Search PubMed⌕ Search

Biomedical subjects

G Bellotti

Publications and source records attributed to G Bellotti.

At least 109 records · Page 6Linked to original sources
PubMed1994

Magnetic resonance imaging evaluation of chronic changes in latissimus dorsi cardiomyoplasty.

BACKGROUND: Long-term clinical and hemodynamic benefits of dynamic cardiomyoplasty (DC) have been reported. However, no information is available about long-term morphological changes in the wrapped latissimus dorsi (LD) muscle in humans. METHODS AND RESULTS: The LD muscle flap was evaluated by magnetic resonance imaging (MRI) in 13 patients submitted to dynamic cardiomyoplasty for treatment of severe dilated cardiomyopathy. Eight patients were studied 15 days after the surgery (group 1) and 5 patients were studied from 24 to 52 months after the surgical procedure at the time of the cardiomyostimulator replacement (group 2). In the interim, LD was stimulated with burst of 6 pulses (duration, 185 milliseconds; burst frequency, 30 Hz) synchronized to every cardiac contraction, with a maximum of 100 LD contractions per minute. Images were acquired on a GE Sigma 1.5-T system (echo time, 25 milliseconds; repetition time, R-R x 2; slice thickness, 8 mm). The thickness of the LD decreased from 19.6 +/- 7.3 mm for group 1 to 7.6 +/- 0.8 mm for group 2 (P < .01). In addition, the signal intensity of the LD was compared with that of thoracic skeletal muscle and was found to be significantly increased in group 2 (2.19 +/- 0.42) compared with group 1 (1.04 +/- 0.07, P < .001). The signal intensity for group 2 on the T1-weighted images was similar to that of subcutaneous fat in those images. CONCLUSIONS: Morphological changes in the wrapped LD muscle consistent with fatty degeneration occur after DC and can be detected by MRI. Further studies will be necessary to demonstrate the clinical significance of such LD muscle flap changes.

Adipose Tissue↗
PubMed1994

Arrhythmias and sudden death after dynamic cardiomyoplasty.

BACKGROUND: The main causes of death in patients with severe cardiomyopathy are progressive heart failure and sudden death. The influence of cardiomyoplasty on the incidence of sudden death and arrhythmias in patients with cardiomyopathy remains unclear. The aim of this study was to investigate the occurrence of arrhythmias and sudden death after cardiomyoplasty. METHODS AND RESULTS: We studied 32 patients (26 male, 6 female; mean age, 48 +/- 12 years) who submitted to cardiomyoplasty for treatment of heart failure in New York Heart Association (NYHA) class III (n = 24) or class IV (n = 8). The etiology was idiopathic dilated cardiomyopathy in 27 patients, ischemic heart disease in 3 patients, and Chagas' heart disease in 2 patients. Patients were routinely studied before and every 6 months after cardiomyoplasty by means of radioisotopic angiography and 24-hour Holter monitor recordings. There were no operative or immediate postoperative deaths. During the postoperative period, 5 patients presented with acute atrial fibrillation and 1 had an episode of sustained ventricular tachycardia. All episodes were successfully treated with intravenous antiarrhythmic drugs or cardioversion. During follow-up (from 2 to 66 months), 15 patients died from sudden death (n = 5) or progressive heart failure (n = 10). Survival rates at 1, 2, and 4 years were 79.9 +/- 7%, 62.5 +/- 9.7% and 35 +/- 12.1%, respectively. At 6-month follow-up, NYHA functional class improved from 3.2 +/- 0.4 to 1.7 +/- 0.6 (P = .001) and left ventricular ejection fraction increased from 19.8 +/- 3.3% to 24 +/- 8.2% (P = .004). The mean values per day of premature ventricular complexes (PVCs) and episodes of nonsustained ventricular tachycardia (NSVT) did not change statistically. The mean number of PVCs per 24 hours before and at 6, 12, 24, 36, and 48 months after surgery were 126 +/- 44, 96 +/- 33, 90 +/- 29, 81 +/- 35, 71 +/- 35, and 59 +/- 48. The mean number of episodes of NSVT per 24 hours before and at 6, 12, 24, 36, and 48 months after surgery were 3.3 +/- 1.3, 1.9 +/- 0.5, 1.3 +/- 0.5, 1 +/- 0.5, 1.5 +/- 1.1, and 0.6 +/- 0.5, respectively. With respect to analysis of the idiopathic dilated cardiomyopathy subgroup, there also were no significant differences in the incidences of pre- and postoperative arrhythmias. CONCLUSIONS: Despite NYHA functional class and left ventricular function improvements observed after cardiomyoplasty, the incidence of arrhythmias did not change, and sudden death was an important finding mainly in late follow-up. The problem of sudden death after cardiomyoplasty, the mechanism that produces it, and the means to prevent it remain critical areas for future research.

Arrhythmias, Cardiac↗
PubMed1994

[Thiocyanate toxicity arising from prolonged use of sodium nitroprusside in severe heart failure].

PURPOSE: To evaluate the toxicity of thiocyanate induced by the infusion of sodium nitroprusside in patients with severe congestive failure. METHODS: We studied 23 patients with congestive heart failure, in class IV (NYHA) under continuous infusion of sodium nitroprusside with doses varying between 0.5 and 5.5 micrograms/kg/min. Clinical evaluation, thiocyanate serum dosage and laboratorial evaluation of renal, hepatic and pulmonary functions were done. RESULTS: Seventeen patients (74%) presented toxic levels of thiocyanate (over 10 micrograms/ml), with the average of 29.9 +/- 4.4 micrograms/ml. Only renal function was related to the presence of intoxication. Clinical evaluation was not accurate to diagnose the thiocyanate toxicity in the patients. CONCLUSION: Sodium nitroprusside is potentially toxic, especially when the renal function is abnormal. Thiocyanate dosage is useful in diagnosing nitroprusside induced toxicity and then it contributes to an adequate treatment and prevention of clinical toxicity.

Adult↗
PubMed1994

[Percutaneous transluminal coronary angioplasty after orthotopic heart transplantation].

We report the case of 22 year-old male who developed coronary artery disease two years after orthotopic cardiac transplantation, manifested as congestive heart failure NYHA functional class III. The left ventricular radioisotopic evaluation at rest revealed worsening of left ventricular ejection fraction from 50% to 39% (normal value > or = 55%) and septal hypokinesia. The hemodynamic and coronariographic study showed two subocclusive lesions at the mid portion and distal portion of the left descending coronary artery and the patient underwent PTCA of both lesions, successfully reducing them to 30%. A new radionuclide and echocardiographic evaluation of left ventricular function at rest, showed marked improvement of global function no regional abnormalities, increasing the ejection fraction from 39% to 45%. The patient showed improvement of NYHA functional class, passing to functional class II and was discharged home. We conclude that PTCA could be performed in a successful manner in this patient.

Adult↗
PubMed1994

[Laser coronary angioplasty. Critical analysis of the first patients].

PURPOSE: To evaluate the success rate and complications, as well as the technical difficulties involved catheter laser coronary angioplasty, making evident the unsuccessful cases. METHODS: Twenty eight patients were treated with laser from August to November, 1993. The treatment was complemented with balloon angioplasty. Lesions were complex: 10 (36%) were type B and 18 (64%), type C. Concerning the obstruction grade, 18 (64%) were > or = 95%. Laser generator CVX 300(TM) Spectranectics as well as Extreme(TM) and Vitesse(TM) catheters with 1.4, 1.7 and 2.0mm in diameter, concentric and excentric, were used. Laser procedure success was defined as a reduction > 20% in the obstruction grade. The procedure success was attended when the residual stenosis was < 50% after a 15-minute observation, after balloon complementation. RESULTS: The unsuccess rate with laser catheter (Lc) was 34% (10 lesions) of which 3 cases were solved by other methods, 5 were not successful because of anatomic difficulties in surpassing the lesion and, in the two others the success criterium in the reduction of the obstruction grade of the coronary artery was not achieved, although the lesion surpassing was possible with the use of balloon catheter. The final success reached 89% (21 lesions). The procedure complications were a case of thrombosis, a perforation accompanied by a myocardial infarction and another myocardial infarction (non-Q wave), all with good outcome. CONCLUSION: The use of laser in the treatment of coronary artery obstructive lesions is a viable method. Nonetheless, more experience is necessary to demonstrate its actual value, optimizate the results and may be reduce restenosis rate.

Adult↗
PubMed1994

[Dynamics of patient selection for heart transplantation or cardiomyoplasty].

PURPOSE: To evaluate patient selection for heart transplantation or dynamic cardiomyoplasty. METHODS: We evaluated 380 patients from April 1991 to July 1993. The ages ranged between 16 and 68 (mean 43.5 +/- 11.46) years, 303 (79.7%) were male. The diagnoses were dilated cardiomyopathy in 163 (42.9%), Chagas' cardiomyopathy in 70 (18.4%), ischemic heart disease in 61 (16.1%), hypertensive heart disease in 40 (10.5%), valvular heart disease in 23 (6.1%), alcoholic cardiomyopathy in 12(3.2%), peripartum cardiomyopathy in 5 (1.3%) and myocarditis of unknown etiology in 5 (1.3%). RESULTS: The indication of heart transplantation was eventually done in 55 (14.4%), and 19 (5%) were submitted to transplantation. Dynamic cardiomyoplasty was indicated in 9 (2.3%) patients and was performed in 8 (2.1%). In 30 (7.8%) patients there were clinical contraindications for transplantation. Conventional surgical treatment was indicated for 12 (3.1%) patients: myocardial revascularization and/or ventricular aneurismectomy in 5, surgical treatment of valvular heart disease in 6 and of atrial fibrillation in 1. Socioeconomic limitations precluded transplantation in 43 (11.3%) and psychic limitations hindered transplantation in 23 (6.0%) patients. Refusal of procedure by the patient occurred in 10 (2.6%) cases. Improvement of the symptoms occurred in 69 (18.1%) patients. CONCLUSION: A small percentage of patients are eligible and are eventually submitted to heart transplantation or dynamic cardiomyoplasty. New strategies may be delineated during follow up, as deferring transplantation or conventional surgical treatment of ischemic or valvular heart disease. Sociopsychic evaluation is an important step in the care of the patients.

Adolescent↗
PubMed1994

[Reproducibility of head-up tilt test in patients with neurocardiogenic syncope].

PURPOSE: In order to identify the reproducibility of head-up tilt test, a second test one week later in 22 patients with a positive first test, was performed. METHODS: The test was performed in a fasting state during the morning. The heart rate and blood pressure were monitored during 20 minutes in the supine position and then at 60 degrees for up to 40 minutes. The test were considered positive if the patient experienced syncope or pre-syncope with fall in systolic blood pressure > 30mmHg. The following aspects were evaluated: reproducibility of the positive response; the type of response (hypotension, asystole or hypotension plus bradycardia) and the time interval between tilt and the beginning of symptoms. RESULTS: Eighteen (82%) patients had a second positive response; 14 (77.8%) of then had the same type of response; and 17 (94%) had syncope in similar time interval after tilt. CONCLUSION: The head-up tilt testing has good reproducibility, although its use in the therapeutic management needs a longer period of evaluation.

Adolescent↗
PubMed1994

[Arrhythmias following orthotopic heart transplantation].

PURPOSE: To correlate the incidence of arrhythmias to the degree of allograft rejection on endomyocardial biopsy. METHODS: Seventeen patients who underwent orthotopic heart transplantation were submitted to ambulatory Holter monitoring 24h prior to endomyocardial biopsy. The biopsy results were compared to Holter monitoring results. RESULTS: The mean study period was 252 +/- 166 days (15 to 515). We found a high incidence of ventricular premature beats (> 70%), except in patients with severe rejection (25%), but there was no statistically significant difference between the groups with no rejection, mild and moderate rejection. Atrial premature beats were more common in patients with mild and moderate rejection (53% and 70%, respectively) when compared to patients with no rejection (33%) and patients with severe rejection (9%), (p < 0.05). Sinus bradycardia was present in 50% of patients with severe rejection, but only in 9% of moderate, 3% of mild and 5% of the patients with no rejection (p < 0.05). CONCLUSION: Supraventricular tachycardia and atrial premature beats are related to moderate rejection. Ventricular premature beats are not related to degree of rejection. Sinus bradycardia occurring in the first year after transplantation should suggest severe cardiac allograft rejection.

Arrhythmias, Cardiac↗
PubMed1994

[Hypertension and complex ventricular arrhythmias. Evolution following a long-term blood pressure treatment].

PURPOSE: To evaluate the effects of long-term antihypertensive treatment in the frequency as well as in the complexity of ventricular arrhythmias in arterial hypertension. METHODS: Twenty three patients, 14 males and 11 whites, with mean age of 46 years, were submitted to 24 hours ambulatory electrocardiographic monitoring and echocardiographic studies before and 9 months after antihypertensive treatment. RESULTS: There was no significant serum potassium level alteration, but significant reductions of both systolic (from 192 +/- 29mmHg to 161 +/- 25mmHg) and diastolic (from 122 +/- 17mmHg to 99 +/- 16mmHg) blood pressure. Left ventricular percent of fiber shortening significantly increased, even though only from 26 +/- 9% to 30 +/- 9%, and end-systolic wall stress did not change at all (before 258 +/- 94 10(3) dyn/cm2, after 255 +/- 101 10(3) dyn/cm2). Left ventricular mass index showed significant but also a discrete reduction from 211 +/- 75g/m2 to 196 +/- 70g/m2. Ambulatory electrocardiographic monitoring did not show any significant decrease in neither ventricular ectopic beats nor in couplets. Non-sustained ventricular tachycardia episodes remained unchanged too. Four out of 8 patients with more than 30 ventricular ectopic beats per hour reduced it by more than 70%. On the other hand, the number of patients with couplets was reduced from 10 to 8 whilst those with non-sustained ventricular tachycardia increased from 5 to 7. Furthermore, in 7 patients reevaluated 24 months thereafter results were not expressively dissimilar. CONCLUSION: In hypertensive patients with either severe degree of left ventricular hypertrophy or myocardial dysfunction, long-term blood pressure treatment that produce no impressive changes in these abnormalities also do not modify complex ventricular arrhythmias, in spite of a great reduction in the increase blood pressure.

Adolescent↗
PubMed1994

[Hemodynamic and neurohormonal profile during assisted circulation with heterotopic artificial ventricle followed by heart transplantation].

We describe the hemodynamic and neurohormonal data during ventricular assistance device system support as a bridge to heart transplantation of one patient, 30 years old, with heart failure due to Chagas' heart disease in functional class IV. We determined the pressures in mmHg of right atrium (RA), pulmonary artery pressure (PAP), pulmonary wedge pressure (WEDGE), arterial blood pressure (AP), and the cardiac output (CO) in l/min. In addition, the blood levels of norepinephrine (Ne), renin (Re), epinephrine (Ep), lactate and the mixed venous oxygen pressure (pVO2) were determined. The CO increased from 2.14 to 3.9-4.2 l/min, the AD decreased from 26mmHg to 8mmHg, the MPAP reduced from 38mmHg to 14-24mmHg, the WEDGE reduced from 25 to 4mmHg and the AP become normal. The Ne reduced from 1927pg/ml to 983pg/ml, the lactate reduced from 99mg/dl to 22mg/dl and the pVO2 increased from 28mmHg to 43mmHg. The EP remained between 81pg/ml and 129pg/ml, the renin activity remained between 113ng/ml/hr and 136ng/ml/hr. Thus, during the ventricular assistance device system support there was a improvement in hemodynamic and neurohormonal conditions. The patient underwent successful heart transplantation.

Adult↗
PubMed1994

[Diagnostic value of the tilt test in the evaluation of syncope of unknown origin. Preliminary results].

PURPOSE: In order to identify neurally mediated syncope, head-up tilt testing was performed in patients with recurrent unexplained syncope. METHODS: The tests were performed in 125 patients in the fasting state, between 8:30 and 11:30 a.m. The blood pressure and heart rate were continuously monitored during 20 minutes in the resting state, and then, positioned at 60 degrees angle, for up to 40 minutes. A group of 20 patients with first negative test was submitted to intravenous isoproterenol in bolus of 2 micrograms every 2 minutes until symptoms occur or at a total dose of 8 micrograms. The test was considered positive when systolic blood pressure decreased at least 30 mmHg and the patient experimented syncope or pre-syncope. RESULTS: In 52 patients the test was positive (41.6%), 63.5% of which had hypotension exclusively; 7.7% asystole; and 28.8% had hypotension and bradycardia. Nine of the 20 patients submitted to isoproterenol test were positive (45%). All patients recovered spontaneously after returning to supine position. CONCLUSION: Head-up tilt testing is a safe and effective method for the identification of neurally mediated syncope.

Adolescent↗
PubMed1993

Beta-blocker infusion did not improve left ventricular diastolic function in myocardial infarction: a Doppler echocardiography and cardiac catheterization study.

Left ventricular (LV) diastolic function changes after myocardial infarction. It has been suggested that beta blockers may improve diastolic function in hypertensive and heart failure patients. Doppler echocardiographic filling patterns and invasive hemodynamic indices have been used to analyze LV diastolic function. To determine the effect of beta blockers on LV diastolic function, we studied 32 patients with anterior wall myocardial infarction with a mean age of 53 years. Peak early and late flow velocities, peak early-to-late flow velocities ratio, pressure half time, diastolic filling period, isovolumic relaxation time, cardiac index, mean arterial pressure, wedge pressure, and systemic and pulmonary vascular resistance indices were obtained simultaneously before and after an intravenous infusion of 10 mg of atenolol. Cardiac index decreased from 4.27 +/- 0.97 to 3.19 +/- 0.91 l/min/m2 (p = 0.0001); mean arterial pressure decreased from 85 +/- 10 to 80 +/- 11 mmHg (p = 0.004); wedge pressure increased from 11 +/- 5 to 13 +/- 4 mmHg (p = 0.002); systemic vascular resistance index increased from 1586 +/- 409 to 1980 +/- 634 dyn.m2.s/cm5 (p = 0.0002); pulmonary vascular resistance index increased from 115 +/- 58 to 163 +/- 72 dyn.m2.s/cm5 (p = 0.0004); peak late flow velocity decreased from 64 +/- 15 to 49 +/- 14 cm/s (p = 0.0001); early-to-late ratio increased from 0.95 +/- 0.35 to 1.29 +/- 0.36 (p = 0.0001); diastolic filling period increased from 300 +/- 108 to 400 +/- 110 ms (p = 0.0001) and isovolumic relaxation time increased from 133 +/- 29 to 143 +/- 29 ms (p = 0.009). No significant changes were observed for peak early flow velocity and pressure half-time.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Immunohistochemical characterization of infiltrating cells in human chronic chagasic myocarditis: comparison with myocardial rejection process.

Cellular subpopulations that infiltrate the heart in human chronic chagasic myocarditis were defined immunohistochemically in endomyocardial biopsy (EMB) specimens. T cells formed 96.3% of the inflammatory infiltrate, predominantly CD8+ (cytotoxic/suppressor) T cells. The mean numbers of CD8+ and CD4+ (helper) T cells in the myocarditis were compared to those present in the myocardial rejection process. Mean numbers of CD8+ T cells were similar in both groups of EMB specimens while CD4+ T cell counts, CD4+/CD8+ ratios and CD4+ antigen expression were significantly lower in the chagasic group compared to the myocardial rejection group (P < 0.002). The persistent lower number and diminished expression of CD4+ T cells suggest an immunological imbalance in patients with chronic chagasic myocarditis. A possible participation of Trypanosoma cruzi parasites in the development of such immunological abnormalities is also discussed.

Adult↗
PubMed1993

Early administration of captopril and nitroglycerin in combination after acute myocardial infarction: an invasive haemodynamic study.

The combination of captopril and nitroglycerin early after acute myocardial infarction (AMI) could lead to a dangerous decrease in blood pressure coronary perfusion. To evaluate the safety aspects and haemodynamic effects of this combination, we studied 36 first 'Q wave' thrombolysed anterior wall AMI patients during the 24 h following the onset of symptoms. Afterwards, thrombolysis patients received a continuous infusion of nitroglycerin and were submitted to pulmonary artery catheterization. Those patients with mean arterial pressure (MAP) > or = 70 mmHg, cardiac index > or = 2.2 l.min-1.m-2, and wedge pressure > or = 10 mmHg were included and randomized to receive 6.25 mg of captopril every 6 h on the first day and 12.5 mg qid on the second if MAP > or = 70 mmHg (group 1). A second group (group 2) received a placebo. Haemodynamic parameters were determined after 1, 6 and then every 6 h up to 48 h after basal measurements. Significant differences were observed only for the MAP and the rate-pressure product (reduction in group 1 values, P < 0.05). However, MAP was maintained within acceptable limits. Our data support the fact that the combination of captopril and nitroglycerin in the early hours of a non-complicated anterior wall AMI is safe, and could guarantee its use in large clinical trials to determine the effects on left ventricle remodelling and survival after AMI.

Adult↗
PubMed1993

Maximal functional capacity in patients with endomyocardial fibrosis.

We evaluated objectively the cardiocirculatory dysfunction of patients with EMF, and related the functional class (FC-NYHA) to the data obtained by analysis of maximal functional capacity. We studied 55 subjects, divided into three groups: group 1 (G1) 21 (38.1%) normal persons, group 2 (G2) seven (12.7%) patients with EMF who were in FC I or II, and group 3 (G3) 27 (49%) patients in FC III or IV. Maximal oxygen consumption (VO2max) and O2 pulse index (PO2max) were obtained using a Beckman computerized gas analyser. The mean values were significantly different among the three groups. We conclude that the greater the clinical impairment, the greater the alterations that occur in the indices of cardiac function.

Adult↗
PubMed1993

[Fatal myocardial infarction in a young patient due to coronary arteritis].

A 34 year-old male patient suffered an acute anterior wall infarction at age 32. Myocardial ischemia was demonstrated later by stress testing and thallium myocardial scintigraphy. Coronary arteriography revealed a proximal 90% obstruction of the left anterior descending artery. The patient was submitted to percutaneous transluminal coronary angioplasty. The procedure was unsuccessful as the catheter could not progress through the obstruction. On follow-up, there was less than ideal adherence to medical treatment and the patient complained of occasional atypical non-effort related chest pain. Two years later the patient suffered a large fatal myocardial infarction. Necropsy disclosed that the cause of myocardial infarction was severe coronary arteritis of left circumflex artery with giant cell granulomas.

Adult↗