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P Rizzon

Publications and source records attributed to P Rizzon.

At least 109 records · Page 6Linked to original sources
PubMed1993

On-line assessment of left ventricular function by automatic border detection echocardiography during rest and stress conditions.

A new echocardiographic system, automatic boundary detection (ABD) echocardiography, provides automatic on-line quantification of the left ventricular cavity area. To assess the potential of ABD echocardiography in measuring left ventricular dimensions and detect stress-induced changes in left ventricular function, we studied 25 patients. Thirteen were studied to compare left ventricular cavity areas and fractional area change by using 2DE and ABD echocardiography during routine studies in multiple views; 12 patients were studied during transesophageal atrial pacing by ABD-echocardiography in 4-chamber or short-axis views. End-diastolic and end-systolic left ventricular areas measured by ABD echocardiography were not significantly different from two-dimensional ones for all the echocardiographic views, except the apical 4-chamber view; fractional area change values obtained with ABD were slightly lower than 2DE ones, although not significantly. High correlation values were found between the 2 techniques for end-diastolic area (r = 0.94, SEE = 3.69 cm2), end-systolic area (r = 0.90, SEE = 4.49 cm2) and fractional area change (0.73, SEE = 9.7%); similar results were obtained for each single echocardiographic view. A decrease was found from rest to peak-pacing in end diastolic area (25.2 +/- 5.1 cm2 versus 21.1 +/- 4.3 cm2, p < 0.003), end systolic area (16.2 +/- 6.0 cm2 versus 14.8 +/- 5.3 cm2, p < 0.016) and fractional area change (38.5 +/- 12.7% versus 31.8 +/- 9.6%, p < 0.003) with a return to baseline values in post-pacing (26.3 +/- 4.3 cm2 and 17.0 +/- 5.4 cm2 and 37.3 +/- 11.3%, p < 0.003 versus peak-pacing, NS versus rest for each parameter).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[The Italian contribution to the application of high-technology methods to clinical trials].

Clinical trials are important research tools currently used in assessing new drugs and therapeutic strategies, which are unable to produce large effects evaluable in small series of patients. We describe methodological principles of clinical trials and significant advantages in their implementation produced by using a computer network for long-distance modem transmission of echocardiographic images and clinical data. This network has been recently developed in Italy and is operative at the University of Bari and the Associazione per la Ricerca in Cardiologia. Several clinical participating centers of the CEDIM Study and PHASE Study are connected in real time to a data center via modem by a special telephone network (RFD) of the Italian State Telephone Company (SIP). We describe the configuration, main features and applicative potential of such a powerful research tool in modem clinical trial methodology.

Cardiology↗
PubMed1993

[Role of ultrasonography methods in the imaging of atherosclerosis].

In the last 20 years ultrasonography has played an increasingly important role in the detection, quantification and monitoring of atherosclerosis. Ultrasonography, in fact, can provide a simultaneous report of the morphology (dimensions, configuration and wall composition) by echography and the hemodynamics of atherosclerosis by Doppler. Doppler technology has produced more sensitive pulsed Doppler equipment and color codification. These techniques have given the physicians important quantitative (resistance, compliance and stenosis resistance) and qualitative (color-flow imaging) information on delineation of soft plaques, thrombosis and dolicoarteriopathies. By using high-definition echography the normal pattern of intima and media tunics and the relationship between thickening, risk factors and related pathologies have been assessed. The new insight in vascular echography is quantitative vascular echography. This analysis permits the calculation of arterial diameters, plaque mass and vascular volumes. The information obtained could provide important notice on the mechanism of vascular remodelling in the course of atherosclerosis. In conclusion, ultrasonography can provide a complete report of atherosclerosis in clinical practice and research. It is considered the gold standard in the study of the vascular walls and related pathologies.

Arteriosclerosis↗
PubMed1993

[Multiplane transesophageal echocardiography in the study of expansive mediastinal processes compressing the right heart: a report of clinical cases].

In order to assess the role of multiplane transesophageal echocardiography in detecting mediastinal masses and in evaluating the manifestations of cardiac compression due to tumoral growth, 3 cases of patients with right ventricular outflow obstruction are presented. In each of these patients transesophageal echocardiography provided an accurate evaluation of the hemodynamic consequences of the tumoral process.

Adolescent↗
PubMed1993

[The noninvasive assessment of coronary flow during isometric exercise by Doppler ultrasonography of the internal mammary artery anastomosed to the left coronary].

Isometric contraction of small group of muscles is believed to increase heart rate and contractility and arterial pressure without significant changes in systemic arterial resistance. Such a manoeuvre has been employed in this work to study dynamic changes induced in blood flow into coronary bed, in subjects in which an anastomosis of the internal mammary artery to anterior descending coronary artery was performed. Ten patients with no clinical signs of myocardial ischaemia at rest and during exercise, were requested to perform an endurance left handgrip manoeuvre, at 50% of maximal voluntary contraction. Doppler blood velocity curve in the anastomosed mammary artery; non-invasive blood pressure curve at a finger of the right hand by Finapres; the electrocardiogram, were recorded. A significative increase in heart rate and mean and diastolic blood pressure was found. Blood flow significantly increased, approximately in the same percentage as double product was increased. A calculated index of coronary resistance did not show significant changes. In this group of patients, the handgrip manoeuvre may display the ability of the cardiac pump to match its metabolic needs due to increased pressure load, by employing the same developed pressure load as an adequate coronary perfusion pressure. It is suggested to employ this simple test in the routine monitoring of patients with internal mammary artery bypass grafts.

Aged↗
PubMed1993

The incidence of asymptomatic extracoronary atherosclerosis in patients with coronary atherosclerosis.

Atherosclerosis is a systemic vascular disease that can produce pathologies in any organ. The aim of this study was to evaluate the incidence of asymptomatic peripheral atherosclerosis (PA) in patients symptomatic for angina and myocardial infarction affected by coronary atherosclerosis (CAD). 315 patients (268 male and 47 female) aged between 36 and 69 years, asymptomatic for claudicatio and cerebral ischaemic disease, underwent selective coronary angiography to detect coronary stenosis > or = 50% and Echo-Color-Doppler examination of the epiaortic trunks and upper and lower limb arteries to detect peripheral stenosis > or = 30%. In the total population the incidence of PA in patients with CAD was 23% but in patients with trivascular CAD it was 32%. These data suggest that in patients with trivascular CAD it is necessary to investigate peripheral circulation as, also in asymptomatic patients, polydistrictual atherosclerosis was frequent.

Adult↗
PubMed1992

Propionyl-L-carnitine: a new compound in the metabolic approach to the treatment of effort angina.

The effects of propionyl-L-carnitine on exercise tolerance of 12 patients with stable exertional angina were assessed in a double-blind, placebo-controlled, cross-over protocol using serial exercise tests. Compared to placebo, propionyl-L-carnitine significantly increased total work from 514 +/- 199 to 600 +/- 209 W (P less than 0.05) (17%) and prolonged exercise time and time to ischemic threshold from 515 +/- 115 to 565 +/- 109 sec (P less than 0.05) (10%) and from 375 +/- 102 to 427 +/- 93 sec (P less than 0.01) (14%), respectively. ST segment depression at the highest common work level was significantly reduced from 0.19 +/- 0.08 to 0.15 +/- 0.08 mV (P less than 0.05) (21%). No significant changes in heart rate, systolic blood pressure, and rate-pressure product at rest, at the highest common work level, on appearance of the ischemic threshold, or at peak exercise were observed after propionyl-L-carnitine treatment. No side effects were observed under propionyl-L-carnitine treatment. This study shows that propionyl-L-carnitine can significantly improve exercise tolerance in patients with stable angina. Our data seem to confirm that propionyl-L-carnitine most likely exerts its protective action via the metabolic pathway.

Adult↗
PubMed1992

Ventricular premature beats in young subjects without evidence of cardiac disease: histological findings.

This report describes the results of right ventricle endomyocardial biopsies from 26 subjects (mean age 27 +/- 10 years) with premature ventricular beats and normal cardiac anatomy and mechanical function. Light microscopy examination revealed normal myocardium in 10 subjects (38%), acute myocarditis in two (7%), borderline myocarditis in one (3.5%), non-specific histological abnormalities including cellular hypertrophy, fibrosis and degenerative changes in 11 (42%), vasculitis in one (3.5%) and findings compatible with right ventricular dysplasia in the final subject (3.5%). The frequency of ventricular premature beats, as assessed by Holter monitoring, and the results of electrophysiological testing did not correlate with histopathological findings and their severity. These data indicate that some young subjects with premature ventricular beats of unknown origin have abnormal right ventricular biopsy findings. Adequate follow-up will probably demonstrate the clinical utility of these observations.

Acute Disease↗
PubMed1992

The importance of stress-induced cardiac wall motion abnormalities in the evaluation of drug intervention.

Stress-induced wall motion abnormalities are a sensitive marker of myocardial ischaemia. Stress echocardiography has recently been the subject of increasing interest because of its improved feasibility and compatibility with new and effective alternative stresses. Transoesophageal atrial pacing (TAP) with 2-dimensional echocardiography (2-D echo) is a recently developed echo-cardiographic stress procedure that has been shown to be reliable and effective in both the diagnosis and evaluation of stress-induced myocardial ischaemia. TAP with 2-D echo was performed after treatment with placebo and intravenous gallopamil 0.03 mg/kg in 12 patients with stable, reproducible angina of effort. Compared with placebo, gallopamil treatment increased the time to 1 mm ST-segment depression (6.6 vs 5.3 minutes; p less than 0.05) and improved the ventricular wall motion score at a heart rate of 130 beats/min (17 vs 15; p less than 0.01) and 150 beats/min (13 vs 11; p = 0.07). Three patients who developed angina after placebo administration were symptom-free after gallopamil. Thus, gallopamil exerts a beneficial effect on atrial pacing-induced ischaemia, by increasing the pacing time to the ischaemic threshold and reducing the extent of dysfunctional myocardium during ischaemia.

Aged↗
PubMed1992

[Is it possible to predict the anti-arrhythmic effect of beta blockers based on various relations between premature ventricular beat and the preceding cardiac cycle?].

The aim of our study was to correlate betablocker effects on premature ventricular beats (PVBs) with different patterns between PVB frequency and cardiac cycle. The computer program we used correlates each PVB to the preceding cycle length in a 24-hour electrocardiogram recording. The arrhythmic patterns obtained were defined as tachycardia-dependent, indifferent and bradycardia-dependent. We selected 51 patients (39 males, 12 females, mean age 52 years) with different cardiac diseases, all in sinus rhythm, with > 25 PVBs/h, characterized by PVB stability and reproducible pattern in 2 Holter monitoring recorded at a 3-5 day interval. A tachycardia-dependent pattern (TDP) was demonstrated in 20 patients; 22 patients showed an indifferent pattern (IP) and 9 a bradycardia-dependent pattern (BDP). A third Holter monitoring was performed 4-5 days after nadolol administration (80 mg/day). Nadolol caused a 87.7% PVB suppression in TDP patients (p < 0.001), a 34.8% PVB reduction in IP patients (p < 0.01) and a 36.3% increase in BDP patients (NS). The different effect of nadolol on these groups was highly significant (chi 2 30.9; p < 0.0001). These results indicate that pattern definitions is useful in identifying PVB subsets which are likely to be improved, or not, by betablockers.

Adolescent↗
PubMed1992

[Echo-Doppler evaluation of the internal mammary artery bypass on the left coronary artery: a 4-year follow-up].

In this study ultrasonographic techniques are suggested to monitor internal mammary artery bypass graft on the anterior descending coronary artery. One hundred and fourty patients were studied using 3 different ultrasonographic methods: zero-crossing continuous wave Doppler, fast Fourier transform (FFT) continuous wave Doppler and high resolution echo-Doppler. The patients underwent the ultrasonographic examinations 3 times a year for 4 years. By means of FFT Doppler analysis and echo-Doppler it was possible to perform the study in 138 patients and by zero-crossing system in 127 patients. Ultrasonographic techniques showed pathologies of the graft in 17 (13%) patients: 15 with obstructive pathologies and 2 with haemodetournament of the second intercostal artery.

Adult↗
PubMed1992

[Changes in left ventricular filling after acute increase of afterload in essential arterial hypertension with or without left ventricular hypertrophy].

It is debatable whether a direct causal link exists between left ventricular hypertrophy (LVH) and abnormal left ventricular filling (LVF) in arterial hypertension (AH). To assess if LVH is responsible for peculiar patterns of LVF, we examined 30 selected subjects, similar in age and body surface area, by Doppler echocardiography: 10 hypertensives (SBP: 158 +/- 15; DBP: 105 +/- 7 mmHg) with LVH (IM: 154 +/- 19 mg/m2) (Group 1); 10 hypertensives (SBP: 157 +/- 9; DBP: 101 +/- 5 mmHg) without LVH (IM: 105 +/- 17 mg/m2; Group 2); 10 normotensives without familiar history of AH (Group 3). LVF was analyzed in baseline conditions and during transient afterload increase, obtained by isometric exercise (handgrip, HG, for 5 min at 30% of maximal effort). At rest: 1) A wave peak velocity resulted significantly higher (p less than 0.01) in Group 1 (61 +/- 3 cm/s) versus Group 3 (52 +/- 7 cm/s), and E wave peak velocity was significantly lower in Group 1 (58 +/- 13 cm/s) versus Group 3 (74 +/- 10 cm/s); 2) Group 2 values (E wave: 66 +/- 12; A wave: 58 +/- 15 cm/s) were intermediate between those of groups 1 and 3, and with no significant differences; 3) E/A ratio resulted significantly lower both in Group 1 (1.04 +/- 0.2) and Group 2 (1.21 +/- 0.2) versus Group 3 (1.6 +/- 0.4).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1992

Integrated ultrasound evaluation of dissecting aneurysm of the aorta by the combined use of transesophageal echocardiography and intravascular ultrasound.

In order to obtain complete ultrasound imaging of the entire aorta, transesophageal echocardiography and intravascular ultrasound were performed on 3 patients with acute (2 cases) or chronic (1 case) aortic dissection. In each case the integrated use of transesophageal echocardiography and intravascular ultrasound provided an accurate evaluation of the dissection and of its anatomic extension.

Aged↗
PubMed1991

Thrombolysis in unstable angina: results of clinical studies.

Ample evidence exists to support the major role of intracoronary thrombosis superimposed on a disrupted plaque in unstable angina. Consequently, thrombolytic treatment, already established to be highly beneficial in patients with acute myocardial infarction, might also be indicated in patients with unstable angina. The clinical response to thrombolytic treatment has been evaluated in several small-sized studies with inconsistent and somewhat deceiving results. Thus, the role of thrombolysis in the treatment of unstable angina is still controversial. Two ongoing large-scale, randomized, controlled trials, the Third Thrombolysis in Myocardial Infarction (TIMI III) in the United States testing recombinant tissue-type plasminogen activator and UNASEM in Europe testing anisoylated plasminogen-streptokinase activator complex will, it is hoped, solve the debate. At present, early thrombolysis might be considered for the treatment of the subset of patients with severe rest angina associated with transient ST-T ischemic changes.

Angina, Unstable↗
PubMed1991

Hemodynamic study of intravenous propionyl-L-carnitine in patients with ischemic heart disease and normal left ventricular function.

Propionyl-L-carnitine was given intravenously to ten patients with chronic ischemic heart disease who had normal left ventricular function and had not had a previous myocardial infarction. Subsequently, pulmonary and systemic circulation, left ventricular function, and the relationship between the ventricle and afterload were evaluated. This drug, at a dose of 15 mg/kg, improves ventricular function by easing the load and by enhancing cardiac efficiency. The ejection impedance is reduced with a consequent increase in stroke volume as a result of a) a decrease in systemic and pulmonary resistance and b) an increase in arterial compliance. Arterial pressure is maintained due to an increase in total external heart power. Since the tension time index shows a proportionally smaller increase in the energy requirement, it follows that cardiac efficiency has been improved and ventricle-afterload matching is optimal. These results suggest but do not prove that propionyl-L-carnitine exhibits a positive inotropic property.

Adult↗
PubMed1991

Electrophysiologic evaluation of intravenous L-propionylcarnitine in man.

L-propionylcarnitine, a short-chain acylcarnitine, has been shown in experimental studies to induce, during acidic and hypoxic conditions, some electrophysiological changes such as an increase of duration of the action potential and of the effective refractory period. In this study, the acute electrophysiological effects of intravenous L-propionylcarnitine (30 mg/kg in 3 min) were studied in 12 subjects with estimated normal function of the sinus node and normal parameters for atrioventricular conduction. Statistically significant changes were observed 2 min after infusion. The sinus cycle length shortened (866 +/- 138 vs 818 +/- 124 msec, P less than 0.05) while refractory periods of the atrioventricular node increased (effective by 30-50 msec in four cases; functional from 425 +/- 52 to 436 +/- 55 msec, P less than 0.05). Sinuatrial conduction time, atrial refractory periods, infranodal conduction, bundle branch, His-Purkinje system and ventricular refractoriness were unchanged. Systolic and diastolic blood pressure were also unchanged. Because of the limited effects on electrophysiological parameters, L-propionylcarnitine should be used as a metabolic drug even in patients with mild disturbances of conduction.

Blood Pressure↗