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Biomedical subjects

P Voci

Publications and source records attributed to P Voci.

At least 73 records · Page 4Linked to original sources
PubMed1993

Aortic intussusception: a rare presentation of type A aortic dissection evidenced by transesophageal echocardiography.

Thoracic aorta dissection involving the ascending tract (type A) is an affection which can often become lethal. The possibility of reaching immediate diagnosis and setting up surgical treatment are fundamental for the patient prognosis. In the case report, trans-esophageal echocardiography (TEE) made it possible to reach an immediate diagnosis of an unusual presentation of the dissection of type A, the intussusception of the aorta, not diagnosed by other non invasive methodologies, thus permitting timely surgical treatment.

Aortic Dissection↗
PubMed1993

[The identification of vital myocardium with the dopamine stimulation test: an intraoperative echocardiographic study].

The aim of this study was to detect by dopamine echocardiography dysfunctioning but viable myocardial segments. We have studied 19 patients with 3-vessel disease and chronic, stable angina pectoris. Patients were studied by intraoperative transesophageal echocardiography during coronary artery bypass surgery. The analysis of regional systolic function was performed utilizing the transgastric short-axis view at papillary muscle level and dividing the left ventricle in 8 segments, according to the recommendations of the American Society of Echocardiography. A total of 152 myocardial segments were analyzed. Percent systolic wall thickening was calculated in each segment at baseline (early after pericardiectomy), during dopamine infusion (5 mcg/kg/min) and 30 min after separation from cardiopulmonary bypass (after protamine administration). The administration of vasodilatory or inotropic drugs was avoided. The echocardiographic images were recorded on videotape and analyzed off-line by 2 independent observers. Segments showing at baseline percent systolic wall thickening < 30% were considered dysfunctional (134/152 = 88%). Eighty-four (63%) of these segments, increasing during dopamine infusion percent systolic wall thickening > 10% (from 12.9 +/- 3.5 to 20.7 +/- 5.4%; p < 0.05) were considered responder. On the other hand, 50 segments (37%) showing during dopamine an increment in percent systolic wall thickening < 10%, were considered non-responder. After coronary surgery, responder segments showed a significant increase in percent systolic wall thickening in comparison with baseline values (from 12.9 +/- 3.5 to 22.1 +/- 4.3%; p < 0.05). Segments non-responding to dopamine showed no significant changes in percent systolic wall thickening after myocardial revascularization.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1992

Transesophageal dipyridamole echocardiography for diagnosis of coronary artery disease.

The value of transthoracic dipyridamole echocardiography has been extensively documented. However, in some patients, because of a poor acoustic window, the rest transthoracic examination is not always feasible and the transesophageal approach is more convenient. Therefore, transesophageal echocardiography with high dose dipyridamole (up to 0.84 mg/kg body weight over 10 min) was performed in 32 patients in whom the transthoracic dipyridamole test either was not feasible (n = 29) or yielded ambiguous results (n = 3). The transesophageal echocardiographic test results were considered abnormal when new dipyridamole-induced regional wall motion abnormalities were observed. All 32 patients underwent coronary angiography; significant coronary artery disease was defined as greater than or equal to 70% lumen diameter narrowing in at least one major vessel. All patients also performed a bicycle exercise test 1 day before transesophageal dipyridamole echocardiography. Transesophageal stress studies were completed in all patients, with a maximal imaging time (in tests with a negative result) of 20 min. No side effects or intolerance to drug or transducer was observed. The left ventricle was always visualized in the four-chamber and transgastric short-axis views. High quality two-dimensional echocardiographic images were obtained in all patients both at rest and at peak dipyridamole infusion and were digitally analyzed in a quad-screen format. Coronary angiography showed coronary artery obstruction in 24 patients: 6 had single-, 9 double- and 9 triple-vessel disease. The transesophageal dipyridamole test showed a specificity of 100% and an overall sensitivity of 92%. The sensitivity of this test for single-, double- and triple-vessel disease was 67%, 100% and 100%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Angiography↗
PubMed1992

Intra-operative contrast echocardiography in coronary artery disease.

Intra-operative echocardiography is becoming a reference standard for the evaluation of the results of cardiac surgery. Myocardial contrast echocardiography has been recently introduced to study regional myocardial blood flow and cardioplegia distribution in patients undergoing coronary artery surgery. It can be used in three different stages: before cardiopulmonary bypass, to identify the most hypoperfused myocardial segments; during cardioplegic arrest, to check the adequacy of myocardial protection; postoperatively, to assess graft patency. The priority in revascularization can be assigned according to the regional perfusion pattern, which depends not only on coronary artery narrowing, but also on the extent of collateral circulation. The distribution of cardioplegia to the myocardium can be monitored in real time with clear identification of poorly protected myocardial segments. The injection in the graft after weaning from cardiopulmonary bypass allows assessment of graft patency and measurement of the 'area at risk' for graft occlusion. In conclusion, the information obtained in the operating theatre by myocardial contrast echocardiography is original and promises to have a significant impact on surgical strategy. Implementation of the ultrasonic equipment to obtain quantitative on-line data on myocardial blood flow is desirable.

Blood Flow Velocity↗
PubMed1992

Echocardiographic analysis of dysfunctional and normal myocardial segments before and immediately after coronary artery bypass graft surgery.

Echocardiography has revealed evidence of "subnormal" regional contraction patterns that result from myocardial ischemia and are often accompanied by nonadjacent "hyperkinetic" regions. Whether these regions of hyperkinetic wall motion persist unchanged or revert to normal after coronary artery bypass graft (CABG) surgery has not been studied in humans. Using echocardiography, we evaluated both dysfunctional and normal myocardial regions for changes in segmental wall motion and percent of systolic wall thickening that occurred immediately after CABG surgery in 32 patients. Segmental wall motion analysis before CABG surgery in these patients revealed that 170 (66%) of 256 myocardial segments were subnormal, of which 115 (67%) improved and 102 (60%) returned to normal immediately after CABG surgery. Eleven myocardial segments that were hyperkinetic before CABG surgery returned to normal after CABG surgery. Preoperatively, 162 (63%) of 256 myocardial segments had systolic wall thickening less than 30%, which increased from 11.8% +/- 8.9% to 24.3% +/- 14.3% (mean +/- SD) (P less than 0.01) postoperatively. Conversely, a reverse trend was found when systolic wall thickening was greater than 30% before CABG surgery: thickening decreased from 46.2% +/- 13.8% to 33.4% +/- 14.8% after CABG surgery (P less than 0.01). Thus, we conclude that immediately after CABG surgery, there is a recovery of function in some myocardial segments and a reduction in function in others. Furthermore, we conclude that the semiquantitative assessment of percent of systolic wall thickening is a more reliable (consistent) echocardiographic index of myocardial function compared with the qualitative assessment of segmental wall motion immediately after CABG surgery.

Adult↗
PubMed1992

[The quantization of regional blood flow and volume with contrast echography: a mathematical model].

In this paper is described a new mathematical model for the study of regional blood flow in organs accessible to ultrasonic imaging. A prerequisite for the correct application of this model is the utilization of an echocontrast agent presenting with the same microrheology as red blood cells. This model is derived from an implementation of the indicator-dilution theory and is specifically designed to calculate relative changes in blood flow and volume in neighboring segments within the same organ. With this model is not required the acquisition of an input function, that is one of the major shortcomings affecting the classical theory. The applicability of quantitative contrast ultrasonography in humans may have a significant impact on our understanding of the pathophysiology of cardiovascular diseases.

Algorithms↗
PubMed1992

Reversal of left ventricular dysfunction early after coronary artery bypass grafting.

This study evaluated the early effect of coronary artery bypass grafting (CABG) on left ventricular systolic function. Intraoperative echocardiography was performed in 32 patients with coronary artery disease and chronic, stable angina pectoris. Left ventricular short-axis images at mid-papillary muscle level were videotaped at similar loading conditions shortly after pericardiotomy and 28 +/- 5 min after weaning from cardiopulmonary bypass. Inotropic or vasodilator administration was avoided or suspended at least 5 min before echocardiography. The left ventricle was divided off-line into 8 segments. The ejection fraction and percent systolic wall thickening (PSWT) were calculated pre- and post-CABG. A total of 256 myocardial segments were analyzed. Any segment showing a preoperative PSWT of less than 30% was considered dysfunctional, while segments with a PSWT of greater than 30% were considered normal. After surgery, the PSWT in 162 dysfunctional segments (63%) increased from 11.8 +/- 8.9 to 24.3 +/- 14.3% (p less than 0.001). Conversely, a reverse trend was found in the remaining 94 normal segments (37%) with a decreasing PSWT from 46.2 +/- 13.8 to 33.4 +/- 14.8% (p less than 0.001). Ejection fraction also increased from 47.2 +/- 3.5 to 58.5 +/- 18.9% (p less than 0.05). Thus, CABG is followed by an immediate recovery of systolic function in dysfunctional myocardial segments, while compensatory hyperfunction is reduced in normal segments. These results indicate that the post-CABG improvement in PSWT is due to redistribution of coronary blood flow, rather than to pharmacological or hormonal influences. Intraoperative echocardiography is a useful technique to monitor left ventricular function during surgery.

Adult↗
PubMed1991

Aldosterone-secreting adenoma and dysautonomic failure: the challenging association of 2 extreme conditions.

This is the first published report describing the association between primary aldosteronism and chronic idiopathic orthostatic hypotension. The clinical history of a 57 year old man with incapacitating postural hypotension and severely symptomatic supine hypertension, is described. A possible occupational etiology of postural hypotension, with regard to a prolonged exposure to cutting oils, is considered. The intriguing pathophysiologic aspects of this unique association are discussed. The Authors suggest that, although supine hypertension is common in chronic idiopathic orthostatic hypotension, a careful examination of the adrenal glands is advisable in these patients, to rule out the presence of an associated adrenal adenoma.

Adenoma↗
PubMed1990

[Primary pulmonary hypertension: a retrospective study of 13 patients].

Twenty-four patients (9M and 15F, mean age 28 years) with primary pulmonary hypertension underwent cardiac catheterization in our institution from 1955 to 1989. The prevalence of the disease in our population was lower (0.2%) than that reported by other Authors (1%). Thirteen of these patients (4 M and 9 F, mean age 32 years) evaluated between January 1979 and December 1989, were followed. Five were alive after 52 +/- 30 months (Group A) while 8 died after 11 +/- 9 months (Group B). In Group B mean pulmonary pressure was significantly higher than in Group A (66.7 +/- 17.2 vs 41.2 +/- 19.0 mmHg, p less than 0.05, respectively). Cardiac index and systolic volume index were lower in Group B than in Group A (2.07 +/- 0.85 vs 3.72 +/- 1.32 l/min/m2, p less than 0.01 and 24.43 +/- 10.25 vs 41.08 +/- 16.97 ml/m2, p less than 0.05, respectively). Pulmonary resistance index and systemic resistance index were higher in Group B than in Group A (3039 +/- 1519 vs 1181 +/- 1236 dyne x s x cm-5/m2, p less than 0.01; 4277 +/- 1794 vs 2309 +/- 1238 dyne x s x cm-5/m2, p less than 0.01). One patient underwent repeated cardiac catheterization after 2 years. This patient showed a deterioration of the hemodynamic parameters, consistent with the worsening of the clinical conditions. In conclusion, in our population of patients with primary pulmonary hypertension, an increase in pulmonary artery pressure and pulmonary resistances, as well as a decrease in cardiac index, are associated with a reduced life expectancy. On the other hand, right atrial pressure does not affect mortality.

Adolescent↗
PubMed1990

[Hypomagnesemic coma in heart failure: description of a case].

The case of a patient developing hypomagnesemic encephalopathy and coma secondary to intensive treatment for severe cardiac failure, is reported. Following an early improvement of symptoms and signs of cardiac failure, a rapidly developing neurologic disorder appeared. This was characterized by insomnia, agitation, mental derangement and, finally, sopor and I-II degree coma. Serum magnesium concentration was 1.0 mEq/l. Magnesium sulfate iv infusion was followed by a immediate and complete recovery from the neurological disorder. Patients with cardiac failure undergoing prolonged intensive therapy are prone to develop hypomagnesemia. This electrolyte alteration may be responsible for symptoms and signs of central nervous system involvement (metabolic encephalopathy) that need to be differentiated from those of organic origin.

Coma↗
PubMed1989

Quantitation of renal blood flow by contrast ultrasonography: preliminary results.

Contrast ultrasonography, employing tracers behaving like red blood cells, is a promising technique to study regional blood flow distribution. Aim of this note is to quantitate renal blood flow in the dog using contrast ultrasonography. Mathematical formulae derived from the classical dye-dilution theory are applied. Ten different renal blood flow levels (ranging from 16 to 125 ml/min) were obtained by means of mechanical (stenosis and reperfusion) and pharmacological interventions (iv infusion of adrenaline, noradrenaline and fenoldopam). Renal blood flow was measured by electromagnetic flow-meter and contemporary calculated by contrast ultrasonography. The correlation coefficient between measured and calculated flow was 0.92 (p less than 0.01). Contrast ultrasonography is a technique capable of measuring renal blood flow at a wide range of different flow levels.

Albumins↗
PubMed1984

Nomogram for calculation of stenotic cardiac valve areas from cardiac output and mean transvalvular gradient.

In 15 patients (group 1) with isolated mitral stenosis and in 14 patients (group 2) with isolated aortic stenosis the stenotic valve areas were calculated according to: A) Gorlin's formula; B) Hakki's simplified formula, using mean mitral gradient by planimetry or peak-to-peak aortic gradient; C) the three-point simplified formula, using mean gradient calculated by the three-point method for both mitral and aortic valve. The three-point method is definitely easier to use than planimetry. The values (mean +/- SD) of mitral valve areas in group 1 patients were, respectively: 1.56 +/- 0.63 cm2; 1.56 +/- 0.55; 1.51 +/- 0.53. The values of aortic valve areas in group 2 patients were: 0.91 +/- 0.63; 0.77 +/- 0.41; 0.88 +/- 0.52. An excellent correlation was shown between the valve area calculated by Gorlin's formula and both Hakki's simplified formula and the three-point simplified formula. For aortic valve area the correlation is even better if the mean gradient by the three-point method is used instead of the peak-to-peak gradient. On the basis of the simplified formula, a nomogram was constructed which allows an immediate calculation of valve areas from cardiac output and transvalvular gradient.

Adult↗
PubMedDate not supplied

Acquired coronary-to-left ventricle fistula: evidence by myocardial contrast echocardiography.

The case report subject is a patient with an old anteroseptal myocardial infarction and postinfarction angina who developed, over the years, a small left coronary-to-left ventricle fistula. The first coronary angiogram, performed 4 months after the infarction, was negative for coronary fistula. The diagnosis was made 3 years later, at repeat cardiac catheterization with myocardial contrast echocardiography. Left and right coronary injections of 0.2 cc of sonicated 5% human albumin microbubbles generated a bright cloud of contrast entering the left ventricular cavity at the level of the distal third of the interventricular septum. Conversely, cineangiography failed to show on-line the fistulous communication that was evident only after careful cineangiographic reviewing. This case demonstrates the high efficacy of myocardial contrast echocardiography in identifying very small coronary fistulae.

Cardiomyopathies↗