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G Derchi

Publications and source records attributed to G Derchi.

12 recordsLinked to original sources
PubMed1998

Panoramic coronary angiography.

OBJECTIVES: We describe a new imaging technique for coronary angiography. BACKGROUND: The conventional approach to coronary angiography exploits static perspective imaging over multiple cardiac cycles, using a limited number of empirically selected views. This approach entails both lack and redundancy of information and may result in suboptimal visualization of the individual lesion, contributing to diagnostic inaccuracy. METHODS: We developed a new imaging technique exploiting dynamic perspective, obtained by transverse 180 degree rotation of the C arm of a conventional angiographic unit during standard selective coronary opacification and filming. This technique yields a picture of the coronary tree isocentrically rotating around the longitudinal axis and conveying complete three-dimensional information. RESULTS: A complete diagnostic run for both coronary arteries, including two 25 degree cranial and two 25 degree caudal scans is accomplished with a total cine time of 16 s and 45 ml of contrast medium, about half of that required by conventional angiography. In a series of 129 consecutive patients studied by both the conventional and the new technique with quantitative measurements of the severity of the stenoses, the final diagnosis was identical in 65. In no case was a stenosis detected only by the conventional approach. However, in 31 patients the new technique permitted identification of 34 critical stenoses (79+/-8% [mean +/- SD]) either underestimated (61+/-3% n = 24, p < 0.001) or undetected (21+/-22%, n = 10, p < 0.001) in the standard projections. In a further 28 cases, 33 subcritical lesions (60+/-5%) were visualized in the rotational images but were insignificant (24+/-22% p < 0.001) in the standard projections. In five additional patients, distinct laminar plaques were clearly visualized only by the panoramic approach. CONCLUSIONS: This new technique can be easily implemented on conventional angiographic equipment at no additional cost. It provides complete, operator-independent exploitation of the angiographic information, resulting in enhanced diagnostic accuracy.

Coronary Angiography↗
PubMed1994

Atrial natriuretic peptide response is blunted in patients with acute myocardial infarction and mild left ventricular dysfunction.

Neurohumoral parameters in 45 asymptomatic patients with acute myocardial infarction were measured. In patients with mild left ventricular dysfunction (ejection fraction < or = 45% and/or left ventricular end-diastolic pressure > or = 15 mm Hg), atrial natriuretic peptide levels differed significantly from those in patients with normal left ventricular function (127 +/- 74 pg/ml vs. 79 +/- 71 pg/ml; p < 0.001). After stimulus an increase in atrial natriuretic peptide levels (79 +/- 71 to 118 +/- 86 pg/ml; p < 0.001) was found only in patients with normal hemodynamic parameters. These data show that in patients with left ventricular dysfunction, the atrial natriuretic system is activated; however, atrial natriuretic peptide response to stimulus is present only in patients with normal hemodynamics.

Adult↗
PubMed1993

Selective activation of atrial natriuretic peptide in patients with myocardial infarction and mild left ventricular dysfunction.

The purpose of this study was to investigate whether neurohumoral activation occurs in asymptomatic patients with acute myocardial infarction (AMI) and without clinical signs of heart failure. During the early phase of AMI (mean 8 days), the neurohumoral profiles of 60 patients (mean age 59 range 37 to 70) were examined. Blood levels of the following humoral parameters were measured: atrial natriuretic peptide (ANP), plasma renin activity, aldosterone and vasopressin. All patients underwent cardiac catheterization during hospitalization. Baseline hemodynamic characteristics identified left ventricular dysfunction (ejection fraction < or = 45% and/or left ventricular end-diastolic pressure > or = 15 mmHg) in 32 patients; the remaining 28 patients had normal hemodynamic parameters. In patients with AMI, plasma ANP levels differed significantly from control subjects (111 +/- 74 pg/ml vs. 53 +/- 18 pg/ml; P < 0.001). In patients with AMI and mild left ventricular dysfunction ANP levels were significantly increased when compared to patients with AMI and normal left ventricular function (129 +/- 73 pg/ml vs. 82 +/- 69 pg/ml; P < 0.001). The hemodynamic data showed a significant correlation with ANP only in patients with AMI and left ventricular dysfunction (EF% r = 0.42; LVEDP r = 0.44; P < 0.001). These data show that in patients with myocardial infarction and without heart failure, the atrial natriuretic peptide is the only neurohumoral system activated out of all neurohumoral systems tested in this population and its circulating levels are strictly related to the degree of left ventricular dysfunction.

Adult↗
PubMed1993

Paradoxical decrease in circulating neuropeptide Y-like immunoreactivity during mild orthostatic stress in subjects with and without congestive heart failure.

Neuropeptide Y (NPY) is thought to be co-released with catecholamines in response to major cardiovascular stresses, but its relation to the release of catecholamines in response to minor stresses has been less well described. We therefore studied the response of plasma NPY-like immunoreactivity (NPY-Li) levels to standing (10 min) in eight normal subjects and 11 patients with congestive heart failure, and to short-term (6h) vasodilator therapy in 13 patients with congestive heart failure. In both normal and heart failure patients, NPY-Li-decreased (296 +/- 73 to 233 +/- 63 pg.ml-1 and 652 +/- 36 to 516 +/- 25 pg.ml-1 (P < 0.01) respectively) in response to standing, whereas catecholamines increased in both groups (norepinephrine 203 +/- 73 to 507 +/- 165 pg.ml-1 and 493 +/- 197 to 813 +/- 336 pg.ml-1 (P < 0.001) respectively and epinephrine 23 +/- 12 to 38 +/- 12 pg.ml-1 and 46 +/- 19 to 62 +/- 28 pg.ml-1 (P < 0.001) respectively). Both basal circulating NPY-Li and catecholamine levels were markedly increased in congestive heart failure patients, but catecholamines and NPY-Li did not correlate with each other. After 6 h of nitroglycerin infusion, mean arterial pressure was decreased, but circulating neurohumoral levels remained unchanged and NPY-Li levels decreased (653 +/- 37 to 517 +/- 26 pg.ml-1, P < 0.01). It is concluded that basal circulating NPY-Li and catecholamine levels are increased in congestive heart failure and that this neurohormone could play a concomitant role in the increase in peripheral resistance in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Cardiac involvement in thalassaemia major: altered atrial natriuretic peptide levels in asymptomatic patients.

Congestive heart failure is the most common cause of death in young adults with thalassaemia major. In the present study we compared atrial natriuretic peptide levels (ANP) in 30 asymptomatic patients with thalassaemia major (aged 16.6 +/- 6.4 years), normal left ventricular diastolic cavity dimension and systolic function, with 30 aged and sex matched normal control subjects. ANP levels were significantly higher in patients with thalassaemia major compared to controls (93.9 +/- 26.3 pg.ml-1 vs 51.8 +/- 26.5 pg.ml-1; P < 0.001). Plasmatic renin activity, aldosterone, urinary sodium and catecholamine levels at basal conditions did not differ significantly in these two groups (ns). Blood volume stimulation (blood transfusion) in thalassaemic patients was followed by an increase of mean ANP values (93.9 +/- 26.3 to 109.1 +/- 40.5 pg.ml-1; P < 0.03). ANP basal levels above two standard deviations of the mean values obtained in normal control subjects were considered as abnormal and found to be in close correlation with the presence of diastolic dysfunction of the left ventricle identified by Doppler echocardiography. The method has a 57% sensitivity and a 91% specificity for revealing pre-clinical cardiac involvement (P < 0.02). Although a longer observation period is necessary in order to define the clinical and prognostic significance of these data, our results show that an increase in ANP basal values is present in asymptomatic patients with thalassaemia major. This suggests initial myocardial involvement, while ANP response to volume overload is maintained.

Adolescent↗
PubMed1987

[A case of acute voluntary poisoning with flecainide in a suicide attempt].

A case of acute poisoning caused by an overdose of flecainide (1.5 gr. per os), taken in order to commit suicide, is described here. With a plasmatic concentration of 5000 ng/ml the drug induced a soporose condition, shallow breathing with phases of apnea and intermittent muscular clonuses, a clinical picture of shock with a idioventricular rhythm at a rate of 40/min. and widening of the QRS (400 msec.). The infusion of orciprenaline and 5% glucose solution induced an increase in the ventricular frequency and the normalization of the circulatory condition. Twenty hours after ingestion sinus rhythm was restored. Highest therapeutic level of flecainide was reached 48 hours after ingestion. The stimulation threshold during the acute phase was 1.8 mA and came down 1.3 mA after wash-out. The outcome was favourable.

Adult↗