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Biomedical subjects

G M Boffa

Publications and source records attributed to G M Boffa.

At least 55 records · Page 3Linked to original sources
PubMed1988

[Model of the normal left ventricle].

The aim of the present study is to simulate left ventricular function using parametres directly measurable "in vivo". Taking the definition of contractility as sigma EDV/ESV (sigma = end systolic stress; EDV = end diastolic volume; ESV = end systolic volume), a slight modification of Suga's index, and an equation taken from Sunagawa, relating arterial pressure to resistance, compliance and stroke volume, a basic programme able to predict stroke volume and systolic pressure starting from EDV, left ventricular mass, contractility, peripheral resistance and compliance was developed. Various curves describing left ventricular function were simulated: Starling's curve, pump curve (mean left ventricular pressure against mean left ventricular flow), Ford's curve (mass to volume ratio against systemic pressure), and pressure-volume loops. A close affinity with literature data was always found. Left ventricular performances were predicted in 23 normal subjects, using the same input parameters. The correlation with real values was always linear, and particularly striking for cardiac index and source resistance. Thus this model seems to explain low-frequency hemodynamic events adequately, and is therefore suitable of clinical use in order to clarify pathophysiological mechanisms.

Heart↗
PubMed1988

[Arrhythmogenic right ventricular dysplasia. Study of a selected population].

268 patients (pts) aged between 4 and 63 (average block 33.6) years were examined in an effort to detect structural and/or wall motion abnormalities of the right ventricle, consistent with a diagnosis of Arrhythmogenic Right Ventricular Dysplasia (ARVD). The patients included in this study had some of these features: 1) sudden juvenile death (age less than 35 years) due to heart disease; 2) relatives of pts died suddenly of pathologically proven ARVD; 3) pts with ventricular arrhythmias grade Lown greater than 3, and with QRS morphology mainly of left bundle branch block; 4) pts between the ages of 18 and 40, with negative T waves beyond V2; 5) pts with ventricular arrhythmias of left bundle branch block morphology, and grade Lown greater than 1, and negative T waves beyond V1. ARVD was recognized in 108 living and 18 deceased pts. Our data confirm that ARVD is a wide spectrum disease, going from the classical form described by Marcus and Fontaine to concealed forms characterized mainly by premature ventricular complexes.

Adolescent↗
PubMed1986

Pulmonary atresia with intact ventricular septum: a quantitative cineventriculographic study of the right and left ventricular function.

Quantitative cineventriculographic measurements (ventricular volumes, ejection fraction, and myocardial mass) were obtained in 15 neonates with pulmonary atresia and intact ventricular septum. There was a wide dimensional range for the right ventricle, from a reduced through normal to enlarged. A restrictive tricuspid valve (less than 12 mm) was associated with a small or diminutive right ventricle. A normal function of the right ventricle was present only in those cases with normal-sized chambers. The left ventricular end-diastolic volume was always greater than normal. The ejection fraction was normal only if a normal myocardial mass was present. Additional abnormalities were frequent in the myocardium of both ventricles, such as extreme thinning of the wall of the right ventricle and hypoplasia or fibroelastosis of the left ventricle. All these factors can lead to a poor surgical prognosis despite good anatomical correction.

Cardiomegaly↗
PubMed1981

[Study of left ventricular function in chronic volume overload (author's transl)].

Have been studied 51 patients with aortic incompetency (AI), 46 with mitral insufficiency (MI) and 31 with congestive cardiomyopathy (CM) as example of a primitive myocardial lesion. The mean parametres calculated were: the left ventricular end-diastolic pressure (LVEDP), the ventricular volumes, the ejection fraction (EF), the end-sistolic pressure-volume ratio (Emax) and the eccentricity. In the chronic volume overload, the relationship between the pump performance and the contractility (EF-Emax) is parabolic with an initial plateau (myocardial failure without circulatory failure); the EF-Emax relationship, in the CM, is linear without a plateau. The LVEDP is a limiting factor of the pump-contractility relationship in the AI: for the same value of the contractility, the pump function is greater depressed if the LVEDP is 25 mmHg (loss of the preload modulation); in the MI and CM the depression of the pump performance is a function only of the depressed contractility. The end-systolic eccentricity is correlated with Emax: the changes in the geometrical shape of the left ventricular chamber is due to the depressed contractility.

Aortic Valve Insufficiency↗