Modifications in cardiovascular functional parameters with aging.

BACKGROUND: The constant rise in the number of old people involves a great interest towards the aging of the cardiovascular system. Many authors have studied age-adjusted limits to echocardiographic and functional parameters. The aim of this study is to evaluate some functional parameters so as to define the cardiovascular modifications of the aging heart. METHODS: We have studied 66 patients, 32 of mean age 71+/-4 years (Group 1) and 34 with mean age 33+/-6 years (Group 2), without cardiovascular diseases, through basal echocardiography and exercise test. RESULTS: In comparison to group 2, in group 1 we have observed at rest normal ventricular dimensions with increase of the thickness (SIV 11.2+/-0.4 vs 9+0.6, p=0.01; PP 10.6+/-0.6 vs 9.2+0.4, p=0.01), of the left atrium (41.2+/-1.08 vs 36.2+1.3, p=0.05), and of the aortic root (33.2+/-1.3 vs, 30.8+0.9, p=0.05), altered diastolic function (E/A 0.7+/-0.14 vs 1.9+/-0.7, p=0.01), with normal systolic indexes. At 100 Watts workload there was an age-related increase in end-diastolic volume (142+/-10.6 vs 127+/-4.3, p=0.01) and an age related decrease in heart rate (HR 100 W 148+/-10.7 vs 169+/-10.9, p=0.05). CONCLUSIONS: In the heart of an elderly subject therefore there are morphological modifications that in the absence of organic pathologies can support the metabolic demands of the organism and adapt to the physiological modifications of the elderly subject.

Analysis of heart rate variability five minutes before the onset of paroxysmal atrial fibrillation.

BACKGROUND: Various experimental and clinical observations suggest changes in sympathetic and vagal neural regulatory mechanisms play a critical role in altering cardiac electrical properties and favor the occurrence of arrhythmic events. There is limited information about the influences of the autonomic tone on the development of episodes of paroxysmal atrial fibrillation in patients with no evidence of organic heart disease. The aim of this study was to investigate changes in sympatho-vagal balance 5 minutes before the onset of atrial fibrillation. METHODS: We evaluated 28 patients with no history of heart disease who were not undergoing pharmacological treatment and who had at least one episode of paroxysmal atrial fibrillation recorded during an 24-hour ECG Holter monitoring. We analyzed values of frequency domain heart rate variability parameters 5 minutes before the onset of atrial fibrillation (prefa period) compared to an equivalent period at least 1 hour after from atrial fibrillation (random period). RESULTS: Thirty-six episodes of atrial fibrillation were recorded and our results showed we had two types of episodes. Eighteen were classified as Type A, in which we had an increase of low frequency (LF) (79.15 +/- 10.76 in comparison with 62.64 +/- 19.55) (P = 0.004) and a decrease of high frequency (HF) (20.82 +/- 10.74 in comparison with 37.64 +/- 20.20) (P = 0.004) consistent with an increase of sympathetic tone; and 18 were classified as Type B in which there was a decrease of LF (62.82 +/- 15.38 in comparison with 85.97 +/- 8.48) (P < 0.001), and an increase of HF (36.79 +/- 14.72 compared with 14.01 +/- 8.48) (P < 0.001), consistent with an increase of parasympathetic tone. CONCLUSION: We observed abrupt changes in sympathovagal balance in the last 5 minutes preceding an episode of atrial fibrillation. This can be related to a double behavior in the neurogenic drive: in Type A episodes there is an increase of the LF spectrum, LF:HF ratio, and a decrease of the HF spectrum consistent with an increase of neurogenic sympathetic drive; in Type B episodes there is a reduction of the LF spectrum, LF/HF ratio, and an increase of HF spectrum consistent with an enhancement of the neurogenic parasympathetic drive. In some patients, we found that the two mechanisms operate during different hours of the day and that sometimes there is an increase of sympathetic tone, and in the same instances an increase of parasympathetic tone. Heart-rate variability measures fluctuation in autonomic inputs to the heart rather than the mean level of autonomic impulse; autonomic imbalance is probably more important than the vagal or sympathetic drive alone.

[Cardiorenal physiopathology and heart failure: current aspects and therapeutic prospects]. / Fisiopatologia cardio-renale e scompenso cardiaco: attualità e prospettive terapeutiche.

The heart and the kidney exert a reciprocal control of their function in order to maintain a steady state of haemodynamics, both in physiological and pathological conditions. The functional relationship between the two organs becomes particularly evident during heart failure. The knowledge of such relationship may play an important role in the management of heart failure. We also report here our experience in the treatment of congestive heart failure with depletive techniques vicarious of kidney function.

[Treatment of refractory heart failure with different dialysis technics]. / Il trattamento dello scompenso cardiaco refrattario con differenti tecniche dialitiche.

The efficacy of the dialysis in the heart failure non responsive to the traditional methods is well known. In our study we have evaluated the effects of three different dialytic methods (UFI: ultrafiltration isolate; HF: hemofiltration; CAVH: continuous arteriovenous hemofiltration). These methods are used to cause a good depletion in the patients with intractable heart failure following from ischaemic valvular or primitive cardiomiopathy. We have treated 18 patients (6 for each method) and the patients with organic or functional renal disease were treated with the methods (HF and CAVH) that have depletive and depurative effects. Each of these methods is capable, without important differences, of achieving the following aim: the hydro-sodium depletion, the correction of the haemodynamic alteration and the re-establishment of the response to the traditional medical treatment. Using the hemofiltration and continuous arteriovenous hemofiltration, both soft methods, we have obtained values of dehydratation, absolute and for each session, higher than isolated ultrafiltration. The follow-up has not pointed out differences, of both prognosis and survival among patients treated with the three methods studied, whose effects are always only temporary; only the heart transplantation or the valvular correction, by operating in a very important way on the basal cardiopathy, is the resolutive event.

[Report on long-term hemofiltration in the treatment of end-stage renal failure]. / Bilancio di una esperienza a lungo termine con emofiltrazione nel trattamento della insufficienza renale cronica terminale.

Thirteen uraemic patients in chronic hemofiltration was studied over a 37.3 +/- 25.4 months period. Hemofiltration value in long-term treatment of uraemia was verified by: dialytic adequacy, clinical data, complications, drop-out morbidity and survival. Our experience indicates that hemofiltration and especially high efficiency hemofiltration is an effective and soft therapy for substitutive long-term treatment in high risk patients.

Bezafibrate-induced myopathy: no evidence for defects in muscle metabolism.

A 58-year-old man with chronic renal failure developed severe muscle pain and tenderness 1 week after starting bezafibrate 400 mg daily. Serum creatine kinase was 32,280 U/l. Muscle biopsy revealed scattered necrotic fibers and mild type 2b atrophy. Muscle total and free carnitine were at the upper limits of the normal range. Biochemical investigations of muscle homogenate showed normal carnitine pelmityl transferase (CPT) as well as normal individual glycolytic and mitochondrial enzyme activities. Withdrawal of the drug was followed by rapid clinical improvement. Our study casts doubt on the hypothesis that bezafibrate is able to affect muscle metabolic pathways. It is likely that the drug acts on cholesterol constituents of the muscle membrane, producing discontinuities of the sarcolemma and initiating cell necrosis.

[A case of severe recurrent transient granulocytopenia during hemofiltration: possible pathogenetic interpretations]. / Su di un caso di severa granulocitopenia transitoria ricorrente in corso di emofiltrazione: possibili interpretazioni patogenetiche.

The authors report a case of severe granulocytopenia without increased susceptibility to infections in a patient with IRC (chronic renal failure) on hemofiltration treatment. The possible pathogenetic mechanisms are examined. The phenomenon is probably due to an altered compartmentation of neutrophils; the temporariness and the quick correction of the granulocytopenia explain the lack of clinical manifestations.