[Regional function of the left ventricle: dynamic geometry of the post-extrasystolic potentiation].
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Biomedical subjects
Publications and source records attributed to G M Boffa.
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New parameters for the study of ventricular dynamic, which analyze the perimetric dimensional variations of the ventricular margin on the cineventriculographic projective plain, were introduced. Three usable methods for these determinations are described: 1) the systolic dimensional variation of the total perimeter; 2) the contribution to the total perimetric length and the systolic shortening of the anterior and posterior wall; 3) the contribution of the telediastolic and the telesystolic length to the anterior or posterior wall and the systolic shortening (in mm/m2 of the corporeal surface and in the percentage of the respective telediastolic length) of each marginal region.
51 patients with primitive cardiomyopathy were studied and classified (5 groups) on the basis of hemodynamic parametres and the modalities of left ventricular contraction: the first group was made up of patients with "frontal sector" hyperkinesia, normal ejection fraction and without any dynamic obstruction of the ventricular flow; the second, of patients with hyperkinesia "frontal and rear sector" raised ejection fraction and with dynamic obstruction; the third group was composed of patients with "frontal sector" hyperkinesia, reduced motility of the mitralic valvular level with appearance of insufficiency (maintained in the subsequent groups) and depression of the ejection fraction; dynamic obstruction was present. Groups IV and V included patients with progressive extension of hypokinesia to all marginal regions, up to the contraction pattern characterized by "serious and diffused hypokinesia". To conclude, a correlation of the contraction patterns is made, characterizing the various groups with a pathophysiological interpretation.
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A study of left ventricular volume was carried out on ten normal subjects. The average values and the standard deviations of the end-diastolic (EDV) and end-systolic volumes (ESV), the systolic throw and the ejection (EF) are reported. They were obtained by using the single-plane cineventriculography method in the OAdx projection of 30 degrees.
A new method for evaluating the systolic displacement of the left ventricle profile is proposed. It rests on the definition of an intracardiac axis and the identification of equivalent points on cardiac end-systolic and end-diastolic silhouettes separately. Displacement in then evaluated by means of vector methods. The results in ten normal subjects are reported. Systolic displacement is visualized by means of maps, uhich reflect the geometric properties of left ventricle normal contraction.
In 21 patients aortic pressure was recorded just above the diaphragm. The curve after the dicrotic notch is an exponential function of the time, and it is possible to characterize it by a unique time-constant. This constnat is shown to depend on aortic compliance and peripheral resistance: as aortic compliance does not vary abruptly in physiological conditions, this allows monitoring of peripheral resistance by monitoring time constant. Mathematical bases of time constant and of the peripheral resistance are briefly discussed.
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The authors report seven cases of congenital coronary artery fistula observed in the Cardiology Department of Padua Medical School. The cardiopathy, the anatomo-histological characteristics, evolution and embriology are described. The anamnesic, clinical, electrocardiographic, X-Ray, phonocardiogram, haemodynamic, and contrastographic findings for each case are given. They are discussed and interpreted in the light of the pathophysiology of the disease.
In this study we have investigated the possibility that D-600, a phenylalkylamine calcium antagonist, protects the isolated rabbit heart against ischemia and reperfusion-induced damage. D-600 was either subcutaneously injected (2mg/kg, twice daily for 5 to 6 days) in the rabbit before isolation of the heart, or delivered to the isolated hearts in the perfusate (10(-7) M), either at the onset of ischemia and during reperfusion, or only during post-ischemic reperfusion. Ischemia (90 min) was induced by reducing coronary flow from 25 to 1 ml/min, followed by 30 min of reperfusion. Myocardial damage was determined in terms of mechanical function, release of creatine phosphokinase (CPK) and noradrenaline, mitochondrial function, calcium homeostasis, and endogenous stores of ATP and creatine phosphate (CP). Administration of D-600 to the rabbits or to the isolated hearts at the time of ischemia exerted protection. There are four groups of evidence in support of this conclusion: 1) the rise in diastolic pressure during ischemia was diminished with greater recovery of developed pressure during reperfusion; 2) CPK and noradrenaline release during reperfusion were reduced; 3) the oxygen consumption and ATP generating capacities of mitochondria were better maintained; and 4) associated with this preservation of mitochondrial function was the maintenance of near normal calcium homeostasis and of endogenous ATP and CP stores. The two different modalities of administration did not produce substantially different results. When administered to the isolated hearts after the ischemic period, D-600 failed to improve mechanical recovery and release of endogenous substances. However, it reduced mitochondrial calcium overload and improved ATP production. The mechanism of the protective effect of D-600 seems to be multiple: energy-sparing effect, reduction of the toxicity mediated by endogenous catecholamines, and direct inhibition of mitochondrial calcium transport.
A correct clinical diagnosis in end-stage patients undergoing cardiac transplantation may have important prognostic and therapeutic implications. A retrospective clinico-pathologic study was carried out in 257 patients who had undergone cardiac transplantation at the University of Padua. A discrepancy between clinical and pathological diagnosis was found in 20 cases (8%). Among 126 patients with the clinical diagnosis of dilated cardiomyopathy, seven were found eventually to have ischemic heart disease (IHD), five myocarditis, one arrhythmogenic right ventricular cardiomyopathy (ARVC), and one non-compacted myocardium. Among the 87 patients with clinical diagnosis of IHD, three turned out to be dilated cardiomyopathy and one granulomatous myocarditis. Among the 10 patients with the clinical diagnosis of hypertrophic-restrictive cardiomyopathy, one had ARVC and one had cardiac fibroma. Altogether, only 24.5% underwent endomyocardial biopsy (EMB) and 75% coronary angiography before transplantation. Missed diagnosis of myocarditis occurred in patients in whom EMB was not carried out. EMB and coronary angiography might be indicated routinely in patients with apparent dilated cardiomyopathy, before proceeding to cardiectomy.
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Because the number of patients who require hospitalization for heart failure is increasing, their treatment is often entrusted to physicians operating in Departments of General Medicine. Published data on the in-hospital treatment of heart failure in Italy have not been available up to now, as they are limited only to patients admitted to Department of Cardiology. This study concerns the patients who were discharged from our Hospital after a diagnosis of heart failure (International Classification of Disease--9th Edition, code 428) from January 1 to February 28, 1998. Information collected from patient hospital records included: age, sex, department to which the patient was referred (General Medicine or Cardiology), cause of heart failure, New York Heart Association (NYHA) functional class, symptoms and signs of heart failure, therapy, length of hospitalization and in-hospital mortality. Of the 178 patients identified (82 males--46.1%, 96 females--53.9%, mean age 78 +/- 11 years) 163 (91.6%) were referred to Departments of General Medicine. The cause of heart failure was coronary artery disease in 88 (49.4%) patients, arterial hypertension in 40 (22.4%), primary cardiomyopathy in 28 (15.7%), valvular heart disease in 22 (12.3%). NYHA functional class was reported or deducible from the severity of dyspnea in 57 (32%) patients. In 8 (4.6%) patients symptoms or signs of heart failure were not reported. Chest X-ray was performed in 77.6% of cases, echocardiography in 41%, ambulatory electrocardiography in 10% and coronary arteriography in 5%. Left ventricular ejection fraction was known in 90 (51.6%) patients, in 44 (48.9%) of these it was > or = 45%. ACE-inhibitors were used in 99 (55.6%) patients, but this percentage rose to 63% when considering only patients with left ventricular ejection fraction < 45%. Eighty-five patients were treated with captopril or enalapril; in 52 patients (61.4%) the daily dose of captopril was < 75 mg and that of enalapril was < 20 mg. Diuretics were utilized in 155 (87%) patients, digoxin in 123 (69%), beta-blocker agents in 5 (2.8%) and other vasodilators in 95 (53%). The mean length of hospitalization was 13 +/- 9 days and the overall in-hospital mortality was 18%. In conclusion, the results of this study demonstrate that the patients who are discharged from our hospital with a diagnosis of heart failure are, on the average, very old. The vast majority of these patients are admitted to the Departments of General Medicine. The advanced age of our patients can explain the limited use of ACE-inhibitors and, especially, of beta-blockers.
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We studied the global and regional left ventricular function, its determinants and its modification with time, in orthotopic heart transplant recipients. We reviewed the left ventricular cineangiography performed 1 (50 patients), 2 (33 patients), 3 (18 patients), and 4 (seven patients) years after operation. Regional wall motion was quantitatively evaluated by the area method. All patients had angiographically normal coronary arteries and no evidence of acute rejection at the time of the study. One year after heart transplantation, cardiac index and left ventricular ejection fraction were mildly but significantly lower than normal. Cardiac index was more than 2.5 L/min/m2 in all but one patient, and ejection fraction was more than 50% in all patients. Only previous acute cardiac rejection necessitating therapy and arterial hypertension showed some influence on the left ventricular function. Two years after operation, the left ventricular end-diastolic volume was increased, and left ventricular mass-volume ratio decreased compared with year 1. Three years after operation, an increase of left ventricular end-diastolic pressure and of left ventricular ejection fraction was also evident. Four years after operation, the heart rate was higher, compared with previous years. Even if the changes in the parameters of left ventricular function were significant, they were small in terms of absolute value. Regional hypokinesia was detected 1 year after heart transplantation in eight patients, involving one segment in six patients and two segments in two patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Coronary artery spasm has rarely been observed in the transplanted, denervated heart. We report two patients who had coronary artery spasm after orthotopic heart transplantation that was documented by coronary angiography while ECG and Holter monitoring showed ischemic changes. Both patients were treated with calcium antagonists with no further evidence of this complication; however, one patient died suddenly at home after calcium antagonists were arbitrarily withdrawn. We believe that coronary artery spasm in heart transplant recipients may occur more frequently than expected. Careful monitoring of 24-hour ECG should be considered routinely in the follow-up of such patients, and when coronary spasm occurs it should be aggressively treated.