real extent of the tumor in obstructive disease or in nonfunctioning kidney. US visualizes the lesion as an echoic mass in the lumen, although it is sometimes difficult to differentiate neoplastic lesions from other filling defects and to visualize the entire ureteral tract. CT is generally employed in the staging of ureteral tumors. CT findings are usually very useful for distinguishing ureteral neoplasms from other filling defects based on their attenuation and enhancement characteristics. Spiral CT with MPRs allows to obtain panoramic views of the urinary tract; these images are more effective than those of IVU, because of their capability to show the longitudinal extension of the lesion and the presence of multicentric tumors. Furthermore with MPRs it is possible to visualize the ureteral tract distal to the lesion, overcoming the limitations of IVU in nonfunctioning kidney or obstructive disease. CONCLUSIONS: Spiral CT with MPRs is useful in the evaluation of ureteral tumors as it is capable of visualizing the whole extension of the lesion and the presence or absence of multicentric lesions, which can change patient management.

Aged↗
PubMed2001

[Effective dose in X-ray examinations: comparison between spiral CT and urography in the study of renal colic].

AIM: The aim of this study was to calculate the effective dose in patients with renal colic undergoing spiral CT examination and IVU examination, and to verify the ability of the systems to measure the effective dose. MATERIAL AND METHODS: Dose measurements were carried out for both diagnostic techniques by employing an anthropomorphic phantom with thermoluminescence detectors (TLDs) fitted inside the phantom. The data so obtained were compared with dose estimations based on published tables, which allow to obtain the effective dose on the basis of the experimental value of common dose indicators, the performance of the equipment and the setting of the acquisition parameters for such examinations. RESULTS: The absorbed dose inside the phantom had an homogeneous distribution during the spiral CT examination, while during the IVU there were significant differences in the absorbed dose between different zones of the body, due to the geometry of the x-ray beam. The mean effective dose, which corresponds to the average of values absorbed by males and females, measured by TLD dosimeters for spiral CT examination was 3.3 time that for IVU. For both spiral CT and IVU the dose to the male was significantly lower than that to the female, owing to the anatomic position of female gonads that are completely exposed to the x-ray radiations during the study, while male gonads lie outside of the exposed area. Both methods for estimating the effective dose in spiral CT, based on CTDI value, significantly underestimated the value derived from experimental TLDs measurement. The evaluation of effective dose in IVU, based on the measurement of the skin dose in air, overestimated the measurement performed by TLDs. DISCUSSION AND CONCLUSIONS: Dose measurement performed by TLD dosimeters fitted inside an anthropomorphic phantom has the advantage of calculating experimentally the absorbed dose in different anatomic districts. However, the method is quite difficult, and introduces some imprecisions due to the simplified morphology of the phantom and the measuring system of TLDs (+/- 10%). Another possibility is to make theoretical estimations on the basis of simple dose measurements. Also these methods are affected by many factors that may introduce imprecisions, such as the patient geometry which has a considerable effect on the dose distribution inside the body. Therefore the methods of measurement based on CTDI value can provide only rough estimations of effective dose. The same considerations can be applied to IVU; in this case the theoretical estimations are based on skin dose measurements, which are very accurate but cannot foresee the behaviour of x-rays inside the patient. As regards the diagnostic procedures evaluated, the gonadic absorbed dose has a greater effect on the effective dose value as a consequence of the weight tissue ratio Wt. In this respect we should underline that, while female gonads are completely irradiated during spiral CT and IVU examinations, the male gonads are exposed only to diffuse radiation; this entails a great difference between the effective dose to the male and that to the female. For this reason the effective dose should be expressed not only for the average man (that is the mean value between males and females), but also distinguishing by patient sex. Although the comparison of different evaluating methods confirmed the difficulties in obtaining the exact effective dose, all the measurements performed with IVU and spiral CT showed that the effective dose for CT is 3.3 times that for IVU. However, the excellent image quality obtained by spiral CT and the high intrinsic contrast of stones probably makes it possible to reduce the dose with this technique, preserving an acceptable quality of the diagnostic images.

Colic↗
PubMed2000

Cost analysis of different protocols for imaging a patient with acute flank pain.

The aim of this study was to analyse the costs of different diagnostic approaches to patients with acute flank pain. Four different diagnostic approaches were considered: (a) spiral CT without contrast medium (CM); (b) plain film, ultrasonography (US) and intravenous urography (IVU)--the latter procedure is used in our department in cases still unsolved following the former investigations (28% in our experience); (c) plain film, US and spiral CT without CM (as an alternative to IVU in 28% of cases); and (d) IVU. The cost of each procedure in a university hospital was calculated, following analysis of the differential costs of each investigation (equipment, depreciation and maintenance costs, related materials and services, radiologists, radiographers, nurses) and their common costs (auxiliary personnel and indirect internal costs). Finally, we calculated the full cost of each procedure and applied it to the different diagnostic approaches. The full cost of each approach was: (a) spiral CT without CM = 74 Euro; (b) plain film, US and IVU (28%) = 66.89 Euro; (c) plain film, US and spiral CT without CM (28%) = 64.93 Euro; (d) IVU = 80.90 Euro. Intravenous urography alone or in unsolved cases is not to be considered because it provides higher costs and worse diagnostic results, whereas X-ray dose to patient is almost equal between IVU and spiral CT. Spiral CT integrated to plain film and US in unsolved cases could be preferred because of lower cost and dose to patient, though reaching a diagnostic conclusion may take longer than an immediate spiral CT.

Acute Disease↗
PubMed2000

New onset atrial flutter termination by overdrive transoesophageal pacing: effects of different protocols of stimulation.

AIM: We evaluated the effect of different stimulation protocols on atrial flutter interruption by transoesophageal pacing. METHODS AND RESULTS: Eighty patients with new onset atrial flutter were randomized into four groups. Pacing was attempted under the following conditions: with short bursts (5 s), without treatment (group A) and after oral administration of propafenone 600 mg (group B); with prolonged bursts (30 s), without treatment (group C) and after oral administration of propafenone 600 mg (group D). Pacing interrupted atrial flutter in 20% of patients in A, 55% in B, 50% in C and 85% in D. The use of longer bursts gave better results both in patients without treatment (P < 0.05: C vs A) and in patients with propafenone (P < 0.05: D vs B). Comparing groups with the same stimulation protocol, we observed a better response in patients treated with propafenone (P < 0.05: B vs A and D vs C). In the groups without treatment the use of shorter bursts was associated with a lower induction of stable atrial fibrillation (three vs nine episodes), in the groups on propafenone no differences were observed (one vs one episode). CONCLUSIONS: We conclude that the association of propafenone with long bursts gives the best result for interruption of new onset atrial flutter by transoesophageal pacing.

Administration, Oral↗
PubMed2000

[Kidney obstruction: potential use of ultrasonography and Doppler color ultrasonography].

Ultrasonography is the first imaging approach in evaluation of patients with urinary obstruction. Presence of hydronephrosis, urinomas and inflammatory complications can be assessed. Moreover, the level and the cause of obstruction are often identified. The major limits of ultrasonography are poor visibility of the lumbar portion of the urinary tract and lack of specificity in detection of pyelocaliectasis. These limits are partially overcome with Doppler studies. Several factors can bias diagnostic accuracy of colour Doppler ultrasonography in evaluating renal obstruction; in particular, partial or intermittent obstruction cause minimum hemodynamic changes in patients with renal colic. Sensitivity of colour Doppler ultrasonography to detect obstruction decreases following medical treatment with NSAID and increases following hydration and diuretics administration. Diuretic ultrasound, colour Doppler evaluation of ureteral jets and evaluation of the twinkling artefact of stones are useful imaging techniques as well. Tissue harmonic imaging is a new imaging technique available in most latest generation US equipments. Evaluation of the kidney and of the urinary tract improves using this technique due to artefact reduction and increased contrast resolution.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1999

Digital vs conventional radiography: cost and revenue analysis.

The objective of this study was to analyse and compare the operating and investment costs of two radiographic systems, a conventional and a digital one, and to evaluate the cost/revenue ratio of the two systems. The radiological activity over 1 year for chest and skeletal exams was evaluated: 13,401 chest and 7,124 skeletal exams were considered. The following parameters of variable costs were evaluated: the difference between variable proportional costs of the two technologies, the effective variable cost of any size film, including the chemicals, and for different sizes of digital film, variable costs of chest plus skeletal exams performed with the two techniques. Afterwards the economical effect was considered taking into account depreciation during a time of utilization ranging between 8 and 4 years. In the second part of the analysis the total cost and the revenues of the two technologies were determined. The comparison between the digital and conventional systems has shown the following aspects: 1. Digital radiography system has a much higher investment cost in comparison with the conventional one. 2. Operating costs of digital equipment are higher or lower depending on the film size used. Evaluating chest X-ray we reach a breakeven point after 1 year and 10,000 exams only if displayed over 8 x 10-in. film and after 30,000 if displayed over a 11 x 14-in. film. 3. The total cost (variable cost, technology cost, labour cost) of digital technology is lower than that of the conventional system by 20 % on average using 8 x 10-in. film size. 4. Digital technology also allows lesser film waste and lesser film per exam

Bone and Bones↗
PubMed1996

Type II atrial flutter interruption with transesophageal pacing: use of propafenone and possible change of the substrate.

Type II atrial flutter (AFII) is an arrhythmia which usually cannot be interrupted by atrial pacing: the underlying mechanism is considered to be a leading circle without an excitable gap. We investigated whether the administration of propafenone, an antiarrhythmic drug, which primarily decreases conduction velocity, has a beneficial effect on AFII interruption using transesophageal pacing. Twelve patients with an AFII were randomized into 2 groups in which pacing was performed without treatment (group A) or two hours after the administration of 600 mg of oral propafenone (group B). Sinus rhythm was attained in 0 of 6 patients in group A and in 4 of 6 patients in group B (P < 0.05). The baseline mean cycle length was the same in both groups (175 +/- 7 (A) vs 168 +/- 8 ms (B); it lengthened significantly after the administration of propafenone (219 +/- 33 vs 168 +/- 8 ms; P < 0.05). Propafenone did not significantly lengthen the cycle in the two patients in whom interruption of the arrhythmia was impossible. Our data show that propafenone has a facilitating effect on atrial pacing only when it significantly prolongs the cycle length of the arrhythmia, possible expression of a conversion of AFII into type I, with an anatomical substrate and an excitable gap allowing arrhythmia capture and interruption. In the two patients in whom sinus rhythm was not restored, the absence of a direct dependence of the cycle length on the change in conduction velocity induced by propafenone may be explained by the persistence of a functionally determined circuit, resistant to atrial pacing.

Administration, Oral↗
PubMed1996

[Facilitating effect of propafenone pretreatment in the interruption of atrial flutter by transesophageal pacing].

Transesophageal atrial pacing is effective in the interruption of atrial flutter, and being simple and minimally invasive, is easily performed even on outpatients. The influence of antiarrhythmic drugs on this procedure is controversial. We investigated whether the administration of oral propafenone may facilitate the procedure. Thirty patients with type I atrial flutter were randomized into two groups in which transesophageal pacing was attempted, respectively, without treatment (Group A) and after oral administration of propafenone 600 mg (Group B). Transesophageal pacing was effective in interrupting atrial flutter in 53% (8/15) of patients in Group A and in 85% (13/15) of patients in Group B. A significant lengthening of the flutter cycle was observed in patients treated with propafenone (261 +/- 23 vs 217 +/- 25 ms, p < 0.01). Sinus rhythm resumed at a shorter paced cycle in patients of Group A (166 +/- 13 vs 187 +/- 14 ms, p < 0.01). The transesophageal threshold for stable atrial capture was significantly lower in Group A (20.5 +/- 0.2 vs 23.3 +/- 1.2 mA, p < 0.01). In no patient the threshold for atrial capture was higher than the pain threshold. We did not observe abrupt enhancement of atrioventricular conduction. We can conclude that propafenone is effective and safe when used with transesophageal pacing in the termination of atrial flutter. The depressing effect of the drug on intraatrial conduction and the possible stabilizing effect on the reentry circuit appear to be outweighed by the positive effect of propafenone on the excitable gap of the circuit, facilitating its capture and account for the beneficial effect of the drug on arrhythmia termination.

Adult↗
PubMed1995

Atrial flutter termination by overdrive transesophageal pacing and the facilitating effect of oral propafenone.

Transesophageal overdrive atrial pacing is effective and safe for atrial flutter termination. The influence of antiarrhythmic drug therapy on this procedure is controversial. In this study, we investigated whether oral propafenone may facilitate this procedure. Thirty patients with type I atrial flutter were randomized into 2 groups in which transesophageal pacing was attempted: group A, without treatment; and group B, after oral administration of propafenone 600 mg. Transesophageal pacing was effective in interrupting atrial flutter in 53% of patients (8 of 15) in group A and in 87% of patients (13 of 15) in group B. A significant lengthening of the flutter cycle was observed with respect to the baseline in patients given propafenone (261 +/- 23 vs 217 +/- 25, p < 0.01). Sinus rhythm resumed at a shorter paced cycle in group A patients (166 +/- 13 vs 187 +/- 14 ms, p < 0.01). The transesophageal threshold for stable atrial capture was significantly lower in group A (20.5 +/- 0.2 vs 23.3 +/- 1.2, p < 0.01). In no patient was the threshold for atrial capture higher than the pain threshold. We did not observe abrupt enhancement of atrioventricular conduction. We conclude that propafenone is effective and safe when used with transesophageal pacing in the termination of atrial flutter. The slowing effect of the drug on intraatrial conduction and the possible stabilizing effect on the reentry circuit appear to be outweighed by the positive effect of propafenone on the excitable gap of the circuit, facilitating its capture and accounting for the beneficial effect of the drug on arrhythmia termination.

Administration, Oral↗
PubMed1990

Changes in circulating norepinephrine with hemofiltration in advanced congestive heart failure.

In congestive heart failure (CHF), hemofiltration is associated with an obvious decrease in circulating norepinephrine. This method was used for investigating the mechanisms whereby plasma norepinephrine is increased in chronic CHF. In 23 cases of advanced CHF, hemofiltration (2,983 +/- 1,228 ml) lowered plasma norepinephrine by 515 +/- 444 pg/ml. This effect was prompt, persisted or became greater in the next 24 hours. It was not associated with significant changes in cardiac output, aortic pressure or systemic vascular resistance. It did not appear to depend on variations in parameters related to the sympathetic activity, such as plasma renin, right atrial, wedge pulmonary artery and renal perfusion pressures, and was independent of duration and amount of hemofiltration. These observations did not support the concept that the norepinephrine decrease was the main consequence of a neural sympathetic inhibition. Hemofiltration increased diuresis by 606 +/- 415 ml; changes were prompt and correlated inversely (r = -0.7; p less than 0.01) with those in plasma norepinephrine. The same unknown mechanism of the increased urinary output might potentiate the norepinephrine removal from the blood by the kidney, or hemofiltration and the augmented diuresis might result in a regression of congestion of lungs and kidneys, leading to an improved extraction of norepinephrine. In CHF, a relation may exist between fluid retention and norepinephrine and in advanced stages, circulating norepinephrine, although strikingly increased, is devoid of important cardiovascular effects. At these stages, plasma norepinephrine is probably unreliable as an index of the sympathetic neural activity.

Adult↗
PubMed1990

Isolated ultrafiltration in cardiogenic pulmonary edema.

Twenty patients (ten with mitral and/or aortic valve disease and ten with ischemic heart disease, all in the New York Heart Association class IV, aged between 18 and 74 yr, with cardiogenic pulmonary edema unresponsive to drug treatment) were treated with polysulphone membrane ultrafiltration (UF) in a veno-venous circuit. All patients had dyspnea, pulmonary rales, hypoxemia, tachycardia, hypotension, overhydration, radiologic evidence of engorged pulmonary vasculature, and Kerley-B lines. Systemic and pulmonary arterial pressures, cardiac output (by thermodilution), and intrapulmonary shunt fraction (Qsp/Qt) were determined and chest x-ray was obtained at the beginning and the end of UF. Average duration of the treatment was 150 +/- 28 min; UF volume averaged 3000 +/- 170 ml. UF reduced the Qsp/Qt by 58% from control condition, and did not significantly affect hemodynamic variables. Chest x-rays documented clearing of alveolar edema and venous congestion. These changes were associated with unequivocal clinical improvement and no mechanical ventilation was necessary to improve gas exchange. Short-term fluid subtraction did not result in undesired circulatory alternations. Because the ultrafiltrate composition is similar to plasmatic fluid, no modification in the plasma osmolarity was detected. In conclusion, UF may be considered an effective tool for the treatment of acute pulmonary edema refractory to drug therapy, as an alternative to mechanical ventilation, and as a remedy for excessive extravascular lung water.

Adult↗
PubMed1990

[Neurohumoral changes induced by hemofiltration in congestive heart failure: physiopathological inferences].

Hemofiltration is a method suitable for rapid substraction of plasma water that generally allows reduction of circulating levels of norepinephrine. Using that non-pharmacological approach we investigated the mechanisms involved in the metabolism of the hormone as well as the hemodynamic correlates of a prompt and great fall of the sympathetic neurotransmitter in patients with chronic refractory congestive heart failure (CHF). In 23 patients with CHF, hemofiltration of 2983 +/- 1228 ml of plasma water (in 5 +/- 2 hours of treatment) increased urinary output by 606 +/- 415 ml in the day of the procedure as well as sodium excretion by 53 +/- 38 mEq/24 h; simultaneously, a mean fall in plasma norepinephrine concentration by 515 +/- 444 pg/ml was observed. These effects were prompt and persisted or even rose in the next 24 and 48 hours, not being related to changes in plasma renin activity, right atrial, wedge pulmonary artery and renal perfusion pressures and to the amount and duration of hemofiltration. Our data did not clarify the mechanism involved in the increase of the diuresis and for its coupling with the fall in plasma norepinephrine. Nevertheless, we found a strong and statistically significant correlation (r = 0.7; p less than 0.01) between percent changes from baseline values of norepinephrine and diuresis. It is therefore suggested that the same, still unknown, mechanism which increased urinary output also potentiated norepinephrine removal by the kidney: or that water reabsorption from extravascular spaces (triggered by hemofiltration and continued by increased diuresis) resulted in regression of organ congestion leading to an improved clearance of norepinephrine by different organs.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[Efficacy of disopyramide in the treatment of atrial flutter with overdrive pacing].

Thirty patients with long-standing (mean 30 days) type I atrial flutter (AF) were treated with overdrive atrial pacing. To evaluate the effect of pretreatment with disopyramide (DISO), the study population was divided into 3 groups of 10 patients each: no therapy (Group A); intravenous DISO (maximum dose 250 mg in 1 hour) (Group B), oral DISO (400 mg/day for 4 days) (Group C). The mean cycle length of AF was 215 +/- 24 ms in Group A, 222 +/- 28 in B and 224 +/- 11 in C (NS). After DISO, AF cycle length increased to 287 +/- 24 in Group B (p less than 0.001) and to 264 +/- 29 in C (p less than 0.001). Overdrive pacing was performed from a maximum of 3 atrial sites up to the shortest paced cycle of 150 ms. Reversion to sinus rhythm (SR) occurred in 20% of patients in Group A, 70% in B and 50% in C. In all these cases SR was obtained with paced cycle length that was 70-90% of the baseline cycle length. Pacing was performed from a mean number of 2.1 sites per patient in Group A, 1.2 in B and 2.0 in C. Atrial fibrillation occurred in 7, 3 and 4 patients, respectively. Acceleration of atrial flutter to a faster form of AF occurred in 3, 3 and 4 patients, respectively. The administration of DISO prior to overdrive atrial pacing improves the rate of conversion to SR and allows an easier stimulation protocol with a lower incidence of pacing-induced atrial fibrillation. The administration of DISO is beneficial when overdrive atrial pacing is performed for the treatment of long standing AF in patients with organic heart disease.

Aged↗
PubMed1988

Facilitating influence of disopyramide on atrial flutter termination by overdrive pacing.

Long-lasting (mean 30 days) type I atrial flutter was treated with overdrive pacing in 30 patients (mean age 69 years) with organic heart disease. To evaluate the effect of pretreatment with disopyramide, the study population was divided in 3 groups of 10 patients each: group A, no disopyramide therapy; group B, intravenous disopyramide (maximum dose 250 mg in 1 hour); and group C, oral disopyramide (400 mg daily for 4 days). There were no differences in baseline cycle length of atrial flutter among the 3 groups before drugs were given. The stimulation protocol included overdrive atrial pacing up to the shortest paced cycle of 150 ms performed at a maximum of 3 atrial sites. Reversion to sinus rhythm occurred in 2 patients in group A, 7 in group B (p less than 0.01) and 5 in group C. Pacing was performed from a mean number of 2.1 sites/patient in group A, 1.2 in group B and 2.0 in group C. Atrial fibrillation occurred in 7, 3 and 4 patients, respectively. Acceleration to a faster form of atrial flutter occurred in 3, 3 and 4 patients, respectively, and reversion to sinus rhythm occurred in all patients who had intravenous disopyramide and in 1 who took the drug orally. The administration of disopyramide before overdrive pacing improved the rate of conversion to sinus rhythm and allowed an easier stimulation protocol with a lower incidence of pacing-induced atrial fibrillation. Disopyramide is beneficial when overdrive atrial pacing is performed for the treatment of long-standing atrial flutter in patients with organic heart disease.

Administration, Oral↗
PubMed1987

Hemofiltration as short-term treatment for refractory congestive heart failure.

Hemofiltration has been suggested as a new therapeutic tool in refractory heart failure. In this study, 11 patients with primary or ischemic heart disease in New York Heart Association class IV, in whom there was no response to medical treatment, were subjected to hemofiltration. The pathophysiologic adjustments promoted by subtraction of plasma water were investigated, and guidelines for an appropriate use of this procedure in heart failure are provided. Fluid was removed from plasma at a rate of 500 ml/hour until either normalization of the right atrial pressure (which was increased in all cases) was achieved or the hematocrit exceeded 50 percent. According to these criteria, the duration of treatment ranged from four to six hours and the total amount of fluid removed was 2,000 to 3,000 ml. In each case, hemofiltration promoted relief of dyspnea and of clinical and radiographic evidence of lung congestion and pleural effusion, and substantially reduced the dependent edema and abdominal girth. These effects were paralleled by progressive decrease of the right (-70 percent) and left (-45 percent) ventricular filling pressures and of the pulmonary arterial pressure and arteriolar resistance, without significant variations in heart rate, aortic pressure, cardiac index, and systemic vascular resistance. Changes in the right atrial and wedge pulmonary pressures are interpreted as reflecting a combined effect of a decrease in pressure on the outside of the heart due to fluid reabsorption (from lung interstitial spaces and pericardial, pleural and abdominal cavities) and of intravascular volume subtraction. The arterial partial pressure of oxygen was raised, the partial pressure of carbon dioxide and pH were unchanged, and urinary output was substantially enhanced by the procedure. The study indicates that: hemofiltration may be a short-term treatment for refractory cardiac insufficiency with overhydration; a filtration rate of 500 ml/hour is effective and safe; and the central venous pressure may be a reliable guide to volume subtraction.

Aged↗