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Biomedical subjects

R Bernabei

Publications and source records attributed to R Bernabei.

At least 109 records · Page 6Linked to original sources
PubMed1995

Effect of age and pathology on left ventricular diastolic function: the diagnostic yield of Doppler echocardiography.

BACKGROUND: Doppler echocardiography has been proposed to detect left ventricular (LV) diastolic dysfunction in the elderly. However, the validity of this technique in differentiating the effects of pathology from those of normal aging has not been defined. METHODS: Doppler indices of LV diastolic function were obtained in 85 patients (34 hypertensive, 29 with coronary artery disease, 22 with both conditions) and in 56 healthy volunteers. RESULTS: A linear correlation with age was found for all parameters in controls, and for many parameters in patients. Also, in the presence of heart diseases, age exerted a powerful, independent effect on Doppler parameters. None of these differed between patients and controls in advanced age. CONCLUSION: Due to the prevailing age-related variations in Doppler indices of diastolic performance occurring beyond the age of 65, Doppler echocardiography cannot be employed to diagnose LV diastolic dysfunction in the elderly.

Adult↗
PubMed1994

Effect of age on left atrial function in patients with coronary artery disease.

Both coronary artery disease and aging produce a similar pattern of left ventricular diastolic dysfunction with increased left atrial (LA) activity. We studied the Doppler left ventricular filling pattern in 75 patients (age 40-91 years) with coronary artery disease. A linear correlation with age was found for isovolumic relaxation time, peak atrial flow velocity, and atrial filling fraction; an independent effect of age and LA size on these parameters could be demonstrated. As an overall correlation was found between LA diameter and atrial function indexes, we compared such parameters among four subgroups with increasing LA size; the LA function indexes were increased with minor degrees of LA dilation and decreased with further LA expansion. As LA dilation was found only in older patients, it can be supposed that the combined effects of aging and disease on LA wall stress accounted for LA dilation and dysfunction in these subjects.

Aged↗
PubMed1994

Postsurgical complications in older patients. The role of pharmacological intervention.

The number of elderly patients undergoing surgery has been rapidly increasing during the last few years. Following surgical interventions, high rates of mortality and morbidity have been reported in the most advanced age groups. Nevertheless, perioperative evaluation and postoperative care are the major determinants of the overall outcome. Postsurgical complications are common in advanced age, since multiple pathology is often present in geriatric patients. Furthermore, the decreased efficiency of homeostatic mechanisms may facilitate the development of multiple organ failure (MOF), even as a consequence of apparently slight alterations in immune, cardiac or respiratory systems. Thus, prompt recognition and treatment of any complication often prevents the development of irreversible conditions. While cardiac and pulmonary complications account for 50% of early postoperative adverse events, infections, thromboembolism, renal failure, stress ulcers and coagulation disorders may occur well after surgical procedures. An important part of postoperative geriatric care is the diagnosis and correction of fluid, electrolyte and acid-base disturbances. These disturbances may manifest as mild, atypical signs, such as slight neuromuscular depression or delirium. Yet, they often constitute life-threatening conditions that should be rapidly and properly corrected. Finally, it should be remembered that, due to the frequent use of multiple drugs, elderly patients are at high risk of developing adverse drug reactions. Thus, the treatment of postoperative complications requires a strong rational effort to disentangle the combined effects of aging, drugs and pathology.

Analgesics↗
PubMed1993

Continuous geriatric care in orthopedic wards: a valuable alternative to orthogeriatric units.

The aim of this study was to assess whether assigning a geriatrician to provide daily medical care to geriatric patients in the orthopedic ward can improve the prognosis and reduce the length of stay. Time series analysis was performed in two parts: 1) prospective analysis of two years' workload, and 2) retrospective analysis of data collected over the 4 years prior to the intervention. Intervention and control populations were pooled, and the effects of geriatric care and patient-related factors on outcome measures were assessed by logistic regression analysis. All subjects were patients aged > or = 70 years who attended the orthopedic ward in a university hospital in years 1989-90 (studied group: 287 cases) and in years 1985-88 (control group: 474 cases). In the study period, mortality was 8.4% compared to 18% in 1985-86 (p < 0.0006) and 14% in 1987-88 (p < 0.01). The operation rate in the study period was 89.9% vs 83.8% in 1985-86 (p < 0.02) and 81.8% in 1987-88 (p < 0.005). Length of stay was 26.2 +/- 14.4 days vs 32.9 +/- 30.9 days in 1985-86 (p < 0.05) and 26.9 +/- 16.5 days in 1987-88 (NS). Length of stay was more strikingly shortened in the subset of patients with femoral fracture undergoing surgical management (28.5 +/- 12.7 vs 37.6 +/- 32.6 days in 1985-86, p < 0.003, and 30.8 +/- 15 days in 1987-88, p < 0.02). Given the positive relationship between geriatric care and operation rate (o.r. = 1.5, CI = 1.1-1.9), the protective effect of surgical treatment on mortality (o.r. = 0.6, CI = 0.4-0.8) to some extent may mask the collinear effect of geriatric care. We conclude that assigning a geriatrician to assist with the medical care of elderly orthopedic patients in orthopedic wards is associated with increased operation rate, decreased mortality and shortened length of stay.

Aged↗
PubMed1993

The impact of age on risk of adverse drug reactions to digoxin. For The Gruppo Italiano di Farmacovigilanza nell' Anziano.

To assess the association of age and other potential risk factors with digoxin toxicity, adverse drug reactions to digoxin (ADRDIG) were studied in all patients (n = 1338) on digoxin therapy consecutively admitted to 41 clinical wards throughout Italy during 4 months in 1988. At the time of admission, 28 patients (2.1%) had evidence of ADRDIG. In multivariate logistic regression analysis, significant associations with ADRDIG were found for age > or = 80 years compared to age 65-79 years (OR = 2.75, 95% CI = 1.17-6.45), daily digoxin dosage of > or = 0.25 mg (OR = 2.51, 95% CI = 1.16-5.47), serum creatinine > or = 120 mumol/L (OR = 3.75, 95% CI = 1.69-8.32), and for treatment with amiodarone, propafenone, quinidine or verapamil (OR = 2.60, 95% CI = 1.07-6.30). Those aged < 65 years had a similar risk of digoxin toxicity as those aged 65-79 years (OR = 1.07, 95% CI = 0.28-4.12). Adverse drug reactions to digoxin were found in 1 in 50 patients hospitalized on digoxin therapy. Patients aged 65-79 years were not at increased risk for digoxin toxicity compared to younger patients, while advanced age (> or = 80 years) was an independent risk factor for this outcome.

Adolescent↗
PubMed1992

Temperature-dependence of the age-related difference in the inotropic effect of norepinephrine in the rat myocardium.

The influence of temperature on the myocardial inotropic response to norepinephrine was studied in rats of different ages. Right papillary muscles isolated from 3-, 12-, and 24-month-old rats were superfused at two temperatures (29 degrees C and 37 degrees C) with progressively larger doses of norepinephrine. At 29 degrees C, the contraction duration was longer and the inotropic effect of norepinephrine was significantly smaller in 24-month muscles than in 3- and 12-month preparations. In muscles superfused at 37 degrees C, these age-related differences in the contraction duration and in the response to norepinephrine disappeared. Analysis of variance and covariance showed that temperature, but not age, is responsible for the differences in the inotropic response to norepinephrine observed. These results show that experimental conditions, among which temperature may play a major role, deeply affect the responsiveness of cardiac preparations to beta-adrenergic agonists.

Aging↗
PubMed1991

Is age an independent risk factor of adverse drug reactions in hospitalized medical patients?

OBJECTIVE: To study the incidence and the risk factors of adverse drug reactions. DESIGN: Multicenter survey. SETTING: Hospitalized care: 22 internal medicine and 19 geriatric wards. PATIENTS: All patients (n = 9,148) consecutively admitted during two observation periods of 2 months. MAIN OUTCOME MEASURE: Incidence of adverse drug reactions. RESULTS: The mean age was 67.1 +/- 0.17 years (median 72); the mean duration of hospital stay was 18.1 +/- 0.19 days (median 14). Each patient was administered 5.1 +/- 0.03 (median 5) drug prescriptions. The incidence of probable or definite adverse drug reactions was 5.8% (532/9,148). In univariate analysis, the incidence of adverse drug reactions increased from 3.3% at under age 50 to 6.5% at age 70-79 and decreased over age 80 (5.8%). In multivariate logistic regression, taking more than four drugs (OR = 2.94, CI = 2.38-3.62), staying in hospital more than 14 days (OR = 2.82, CI = 2.26-3.52), having more than 4 active medical problems (OR = 1.78, CI = 1.29-2.45), staying in a medical ward instead of geriatric ward (OR = 1.33, CI = 1.09-1.63), and drinking alcohol (OR = 1.28, CI = 1.03-1.58) were positively correlated with adverse drug reactions occurrence (P less than 0.05). Age, gender, and smoking cigarettes were not significant predictors of adverse drug reactions. CONCLUSION: Age is not an independent risk factor of adverse drug reactions, and good geriatric care can reduce the incidence of adverse drug reactions.

Age Factors↗
PubMed1991

Enalapril prevents cardiac fibrosis and arrhythmias in hypertensive rats.

To evaluate the effects of hypertension on cardiac hypertrophy, on myocardial structure, and on ventricular arrhythmias, 27 3-month-old spontaneously hypertensive rats were treated with enalapril (10 mg/kg) daily for 11 months and compared with 26 untreated control rats. Systolic arterial pressure was significantly decreased in treated rats, and at the end of the experiment, it was 199 +/- 3 mm Hg (treated) versus 237 +/- 3 mm Hg (controls) (p less than 0.001). At this time, spontaneous arrhythmias and induced arrhythmias either by programmed electrical stimulation (train of stimuli +1 or 2 extrastimuli) or by trains of eight stimuli at decreasing coupling intervals were observed in isolated heart preparations. Comparing enalapril-treated and control rats, spontaneous arrhythmias (9 of 27 versus 20 of 26, respectively; p less than 0.01), programmed stimulation-induced arrhythmias (3 of 26 versus 12 of 23, respectively; p less than 0.01), and trains of stimuli-induced arrhythmias (4 of 26 versus 14 of 19, respectively, p less than 0.001) were less frequent in the enalapril group. Left ventricular weight was decreased in treated rats by 18% (p less than 0.001). Enalapril administration diminished the fraction of myocardium occupied by foci of replacement fibrosis normally occurring in control rats by 59% (p less than 0.001). Finally, a significant correlation was found between left ventricular weight, the extent of myocardial fibrosis, and the occurrence of ventricular fibrillation. It was concluded that chronic treatment with enalapril, which resulted in attenuation of systemic arterial pressure by limiting cardiac hypertrophy and myocardial fibrosis, decreases the propensity of the heart of hypertensive rats to arrhythmogenesis.

Analysis of Variance↗
PubMed1991

[Cardiovascular therapy problems in the elderly patient].

The therapeutic management of elderly patients should be extremely careful, particularly in those over 75 years of age. As a matter of fact, in such patients a steep increase of the risk of comorbidity and of dependence has been evidenced. This implies a more complex therapeutic management, that must be oriented to the amelioration of quality of life more than to the resolution of the single pathologies. However, all the intervention trials so far conducted excluded such patients. Therefore, they cannot be considered representative of the geriatric epidemiological reality. As a result, there is virtually no useful information on the efficacy and safety of cardiovascular drugs in patients over 75 years of age. However, the following items should be pointed out: only drugs whose efficacy has been proved should be used, and only after a thorough diagnosis; a multidimensional evaluation should be performed, also addressing psychological, social, environmental and economical factors that could affect the clinical course; the risks and benefits of any therapy should be considered, particularly in the presence of comorbidity, as the number of assumed drugs directly correlates with the risk of developing adverse reactions; drugs should be dosed according to renal function and body weight, possibly starting with half the dosage of younger patients; after starting the therapy, patients should be kept under strict clinical control, and every new symptom should be considered an adverse reaction, unless it will not disappear after withdrawal of the drug; serum drug concentration should be monitored whenever possible, given its larger variability in advanced age.

Aged↗
PubMed1990

Cardiac aging, calcium overload, and arrhythmias.

The effect of aging was tested on experimental ventricular arrhythmias in isolated heart preparations from normal Wistar rats (NWR), Wistar Kyoto rats (WKY), and spontaneously hypertensive rats (SHR). Delayed afterdepolarizations and triggered activity induced by high-calcium perfusion (16 mM) in isolated papillary muscles were more frequent in the 24-month-old than in 6-month-old NWR. Reperfusion-VA were more severe in 14-month-old SHR than in WKY. The authors have previously shown that: (1) reperfusion- and reoxygenation-induced VA, in the isolated Langendorff perfused heart, were significantly more severe and frequent in 24-month-old than in 6-month-old NWR; (2) no age-related difference in the incidence of programmed electrical stimulation (PES, train of stimuli + 1 or 2 extrastimuli)-induced VA was observed in isolated NWR hearts during control perfusion, after coronary artery ligation or during hypoxia; (3) on the contrary, the incidence of PES-induced VA was significantly higher in isolated hearts from 14-month-old SHR than from 3-month-old SHR, and 3-month-old and 14-month-old WKY. It was concluded that "physiological" aging is associated with a higher propensity to calcium-related VA, while "pathological" aging characterized by hypertension of long duration increases the incidence of PES-induced VA, probably caused by myocardial fibrosis, which could facilitate reentry.

Aging↗
PubMed1989

Age-related increase in the incidence of ventricular arrhythmias in isolated hearts from spontaneously hypertensive rats.

In order to test the effect of arterial hypertension on cardiac electrical activity, isolated Langendorff perfused hearts from spontaneously hypertensive (SHR) and normotensive (WKY) rats were studied. The incidence of spontaneous ventricular arrhythmias occurring during the control perfusion was 0% (n = 28) in WKY, 31% in SHR (n = 29, p less than 0.01), 7% (n = 14) in 3-month-old SHR, and 53% in 14-month-old SHR (n = 15, p less than 0.05). The incidence of ventricular arrhythmias induced by programmed electrical stimulation (PES = stimulus train + two extrastimuli) was 18% in WKY (n = 28), 48% in SHR (n = 27, p less than 0.05), 29% (n = 14) in 3-month-old SHR, and 69% (n = 13) in 14-month-old SHR (p less than 0.05). The incidence of PES-induced irreversible ventricular fibrillation was 0% in WKY and in 3-month-old SHR (n = 42), whereas it was 38% (n = 13) in 14-month-old SHR (p less than 0.001). Myocardial norepinephrine was significantly reduced in SHR with respect to WKY, but no significant difference was observed between 3-month-old SHR and 14-month-old SHR. Thus, no correlation between myocardial norepinephrine and ventricular arrhythmias could be found. It was concluded that the duration of hypertension was the most important factor in the development of severe ventricular arrhythmias.

Aging↗
PubMed1989

Effects of verapamil on reoxygenation and programmed electrical stimulation-induced ventricular arrhythmias in the isolated heart.

The antiarrhythmic effect of verapamil was tested on spontaneous ventricular arrhythmias during reoxygenation after 15 min of glucose-free hypoxia and on programmed electrical stimulation-(8 stimuli + 1 or 2 extrastimuli) induced ventricular fibrillation in isolated Langendorff perfused guinea pig hearts. Verapamil (1 mg/l) added during hypoxia and reoxygenation significantly reduced, during reoxygenation, the incidence of arrhythmias (46%, N = 13 vs. controls 87%, N = 30; P less than 0.01), of ventricular fibrillation (0%, N = 13 vs. controls 70%, N = 30; P less than 0.001) and of programmed stimulation-induced ventricular fibrillation (0%, N = 10 vs. controls 100%, N = 16). No effect was observed on programmed stimulation-induced ventricular fibrillation during hypoxia (90%, N = 10 vs. controls 100%, N = 10). Verapamil added during reoxygenation reduced the incidence of reoxygenation arrhythmias and ventricular fibrillation (47% and 29%, N = 17, P less than 0.01 and P less than 0.05 vs. controls, respectively) but it had no effect on programmed stimulation-induced ventricular fibrillation (100%, N = 10). It is likely that verapamil exerts its antiarrhythmic effect by preventing cellular calcium overload during hypoxia and reoxygenation.

Animals↗
PubMed1989

Programmed electrical stimulation-induced arrhythmias in isolated hearts from adult and senescent rats.

In isolated hearts from normal rats, we previously demonstrated an age-related increase of spontaneous ventricular arrhythmias. The aim of the present experiments was to test the possible effect of aging on ventricular arrhythmias induced by programmed electrical stimulation. Experiments were performed in isolated cardiac preparations of 6- and 24-month-old normal Wistar rat hearts. Programmed electrical stimulation (single or double premature stimuli following a stimuli train) was tested in isolated Langendorff perfused hearts during control perfusion, after left anterior descending coronary artery ligature and during global hypoxia. No significant differences were observed between adult and senescent hearts in the incidence of programmed electrical stimulation-induced ventricular arrhythmias during these three different situations. These experiments demonstrate that the cardiac "physiological" aging process is not associated with a greater propensity to programmed electrical stimulation-induced arrhythmias.

Aging↗
PubMed1988

Electrical and ionic mechanisms of early reperfusion arrhythmias in sheep cardiac Purkinje's fibers.

The mechanisms of induction of early reperfusion arrhythmias were studied in sheep cardiac Purkinje's fibers superfused in vitro. Transmembrane potentials, intracellular sodium activity (aiNa), and contractile force were recorded. Stoppage of the flow of Tyrode's solution (ischemia) for 1 hour initially decreased slightly aiNa (-0.57 mmol -7.2%), increased the action potential amplitude (+6.1%) and duration (+7.8%), and decreased diastolic depolarization slope (-45.2%). As the ischemia continued, aiNa increased progressively (to 12.53 mmol, +56.2%), whereas force peaked (+395%) after about 30 minutes and then began to decrease. By the end of ischemia, there was a decrease in action potential amplitude (-14.9%) and duration (-39.6%), whereas diastolic depolarization slope reincreased again almost to control value (-7%). When the flow of Tyrode's solution was resumed (reperfusion), force markedly increased (+211.1%) and oscillatory potentials initiated arrhythmias (extrasystoles and repetitive fast discharge) in 64% of tests. Force and aiNa decreased relatively rapidly. The arrhythmias initiated after 58.4 +/- 1.8 seconds of reperfusion and lasted 101.5 +/- 3.2 seconds. When [Na]o was increased by +19.2%, reperfusion arrhythmias occurred after only 30 minutes of ischemia. Thus, in Purkinje's fibers superfused in vitro, early reperfusion arrhythmias are induced by oscillatory potentials caused by calcium overload, which is enhanced by the increase in aiNa during ischemia.

Animals↗
PubMed1988

Electrophysiological mechanism for the antiarrhythmic action of propafenone: a comparison with mexiletine.

1. The antiarrhythmic potency of propafenone was evaluated in the guinea-pig isolated heart; arrhythmias were induced with (a) digitalis intoxication and (b) hypoxia followed by reoxygenation. 2. Propafenone, 0.5 microM, was found to be the minimal but effective antiarrhythmic concentration. The antiarrhythmic activity of propafenone developed slower than that of 10 microM mexiletine, which was the lowest effective concentration under the same experimental conditions. 3. The electrophysiological effects of propafenone were then studied on sheep cardiac Purkinje fibres (manifesting oscillatory afterpotentials and triggered automaticity induced by barium or strophanthidin) and compared with those of 10 microM mexiletine. 4. Both 0.5 microM propafenone and 10 microM mexiletine consistently blocked triggered activity in sheep Purkinje fibres. The onset of the effect of propafenone was slower than that of mexiletine. 5. Unlike mexiletine, propafenone did not reduce the amplitude of oscillatory afterpotentials. 6. In contrast, propafenone significantly reduced Vmax in barium- and strophanthidin-treated preparations. 7. It is concluded that the antiarrhythmic action of propafenone on digitalis- and reoxygenation-induced arrhythmias is probably due to an electrophysiological mechanism different from that of mexiletine. Mexiletine, by reducing the amplitude of oscillatory afterpotentials, prevents the attainment of the threshold; propafenone, by reducing the excitability of the cell, increases the threshold and consequently an oscillatory afterpotential of the same amplitude will not generate arrhythmias.

Animals↗