Predictive value of less than moderate residual mitral regurgitation as assessed by transesophageal echocardiography for the short-term outcomes of patients with mitral regurgitation treated with mitral valve repair

Background

Traditionally, in patients with mitral regurgitation (MR) a successful mitral valve repair is considered when residual MR by post-pump transesophageal echocardiography (TEE) is less than moderate or absent. Little is known about the prognostic value of less than moderate (mild or mild-to-moderate) residual MR for the early outcome of patients treated with mitral valve repair.

Methods

Eligible for this study were patients undergoing isolated mitral valve repair. Patients with moderate or severe residual MR after valve repair were excluded. The primary endpoint of the study was the composite of death or need of reintervention.

Results

A total of 98 patients (54 with no residual MR-Group 1, and 44 with less than moderate residual MR-Group 2) were analyzed. Of these, 72% presented with New York Heart Association (NYHA) 3/4, and 38% were women. The primary endpoint of the study occurred in 3 (5.5%) patients in Group 1 and 6 (13.6%) patients in Group 2 MR (P = 0.31). There was a trend toward a higher incidence of use of inotropic drugs post-interventional (P = 0.12), and a longer hospital stay among patients with less than moderate residual MR (P = 0.18).

Conclusion

In our study population, patients with less than moderate residual MR had a trend toward a higher risk of early adverse outcomes as compared with patients with no residual MR by post-pump TEE. Studies with a larger patient population and longer follow-up data may be useful to better define the clinical significance of residual mild MR after mitral vale repair.

[Silica risk in construction industry: an investigation on raw materials]

Typical construction activities like demolition, excavation and sanding can expose workers to silica, but there are few investigations carried out with the aim of evaluating the silica content in raw materials used for these activities (mortars, plasters, cement...). Our intervention has been directed in looking for free crystalline silica in samples of raw materials. We have measured the silica content in these materials comparing declared and real composition found in the products. Our intent was to obtain more information about the working activities which expose workers to free crystalline silica in construction industry and to highlight the silica presence in raw materials also when the companies don't declare it, against labeling rules based on Italian law D.lgs 65/03.

An increased platelet–leukocytes interaction at the culprit site of coronary artery occlusion in acute myocardial infarction: A pathogenic role for “no-reflow” phenomenon?

BACKGROUND

Distal protection devices have been shown to reduce the incidence of "no flow" phenomenon during primary percutaneous coronary intervention (PCI). So far, it has not been well clarified which mechanism is mainly involved in distal coronary protection.

AIM

To investigate the activation state of leukocytes and platelets locally present within the blood from the site of coronary occlusion.

METHODS

Ten patients with acute myocardial infarction (AMI) underwent primary PCI with an embolization protection device and aspiration catheter (PercuSurge GuardWire) were included. The following functional parameters: a) monocyte and neutrophils surface molecules; b) platelet surface activatory antigens; c) leukocytes-platelet conjugates were studied by flow cytometry in blood obtained from the site of coronary occlusion and from peripheral femoral artery.

RESULTS

The leukocyte-platelet adhesion index was significantly higher in the aspirated blood at the site of coronary occlusion than in the peripheral arterial blood for both monocytes (0.226+/-0.04 vs. 0.084+/-0.01; p=0.004) and neutrophils (1.372+/-0.3 vs. 0.524+/-0.1; p=0.02). Moreover, the volume of coaggregates exhibited a significant increase in coronary blood for both populations (p=0.02 for monocytes and for neutrophils). Interestingly, a significant up-regulation of the adhesive molecule CD18 was observed in coronary blood respect to systemic circulation either in monocytes (p=0.01) than in neutrophils (p=0.003). A significant up-regulation of monocyte (HLA-DR) and neutrophil (CD66b) activatory molecules expression was also observed in the aspirated coronary compared to peripheral artery blood (p=0.02 and p=0.03 for HLA-DR and CD66b, respectively).

CONCLUSIONS

These data indicate an increased leukocyte-platelet functional interaction in AMI at the site of plaque rupture relative to the systemic circulation, which may be one of the pathogenetic mechanisms responsible for myocardial "no-reflow" phenomenon.

Platelet activation predicts recurrent ischemic events after percutaneous coronary angioplasty: a 6 months prospective study

INTRODUCTION

An increasing amount of evidence indicates that platelet reactivity, despite a standard anti-thrombotic therapy, is a potential risk factor for recurrent myocardial ischemia in patients with coronary artery disease. We now hypothesize that this condition, measured by collagen-epinephrine (CEPI) or collagen-ADP (CADP) closure times (CT) by Platelet Function Analyzer (PFA-100), may predict the recurrence of coronary events after percutaneous coronary intervention (PCI).

MATERIALS AND METHODS

CEPI and CADP-CT were measured 30+/-8 h after PCI in 175 consecutive patients admitted with a diagnosis of stable angina (n=94) or acute coronary syndromes (n=81) and prospectively followed up for a mean period of 6 months. We stratified the patients in accordance to both the CEPI-CT (<or> 190 s), reflecting the intensity of cycloxygenase inhibition by aspirin and the distribution into quartiles for CADP-CT.

RESULTS

CEPI-CT<190 s as well as CADP-CT<82 s were associated with a higher rate of clinical recurrence (hazard ratio 8.5, p<0.001 and 22.9, p<0.001, respectively). Multivariate analysis after adjustment for other risk factors confirmed that the lowest CADP-CT quartile significantly correlates with the risk of recurrent coronary events (hazard ratio 36.5, p<0.01), as well as CEPI-CT<190 s (hazard ratio 6.7, p=0.01).

CONCLUSIONS

An enhanced platelet function after PCI when measured under high shear rates by PFA-100 is an independent predictor of a worst clinical outcome, even during a short term follow-up and may help in patients risk stratification.

Mathematical modelling of the impact of preoperative hypertrophy on the outcomes of completion of the Fontan circuit

The identification of the important relationship between shape and function of ventricular chambers represents a milestone of modern cardiology. Application of the law of Laplace for an ideal sphere furnishes intuitive insights on the progression of heart failure. A dilated heart, by virtue of its large size, must generate greater stress in the myocardial wall to achieve sufficient pressure so as to eject the required amount of blood. The mural hypertrophy represents a compensatory mechanism, guaranteeing a lower stress. When the ratio between the radius of the chamber and the thickness of its wall increases abnormally, the heart fails.

Turbulence and coarsening in active and passive binary mixtures

Phase separation between two fluids in two dimensions is investigated by means of direct numerical simulations of coupled Navier-Stokes and Cahn-Hilliard equations. We study the phase ordering process in the presence of an external stirring acting on the velocity field. For both active and passive mixtures we find that, for a sufficiently strong stirring, coarsening is arrested in a stationary dynamical state characterized by a continuous rupture and formation of finite domains. Coarsening arrest is shown to be independent of the chaotic or regular nature of the flow.

Ocular 'non-scarring' mucous membrane pemphigoid associated with anti-laminin-5 antibodies

Mucous membrane pemphigoid is a rare, chronic autoimmune disease characterized by subepidermal blistering and scarring, predominantly affecting mucous membranes. Ocular involvement frequently occurs and often represents the only manifestation of the disease. We describe a 62-year-old woman with a bilateral 18-month duration of conjunctival hyperaemia, associated with erythema and oedema of the eyelids, lacking any typical ocular signs of mucous membrane pemphigoid such as sub-conjuctival fibrosis and scarring. Histology was not significant. Direct immunofluorescence of the conjunctiva showed IgG, IgA and complement deposition along the basement membrane zone. Immunoprecipitation analysis of affinity purified laminin-5 revealed a band consistent with the beta3 chain of laminin-5. This represents the first case of pure ocular mucous membrane pemphigoid associated with anti-laminin-5 antibodies.

Mixing and reaction efficiency in closed domains

We present a numerical study of mixing and reaction efficiency in closed domains. In particular, we focus our attention on laminar flows. In the case of inert transport the mixing properties of the flows strongly depend on the details of the Lagrangian transport. We also study the reaction efficiency. Starting with a little spot of product, we compute the time needed to complete the reaction in the container. We find that the reaction efficiency is not strictly related to the mixing properties of the flow. In particular, reaction acts as a "dynamical regulator".

Detection of mtDNA with 4977 bp deletion in blood cells and atherosclerotic lesions of patients with coronary artery disease

Recent evidence suggests that somatic mutations in nuclear and mitochondrial DNA accumulated during aging, may significantly contribute to the pathogenesis of chronic-degenerative illness such as coronary artery disease (CAD). Mitochondrial DNA with 4977 bp deletion mutation (mtDNA4977) is a common type of mtDNA alteration in humans. However, little attempt has been made to detect the presence of mtDNA4977 deletion in cells and tissues of cardiovascular patients. This study investigated the presence of mtDNA4977 in blood samples of 65 cardiovascular patients and 23 atherosclerotic plaques of human coronaries with severe atherosclerosis. Moreover, the presence of the deletion has been investigated in blood cells from 22 healthy age-matched subjects. The detection of mtDNA4977 has been performed by using a nested polymerase chain reaction (PCR) protocol and normalized to wild-type mtDNA. A significant higher incidence of mtDNA4977 was observed in CAD patients with respect to healthy subjects (26.2% versus 4.5%; P=0.03). Furthermore, the relative amount of the deletion was significantly higher in the patients compared to the control group (P=0.02). The mtDNA4977 was detected in 17 of the 65 patients blood samples (26.2%) and deletion levels ranged from 0.18 to 0.46% of the total mtDNA (mean: 0.34+/-0.02%). For what concerns atherosclerotic lesions, 5 patients (21.7%) showed the deletion ranging from 0.13 to 0.45% of the total mtDNA (mean: 0.35+/-0.06%). In both samples from patients, the incidence and the relative amount of mtDNA4977 was not significantly influenced by atherogenic risk factors and clinical parameters. The obtained results may suggest that the increase of oxidative stress in cardiovascular disease may be responsible for the accumulation of mtDNA damage in coronary artery disease patients.

C677T polymorphism of the methylenetetrahydrofolate reductase gene is a risk factor of adverse events after coronary revascularization

BACKGROUND

A common point mutation (C677T) in the gene for 5,10-methylenetetrahydrofolate reductase (MTHFR) is associated with hyperhomocysteinemia, an independent risk factor and a strong predictor of mortality in patients with coronary artery disease (CAD). The aim of this study was to investigate whether C677T polymorphism can be a predictor of major adverse cardiac events after myocardial revascularization.

METHODS

We determined MTHFR genotype in 159 patients with CAD undergoing myocardial revascularization [72 percutaneous transluminal coronary angioplasty (PTCA) and 87 coronary artery bypass graft (CABG)]. Recurrent angina, nonfatal myocardial infarction (MI), target vessel revascularization, heart failure and cardiac death were considered major adverse cardiac events that occurred after discharge from index hospitalization.

RESULTS

During the follow-up (6.9+/-0.3 months, mean+/-S.E.M.), the composite endpoint accounted for 25.9%, 11.4% and 4.3% for TT, CT and CC genotype (log-rank statistic 5.2, p=0.02), respectively. Subjects with mutant TT genotype had a threefold increase of any cardiac event (hazard ratio [HR]=3.0; 95% [CI], 1.1-8.1). In multiple-variable regression Cox, predictors of events were TT genotype (HR=2.8; 95% CI, 1.01-7.62, p=0.047), low-ejection fraction<40% (HR=4.5; 95% CI, 1.62-12.6, p=0.004) and revascularization procedure (HR=6.1; 95% CI, 1.86-20.34, p=0.003).

CONCLUSIONS

These data indicate that the TT genotype seems to be significantly associated with major adverse cardiac events after myocardial revascularization in CAD patients, suggesting a potential pathological influence of homocysteine in the clinical outcome.

A study of the Fontan circulation and ventricular energetics based on a model

patients with congenitally malformed hearts characterised by a functionally single ventricle are currently treated using several procedures that bypass the right heart, such as the fontan and hemi-fontan operations, the bidirectional cavopulmonary anastomosis, and the total cavopulmonary connection. all these options are based on the procedures introduced for palliative correction of tricuspid atresia by fontan and baudet in 1971. introduced with the purpose of reducing the pre-operative volume overload, the surgical task mainly consists of separating the pulmonary from the systemic circulation. irrespective of the specific operation performed, we can call the resulting circulation the fontan circulation.

The role of T lymphocytes and cytokines in the pathogenesis of pemphigoid gestationis

BACKGROUND

Pemphigoid gestationis (PG), also known as herpes gestationis, is a rare autoantibody-mediated bullous disease, usually associated with pregnancy and the postpartum period. However, infiltrating cells have recently been suggested to also contribute to the pathogenesis of cutaneous lesions.

OBJECTIVES

To evaluate the immunophenotype of T cells infiltrating the PG lesional skin and their prevalent cutaneous cytokine expression, as well as the presence and distribution of mast cells, eosinophils and neutrophils. Methods We performed an immunohistochemical study with a large panel of monoclonal antibodies to CD3, CD4, CD8, HLA-DR, CD25, myeloperoxidase, tryptase, eosinophil cationic protein EG2, human interleukin (IL)-2, -4, -5, -8, interferon (IFN)-gamma, and granulocyte-macrophage colony-stimulating factor using the alkaline phosphatase-antialkaline phosphatase procedure on lesional skin of seven patients with PG. Skin from four subjects with pruritic urticarial papules and plaques of pregnancy and three additional healthy donors were used as controls.

RESULTS

The findings indicate that there is a T-cell population with a prevalent T-helper (Th) 2 phenotype in the lesional skin of PG subjects. We also found a number of eosinophils and neutrophils with clear signs of activation.

CONCLUSIONS

These data suggest that an inflammatory infiltrate is involved in the production of PG bullous lesions. In particular, we assume that the Th2 cells might be implicated in the very early stages of autoimmune response and may exercise a broad influence in blister formation in this disease.

Evidence for enhanced 8-isoprostane plasma levels, as index of oxidative stress in vivo, in patients with coronary artery disease

BACKGROUND

It is well known that free radicals contribute to endothelial dysfunction and are involved in ageing and in the pathogenesis and development of many cardiovascular diseases, such as atherosclerosis. Measurement of F(2)-isoprostanes has emerged as probably the most reliable approach to assess oxidative stress status in vivo. In particular, 8-isoprostane (8-epiPGF(2alpha)) has been indicated as a marker of antioxidant deficiency and oxidative stress of potential relevance to assess human vascular diseases.

DESIGN

To provide evidence for enhanced oxidative stress in coronary artery disease (CAD).

METHODS

Plasma levels of 8-epiPGF(2alpha) (EIA, Cayman Chemicals, Ann Arbor, Michigan, USA) were measured in 51 patients (19 females, 32 males, age: 58.7+/-1.6 years, mean+/-SEM). Subjects included 13 healthy control subjects (group I), and 38 patients underwent coronary angiography; 11 patients without coronary artery atherosclerotic lesions (group II), and 27 with angiographically proven CAD (group III).

RESULTS

Plasma levels of 8-epiPGF(2alpha) were 123.2+/-9.5, 314.6+/-40 and 389.6+/-36.2 pg/ml in groups I, II and III respectively (P<0.05 and P<0.001 groups II and III versus group I, respectively). In group III, 8-epiPGF(2alpha) levels increased with the number of affected vessels (324.4+/-47.2 and 408.3+/-44.1 pg/ml for one- and multi-vessel disease, P=0.07 and P<0.001 versus control subjects, respectively). A significant difference in 8-epiPGF(2alpha) levels was observed between patients with and without hypertension (394.2+/-42.7 and 232.7+/-25.1 pg/ml, P<0.01, respectively). In addition, patients with dyslipidaemia presented higher 8-epiPGF(2alpha) levels with respect to non-dyslipidaemic patients (359.1+/-35.6 and 240.3+/-34.3 pg/ml, P<0.05, respectively). A positive relationship was found between age and 8-epiPGF(2alpha) levels (r=0.42, P<0.01) in the whole population.

CONCLUSION

These findings indicate that elevated levels of plasma 8-epiPGF(2alpha) levels are associated with the extent and the severity of coronary artery disease and with the occurrence of different atherogenic risk factors, supporting the hypothesis that the evaluation of oxidative stress may represent an additional prognostic predictor in such events and a potential target of future therapeutic interventions.

Deoxyribonucleic acid damage in human lymphocytes after percutaneous transluminal coronary angioplasty

OBJECTIVES; We investigated the presence of oxidative deoxyribonucleic acid (DNA) damage in the peripheral lymphocytes of patients undergoing percutaneous transluminal coronary angioplasty (PTCA) by using the micronucleus test and comet assay, which are sensitive biomarkers of DNA damage. BACKGROUND; Although it has recognized that ischemia-reperfusion can induce oxidative DNA damage, its occurrence in patients undergoing PTCA has not yet been demonstrated.

METHODS

Three groups of patients were enrolled: 30 patients with documented coronary heart disease who underwent elective PTCA (group I); 25 patients who underwent elective coronary angiography for diagnostic purpose (group II); and 27 healthy, age- and gender-matched subjects (group III). For each subject, the frequency of micronucleated binucleated (MNBN) cells, DNA single-strand breaks (SSBs), endonuclease III-sensitive sites, and sites sensitive to formamidopyrimidine glycosylase (FPG) were analyzed before and after diagnostic procedures.

RESULTS

The mean basal values of MNBN cells (p = 0.04), DNA-SSBs (p = 0.001), endonuclease III-sensitive sites (p = 0.002), and FPG sites (p < 0.0001) were significantly higher in groups I and II than in group III. A high significant increase of MNBN cell frequency was observed in group I after the PTCA procedure (11.0 +/- 1.3 vs. 19.8 +/- 1.6, p < 0.0001), whereas no significant difference was observed in group II (10.2 +/- 1.3 vs. 12.9 +/- 1.4, p = 0.18). A significant positive correlation was observed between the increase in the MNBN cell rate and total inflation time during PTCA (R = 0.549, p = 0.0017). The levels of DNA-SSBs (11.7 +/- 1.4 vs. 26.5 +/- 3.0, p = 0.0003) and FPG sites (13.8 +/- 1.8 vs. 22.5 +/- 2.4, p = 0.01) were also higher after PTCA.

CONCLUSIONS

Our results provide evidence for oxidative DNA damage after PTCA, likely related to ischemia-reperfusion injury.

Successful treatment with doxycycline and nicotinamide of two cases of persistent pemphigoid gestationis

Pemphigoid gestationis (PG) is a rare dermal-epidermal autoimmune bullous disease of pregnancy and postpartum, which relapses more seriously and earlier during following pregnancies. PG also occurs in association with trophoblastic tumours or oral contraceptive treatment. The term 'persistent PG' represents the cases where active disease persists for months to many years after delivery. Four cases of persistent PG have been reported to date in the literature. So far, systemic cortico-steroids have been the main PG therapy and the use of cyclophosphamide, dapsone, pyridoxine, methotrexate, plasmapheresis or ritodrine has also been reported, with contradictory results. In this paper are described two patients with persistent PG who were successfully treated with doxycycline (200 mg/day) and nicotinamide (500 mg/day), a treatment that was demonstrated to be safe and efficacious in bullous pemphigoid.

A comparison of auditory and visual distraction effects: behavioral and event-related indices

Infrequent task-irrelevant deviations in the frequency of a tone may distract our attention away from the processing of task-relevant tone duration. The distraction obtained in the auditory paradigm is reflected in prolonged reaction times in duration discrimination and in P3a. The P3a is followed by a late negative component, which may be related to a re-orienting process following distraction (RON, re-orienting negativity). The present study aimed at comparing effects of the auditory and a corresponding visual distraction paradigm. Distraction elicited a deviance-related negativity which revealed a modality-specific distribution. It was followed by P3a (350-ms post-stimulus) and by RON (500-ms post-stimulus). RON did not occur with long-duration visual stimuli indicating a difference in visual and auditory distraction. Moreover, the results suggest that in both tasks irrelevant deviants were detected by modality-specific processes which caused an attention shift.

Attentive and pre-attentive periodicity analysis in auditory memory: an event-related brain potential study

In an event-related potential (ERP) study we presented human subjects with streams of repetitive white noise (semi-periodic noise) under attend and ignore conditions to investigate whether the perception of the periodicity with short cycle-lengths is due to lower level, pre-attentive sensory memory processing or higher level, attentive working memory processing. The ERPs of both conditions reveal N1-like deflections that are time locked on the semi-periodic noise suggesting that the processing of the periodicity is due to a pre-attentive rather than an attentive process. The topography of the deflections suggests that its generators are located in the supratemporal plane. Additionally, the ERPs elicited by infrequent disruptions in the periodicity show differences between the conditions suggesting that the detection of disruptions in periodicity is facilitated by attention.

Event-related brain potentials dissociate visual working memory processes under categorial and identical comparison conditions

Event-related potentials (ERPs) have been successfully employed to examine the functional and neuronal characteristics of working memory processes. In the present study, we examined the ERP waveforms in a delayed matching task to examine the cognitive processes underlying category and identity comparison and the effects of stimulus complexity. Subjects had to decide whether two visual stimuli are (a) physically identical (identical comparison condition, IC) or (b) identical, irrespective of their orientation (categorial comparison condition, CC). The stimuli were structured five-point patterns, which varied in complexity. For the ERPs elicited during the 1500 ms retention interval, the following pattern of results was obtained: Stimuli in the CC-condition elicited larger P300 components than in the IC-condition. In the IC-condition, the P300 was followed by a broadly distributed negative slow wave. Moreover, complex patterns elicited a posteriorily distributed negativity at 350 ms (N350), whereas the less complex patterns gave rise to a fronto-centrally distributed slow wave that started around 500 ms. These results suggest that S1 was more elaborately processed in the CC-condition, while the more complex figures were associated with an early classification process during the retention interval.

Size determination of bacterial capsular oligosaccharides used to prepare conjugate vaccines

We recently described the use of ion exchange chromatography for analysis and the industrial scale preparation of pools of oligosaccharides of intermediate chain length from polysaccharides of Haemophilus influenzae type b (Hib) and Neisseria meningitidis groups A and C. These negatively charged "sized" oligosaccharides are activated and conjugated to the carrier protein (CRM197) to prepare the corresponding glycoconjugate vaccines. Characterization and accurate determination of the degree of polymerization (DP) of the pool of oligosaccharides is essential for the consistent production of these conjugate vaccines. This paper describes the colorimetric assays used for determination of the average DP of the Hib and meningococcal oligosaccharides, and the qualification of these assays achieved by size characterization of the respective oligosaccharides by use of physicochemical methods, including liquid chromatography, mass spectrometry (ionspray) and NMR spectroscopy.

[A case of intestinal obstruction after migration of esophageal endoprosthesis]

Endoscopic dilatation and stenting are the procedures of choice in the treatment of oesophago-gastric anastomotic stricture following oesophagectomy, leading to immediate relief of dysphagia with a low procedure-related risk. Prosthesis displacement is a described late complication, easy detected and sorted out whenever possible with endoscopic retrieval. A case in which stent migration ended at the terminal part of the small intestine, presenting with the clinical features of mechanical ileum, is described.

[Kimura disease]

Kimura's disease is a chronic inflammatory pathology belonging to the angio-lymphatic proliferative disorders. The clinical features are a tumour-like swelling usually in the head and neck, with or without lymphadenopathy, often accompanied by eosinophilia and elevated serum IgE. It could be confused with angiolymphoid hyperplasia with eosinophilia. Other clinical differential diagnosis to Kimura's disease are reactive lymphadenopathy, lymphoma, parotid tumor with nodal metastasis and Mikulicz disease. The diagnosis is achieved by excisional biopsy which is also the therapy of choice. The prognosis is excellent. A case of Kimura's disease in an Italian female is presented together with a review of the literature.

Circulatory model in metabolic studies of rapidly renewed hormones: application to ANP kinetics

In an attempt to identify and quantify the sites of atrial natriuretic peptide (ANP) degradation, a new tracer experiment has been developed. 125I-ANP was injected as a bolus just upstream from the right atrium, and blood was sampled from two different sites (pulmonary artery and aorta) in eight cardiac patients. Data were analyzed using a physiologically based circulatory model consisting of three blocks in series (right heart, lungs and left heart, and periphery) supplied by the same flow (cardiac output, measured by thermodilution); the extraction coefficients of the three blocks and of the whole body could be determined from the areas under tracer concentration curves in plasma (AUCs). The values for AUCs (means +/- SD) were 64.8 +/- 9.4 and 65.5 +/- 10.7% dose.l-1.min-1 for pulmonary artery and aorta curves, respectively; the area under the pulmonary artery curve could be subdivided into the area under the first-pass curve (30.6 +/- 4.7% dose. l-1.min-1) and the area under the recirculating curve (34.0 +/- 7.7% dose.l-1.min-1). The metabolic clearance rate of 125I-ANP, computed as dose divided by the area under the recirculating curve, was 3.1 +/- 0.7 l/min, and the whole body extraction was 47.6 +/- 6.6%. In our patients with myocardial dysfunction, neither right heart block nor lungs and left heart block significantly extracted ANP, and periphery block accounted for almost all removal of the hormone from the blood.

[Coronary arteriography with a very low profile catheter: efficacy and safety of the procedure and of the 60 minute hospital discharge]

PURPOSE

To evaluate the feasibility, efficacy and safety of the use of 4F Judkins catheters for coronary angiography.

METHODS

From August/95 to January/96, 70 patients with suspected coronary artery disease underwent coronary cineangiography by the Judkins technique, with 4F catheters. Following puncture of the right femoral artery, 4F sheaths were introduced. At the end of the procedure, the sheath was removed and manual compression was applied for 15 min. Patients were oriented to walk under specialized supervision, 60 min after the procedure, and discharged after 4h.

RESULTS

Thirty nine (56%) patients were male, the age ranged from 31 to 83 (mean 57) years and weight from 43 to 101 (mean 69) kg. Optimal quality images were obtained in 62 patients (88%). It was necessary to use larger caliber catheters (6 and 8F) in 8 patients, due to femoral tortuosity or inadequate opacification of coronary arteries. There were no vascular complications nor major bleedings. In only 2 cases (3%) there was a minor bleeding, treated by new local compression. Sixty (85%) patients walked after 60 +/- 5 min and were discharged after 4h.

CONCLUSION

The use of 4F catheters for coronary angiography by femoral approach allowed early deambulation with no major bleeding. Image quality was good, with little contrast used and short hospital stay. This technique may lead to a simpler less traumatic and less invasive coronary angiography.

On the contribution of biomedical engineering and technology to the understanding and the management of arterial hypertension

There are several reasons why arterial blood pressure, i.e. the pressure within the large arterial vessels, is out of the physical parameters of the human body, one of the most frequently measured. Firstly, arterial blood pressure is a physiologically meaningful parameter, since it represents the driving pressure generated by the heart which maintains blood perfusion in the periphery. Secondly, it is a clinically important parameter: a decline of arterial blood pressure (e.g. in shock) may represent a life-threatening emergency which requires prompt recognition and correction; elevated blood pressure (hypertension) on the other hand is a very common condition, which bears a high risk of cardiovascular mortality and morbidity and can be controlled with appropriate pharmacological means. Thirdly, but not lastly, arterial blood pressure is easily measurable with a fair degree of accuracy by the standard manual sphygmomanometric method and, more recently, by non-invasive automatic techniques. This paper discusses some of the aspects related to arterial blood pressure measurement, in which, in the author's opinion, medical engineering and technology are expected to provide useful advancements. Two major areas will be considered. The first regards the methodologies for arterial blood pressure assessment; the second the identification and acquisition of information additional to blood pressure which would be helpful for a better understanding of blood pressure measurements and/or of risk profiling. For the purpose of this brief paper, we shall mainly use examples and reasonings from our own experience.

Evidence that atrial natriuretic peptide tissue extraction is not changed by large increases in its plasma levels induced by pacing in humans

Atrial natiurectic peptide (ANP) is a cardiac hormone with a very short plasma half-life, which plays an important role in a variety of clinical conditions associated with an increase in pressure and/or volume overload on the heart. The MCR of the hormone is considered to represent a stable parameter, reflecting the uptake and degradation rate of ANP by the periphery, only scarcely affected by rapid oscillations of circulating levels. To evaluate the extent to which MCR is affected by rapid and large variations of circulating levels of the hormone, we measured MCR in five patients with different degrees of myocardial function (from normal to severely impaired), in whom changes in ANP levels were induced by atrial and/or ventricular pacing. Cardiac output was simultaneously measured by thermodilution to calculate whole body extraction of ANP. During constant i.v. infusion of [125I]ANP, the hormone MCR was determined both under basal conditions (at tracer equilibration, 20-30 min after the start of infusion) and during atrial and ventricular pacing. Pacing maneuvers, begun 50 min after the start of infusion, induced a marked and rapid increase in endogenous plasma ANP values in all patients (on the average, 3,7-fold compared to basal values; range, 1.8-5.68), whereas corresponding values of [125I]ANP only minimally changed. The MCR of ANP (3.62 +/- 1.06 L/min, mean +/- SD) slightly decreased (by repeated measures ANOVA, P = 0.0458) during atrial and ventricular pacing procedures (3.35 +/- 1.03 and 3.15 +/- 0.74 L/min, respectively), reaching a mean value of 88.7 +/- 9.0% compared to basal. The small decrease in MCR could be almost completely ascribed to hemodynamic factors; indeed, basal cardiac output (5.76 +/- 1.70 L/min) was found, on the average, to be slightly decreased during atrial and ventricular pacing (5.28 +/- 1.46 and 5.16 +/- 1.33 L/min, respectively), and so whole body extraction of the hormone, measured before pacing (50.0 +/- 12%), remains stable throughout the study period (50.4 +/- 10.6% and 49.6 +/- 10% during atrial and ventricular pacing, respectively). Our findings demonstrate that degradative mechanisms involved in ANP clearance are not saturable at least for acute elevations of ANP plasma levels up to 3-5 times the basal level.

Acute effects of amiodarone administration on thyroid function in patients with cardiac arrhythmia

Because little has been published on early effects of treatment with amiodarone on thyroid function, we studied serum total and free thyroid hormone, reverse T3, and TSH levels in patients with cardiac arrhythmias during the first 10 days of treatment with a loading dose of amiodarone by iv infusion. Twenty-four patients were enrolled in the study. A standardized loading regimen for the i.v. infusion of amiodarone was used. The protocol provided the i.v. infusion of 20 mg/kg per day on day 1, the i.v. infusion of 10 mg/kg per day on day 2, then 600 mg/day per os for 7-10 days, and finally, in patients chronically treated with the drug, the dose was gradually reduced to 400-200 mg/day per os. Total and free concentrations of T4 tended to progressively and significantly increase (P < 0.0001 repeated measures ANOVA) starting from the fourth day of therapy, whereas total T3 decreased from the second day progressively (P < 0.0001) throughout the study; free T3 did not significantly change. TSH levels early and significantly (P < 0.001, by ANOVA) increased throughout the study, starting from the first day of therapy and reaching at 10 days a value 2.7 times higher than the basal value. Reverse T3 levels progressively and significantly (after 2 days of treatment) increased and paralleled the TSH values, reaching at the 10th day a value about 2 times higher than basal value. In conclusion, our data suggest that after i.v. treatment with amiodarone: 1) TSH is the first hormone to change significantly followed by reverse T3, T4, and T3; 2) the progressive fall of T3 levels reflects an inhibition of the peripheral conversion of T4 to T3; 3) the observed later increase of total and free T4 levels may be explained by a contribution of direct thyroidal stimulation by TSH and/or by a reduction in T4 clearance.

Analytical performance and clinical usefulness of a commercially available IRMA kit for measuring atrial natriuretic peptide in patients with heart failure

We evaluated the analytical characteristics and clinical usefulness of a commercially available IRMA kit for measuring plasma concentrations of atrial natriuretic peptide (ANP) in healthy subjects and in patients with heart failure. The method uses two monoclonal antibodies prepared against sterically remote epitopes of the ANP molecule; the first antibody is coated on the solid-phase beads, and the second is radiolabeled with 125I. Fifty-nine healthy subjects and 77 patients with heart failure were studied. After subjects had rested 20 min in a recumbent position, blood samples were collected from a brachial vein into ice-chilled disposable polypropylene tubes containing aprotinin and EDTA. Plasma samples were immediately separated by centrifugation and stored at -20 degrees C until assay. The working range (CV &lt;15%) was 10-2000 ng/L. The detection limit (2.13 +/- 0.91 ng/L) was similar to those reported for other IRMAs but was much better than those of RIAs. For healthy subjects, the results of this method (18.0 +/- 10.6 ng/L, range 4.7-63 ng/L, median 16.7 ng/L, n = 59) were similar to those generally reported for the most accurate methods, i.e., those using preliminary extraction and chromatographic purification of plasma samples. Measured plasma ANP was significantly associated with the severity of clinical symptoms, i.e., NYHA class (ANOVA, P &lt;0.0001), and with the left ventricular ejection fraction (n = 62, r = 0.618, P &lt;0.0001). Patients with severe heart failure showed greatly increased values (NYHA III-IV: 257.4 +/- 196.6 ng/L, n = 23).

Analytical performance and clinical usefulness of a commercially available IRMA kit for measuring atrial natriuretic peptide in patients with heart failure

We evaluated the analytical characteristics and clinical usefulness of a commercially available IRMA kit for measuring plasma concentrations of atrial natriuretic peptide (ANP) in healthy subjects and in patients with heart failure. The method uses two monoclonal antibodies prepared against sterically remote epitopes of the ANP molecule; the first antibody is coated on the solid-phase beads, and the second is radiolabeled with 125I. Fifty-nine healthy subjects and 77 patients with heart failure were studied. After subjects had rested 20 min in a recumbent position, blood samples were collected from a brachial vein into ice-chilled disposable polypropylene tubes containing aprotinin and EDTA. Plasma samples were immediately separated by centrifugation and stored at -20 degrees C until assay. The working range (CV <15%) was 10-2000 ng/L. The detection limit (2.13 +/- 0.91 ng/L) was similar to those reported for other IRMAs but was much better than those of RIAs. For healthy subjects, the results of this method (18.0 +/- 10.6 ng/L, range 4.7-63 ng/L, median 16.7 ng/L, n = 59) were similar to those generally reported for the most accurate methods, i.e., those using preliminary extraction and chromatographic purification of plasma samples. Measured plasma ANP was significantly associated with the severity of clinical symptoms, i.e., NYHA class (ANOVA, P <0.0001), and with the left ventricular ejection fraction (n = 62, r = 0.618, P <0.0001). Patients with severe heart failure showed greatly increased values (NYHA III-IV: 257.4 +/- 196.6 ng/L, n = 23).

[Adenocarcinoma of the anal glands. Description of a clinical case and review of the literature]

Adenocarcinoma of the anal glands is a rare slow-growing tumor with a more favorable prognosis compared with colorectal adenocarcinoma, especially if an early diagnosis is established. Clinical symptoms of this disease, often associated with a fistula in ano as in the reported case, include: perianal pain, rectal bleeding and presence of perianal mass. Also perianal Paget's disease may be a not rare association with adenocarcinoma of the anal glands. We believe, therefore, that a histological examination of the resected fistulas in ano should be performed, in searching for the presence of mucinous granules. In addition, it's very important to carry out a careful examination of those patients presenting pruritus ani or eczematous lesions of the anal region. In fact adenocarcinoma of the anal glands may be due to a chronic irritation of the epithelium over a period of years. Radiation therapy and chemotherapy have proved not to provide survival benefit in the treatment of this disease; the same result is obtained with a local excision of the lesion. The only chance for cure, therefore, is early diagnosis followed by radical operation. Miles abdominoperineal resection represents the approach of choice we have adopted for our patient. A radical groin dissection should be carried out only if there are metastases to the inguinal nodes. If necessary, abdomino-perineal resection may be folowed by adjuvant irradiation.

Normalization of peripheral thyroid hormone metabolism induced by successful chronic amiodarone treatment in patients with ventricular arrhythmias

Amiodarone, an antiarrhythmic agent, is also known to have important effects on the peripheral metabolism of thyroid hormones; the relationship between these two effects of the drug, however, is not well established. We tested the hypothesis that the antiarrhythmic effect of amiodarone might be mediated by its effect on the metabolism of thyroid hormones. Peripheral thyroid hormone metabolism was investigated using a double-tracer ([125I]-T4 and [131I]-T3) procedure in 10 normal volunteers and 10 euthyroid patients with complex ventricular arrhythmias before and during 6 months' amiodarone treatment. The underlying cardiac disease was coronary artery disease in four cases, dilated cardiomyopathy in three and idiopathic arrhythmias in three. In all but one patient with complex ventricular arrhythmias amiodarone treatment resulted in a reduction of > or = 80% of premature ventricular contractions and complete suppression of episodes of ventricular pairs or ventricular tachycardia. In all cases successful treatment with amiodarone was accompanied by normalization of all kinetic parameters: T4 to T3 conversion ratio and T3/T4 molar ratio of production decreased to mean values of 24.7 +/- 17.5% and 0.35 +/- 0.22% respectively, whereas T4 production rate increased (mean value 75.9 +/- 30.0 nmol day-1 m-2). Our kinetic data indicate that long-term therapy with amiodarone, when effective in suppressing cardiac arrhythmias, also reduces peripheral T4 to T3 conversion, hence restoring the normal peripheral thyroid hormone metabolic pattern. In conclusion, our study confirms that the antiarrhythmic action of amiodarone may be (at least partially) mediated by its action on thyroid hormone metabolism, and may justify the hypothesis that an altered peripheral metabolism of thyroid hormones may play a role in the pathogenesis of complex ventricular arrhythmias.

Acute enoximone effect on systemic and renal hemodynamics in patients with heart failure

Patients with heart failure generally show improvement in their clinical condition after enoximone infusion over the period of treatment; this effect cannot be ascribed only to the known hemodynamic action of this drug. Thirty-six patients (age range 44-82 years) with heart failure (NYHA class II-IV) underwent 48-hour enoximone infusion to study whether this prolonged improvement might depend on changes in systemic or renal hemodynamics or in neurohormonal balance. All patients underwent Swan-Ganz hemodynamic monitoring; renal plasma flow, glomerular filtration rate, plasma atrial natriuretic factor (ANF), and plasma renin activity (PRA) were all measured at baseline, at the peak of the enoximone action, and 48 hours after drug discontinuation. The main hemodynamic parameters were significantly improved during enoximone infusion and after drug discontinuation. The cardiac index basal value of 2.2 +/- 0.1 l/min/m2 increased to 3.1 +/- 0.1 l/min/m2 after 24-hour therapy (p < 0.01); similarly, pulmonary wedge pressure, mean pulmonary arterial pressure, and right atrial pressure decreased markedly (p < 0.01). Beneficial effects were also observed in renal hemodynamics; indeed, renal plasma flow (basal value 485 +/- 39 ml/min) increased significantly after 24-hour enoximone infusion (575 +/- 35 ml/min; p < 0.01), and this tendency was also observed 48 hours after drug discontinuation. No significant modifications were observed in plasma hormone data; however, the PRA plasma level had a tendency to decrease. We conclude that in patients with heart failure, enoximone infusion has a less marked effect on renal hemodynamics, but this is more lasting than systemic hemodynamic effects. The tendency of PRA to decrease (although not statistically significant), still detectable 2 days after treatment in the presence of steady high plasma ANF concentrations, may also contribute to the paradoxical longlasting benefit despite the short-lived improvement in systemic hemodynamics after brief cycles of enoximone infusion.

[Treatment of large bowel obstruction. Experience with intra-operative wash-out of the colon]

The treatment of colorectal obstructions is a surgical problem. The surgeon can choose between primary resection with anastomosis and the staged operations. The one stage procedures need colon decompression or intraoperative colonic lavage. In our experience between 1990 and 1993, 23 patients required an emergency intervention for colon obstruction; between them 13 patients were affected by a left colonic obstruction and were treated with a staged procedure (like Hartman operation) in 9 cases and with intraoperative colonic wash-out with primary anastomosis in 4 cases. The last group had a good postoperative course without an increased incidence of anastomotic leakage (no one in our limited experience). Compared with staged surgery, immediate resection and anastomosis had significant advantages for the patients because: 1) the quality of the life is better (absence of colonstomy); 2) the cumulative hospitalization is reduced (15 days vs 32 days); 3) there is a reduction in operative risk and in the cumulative intra- and postoperative immunodepression. The correct evaluation of the effect on the long-term survival of these factors needs larger series and of longer follow-up.

Altered tissue degradation and distribution of atrial natriuretic peptide in patients with idiopathic dilated cardiomyopathy and its relationship with clinical severity of the disease and sodium handling

BACKGROUND

Atrial natriuretic peptide (ANP) has been suggested to play an important role in heart failure, preserving cardiorenal homeostasis through maintenance of the sodium balance and inhibition of the detrimental effects of the neurohormonal vasoconstrictor system. The current study was designed to investigate whether there is a disturbed renewal and distribution of ANP in patients with idiopathic dilated cardiomyopathy (IDC) with differing clinical severity of disease.

METHODS AND RESULTS

We used a tracer method to perform a cross-sectional study of 15 IDC patients with differing clinical severity (New York Heart Association functional class I to III), prospectively divided into two groups according to their functional class (group 1, classes I and II; group 2, classes II-III and III). Eleven normotensive, nonobese male volunteers also were studied as a control group. Main ANP kinetic parameters were derived from the disappearance curve of the labeled hormone after the bolus injection of [125I]-labeled ANP. A high-performance liquid chromatography technique was used to separate the radiolabeled hormone in each plasma sample. Patients in group 1 showed higher ANP metabolic clearance rate (MCR) (2731.9 +/- 726.2 mL.min-1.m-2) than patients of group 2 (1718.4 +/- 621.2 mL.min-1.m-2) and control subjects (1873.1 +/- 551.2 mL.min-1.m-2). ANP disposal (MCR) positively correlated with biological hormonal effect (urinary sodium excretion) both in control subjects and in patients. In IDC patients of both groups, however, MCR values were always higher (approximately doubled) than the values found in control subjects at the corresponding sodium excretion. This finding indicates that a reduced ANP biological activity is associated with hormone degradation in patients. Moreover, patients of group 2 showed significantly higher ANP production rates (395.6 +/- 183.8 ng.min-1.m-2) than group 1 (166.0 +/- 139.0 ng.min-1.m-2) and control subjects (130.7 +/- 105.4 ng.min-1.m-2) despite a marked reduction in sodium excretion. Patients with IDC showed a progressive reduction in the total distribution volume (group 1, 19.8 +/- 5.8 L/m2; group 2, 12.7 +/- 6.9 L/m2; control subjects, 27.0 +/- 11.6 L/m2) of the hormone; this probably was due to a reduction in exchanges of ANP with peripheral tissues.

CONCLUSIONS

Our study demonstrates a markedly altered degradation and distribution of ANP in patients with IDC, even in those at the early stage of clinical disease (classes I and II, group 1) who have ANP plasma levels in the normal range.

In vivo measurement of ANP overall turnover and identification of its main metabolic pathways under steady state conditions in humans

Using a tracer method, we evaluated, in vivo, the main turnover parameters and the main metabolic pathways of ANP in 10 normal subjects. HPLC was used to purify the labeled hormone and the principal labeled metabolites present in venous plasma samples collected at determined times after tracer injection. The main ANP kinetic parameters were derived from the disappearance curves of [125I] ANP, which were satisfactorily fitted by a biexponential function in all subjects. Newly produced ANP initially distributes in a large, plasma equivalent space (10.9 +/- 3.6 l/m2 body surface); the hormone rapidly leaves this space due to both degradation and to distribution in peripheral spaces. The mean residence time in the body (19.4 +/- 19.8 min) and the plasma equivalent total distribution volume (28.2 +/- 11.5 l/m2) indicate that ANP is also widely distributed outside the initial space in humans (circulating ANP is no more than 1/15 of the body pool). Metabolic clearance rate values were distributed across a wide range (from 740 ml/min/m2 to 2581 ml/min/m2, mean 1849 ml/min/m2), and were shown to strongly correlate (R = 0.962) with the daily urinary excretion of sodium. A complete separation of labeled ANP from its labeled metabolites was achieved by the HPLC technique; at least 3 different peaks due to labeled metabolites in vivo produced from the injected [125I]ANP1-28 were found. The first chromatographic peak eluted showed an identical elution time to monoiodotyrosine. At least two other peaks due to in vivo generated labeled metabolites were well identified in the chromatograms: one peak (coeluting with labeled COOH-terminal tripeptide, H-Phe-Arg-Tyr-OH) was eluted ahead and one (coeluting with labeled peptide fragments ANP7-28, ANP13-28, and ANP18-28) behind the elution peak of the labeled ANP. The peak of labeled tyrosine appearing in the plasma ranged between 3 and 5 min after tracer injection; the other two peaks of radioiodinated metabolites showed their highest activity in the first sample (1.5 min), suggesting an earlier occurrence of their peaks. These labeled metabolites seem to be intermediate peptides, between the intact circulating form of the hormone and the final labeled metabolite (tyrosine), which is the last amino acid of the peptide hormone, produced in vivo after injection of the tracer.(ABSTRACT TRUNCATED AT 400 WORDS)

Kinetic study of atrial natriuretic peptide in patients with idiopathic dilated cardiomyopathy: evidence for resistance to biologic effects of the hormone even in patients with mild myocardial involvement

Atrial natriuretic peptide (ANP) kinetics was studied in 12 patients with idiopathic dilated cardiomyopathy at different sodium excretion (30-175 mmol/day) and variable degrees of hemodynamic dysfunction [New York Heart Association (NYHA) class range I-III] to investigate whether differences in renewal and distribution of this hormone (as compared with those of a control group) play a role in pathogenesis and evolution of heart failure. [125I]Labeled ANP was injected as a bolus, and a high-performance liquid chromatography (HPLC) procedure was used to purify the labeled hormone in venous plasma samples collected for < or = 50 min after injection; the main ANP kinetic parameters were then derived from the disappearance curve of the labeled hormone. As in controls, a positive linear regression between ANP metabolic clearance rate (MCR, ml/min/m2) values and daily urinary excretion of sodium (NaUE, mmol/day) was noted in patients. The different linear regression coefficients between normal subjects (MCR = 365 +/- 8.08 NaUE, r = 0.986, p < 0.0001) and patients (MCR = 497 + 18.5 NaUE, r = 0.867, p = 0.001) indicate that in patients a higher peptide clearance rate is needed to obtain the same biologic effect (sodium excretion) and suggest that resistance to biologic effects of the hormone exists in patients at an early stage of disease (NYHA class I). When the efficiency of the ANP system in excreting sodium was expressed as the ratio of NaUE to ANP production rate (PR = MCR x ANP plasma concentration, microgram/day/m2) patients showed significantly lower values (p = 0.0126) than normal volunteers, thus confirming resistance to the hormone effects. Significantly lower values for ANP total distribution volume (16.5 +/- 8.4 L/m2), mean residence time in the sampling space (4.04 +/- 1.14 min), mean residence time in the body (7.25 +/- 2.13 min), and fewer recycles through the initial (sampling) space (0.27 +/- 0.16) were noted in patients, indicating an altered mechanism regulating distribution of the hormone. The positive correlations between ANP MCR (L/min/m2) values and cardiac index (CI, L/min/m2) (MCR = -1.24 + 1.17 CI, r = 0.689, p = 0.0092) and between initial distribution volume (IDV, L/m2) and CI (IDV = -11.2 + 6.85 CI, r = 0.730, p = 0.0046) in all patients indicate that hemodynamic factors contribute to the progressive reduction in MCR and IDV values throughout the progression of myocardial involvement.(ABSTRACT TRUNCATED AT 400 WORDS)

ANP kinetics in normal men: in vivo measurement by a tracer method and correlation with sodium intake

125I-labeled atrial natriuretic peptide (ANP) was bolus injected into seven healthy human male subjects on an unrestricted diet (sodium intake ranging from 80 to 300 mmol/day). A high-performance liquid chromatographic procedure was used to purify the labeled hormone and the principal labeled metabolites in venous plasma samples collected up to 50 min after injection. The main ANP kinetic parameters were derived from the disappearance curves of the 125I-ANP, which were satisfactorily fitted by a biexponential function in all subjects. Newly produced ANP initially distributes in a large space (plasma-equivalent volume is 12.1 +/- 3.6 l/m2 body surface); the hormone rapidly leaves this sampling space through both degradation and distribution in peripheral spaces, as indicated by the single-pass mean transit time through the sampling space (3.9 +/- 1.2 min). The mean residence time in the body (22.7 +/- 23.1 min) and the plasma-equivalent total distribution volume (30.9 +/- 12.0 l/m2) indicate that ANP is also widely distributed outside the initial space. Metabolic clearance rate (MCR) values were distributed across a wide range (from 740 to 2,581 ml.min-1 x m-2) and were shown to correlate strongly with the daily urinary excretion of sodium. These results indicate that: 1) newly produced ANP is rapidly distributed and degraded, 2) the body pool of the hormone can be considered as a combination of two exchanging spaces, 3) circulating ANP is < or = 1/15 of the body pool, and 4) MCR of ANP is closely related to sodium intake, at least in normal subjects on a free sodium intake diet.

Histologic evidence of myocardial damage in apparently healthy subjects with ventricular arrhythmias and myocardial dysfunction

The association of ventricular arrhythmias and myocardial dysfunction could be considered an early step toward cardiomyopathy; therefore, we studied 28 patients in NYHA class I and II, characterized by complex ventricular arrhythmias (VA) on 24-h Holter monitoring and volumetric and/or contractile abnormalities on a standard two-dimensional echocardiogram (2-D echo). All patients underwent radioisotopic angiography, 20 patients complete hemodynamic study, and 15 patients endomyocardial biopsy. Ambulatory ECG monitoring showed the presence of frequent premature ventricular contractions in 14 patients (50%) and episodes of ventricular tachycardia in 16 patients (57%). 2-D echo showed mono- or biventricular enlargement and dyssynergies in 25 patients (89%) (left ventricle in 6, right ventricle in 11, both in 8). Two patients showed only left ventricle enlargement and one patient isolated left ventricular dyssynergies. Radioisotopic angiography showed mono- or biventricular ejection fraction reduction in 24 patients (85%) and regional dyssynergies in 24 patients (85%) in accordance with 2-D echo. Hemodynamic study showed in all patients normal coronary arteries, and right and left angiography confirmed enlargement and/or regional dyssynergies. Endomyocardial biopsy was abnormal in 11 of 15 patients: various degrees of hypertrophy, parcellar fibrosis, and adipogenic infiltration were found. Our preliminary data suggest that the simultaneous occurrence of ventricular arrhythmias and ventricular dyssynergies and/or enlargement in patients without apparent clinical heart disease may represent an early stage of dilated cardiomyopathy.

Atrial natriuretic peptide during different pacing modes in a comparison with hemodynamic changes

The study investigates the response of atrial natriuretic peptide (ANP) to different cardiac pacing modes in comparison with hemodynamic changes. Ten patients underwent Swan-Ganz catheterization during pacemaker implant. Atrioventricular and ventricular pacing were performed consecutively at three pacing rate levels (80, 100, and 110 ppm). Blood samples were taken from the pulmonary artery for ANP determination, both basally and at the end of each pacing period. Concomitantly, mean pulmonary capillary wedge pressure (PCWP) and mean pulmonary artery pressure (PAP) were measured. Cardiac output (CO) was determined by thermodilution both basally and during the 110 ppm steps. During atrioventricular pacing, whereas no significant changes were observed for ANP, PCWP and PAP, CO increased significantly (P less than 0.0005). At the beginning of ventricular pacing hemodynamic parameters and ANP levels were comparable with those of baseline conditions. During subsequent ventricular pacing PCWP and ANP increased significantly at the 110 ppm rate step (P less than 0.05). PAP did not change significantly, whereas CO decreased in all cases (P less than 0.01). A positive correlation was observed between ANP and PCWP during ventricular (P less than 0.001), but not atrioventricular pacing. The results, while confirming the hemodynamic advantages of atrioventricular pacing, point to a major stimulation of ANP secretion during ventricular pacing. This fact, together with the observed drop in CO and the correlation between ANP and PCWP, suggest that the increase of ANP in ventricular pacing may be the expression of a compensatory mechanism to the hemodynamic disadvantages of atrioventricular asynchrony.

[Ambulatory electrocardiography in the screening of patients with palpitations]

The role of 24 hour Holter monitoring in the screening of patients complaining of palpitations is reviewed. The term "palpitations", although not always unequivocally used, implies the presence of an arrhythmia. The clinical-instrumental correlation of an intermittent symptom is made possible by continuous electrocardiographic monitoring. Answers to be expected from a 24 hour Holter monitoring in order to achieve an early characterization of the arrhythmia are related to: site of origin, incidence, circadian distribution, prognostic stratification, events aggregation, presence of other asymptomatic abnormalities (rhythm, ST-T).