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Biomedical subjects

M Sesto

Publications and source records attributed to M Sesto.

28 records · Page 2Linked to original sources

[Abolition of pacing induced akinesia after aorto-coronary bypass grafting in patients with stable angina (author's transl)].

Hemodynamic studies were performed in 6 normal individuals, 8 patients with severe obstruction (more than 85% stenosis) of the left anterior descending coronary artery (LAD), 10 patients with patent LAD grafts and 4 patients with stenosed or occluded LAD grafts. All patients were suffering from stable angina before operation. Monoplane ventriculograms and left ventricular pressure determinations were carried out at rest and immediately after ventricular pacing (170/min.). Anterior wall motion was determined from half-diameter shortening and ejection fraction was calculated using the area-length method. Heart rate and left ventricular systolic pressure were comparable in all 4 groups at rest and after pacing. Normal individuals and patients with patent grafts to the LAD showed no significant change of anterior wall motion, ejection fraction and left ventricular enddiastolic pressure after pacing as compared to rest. Patients with LAD stenosis showed a significant decrease of anterior wall motion, of ejection fraction and an increase of left ventricular end-diastolic pressure. Patients with graft failure revealed a drastic though not significant decrease of anterior wall motion. Decrease of ejection fraction and increase of left ventricular end-diastolic pressure were significant. Thus, in patients with stable angina and severe coronary stenosis regional and total left ventricular function may well be maintained at rest but become severely impaired after pacing. Successful revascularization abolishes this ischemic response.

Angina Pectoris↗

Recovery from myocardial failure after aortic valve replacement.

Left ventricular hypertrophy and function were studied in 27 consecutive patients with chronic aortic valve disease before and 6.4 +/- 2.2 (S.D.) months after aortic valve replacement with Björk-Shiley prostheses. Four patients were excluded because of postoperative paravalvular regurgitation. Five patients had aortic stenosis (AS), seven patients AS plus insufficiency (AS-AI), and 11 patients aortic insufficiency (AI). Left ventricular muscle mass (LVMI), ejection fraction (EF), mean circumferential fiber shortening rate (VCF), mean normalized systolic ejection rate (MNSER), and peak systolic wall stress (PSWS) were determined angiographically. LVMI fell significantly after corrective surgery, whereas EF, VCF, and MNSER increased. PSWS decreased after the operation. Comparison of stress ventriculograms before and after surgery in six patients with predominant AS (isoproterenol infusion, 0.3 microgram per kilogram of body weight per minute) showed an increase of EF, VCF, and MNSER and a decrease of PSWS. We conclude that hypertrophy in chronic aortic valve disease regresses after aortic valve replacement, and thereby depressed cardiac function and reserve recover.

Adult↗

[Vagal tone in symptomatic sinus node dysfunction (author's transl)].

Under investigation in this study were the role of vagal tone in symptomatic sinus node dysfunction and the relationship between hypersensitive carotid sinus reflex (HCSR) and sick sinus syndrome (SSS). In 168 symptomatic patients (pts) resting heart rate (HR), maximal corrected sinus node recovery time (CSRTmax) and maximal carotid sinus pressure results (CSPmax) were determined before and after Atropine, 1 mg i.v. (A). According to test results, 103 pts had HCSR (1), 33 had HCSR + SSS (II), 30 pts had isolated SSS (III) and 20 pts with normal test results served as controls (IV). Mean age was the same in groups I--IV (p greater than 0.05). Groups I--III had a HR less than or equal to 60 bpm, rising 31% after A in groups I--IV, but absolute values were below those in group IV. In groups I--III CSP normalized after A and CSRT remained unchanged (p greater than 0.05). We conclude that increased vagal tone plays but one role in groups I--III and the combination HCSR + SSS seems rather frequent. Specific testing clearly separated HCSR from SSS.

Adult↗

[The significance of electrophysiologic findings and clinical course in symptomatic sinus node dysfunction (author's transl)].

Under investigation in this study were the relationship between hypersensitive carotid sinus reflex (HCSR) and sick sinus snydrome (SSS), the significance of clinical symptomatology versus electrophysiologic test results and the natural course of both syndromes. In 186 symptomatic patients (pts) resting heart rate, maximal corrected sinus node recovery time (CSRTmax) and maximal carotid sinus pressure results (CSPmax) were determined. According to test results, 103 pts had HCSR (I), 33 had HCSR + SSS (II), 30 pts had SSS (III), and 20 pts with normal test results served as controls (IV). Mean age was the same in groups I--IV (p greater than 0.05). Groups I--III had a heart rate less than or equal to 60 bpm. There was no correlation between patients test data and the occurrence of syncopes in each of groups I--III (p greater than 0.05). In 16 pts with SSS, test results remained unchanged 16 months later (p greater than 0.05). More pts (31%) in group II died in a shorter period of time after pacer application (1.4 +/- 1 year) than pts with AV III degrees block (25%, 1.8 +/- 1.6 years) after pacer application. We conclude that the combination HCSR + SSS seems rather frequent. Specific testing separated HCSR from SSS, but failed to predict syncopes and thereby cannot aid in the indication for pacer application. The 16 months prognosis of SSS proved unfavorable. Mortality after pacer application in HCSR + SSS seems less favorable than in AV III degrees block (p less than 0.05), but depends largely on the severity of associated diseases.

Adult↗

Effects of nitroglycerin, postextrasystolic potentiation, and pacing-induced ischaemia on wall motion in patients with ischaemic heart disease.

The influence of nitroglycerin, postextrasystolic potentiation, and rapid ventricular pacing on total and regional ventricular function was studied in 32 patients with normal ventricular function and in 44 patients with left ventricular asynergy caused by obstructive coronary artery disease. Total ventricular function was assessed by ventriculography and regional ventricular function was analysed by use of 7 hemiaxes. Nitroglycerin increased ejection fraction and decreased left ventricular systolic and end-diastolic pressures in the normally functioning ventricles; apical wall motion increased, while basal wall motion remained unchanged after nitroglycerin in these ventricles. Pressures fell significantly in ventricles with asynergy after nitroglycerin; ejection fraction decreased while wall motion in asynergic areas was inconsistently influenced. Postextrasystolic potentiation augmented ejection fraction by a powerful and homogeneous increase of wall motion in normally functioning ventricles. Asynergic areas and normal areas in diseased ventricles showed identical augmentation of wall motion after a premature beat. Rapid venticular pacing produced a significant increase in end-diastolic pressure and a fall in ejection fraction in patients with obstructive coronary artery disease. Wall motion in normal areas perfused by arteries with critical stenoses was dramatically depressed after pacing, while asynergic areas and normal areas perfused by normal arteries remained unchanged. The results show that normal contractile behaviour can be detected by postextrasystolic potentiation in asynergic areas, suggesting that some normally perfused muscle exists in these areas. Pacing stress does not further deteriorate function in asynergic areas, which suggests the presence of viable and well perfused muscle (within scar tissue) whose function may not profit from revascularization. Pacing-induced asynergy identifies the functional significance of coronary stenoses and suggests that bypass surgery might be beneficial.

Cardiac Volume↗