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Biomedical subjects

P Melacini

Publications and source records attributed to P Melacini.

At least 37 records · Page 2Linked to original sources

Long-term results of mitral commissurotomy.

Between January 1968 and December 1989, 280 patients underwent conservative surgical treatment for pure mitral stenosis. Closed commissurotomy was utilized in 134 patients, with a mean age of 38 +/- 11 years and a mean valve area of 1.0 +/- 0.29 cm2. Open commissurotomy was performed in 146 older patients (mean age 44 +/- 11 years) with a mean valve area of 0.9 +/- 0.3 cm2. The perioperative mortality was 3% in closed procedures and 3.4% in open procedures. Surviving patients were evaluated by questionnaires or phone interviews, and 129 patients were examined by two-dimensional echocardiography with the purpose of analyzing long-term results. Follow-up was 95% complete (Grunkemeier-Starr method), with a median of 18 years in patients with closed commissurotomy and 6.6 years in patients with open commissurotomy. The actuarial survival at 21 years was 60.8% (70% confidence limits 55% to 66%) in patients having closed commissurotomies and 60.6% (70% confidence limits 49% to 71%) at 22 years in patients having open commissurotomies. The "effective palliation" rate, defined by clinical and echocardiographic criteria, was 47% at 15 years and 15% at 20 years. We conclude that mitral commissurotomy is the procedure of choice in pure mitral valve stenosis and should be applied early. When performed in patients aged less than 40 years, a 78% (70% confidence limits 72% to 84%) survival at 18 years and 67% "effective palliation" at 15 years were observed. The closed valvotomy results of our study support the present trend toward use of percutaneous balloon valvotomy.

Adolescent↗

Long-term echocardiographic Doppler monitoring of Hancock bioprostheses in the mitral valve position.

Echocardiographic and Doppler studies were performed in 134 patients with a Hancock bioprosthesis in the mitral valve position during a follow-up period of 1 to 216 months. Among the xenografts, 57% were clinically normal and 43% had severe dysfunction. Among the normal bioprostheses, 35% had echocardiographically thickened mitral cusps (> or = 3 mm) with normal hemodynamic function; by setting the lower 95% confidence limit of valve area at 1.7 cm2 these patients had a significantly (p < 0.01) smaller valve area than that of normal control subjects. Evaluation of all thickened normal mitral valves showed the highest incidence of thickening at 9 years after implantation. Valve replacement surgery was subsequently performed in 33 patients with dysfunctioning bioprosthetic and echocardiographic diagnosis was confirmed in 91% of explanted valves (bioprosthetic stenosis 21%, incompetence 46%, and combined stenosis and regurgitation 33%). In 2 valves that were found to be stenotic on echocardiographic examination, a calcium-related commissural tear was also observed at reoperation, and in another, a paravalvular leak was found. Dystrophic calcification, isolated (64%) or occasionally associated with fibrous tissue overgrowth (21%), was the main cause of failure. Pannus was present in prostheses with longer satisfactory function (168 +/- 31 vs 124 +/- 21 months; p < 0.001). Long-term performance was evaluated by the Kaplan-Meier method for up to 18 years of follow-up. Freedom from structural valvular disfunction after mitral replacement was 89% at 6 years, 77% at 8 years, 56% at 10 years, 31% at 12 years, 16% at 15 years, and 15% at 18 years.

Actuarial Analysis↗

Evolution of cardiac involvement in progressive ophthalmoplegia with deleted mitochondrial DNA.

A 43-year-old woman with progressive external ophthalmoplegia developed a bifascicular block and dilatation of the right ventricle during 4 years of follow-up. Histochemical and electron microscopy studies detected mitochondrial abnormalities in ocular, skeletal muscle and cardiac biopsies. This case registers disease progression from the external ocular to the skeletal and cardiac muscles. Mitochondrial DNA was deleted in relation to the morphological abnormality.

Adult↗

[Contribution of electrovectorcardiography in the diagnosis of hypertrophic cardiomyopathy. Comparative study with an echocardiographic score].

The object of the study was to define spreading and quantitative criteria of left ventricular hypertrophy in echocardiography by using a "score"--for this, the left ventricle has been divided into 11 regions and a "score" attributed to each one of them--and to find the correlation with the vectocardiogram (VCG) in 42 patients with hypertrophic myocardiopathy (HM). The results obtained show the following: 1) the left ventricular hypertrophy aspect on the ECG and the VCG is very sensitive for the identification of a diffuse HM; 2) the necrosis, hemiblock or septal hypertrophy indicate a hypertrophy located in the forepart septum or the whole of the septum; 3) the giant T waves indicate a hypertrophy of the apex; 4) a left ventricular hypertrophy associated with a necrosis or a hemiblock indicate a global myocardiopathy, with the basal region of the septum largely affected.

Adolescent↗

Hypertrophic cardiomyopathy: two-dimensional echocardiographic score versus clinical and electrocardiographic findings.

The severity and site of hypertrophy is important in determining the clinical picture and the natural history of hypertrophic cardiomyopathy (HCM). We evaluated left ventricular hypertrophy by means of two-dimensional echocardiographic score and score index, and correlated these findings with symptoms, electrovector-cardiographic data, and ventricular arrhythmias. A total of 42 patients with HCM were studied by clinical examination, ECG, VCG, M-mode and 2D echocardiography, and 24-h Holter monitoring. The extent and severity of the hypertrophic process were calculated by a score system. The left ventricle was divided into 11 segments and a hypertrophic score (HS) was given to each segment. A hypertrophy score index (HSI) was also calculated by dividing the number of hypertrophied segments by 13. No correlation was found between symptoms and HS and HSI, nor ECG-VCG abnormalities and HS and HSI. A statistically significant relationship between the severity of ventricular arrhythmias and HS and HSI was found (p less than 0.01). The mechanism responsible for ventricular tachyarrhythmias in severe and diffuse hypertrophy might reside in the high intraventricular pressures which produce or worsen areas of myocardial ischemia.

Adolescent↗

The natural history of cardiac involvement in myotonic dystrophy: an eight-year follow-up in 17 patients.

We evaluated the progression of conduction system and myocardial disease in 17 asymptomatic myotonic dystrophy patients by clinical evaluation, electrocardiography, vector cardiography, and echocardiography. An exercise test was done in 10 patients. After 8 years, a follow-up study of 12 of the 17 original patients was done with a similar protocol. During this period, 2 patients died: one of sudden death while the other had acute left ventricular failure. In our first control study, we found EKG abnormalities in 15 of our patients, consisting mostly of conduction defects or pseudonecrotic patterns. In our second control, all patients had conduction system disease and, in addition, 3 of them had premature ventricular beats. One patient developed dilated cardiomyopathy. In 6 patients, structural involvement of the right ventricle was found. We conclude that even in asymptomatic myotonic dystrophy patients a conduction system deficit is present and progresses, and cardiac death may occur in about 12% of these patients.

Adult↗

[Quantitative echocardiographic study of the left ventricular function in acute aortic infective endocarditis].

Left ventricular (LV) function in 45 patients with native aortic valve infective endocarditis was studied in order to identify high surgical risk patients and the pattern of irreversible myocardial damage. LV function was studied by M-mode and 2D-echocardiography (LV volumes; ejection fraction, EF; peak systolic pressure to end-systolic volume ratio (PAP/ESV) as an index of myocardial contractility; LV mean systolic wall stress as an index of LV afterload and the radius to thickness ratio (R/Th). Thirteen patients underwent aortic valve replacement with an overall operative mortality of 15%. The cause of death was intractable heart failure. Different EF vs stress relationships could be described for different level of myocardial contractility: patients with intractable heart failure had a severely depressed myocardial contractility so that for a given level of LV stress, EF was significantly lower. High operative risk patients were identified by the PAP/ESV vs R/Th relation. All surgical deaths occurred in patients with a severely depressed myocardial contractility (PAP/ESV less than 2) and inadequate hypertrophy (R/Th greater than 4). Reversal of LV dysfunction in patients with moderately depressed myocardial contractility depended on the pattern of LV hypertrophy; a normal post-operative EF was achieved only in patients with adequate hypertrophy (R/Th less than 4).

Acute Disease↗

[Evaluation of clinical data and effort test in patients with angina pectoris: an approach to a multivariate analysis in different groups].

One-hundred and eighty-nine patients who underwent cardiac catheterization for suspected ischemic heart disease were assigned to four different groups depending on the number of diseased vessels (0, 1, 2, 3), the dominant artery and the presence of left main coronary stenosis. Among the 45 parameters obtained from history, physical examination, E.C.G., and exercise test multivariate analysis identified (positive stress test, maximal systolic blood pressure, documented myocardial infarction, maximal heart rate, ipercholesterolemia, lateral myocardial infarction, angina during stress test) that were statistically significant. A score system was devised on the basis of the summed-up value of the seven parameters. When the patients were assigned, according to the score, to one of the previously mentioned 4 groups, the classification proved to be correct in 54% of the cases. When we divided the patients in two groups with or without coronary artery disease so that the attribution turned out to be correct in 92% of the cases (sensitivity 94%, specificity 77%), whereas when based on ST segment depression only, the classification was correct in 85% of the cases (sensitivity 84%, specificity 88%).

Adult↗

[The heart in myotonic dystrophy. Clinical and instrumental study in 17 patients (author's transl)].

17 patients with myotonic dystrophy have been studied. The skeletal muscle disease has been assessed by history, physical examination, electro-myography and muscle biopsy. Cardiac evaluation has been obtained by history, physical examination, chest X-ray, ecg at rest and after exercise, vectorcardiography and echocardiography. Only two patients presented symptoms and clinical findings of cardiac disease, otherwise conduction disturbances have been founded in 15 cases, pseudoinfarct pattern in 5 cases and loss of anterior vectors in 2 cases. Has to be remembered that in myotonic dystrophy sudden death has a very high incidence, which could be explained by the development of complete a-v block, because of the impairment of the conduction system. Therefore, in those patients with bifascicular blocks (3 cases), the electrophysiological study may be useful in order to evaluate the opportunity to put on a permanent pace-maker, to prevent sudden death.

Adolescent↗

Effects of digoxin on plasma renin activity in hypertensive patients.

The effects of digoxin have been studied on PRA of 11 hypertensive patients treated with a single oral administration of the glycoside or submitted to a prolonged treatment. The experiments performed with a single oral administration (0,5 mg) showed that digoxin induces a significant decrease of the hyperreninemic response induced by furosemide. This effect of digoxin develops very quickly and is well evident when plasma levels of the glycoside are still low. However, in the patients pretreated with a beta blocker, digoxin was completely ineffective in preventing the response to furosemide. In view of the results, the hypothesis is put forward that digoxin mainly acts at renal level through an antiadrenergic activity.

Adult↗

A pharmacological approach to the study of AV conduction in man.

Smooth and interrupted curves of AV conduction, generated with an atrial extrastimulus technique, are seen in man, suggesting the involvement of two physiological AV pathways named "alpha" and "beta" and leading to a final common pathway (FCP). In view of this knowledge, the effects of some representative antiarrhytmic agents (Atropine, Verapamil, Ajmaline) were studied in eight patients in order to elucidate the physiological role of the various components of AV junction. Verapamil decreased conduction velocity of both "alpha" and "beta" pathways and increased their refractoriness; Atropine decreased "alpha" and "beta" pathways' refractory periods and increased their conduction velocity; further studies are required to clarify the effects of Ajmaline on AV conduction.

Adolescent↗