Thyroid Hormone and Thyrotropin Regulate Intracellular Free Calcium Concentrations in Human Polymorphonuclear Leukocytes: In Vivo and in vitro Studies

Intracellular free calcium concentrations ([Ca++]1) were studied in polymorphonuclear leukocytes (PMNs) from 13 athyreotic patients who had been previously treated by total thyroidectomy and radioiodine therapy for differentiated thyroid carcinoma, and from age- and sex-matched euthyroid healthy controls. Patients were studied twice, when hypothyroid (visit 1) and after restoration of euthyroidism by L-T4 TSH-suppressive therapy (visit 2). PMNs from patients at visit 1 had significantly lower resting [Ca++]1 levels compared to both visit 2 and controls. Values at visit 2 did not differ from those of the controls. Stimulus-induced [Ca++]1 rise was also significantly blunted at visit 1 and normalized at visit 2, possibly through a differential contribution of distinct intracellular Ca++ stores, as suggested by the response pattern to the chemotactic agent, N-formyl-Met-Leu-Phe (fMLP), to the selective SERCA pump inhibitor, thapsigargine, and to the mitochondrial uncoupler, carbonyl cyanide p-trifluoromethoxyphenyl-hydrazone (FCCP). In vitro treatment of PMNs from healthy subjects with high TSH concentrations impaired intracellular Ca++ store function. Both resting [Ca++]1 levels and fMLP-induced [Ca++]1 rise increased in the presence either of low-concentration TSH or of T4, but effects of TSH and T4 were not additive. T3, rT3, and TRIAC had no effect. In conclusion, this study provides evidence for a direct relationship between thyroid status and [Ca[Ca++]1 homeostasis in human PMNs, mainly related to direct actions of TSH and T4 on these cells.

Loss of Mrap2 is associated with Sim1 deficiency and increased circulating cholesterol

Melanocortin receptor accessory protein 2 (MRAP2) is a transmembrane accessory protein predominantly expressed in the brain. Both global and brain-specific deletion of Mrap2 in mice results in severe obesity. Loss-of-function MRAP2 mutations have also been associated with obesity in humans. Although MRAP2 has been shown to interact with MC4R, a G protein-coupled receptor with an established role in energy homeostasis, appetite regulation and lipid metabolism, the mechanisms through which loss of MRAP2 causes obesity remains uncertain. In this study, we used two independently derived lines of Mrap2 deficient mice (Mrap2(tm1a/tm1a)) to further study the role of Mrap2 in the regulation of energy balance and peripheral lipid metabolism. Mrap2(tm1a/tm1a) mice have a significant increase in body weight, with increased fat and lean mass, but without detectable changes in food intake or energy expenditure. Transcriptomic analysis showed significantly decreased expression of Sim1, Trh, Oxt and Crh within the hypothalamic paraventricular nucleus of Mrap2(tm1a/tm1a) mice. Circulating levels of both high-density lipoprotein and low-density lipoprotein were significantly increased in Mrap2 deficient mice. Taken together, these data corroborate the role of MRAP2 in metabolic regulation and indicate that, at least in part, this may be due to defective central melanocortin signalling.

Pulmonary embolism severity index accurately predicts long-term mortality rate in patients hospitalized for acute pulmonary embolism

BACKGROUND

The Pulmonary Embolism (PE) Severity Index (PESI) is a clinical prognostic rule that accurately classifies PE patients into five risk classes with increasing mortality. PESI score has been validated in studies with a relatively short-term follow-up and its accuracy in predicting long-term prognosis has never been established.

METHODS

Consecutive patients admitted to the tertiary care hospital of Varese (Italy) with an objectively diagnosed PE between January 2005 and December 2009 were retrospectively included. Information on clinical presentation, diagnostic work-up, risk factors, treatment and mortality during a 1-year follow-up was collected.

RESULTS

Five hundred and thirty-eight patients were enrolled in this study. The mean age was 70.6 years (± SD 15.2), 44.4% of patients were male, and 27.9% had known cancer. One-year follow-up was available for 96.1% of patients. The overall mortality rate was 23.2% at 3 months, 30.2% at 6 months and 37.1% at 12 months. The discriminatory power of the PESI score to predict long-term mortality, expressed as the area under the ROC curve, was 0.77 (95%CI, 0.72-0.81) at 3 months, 0.77 (95%CI, 0.73-0.81) at 6 months and 0.79 (95%CI, 0.75-0.82) at 12 months. The PESI score confirmed its accurate prediction in patients without cancer. Simplified PESI had a similar overall accuracy to the original PESI at 3 and 6 months, but this was significantly lower at 1 year.

CONCLUSIONS

The results of this study suggest that PESI score may also be an accurate tool to define the 6-month and 1-year mortality rates in PE patients.

Left ventricular remodeling in patients with metabolic syndrome: influence of gender

AIM

The study was aimed to evaluate the influence of gender on left ventricular (LV) remodeling in metabolic syndrome (MetS).

METHODS AND RESULTS

We enrolled 200 subjects without diabetes or overt cardiovascular diseases, never treated with anti-hypertensive drugs or statins: 60 men and 40 women with MetS matched by age, gender and 24 h systolic and diastolic blood pressure (BP) with 60 men and 40 women without MetS. The patients underwent blood tests, 24 h our BP monitoring, LV echocardiographic examination. LV mass indexed by eight(2.7) was significantly greater in men and women with MetS than without MetS. Compared with women without MetS, women with MetS had significantly higher posterior wall thickness and relative wall thickness, greater prevalence of LV concentric remodeling/hypertrophy and lower indices of LV diastolic function, whereas all these parameters were not significantly different between men with and without MetS. MetS was an independent predictor of relative wall thickness and LV mass index in women, but not in men.

CONCLUSION

The impact of MetS on LV remodeling is significantly influenced by gender: the effects of MetS are more pronounced in women, with development of LV concentric hypertrophy/remodeling and preclinical diastolic dysfunction.

Diagnostic accuracy of lung ultrasound for pulmonary embolism: a systematic review and meta-analysis

BACKGROUND

Computed tomographic pulmonary angiography (CTPA) has simplified the diagnostic approach to patients with suspected pulmonary embolism (PE). However, PE diagnosis is still probabilistic and CTPA should be used with caution in some patient groups, such as patients with severe renal insufficiency and pregnant women. Among alternative imaging tests, lung ultrasound is the most promising technique. We aimed to systematically assess the diagnostic accuracy of lung ultrasound for PE diagnosis.

METHODS

Studies evaluating the diagnostic accuracy of lung ultrasound for the diagnosis of PE were systematically searched for in the MEDLINE and EMBASE databases (up to June 2012). The QUADAS-2 tool was used for the quality assessment of the primary studies. A bivariate random-effects regression approach was used for summary estimates of both sensitivity and specificity.

RESULTS

Ten studies, for a total of 887 patients, were included. A composite reference test was used in six studies, with single-row detector CTPA as the principal imaging test in four studies. Overall, seven studies used a proper reference test. Lung ultrasound bivariate weighted mean sensitivity was 87.0% (95% confidence interval [CI] 79.5, 92.0%), whereas bivariate weighted mean specificity was 81.8% (95% CI 71.0, 89.3%).

CONCLUSIONS

Our findings suggest that lung ultrasound may be a useful diagnostic tool in the management of patients with suspected PE. However, several methodological drawbacks of the primary studies limit any definite conclusion. Further well-designed accuracy studies are necessary before planning diagnostic management studies, in particular in those with a contraindication for CTPA.

Changes in autonomic modulation to the heart and intracellular catecholamines. A longitudinal study in differentiated thyroid carcinoma during short-term hypothyroidism and thyroid hormone replacement

BACKGROUND

The effects of thyroid deprivation on the autonomic modulation to the heart remain controversial.

METHODS

In this study in patients followed for thyroid carcinoma, we investigated (1) heart rate variability parameters and the baroreflex gain and (2) intracellular catecholamine levels in circulating lymphocytes during short-term hypothyroidism (phase 1) and after reinstitution of TSH-suppressive thyroid hormone replacement (phase 2).

RESULTS

The RR interval value (p < 0.01) and systolic blood pressure (p < 0.05) were higher in phase 1 than in phase 2. The low-frequency/high-frequency (LF/HF) ratio was significantly lower in the hypothyroid state (p < 0.05), with a higher HF component (p < 0.05). After adjusting for mean RR interval in the regression model, the difference between the power of RR interval oscillations calculated in the two states was greater for the LF band (p = 0.005) and it was borderline significant for the HF band (p = 0.052). The baroreflex gain alpha(LF) index was similar in the two phases. The stimulus-induced cellular production of norepinephrine and epinephrine in peripheral blood mononuclear cells was significantly higher in phase 2.

CONCLUSION

The neurally-mediated influences on the sinus node and the study of intracellular catecholamine production suggest a reduced sympathoexcitation in hypothyroidism compared with the treatment phase. The early increase in blood pressure observed after thyroid hormone withdrawal is not due to impaired sensitivity of the baroreflex arc.

Thyroid hormone and thyrotropin regulate intracellular free calcium concentrations in human polymorphonuclear leukocytes: in vivo and in vitro studies

Intracellular free calcium concentrations (Ca++i) were studied in polymorphonuclear leukocytes (PMNs) from 13 athyreotic patients who had been previously treated by total thyroidectomy and radioiodine therapy for differentiated thyroid carcinoma, and from age- and sex-matched euthyroid healthy controls. Patients were studied twice, when hypothyroid (visit 1) and after restoration of euthyroidism by L-T4 TSH-suppressive therapy (visit 2). PMNs from patients at visit 1 had significantly lower resting (Ca++)i levels compared to both visit 2 and controls. Values at visit 2 did not differ from those of the controls. Stimulus-induced (Ca++)i rise was also significantly blunted at visit 1 and normalized at visit 2, possibly through a differential contribution of distinct intracellular Ca++ stores, as suggested by the response pattern to the chemotactic agent, N-formyl-Met-Leu-Phe (fMLP), to the selective SERCA pump inhibitor, thapsigargine, and to the mitochondrial uncoupler, carbonyl cyanide p-trifluoromethoxyphenyl-hydrazone (FCCP). In vitro treatment of PMNs from healthy subjects with high TSH concentrations impaired intracellular Ca++ store function. Both resting (Ca++)i levels and fMLP-induced (Ca++)i rise increased in the presence either of low-concentration TSH or of T4, but effects of TSH and T4 were not additive. T3, rT3, and TRIAC had no effect. In conclusion, this study provides evidence for a direct relationship between thyroid status and (Ca++)i homeostasis in human PMNs, mainly related to direct actions of TSH and T4 on these cells.

Interneurons transiently express the ERG K+ channels during development of mouse spinal networks in vitro

During spinal cord maturation neuronal excitability gradually differentiates to meet different functional demands. Spontaneous activity, appearing early during spinal development, is regulated by the expression pattern of ion channels in individual neurons. While emerging excitability of embryonic motoneurons has been widely investigated, little is known about that of spinal interneurons. Voltage-dependent K+ channels are a heterogeneous class of ion channels that accomplish several functions. Recently voltage-dependent K+ channels encoded by erg subfamily genes (ERG channels) were shown to modulate excitability in immature neurons of mouse and quail. We investigated the expression of ERG channels in immature spinal interneurons, using organotypic embryonic cultures of mouse spinal cord after 1 and 2 weeks of development in vitro. We report here that all the genes of the erg family known so far (erg1a, erg1b, erg2, erg3) are expressed in embryonic spinal cultures. We demonstrate for the first time that three ERG proteins (ERG1A, ERG2 and ERG3) are co-expressed in the same neuronal population, and display a spatio-temporal distribution in the spinal slices. ERG immuno-positive cells, representing mainly GABAergic interneurons, were present in large numbers at early stages of development, while declining later, with a ventral to dorsal gradient. Patch clamp recordings confirmed these data, showing that ventral interneurons expressed functional ERG currents only transiently. Similar expression of the erg genes was observed at comparable ages in vivo. The role of ERG currents in regulating neuronal excitability during the earliest phases of spinal circuitry development will be examined in future studies.

Physical and functional interaction between integrins and hERG potassium channels

Integrins are adhesion receptors capable of transmitting intracellular signals that regulate many different cellular functions. Among integrin-mediated signals, the activation of ion channels can be included. We demonstrated that a long-lasting activation of hERG (human ether-a-go-go-related gene) potassium channels occurs in both human neuroblastoma and leukaemia cells after the activation of the β1 integrin subunit. This activation is apparently a determining factor inducing neurite extension and osteoclastic differentiation in both the cell types. More recently, we provided evidences that β1 integrins and hERG channels co-precipitate in both the cell types. Preliminary results suggest that a macromolecular signalling complex indeed occurs between integrins and the hERG1 protein and that hERG channel activity can modulate integrin downstream signalling.

Natriuretic peptides as markers of preclinical cardiac disease in obesity

BACKGROUND

Aim of the study was to evaluate the role of atrial (ANP) and brain natriuretic peptides (BNP) as markers of preclinical cardiac disease in obesity.

METHODS

We selected 26 obese (BMI > 29 kg m(-2)) never-treated hypertensives (24-h BP > 140 and/or 90 mmHg), 26 obese normotensives (24-h BP < 130/80 mmHg) and 25 lean (BMI < or = 25 kg m(-2)) never-treated hypertensives. Each subject underwent measurements of ANP and BNP plasma levels, 24-h ambulatory blood pressure (BP) monitoring, digitized M-mode and Doppler echocardiography.

RESULTS

Mean values of ANP and BNP were similar among the three groups. All the subjects had normal left ventricular (LV) systolic function. Within each group ANP levels were higher in patients with LV diastolic dysfunction than in patients with normal diastolic function, and BNP levels were higher in patients with LV hypertrophy and in patients with LV diastolic dysfunction. Within each group, ANP levels were inversely correlated with LV diastolic indices, whereas BNP levels were directly correlated with LV mass index and inversely correlated with LV diastolic indices. ANP and BNP levels were not correlated with other echocardiographic parameters, age, BMI or 24-h BP values.

CONCLUSION

In normotensive and hypertensive obese subjects the relationships of ANP and BNP levels with LV morpho-functional characteristics follow the same trend as in lean hypertensives, with ANP mainly influenced by diastolic dysfunction and BNP influenced by both LV hypertrophy and LV diastolic dysfunction. Therefore ANP and BNP can be considered useful markers of preclinical cardiac disease in obesity.

HERG potassium channels are constitutively expressed in primary human acute myeloid leukemias and regulate cell proliferation of normal and leukemic hemopoietic progenitors

An important target in the understanding of the pathogenesis of acute myeloid leukemias (AML) relies on deciphering the molecular features of normal and leukemic hemopoietic progenitors. In particular, the analysis of the mechanisms involved in the regulation of cell proliferation is decisive for the establishment of new targeted therapies. To gain further insight into this topic we report herein a novel approach by analyzing the role of HERG K(+) channels in the regulation of hemopoietic cell proliferation. These channels, encoded by the human ether-a-gò-gò-related gene (herg), belong to a family of K(+) channels, whose role in oncogenesis has been recently demonstrated. We report here that herg is switched off in normal peripheral blood mononuclear cells (PBMNC) as well as in circulating CD34(+) cells, however, it is rapidly turned on in the latter upon induction of the mitotic cycle. Moreover, hergappears to be constitutively activated in leukemic cell lines as well as in the majority of circulating blasts from primary AML. Evidence is also provided that HERG channel activity regulates cell proliferation in stimulated CD34(+) as well as in blast cells from AML patients. These results open new perspectives on the pathogenetic role of HERG K(+) channels in leukemias.

Left ventricular changes in isolated office hypertension: a blood pressure-matched comparison with normotension and sustained hypertension

BACKGROUND

Isolated office (IO) hypertension is a benign condition according to some researchers, whereas others believe it is associated with cardiovascular abnormalities and increased cardiovascular risk. The aim of this study is to compare morphofunctional characteristics of the left ventricle (LV) in IO hypertensive subjects, normotensive subjects (hereafter, hypertensives and normotensives), and never-treated sustained hypertensives. The 3 groups were matched not only by age, sex, and body mass index but also by clinic blood pressure (BP) (IO hypertensives and sustained hypertensives) and daytime BP (IO hypertensives and normotensives).

METHODS

We enrolled 42 IO hypertensives (clinic BP > 140 and/or 90 mm Hg and daytime BP < or = 130/80 mm Hg), 42 sustained hypertensives (clinic BP > 140 and/or 90 mm Hg and daytime BP > or = 140 and/or 90 mm Hg) and 42 normotensives (clinic BP < 135 and/or 85 mm Hg and daytime BP < or = 130/80 mm Hg). Left ventricular morphologic features and function were assessed using digitized M-mode echocardiography.

RESULTS

Compared with normotensives, IO hypertensives had significantly thicker LV walls, increased LV mass, reduced diastolic function, increased prevalence of LV hypertrophy, and preclinical diastolic dysfunction. Sustained hypertensives, compared with IO hypertensives, had significantly thicker LV wall, higher LV mass, and lower diastolic function, whereas the prevalence of LV hypertrophy and preclinical diastolic dysfunction was greater than in IO hypertensives, but the difference did not reach statistical significance (P = .29).

CONCLUSIONS

Comparing matched BP groups, IO hypertensives have LV morphofunctional characteristics considerably different from normotensives and qualitatively similar to sustained hypertensives. Therefore, our results support the hypothesis that IO hypertension should not be considered as simply a benign condition.

Autonomic function and baroreflex sensitivity during angiotensin-converting enzyme inhibition or angiotensin II AT-1 receptor blockade in essential hypertensive patients

OBJECTIVE

The influence of ACE-inhibition and angiotensin II ATI receptor blockade on the autonomic function and baroreflex sensitivity was investigated in hypertension.

METHODS AND RESULTS

Heart rate variability was assessed in a resting condition by power spectrum analysis to evaluate the low frequency (LF) power, high frequency (HF) power and LF/HF ratio in 19 hypertensive patients and 23 normotensive controls. Moreover, the coherence between the tachogram and the systogram was evaluated, and the baroreflex gain (alphaLF-index), describing the transfer function of variability in the systolic pressure signal to variability in the RR interval, was obtained. Then a 24-h ambulatory blood pressure monitoring was performed. The 19 hypertensive patients were randomized to either enalapril or losartan treatment, and after 2 months were re-submitted to the RR variability and baroreflex study and to blood pressure monitoring. The subjects then crossed to the other antihypertensive treatment and were re-evaluated after an additional two months. No significant difference was found either in LF power and HF power and LF/HF ratio between normotensive and hypertensive subjects whereas a slight though significant difference was observed in the alphaLF-index. In hypertensive patients, both the treatments with enalapril and losartan reduced blood pressure and had no effect on heart rate. No significant change was observed in autonomic balance or in baroreflex sensitivity during the two antihypertensive treatments.

CONCLUSIONS

In hypertensive patients, the angiotensin system or bradykinins do not seem to have any modulatory effect on the sympathetic/parasympathetic control of blood pressure and baroreflex sensitivity, in a resting condition. Since heart rates were unchanged by the two antihypertensive treatments despite a significant reduction of blood pressure, a resetting of baroreflex function was observed during both ACE-inhibition and angiotensin II ATI receptor blockade.

Microalbuminuria as a marker of preclinical diastolic dysfunction in never-treated essential hypertensives

Using 24-h ambulatory blood pressure (BP) monitoring and digitized M-mode echocardiography, we evaluated whether microalbuminuria is related to preclinical left ventricular (LV) diastolic dysfunction in hypertensive patients. We selected 87 never-treated hypertensive patients (mean 24-h BP > 140 and/or > 90 mm Hg); albuminuria was evaluated as mean value of 24-h urinary albumin excretion (UAE) from two 24-h urine collections. Microalbuminuria was found in 28 patients, classified as MA+ (UAE 30 to 300 mg/24 h); 59 patients had normal UAE (< 30 mg/24 h) and were classified as MA-. The MA+ and MA- groups did not differ with regard to age, sex, body mass index, or 24-h heart rate, whereas 24-h, daytime, and nighttime systolic and diastolic BP were significantly higher in MA+ than in MA-. The LV mass index was greater in MA+, as was the prevalence of LV hypertrophy; peak shortening rate of LV diameter, index of systolic function, was normal in all, but was lower in MA+. Peak lengthening rate of LV diameter and peak thinning rate of posterior wall, indices of diastolic function, were lower in MA+ and the prevalence of diastolic dysfunction was higher in MA+. UAE was inversely correlated with both indices of LV diastolic function, also after correction for age, 24-h heart rate, 24-h BP, and LV mass. In conclusion, in never-treated hypertensive patients, microalbuminuria is not only associated with greater myocardial mass, but is also related with preclinical impairment of LV diastolic function. This relation, independent from increased BP or LV mass, strengthens the role of microalbuminuria as an early and reliable marker of preclinical cardiac involvement.

Longitudinal changes of insulin sensitivity in essential hypertension: influence of blood pressure control and familial predisposition to hypertension

The aim of this study was to evaluate the influence of blood pressure (BP) control and familial predisposition to hypertension on longitudinal changes in insulin sensitivity in essential hypertension. We evaluated 6 groups of subjects twice (basal: before any treatment; 2nd: after at least 18 months): 42 hypertensives (H) with a family history of hypertension (F+) and 30 H without a family history of hypertension (F-) successfully treated with angiotensin-converting enzyme inhibitors and/or calcium channel blockers (2nd: 24-h BP < or = 130/80 mm Hg); 22 untreated (UT) HF+ and 18 UTHF- (2nd: 24-h BP >140 and/or 90 mm Hg); 18 normotensives F+ and 15 normotensives F-. The parameters evaluated were as follows: glucose, insulin, and C-peptide (Cp) response to an oral glucose load. Glucose was normal in all of the subjects, similar among the 6 groups, and unchanged at the 2nd evaluation. At the basal evaluation insulin and Cp were higher and the metabolic clearance rate (MCR) of glucose was lower in the three F+ groups compared with the corresponding F- groups. In the 2nd evaluation insulin and Cp were reduced and the MCR of glucose increased in THF-, whereas all metabolic parameters were unchanged in THF+; in both UT hypertensive groups insulin and Cp increased and the MCR of glucose decreased, more so in F+ than in F-; in normotensive groups metabolic parameters did not change. A familial predisposition to hypertension influences insulin sensitivity changes during successful antihypertensive therapy, with an improvement in insulin sensitivity in F- and no changes in F+. A persistently high BP has a negative influence on insulin sensitivity in F+ and F-; this influence is greater when high BP is associated with a familial predisposition to hypertension.

HERG K+ channels activation during beta(1) integrin-mediated adhesion to fibronectin induces an up-regulation of alpha(v)beta(3) integrin in the preosteoclastic leukemia cell line FLG 29.1

Integrin receptors have been demonstrated to mediate either "inside-to-out" and "outside-to-in" signals, and by this way are capable of regulating many cellular functions, such as cell growth and differentiation, cell migration, and activation. Among the various integrin-centered signaling pathways discovered so far, we demonstrated that the modulation of the electrical potential of the plasma membrane (V(REST)) is an early integrin-mediated signal, which is related to neurite emission in neuroblastoma cells. This modulation is sustained by the activation of HERG K(+) channels, encoded by the ether-à-go-go-related gene (herg). The involvement of integrin-mediated signaling is being discovered in the hemopoietic system: in particular, osteoclasts are generated as well as induced to differentiate by interaction of osteoclast progenitors with the stromal cells, through the involvement of integrin receptors. We studied the effects of cell interaction with the extracellular matrix protein fibronectin (FN) in a human leukemic preosteoclastic cell line (FLG 29.1 cells), which has been demonstrated to express HERG currents. We report here that FLG 29.1 cells indeed adhere to purified FN through integrin receptors, and that this adhesion induces an osteoclast phenotype in these cells, as evidenced by the appearance of tartrate-resistant acid phosphatase, as well as by the increased expression of CD51/alpha(v)beta(3) integrin and calcitonin receptor. An early activation of HERG current (I(HERG)), without any increase in herg RNA or modifications of HERG protein was also observed in FN-adhering cells. This activation is apparently sustained by the beta(1) integrin subunit activation, through the involvement of a pertussis-toxin sensitive G(i) protein, and appears to be a determinant signal for the up-regulation of alpha(v)beta(3) integrin, as well as for the increased expression of calcitonin receptor.

Obesity and left ventricular diastolic function: noninvasive study in normotensives and newly diagnosed never-treated hypertensives

OBJECTIVE

To evaluate the influence of obesity, per se or associated with hypertension, on left ventricular (LV) diastolic function.

PATIENTS

Thirty-two obese newly-diagnosed never-treated hypertensives; 32 obese normotensives matched for age, sex and BMI with hypertensives; 32 lean newly diagnosed never-treated hypertensives and 32 lean normotensives, matched for age, sex and 24 h blood pressure (BP) with the obese subjects.

METHODS

Twenty-four-hour ambulatory blood pressure monitoring and digitized M-mode LV echocardiograms. PARAMETERS EVALUATED: Twenty-four-hour, day-time and night-time BP and heart rate, percentage nocturnal BP fall; LV end-diastolic diameter index, septal and posterior wall thickness, LV mass index, peak shortening and lengthening rate of LV diameter, peak thinning rate of LV posterior wall.

RESULTS

A main effect was found for obesity on LV diameter and LV mass and for hypertension on LV mass; LV systolic function was normal in all the subjects and similar among the four groups; LV diastolic function was significantly reduced in both obese groups with respect to lean ones. This difference persisted after correction of diastolic parameters for 24 h BP and heart rate, LV diameter and LV mass index and disappeared only after correction for body mass index. This latter was inversely related with diastolic parameters only in the obese groups.

CONCLUSIONS

Obesity is associated with a preclinical impairment of LV diastolic function in both normotensives and hypertensives; the diastolic impairment is independent of haemodynamic factors, such as 24 h BP and heart rate, and bears no relation to LV geometry in normotensives and only little relation in hypertensives, having therefore to be ascribed to obesity itself.

Microalbuminuria in never-treated hypertensives: lack of relationship to hyperinsulinemia and genetic predisposition to hypertension

We evaluated the relationship of microalbuminuria to hyperinsulinemia and family history of hypertension in 92 never-treated essential hypertensives (mean 24-h blood pressure >140 or 90 mm Hg), with positive (F+) or negative (F-) family history of hypertension: 31 had microalbuminuria (MA+) (urinary albumin excretion [UAE], 30 to 300 mg/24 h) and 61 had normal (<30 mg/24 h) UAE (MA-). Glucose and insulin values before and 30, 60, 90, and 120 min after an oral glucose load were measured together with an index of peripheral insulin activity (10(4)/ insulin x glucose values at glucose peak). Subjects with and without microalbuminuria did not differ with regard to age, sex, body mass index, and 24-h heart rate, whereas 24-h, daytime, and nighttime systolic and diastolic blood pressure were significantly higher in MA+ than MA- patients. The prevalence of positive family history of hypertension was similar between MA+ and MA-, as were fasting and stimulated glucose and insulin values and the index of peripheral insulin activity. Subdividing the patients on the basis of family history of hypertension (59 F+, 33 F-) UAE was not significantly different between F+ and F-. UAE did not correlate with glucose and insulin parameters. From our results, in never-treated hypertensives, microalbuminuria is associated with higher blood pressure values, but is related neither to genetic predisposition to hypertension, nor to hyperinsulinemia; therefore, impaired insulin sensitivity and microalbuminuria are two components of the hypertensive syndrome, largely independent of each other.

Insulin and diastolic dysfunction in lean and obese hypertensives: genetic influence

We investigated the influence of genetic predisposition to hypertension by studying the relation between insulin sensitivity and left ventricular (LV) mass and function in untreated lean and obese hypertensives. We selected 50 lean hypertensives with normotensive parents (negative family history of hypertension [F-]), 64 lean hypertensives with 1 or both parents hypertensive (positive family history of hypertension [F+]), 40 obese F- hypertensives, and 43 obese F+ hypertensives. The 4 groups were comparable regarding age, gender, 24-hour blood pressure profile, and known duration of hypertension. We measured glucose, insulin, and C-peptide during fasting and during an oral glucose tolerance test; LV morphology and function were assessed by digitized M-mode echocardiography. Glucose (fasting and test) levels were normal in all and similar among the 4 groups. Insulin and C-peptide (fasting and stimulated) levels were higher in obese hypertensives than in lean hypertensives; at similar body mass index, insulin and C-peptide levels were higher in F+ than in F- groups. Compared with lean hypertensives, obese hypertensives had greater LV mass index; LV systolic function was normal in all and similar among the groups. The indices of LV diastolic function were significantly lower in F+ than in F- groups. LV mass index did not correlate with metabolic parameters; the indices of LV diastolic function were inversely correlated with insulin area during test in only the 2 F+ groups. In conclusion, genetic predisposition to hypertension is associated with a reduced insulin sensitivity and affects the response of the myocardium to increased insulin levels, inducing a greater impairment of diastolic function. Insulin sensitivity and genetic predisposition to hypertension seem to have no influence on LV mass.

Relationship between dental pain perception and 24 hour ambulatory blood pressure: a study on 181 subjects

OBJECTIVE

To investigate dental pain perception in a large group of essential hypertensive subjects.

METHODS

A total of 130 hypertensive patients together with 51 normotensive subjects were submitted to tooth-electrical stimulation to determine the dental pain threshold (occurrence of pulp sensation) and tolerance (time when the subject asked for the test to be stopped). Blood pressure was measured at rest, before pain perception evaluation, and during a 24 h period by ambulatory monitoring.

RESULTS

The normotensive and hypertensive subjects differed with regard to pain threshold (P = 0.002) and tolerance (P = 0.01). Pain perception variables were significantly correlated with both resting blood pressure and 24 h, diurnal and nocturnal arterial pressures, the correlation between pain threshold and 24 h systolic blood pressure being the most significant (r = 0.31, P < 0.0001). By contrast, parameters indicating 24 h blood pressure variability (percentage of nocturnal blood pressure reduction and 24 h blood pressure variation coefficients) were not associated with pain perception. Moreover, among the hypertensives only, a significant relationship was observed between pain sensitivity and both baseline and 24 h pressures. No association was found when pain perception and blood pressure were correlated in the normotensive group.

CONCLUSIONS

The correlation between both baseline and 24 h blood pressure and pain perception has been confirmed in a large group study of normotensive and hypertensive subjects. Moreover, even among the hypertensive range of blood pressure, the higher the blood pressure is, the lower the sensitivity to pain is. These findings strengthen the hypothesis of a role of the degree of blood pressure elevation in modulating pain sensitivity.

Autonomic function and baroreflex sensitivity during a normal ovulatory cycle in humans

OBJECTIVE AND DESIGN

Possible variations occurring in the autonomic function during a normal ovulatory cycle have been poorly investigated and it is not known whether the baroreflex sensitivity may change according to the different phases of the cycle. The aim of this study was to evaluate heart rate variability (power spectrum analysis), and baroreceptor sensitivity (alpha-low frequency coefficient) in 13 young women with regular menses during the two phases of the cycle (phase I: 5 +/- 1 days and phase II: 23 +/- 3 days from bleeding).

RESULTS

The low frequency/high frequency ratio was significantly higher in the second phase of the cycle (phase I: 2.8 +/- 2.6; phase II: 5.6 +/- 5.8, p < 0.05), in the presence of increased low frequency and reduced high frequency expressed in normalized units-nu-(phase I: 59.8 +/- 16.7 nu and 32.6 +/- 15.6 nu for low frequency and high frequency, respectively; phase II: 67.7 +/- 18 nu and 25.7 +/- 17.5 nu for low frequency and high frequency, respectively; p < 0.05). The alpha-low frequency coefficient, index of baroreflex sensitivity, did not statistically differ in the two phases (phase I: 10.6 +/- 4.5 msec/mm Hg; phase II: 8.9 +/- 4.9 msec/mm Hg; ns).

CONCLUSIONS

The power spectrum analysis suggests that the autonomic function may be affected by the ovulatory cycle, sympathetic activation being relatively increased in the second phase. On the contrary, the baroreceptor function seems to be scarcely influenced by the two phases of the menstrual cycle.

Individualized versus standardized analysis of ambulatory blood pressure profile: relationship with left ventricular characteristics

OBJECTIVE

Objective To determine whether the use of patients' individual awake/asleep patterns instead of fixed day/night intervals would influence the correlations between blood pressure values and left ventricular morpho-functional characteristics.

METHODS

We enrolled 167 never-treated hypertensives (clinic blood pressures >160 mmHg systolic or 90 mmHg diastolic, or both): 32 had 24h blood pressures <130/80 mmHg [white-coat hypertensives (WCH)] and 135 had 24h blood pressures >130 mmHg systolic or 80 mmHg diastolic, or both (hypertensives). Each patient underwent left ventricular echocardiographic examination and 24h ambulatory blood pressure monitoring, evaluated twice, using standard day/night intervals (daytime 0700-2200 h, night-time 2200-0700 h) and using the patient's individual awake/asleep pattern (an individualized scheme).

RESULTS

Daytime and night-time blood pressures in WCH and daytime and night-time diastolic blood pressures in hypertensives were not affected by choice of using individualized or standard intervals; daytime systolic blood pressure in hypertensives was significantly higher and night-time systolic blood pressure lower with individualized intervals. The non-dippers (nocturnal decrease in blood pressure <10% of daytime blood pressure) were 31 hypertensives and six WCH with standard day/night intervals and 25 hypertensives and four WCH with individualized intervals; nocturnal falls in systolic and diastolic blood pressures were significantly greater with individualized intervals for both groups. Left ventricular hypertrophy was present in 68 hypertensives and seven WCH; left ventricular systolic function was normal in all and left ventricular diastolic function was impaired in 53 hypertensives and seven WCH. Left ventricular characteristics of WCH were not correlated to blood pressure parameters; left ventricular mass index of hypertensives was directly correlated to 24h, daytime and night-time systolic blood pressures, whereas left ventricular diastolic function was inversely correlated to night-time systolic and diastolic blood pressures. The correlations were not affected by choice of using individual awake/asleep patterns.

CONCLUSIONS

Timing day and night in an individualized way seems to improve the evaluation of nocturnal fall in blood pressure, but does not improve the ability to predict the left ventricle's involvement with ambulatory blood pressure monitoring.

Insulin sensitivity in obese normotensive adults: influence of family history of hypertension

OBJECTIVE

To evaluate the influence of family history of hypertension on insulin sensitivity in obese normotensive adults, comparing them with lean subjects.

SUBJECTS

136 normotensives (N)(mean 24 h blood pressure < 130/80 mmHg; age range 35-45 y): 32 lean (body mass index, BMI < or = 25 kg/m2) N with normotensive parents (F-), 37 lean N with one or two parents hypertensive (F+), 32 obese (BMI > or = 30 kg/m2) NF- and, 35 obese NF+.

METHODS

24 h ambulatory blood pressure monitoring; glucose, insulin and C-peptide before and 30, 60, 90 and 120 min after an oral glucose load; index of insulin peripheral activity (Ia: 10(4)/insulin x glucose values at glucose peak); fasting insulin/C-peptide ratio (I/Cp).

RESULTS

The four groups were comparable for age, gender and blood pressure values throughout the 24 h. Glucose, fasting and during test, and I/Cp were similar among the four groups; insulin and C-peptide, fasting and stimulated, were significantly higher and Ia lower in obese N than in lean N; at similar BMI, insulin and C-peptide were significantly higher and Ia lower, in F+ than in F-. The correlation between insulin and BMI was significantly closer in F- than in F+.

CONCLUSIONS

Family history of hypertension appears to be significantly associated with insulin sensitivity in both lean and obese normotensive adults; moreover, overweight and a genetic predisposition to hypertension may have additive adverse effects on insulin sensitivity in normotensive adult subjects.

Ambulatory blood pressure, nocturnal blood pressure reduction and plasma catecholamines

OBJECTIVE AND DESIGN

Controversial data have been reported on plasma catecholamines in hypertensives. Aims of this study were to find whether 24-hour ambulatory blood pressure was correlated with circulating catecholamines and to investigate whether nocturnal blood pressure reduction was associated with baseline plasma catecholamines. Samples for catecholamine determination were obtained in 34 consecutive male subjects after a 30-minute rest and before ambulatory blood pressure monitoring.

RESULTS

Hypertensive patients (n = 22; 24-hour blood pressure: 145 +/- 14/94 +/- 6 mm Hg) showed similar norepinephrine and epinephrine levels when compared with normotensives (n = 12; 24-hour blood pressure: 124 +/- 6/81 +/- 6 mm Hg), and higher dopamine values (hypertensives: 64.6 +/- 58; normotensives: 26.2 +/- 31 pg/ml; p < 0.05). A positive correlation was observed between dopamine and diastolic nocturnal blood pressure (p < 0.05) while a negative correlation was found between dopamine and nocturnal diastolic blood pressure reduction (p < 0.025). No significant relationship was observed between both norepinephrine and epinephrine, and 24-hour blood pressures.

CONCLUSIONS

Since previous reports have documented malfunctioning of dopaminergic system in hypertension, the higher levels of circulating plasma dopamine found in hypertensive patients in the present study may account for a peripheral compensatory increase. The correlation between dopamine and nocturnal blood pressure fall seems to indicate that the impairment of dopaminergic system may influence the 24-hour blood pressure profile, affecting the nocturnal blood pressure reduction.

Treatment with enalapril modifies the pain perception pattern in hypertensive patients

The cardiovascular system shares numerous anatomic and functional pathways with the antinociceptive network. The aim of this study was to investigate whether angiotensin-converting enzyme (ACE) inhibitor treatment could affect hypertension-related hypalgesia. Twenty-five untreated hypertensive patients, together with a control group of 14 normotensive subjects, underwent dental pain perception evaluation by means of a pulpar test (graded increase of test current applied to healthy teeth). After the evaluation of the dental pain threshold (occurrence of pulp sensation) and tolerance (time when the subjects asked for the test to be stopped), all the subjects underwent a 24-hour ambulatory blood pressure monitoring. The hypertensive group then was treated with 20 mg/d enalapril, whereas the normotensive subjects remained without any treatment. After a time interval of 6+/-2 months, the dental pain sensitivity was retested in all the subjects, and ambulatory blood pressure was recorded during treatment in the hypertensive patients. At the first assessment, hypertensive patients showed a higher pain threshold than normotensive subjects (P<.001). On retesting of pain sensitivity in hypertensive patients, a significant decrease of both pain threshold and tolerance, leading to their normalization, was observed during treatment (P<.001 and P<.005, respectively), in the presence of reduced 24-hour and office blood pressure values. A slight, though significant, correlation was observed between variations in pain tolerance and baseline blood pressure changes occurring during treatment. During follow-up, the normotensive subjects did not show any significant pain perception or office blood pressure changes. Hypertension-related hypalgesia was confirmed. Mechanisms acting both through lowering of blood pressure and specific pharmacodynamic properties may account for the normalization of pain sensitivity observed in hypertensive patients during treatment with ACE inhibitors.

Influence of family history of hypertension on insulin sensitivity in lean and obese hypertensive subjects

We evaluated the influence of family history of hypertension on insulin sensitivity in lean and obese hypertensive subjects (H): 40 lean [body mass index (BMI) < or = 25 kg m-2] H with normotensive parents (F-), 50 lean H with one or two parents hypertensive (F+), 30 obese HF- (BMI > or = 30 kg m-2) and 35 obese HF+. The four groups were comparable in terms of age, sex and ambulatory blood pressure values. We evaluated glucose, insulin and C-peptide before and 30, 60, 90 and 120 min after an oral glucose load, insulin sensitivity index (ISI, fasting glucose/insulin ratio), fasting insulin/C-peptide ratio (I/Cp). Glucose, fasting and during test, and I/Cp were similar among the four groups; insulin and C-peptide, fasting and stimulated, were significantly higher and ISI lower in obese H than in lean H; at similar BMI, insulin and C-peptide were significantly higher in F+ than in F-. Insulin directly correlated with night-time blood pressure only in lean HF-. The correlation between insulin and BMI was significantly closer in F-than in F+. In conclusion, family history of hypertension appears to play a relevant role in insulin sensitivity in hypertensive subjects also in the presence of obesity.

Relationship between left ventricular diastolic function and atrial natriuretic factor in never-treated mild hypertensives

Using digitized M-mode echocardiograms, we evaluated the relationship between plasma atrial natriuretic factor (ANF) and morphofunctional characteristics of the left ventricle (LV) in 24 mild hypertensive men, never treated, with normal renal function. For each subject we collected a blood sample for plasma ANF evaluation and, immediately after, we recorded the LV echocardiogram. All the patients had normal LV diastolic diameter and systolic function; LV hypertrophy was present in 10 patients, 7 of whom had left atrial enlargement, and 13 patients had impaired LV diastolic function. ANF was similar between patients with and without LV hypertrophy, as well as between patients with and without left atrial enlargement, whereas ANF was significantly (P < .01) higher in patients with LV diastolic dysfunction than in patients with normal diastolic function. ANF was inversely correlated with both indices of diastolic function (peak lengthening rate and peak wall thinning rate), whereas it did not correlate with blood pressure, heart rate, end-systolic wall stress, and other LV parameters. In conclusion, from our results, ANF level in never-treated mild hypertensives is related neither to the degree of LV hypertrophy nor to the afterload, expressed as blood pressure or end-systolic wall stress, whereas it is mainly influenced by LV diastolic function: the diastolic impairment induces an increase in ANF level, probably through an increased atrial stretch.

Clinical feasibility of echocardiographic automated border detection in monitoring left ventricular response to acute changes of preload in normal subjects

Echocardiographic automated border detection (ABD) provides an instantaneous measurement of left ventricular (LV) volume and its rate of change. We tested the clinical feasibility of ABD in monitoring on-line LV response to acute changes in preload. We examined 20 healthy males in the supine position, with legs elevated, back in the supine position, 5 min after the inflation of blood pressure cuffs at the root of the four limbs, 5 min after the deflation of cuffs. End-diastolic and end-systolic LV volumes significantly increased with elevated legs and decreased during cuff inflation; ejection fraction remained unchanged. Peak filling and peak emptying rates did not change with elevated legs and increased significantly during cuff inflation. The values of LV parameters were stable in the three resting conditions, demonstrating a good reproducibility of the ABD technique. Our results demonstrate that ABD may be useful in clinical practice for monitoring on-line small acute changes in LV volume and function.

Noninvasive evaluation of cardiotoxicity of 5-fluorouracil and low doses of folinic acid: a one-year follow-up study

PURPOSE

To conduct a serial evaluation of the cardiac effects of antineoplastic therapy with 5-fluorouracil (5-FU) and low-dose folinic acid.

PATIENTS AND METHODS

Sixteen patients with colon-rectal carcinoma, without cardiac disease, treated with 400 mg/ m2/die of 5-FU and 20 mg/m2/die of folinic acid for five days, once a month, for six months. Parameters evaluated: blood pressure, ECG, two-dimensional and digitized M-mode echocardiograms before and after the first and fifth drug administrations of the first cycle, after the fifth drug administration of the sixth cycle and six months after the treatment.

RESULTS

Blood pressure, heart rate, left ventricular (LV) diameter and LV mass index did not change; all of the patients showed a decrease in the peak shortening rate of the LV diameter index of systolic function, and of the peak lengthening rate of the LV diameter and peak thinning rate of LV posterior wall, indexes of diastolic function, with abnormal values in 11 patients at the end of treatment LV wall motion remained normal in all; two patients developed transient T wave inversion without chest pain and with normal cardiac enzymes and myocardial scintigraphy during dypiridamole stress test. Six months after the treatment all indexes of LV systolic and diastolic function had returned within the normal limits and were similar to pre-treatment values.

CONCLUSIONS

5-FU and low-dose folinic acid treatment induced a decrease of LV systolic function and an impairment of diastolic function, that developed without symptoms and were transient and reversible.

Endogenous beta-endorphins in hypertension: correlation with 24-hour ambulatory blood pressure

OBJECTIVES

The aims of this study were to determine whether hypertensive patients showed increased endogenous opioid tone and to find a possible correlation between beta-endorphin levels and 24-h ambulatory blood pressure. We also investigated whether circulating beta-endorphin levels were associated with pain perception at rest.

BACKGROUND

Experimental studies suggest an involvement of the endogenous opioid system in cardiovascular control mechanisms.

METHODS

We determined baseline beta-endorphin plasma levels by radioimmunoassay in 81 consecutive subjects (48 hypertensive, 33 normotensive) after a 30-min rest and before 24-h ambulatory blood pressure monitoring. In 72 of 81 subjects with a dental formula suitable for the pulpar test (graded increase of test current -0 to 0.03 mA applied to three healthy teeth), pain perception was also investigated.

RESULTS

Hypertensive patients showed higher beta-endorphin plasma levels than normotensive subjects (p < 0.002). Circulating endogenous opioid levels correlated with 24-h diastolic blood pressure (p < 0.01), whereas the relation with systolic pressure did not reach statistical significance. When 24-h blood pressure recordings were divided into daytime and nighttime values, and blood pressure loads (percent of measurements > or = 140 mm Hg for systolic blood pressure and > or = 90 mm Hg for diastolic pressure) were calculated, a significant correlation was found between beta-endorphin levels and diastolic pressures and load. Similarly, presampling diastolic blood pressure was significantly correlated with beta-endorphin levels. Of the 72 subjects tested, hypertensive patients showed a lower pain sensitivity than normotensive subjects. A positive correlation was found between pain threshold and circulating beta-endorphin levels (p < 0.05).

CONCLUSIONS

Sustained arterial pressure is probably involved in the tonic activation of cardiovascular mechanisms linked to endogenous opioid tone. Circulating plasma endorphins may account, at least in part, for the pain perception pattern relating to blood pressure levels at rest.

Hyperinsulinemia, family history of hypertension, and essential hypertension

The aim of this study was the evaluation of the relationships among hyperinsulinemia, a family history of hypertension, and essential hypertension. Insulin and C-peptide responses to an oral glucose load were studied in 175 lean normotensives (N) and untreated hypertensives (H) with (F+) and without (F-) a family history of hypertension: 30 NF-, 30 NF+, 45 HF-, and 70 HF+. The groups were comparable for age, sex, body mass index, and blood pressure. The following parameters were evaluated: plasma glucose (G), serum insulin (I), and C-peptide (Cp) before and 30, 60, 90, and 120 min after the glucose load, fasting glucose/insulin ratio (ISI), fasting insulin/C-peptide ratio (I/Cp), and 24-h ambulatory blood pressure monitoring. Plasma glucose was measured, fasting and during the test, and it and I/Cp were similar in the four groups. Serum insulin and Cp, both fasting and stimulated, were significantly higher and ISI lower in normotensives and hypertensives with hypertensive parents. Grouping the subjects first on the basis of blood pressure and then on the basis of family history, no differences were found between normotensives and hypertensives, whereas I and Cp, fasting and stimulated, were significantly higher and ISI lower in subjects with positive as compared to negative family history. The closest correlations between insulin and ambulatory blood pressure were found in normotensive with hypertensive parents; in hypertensives with hypertensive parents we only found a direct correlation between fasting Cp and nocturnal blood pressure fall; in hypertensives with normotensive parents insulin inversely correlated with nocturnal blood pressure fall. Insulin resistance seems to have a familial basis, independently of the presence of hypertension. Instead of showing a causal relationship between insulin resistance and hypertension, our results indicate that the two are partly independent components of a common familial pattern.

Effects of arithmetic mental stress test on hypertension-related hypalgesia

AIM

Though hypertension-related hypalgesia has been described, little is known about possible variation of pain perception after mental stress. The aims of the present study were to determine (1) whether mental stress can influence pain perception in normotensive and hypertensive subjects and (2) whether blood pressure levels before pain evaluation can account for changes in pain sensitivity.

PATIENTS AND METHODS

A pulpar test (graded increase in test current of 0-0.03 mA applied on healthy teeth) was performed twice (time interval 15 min) in 62 subjects. Thirty-eight subjects (group 1) performed an arithmetic mental stress test immediately after the first pulpar test while 24 subjects (group 2) did not. The pain threshold (occurrence of pulp sensation) was evaluated as the mean value of three teeth tested on each subject and as the value on the most sensitive tooth.

RESULTS

Twenty-eight subjects with normal 24-h blood pressure showed a lower mean pain threshold than 34 subjects with high 24-h blood pressure values (P<0.02). In group 1 (20 normotensives, 18 hypertensives), even when the mental stress increased the pretest blood pressure, the pressure values immediately before both pulpar tests remained similar. In the second pulpar test, a significant increase in the pain threshold on the most sensitive tooth was observed in group 1 (P<0.005). Though a trend towards an increase in the pain threshold was found in both the subgroups of normotensive and hypertensive subjects, the difference was significant in hypertensives only. However, group 2 subjects showed unchanged pain sensitivity on the second test.

CONCLUSIONS

A mental stress-induced reduction in pain sensitivity was observed in the absence of change in arterial pressure measured immediately before pulpar tests. A blood pressure increase during the test and, more likely, cortical and humoral activation during stress, may account for the variation found in pain perception.

Ambulatory blood pressure and left ventricular changes during antihypertensive treatment: perindopril versus isradipine

Using digitized M-mode echocardiograms and 24-h ambulatory blood pressure (BP) monitoring, we compared the effects on left ventricle (LV) and BP of 6-month treatment with a calcium antagonist or an angiotensin-converting enzyme (ACE) inhibitor in 36 hypertensive patients with LV hypertrophy (group 1, 18 subjects treated with sustained-release isradipine; group 2, 18 subjects treated with perindopril). At the basal evaluation, the two groups had comparable BP and LV parameters. After treatment, both groups showed a similar and significant reduction in 24-h, day- and night-systolic and diastolic BP (SBP, DBP). The reduction in LV mass index was greater (p < 0.01) in group 2. In group 1, percentage of decrease of LV mass correlated significantly with percentage of decrease in 24-h and daytime BP; this was not true of group 2. Together with the reduction in LV hypertrophy, there was a significant increase of peak lengthening rate of LV diameter that was greater (p < 0.01) in group 1. Both drugs can reduce LV hypertrophy and improve diastolic function. The reduction of hypertrophy induced by perindopril appears to be partly independent of BP decrease and therefore partly related to a direct action of perindopril on the myocardium.

Twenty-four-hour noninvasive blood pressure monitoring and pain perception

Although a hypertension-related hypalgesia has been described, the relation between pain perception and the 24-hour blood pressure trend is still unknown. The ambulatory blood pressure monitoring parameters and dental pain sensitivity were correlated in 67 male subjects. The pulpar test (graded increase of test current of 0 to 0.03 mA) was performed on three healthy teeth, and mean dental pain threshold (occurrence of pulp sensation) and pain tolerance (time when the subjects asked for the test to be stopped) were evaluated. Three groups of subjects with normal (n = 34), intermediate (n = 13), and high (n = 20) blood pressure values were identified according to ambulatory monitoring results. Pain threshold differed among the three groups (P < .02), being higher in the group with highest blood pressure. The groups of hypertensive subjects showed higher pain tolerance than the normotensive group (P < .02). Pain threshold was correlated with 24-hour, diurnal, and nocturnal blood pressure values. Pain tolerance was also related to 24-hour blood pressure and to diurnal and nocturnal diastolic and mean arterial pressure values. Systolic and diastolic blood pressure loads were significantly associated with pain threshold, and diastolic load was also associated with tolerance. The blood pressure variability (SD) did not relate to pain perception. The 24-hour arterial pressure was more closely associated with pain perception than the blood pressure values obtained before the pulpar test. A close correlation between pain perception and 24-hour ambulatory blood pressure was demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)

Beta-endorphins during coronary angioplasty in patients with silent or symptomatic myocardial ischemia

OBJECTIVES

The aims of this study were to correlate beta-endorphin plasma levels and anginal pain in patients with ischemia induced by percutaneous transluminal coronary angioplasty and to detect eventual endorphin variations during balloon occlusion.

BACKGROUND

The opioid system appears involved in the absence of pain occurring in silent myocardial ischemia.

METHODS

Beta-endorphin plasma levels were measured 24 h before, just before, during and after coronary angioplasty (performed on the left anterior descending artery) in 53 men with documented coronary artery disease and exercise-induced myocardial ischemia.

RESULTS

Group 1 (33 patients) reported symptoms; group 2 (20 patients) was asymptomatic during angioplasty. In these patients, the prevalence of exercise-induced silent ischemia was 57%. The occurrence of angina during exercise or angioplasty was related to the frequency of angina during daily life when patients were subgrouped. The severity and distribution of coronary artery disease did not differ between the two groups. During angioplasty, the number of balloon inflations and the inflation time and pressure were similar in symptomatic and asymptomatic patients. In each group, no short-term variability of baseline beta-endorphin plasma levels was observed during 2 consecutive days. Corresponding beta-endorphin plasma levels (at baseline and during and after angioplasty) were significantly higher in Group 2. During balloon occlusion, the levels decreased significantly in the symptomatic group at the onset of angina but remained stable in the asymptomatic group.

CONCLUSIONS

Methodologic variables and the severity of coronary artery disease did not influence the presence of symptoms during angioplasty-induced ischemia. Beta-endorphin plasma levels were higher and more stable in patients with silent ischemia during angioplasty, suggesting that opiate levels and their variation during ischemia are associated with individual attitude toward anginal pain.

Mental stress as a provocative test in patients with various clinical syndromes of coronary heart disease

To assess the prevalence of mental stress-induced myocardial ischemia and investigate the pathogenetic mechanisms by which emotional stress may induce myocardial ischemia, we studied 372 patients with angina pectoris who underwent mental arithmetic and exercise stress testings. Hyperventilation tests were also performed in 176 patients, and 340 patients underwent coronary arteriography. Sixty-one patients showed significant ST segment abnormalities during mental arithmetic and exercise stress testings (group 1). Two hundred eleven patients had negative responses to mental stress but positive exercise tests (group 2), whereas both tests were negative in 100 patients (group 3). Mental stress induced significant increases in heart rate and systolic blood pressure in the three groups of patients; however, group 1 patients had higher increases in rate-pressure product (mm Hg x beats/min) than group 2 and group 3 patients (14,909 +/- 3,894 versus 12,985 +/- 2,900 versus 12,724 +/- 4,400 mm Hg x beats/min, p less than 0.01). Group 1 patients had shorter exercise durations than group 2 or group 3 (4.06 +/- 1.55 versus 7.65 +/- 3.07 versus 13.9 +/- 5.31 minutes, p less than 0.01), although rate-pressure products at peak exercise were similar in groups 1 and 2 (20,277 +/- 6,058 versus 20,768 +/- 3,864, p = NS) and significantly higher in group 3 (26,221 +/- 7,100/mm Hg x beats/min, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

[An electrophysiologic and electropharmacological study of functional properties of the bundle of Kent in Wolff-Parkinson-White syndrome]

The aim of this report is to attempt a definition of functional properties of Kent bundle on the basis of electrophysiologic and electropharmacologic data obtained from 89 cases of Wolff-Parkinson-White syndrome selected among a total number of 114 consecutive cases of WPW syndrome that underwent electrophysiologic intracavitary study. In 36 cases anterograde (ant) and retrograde (retr) effective refractory period (ERP) of accessory pathway were evaluated with premature (atrial and ventricular) stimulation at the same driven cycle length. The ant-ERP was longer than retr-ERP in 28/36 patients, shorter in 5 and equal in 2. This strong discrepancy between ant- and retr- ERP suggests an important role of "impedance mismatch" in the activation of ventricular (or atrial) muscle through an anomalous muscular bundle. In 11 cases an intermittent pattern of ventricular preexcitation was observed; in all these patients an anterograde supernormal conduction through the accessory pathway was observed. This aspect could be related to the activation of ventricular muscle, beyond Kent bundle, in its supernormal phase of excitability, suggesting the critical role played by ventricular activation for the appearance of preexcitation. Isoproterenol, injected in 11 cases (1 among them with intermittent ventricular preexcitation in basal conditions), produced a reduction of ant-ERP in all these cases, in spite of its well known poor effect on refractoriness of myocardial fibers. Ajmaline, injected in 32 patients, was able to block ventricular preexcitation in 81% of the cases, in spite of its poor effect on refractoriness of normal tissues. It is very likely that the disappearance of ventricular preexcitation is in this instance expression of lack of ventricular excitation (distal to Kent bundle) consequent to a drug-induced reduction of membrane responsiveness of ventricular cells. In conclusion, all these aspects strongly suggest that the appearance of ventricular (or atrial) preexcitation could be related to the activation of ventricular (or atrial) muscle distal to Kent bundle, rather than to conduction through the Kent bundle itself.

Dental pain threshold and angina pectoris in patients with coronary artery disease

One hundred eight consecutive patients with proved coronary artery disease and reproducible exercise-induced myocardial ischemia were studied. During repeated exercise testing, 52 patients (Group I) had myocardial ischemia in the absence of pain (silent ischemia) whereas 56 patients (Group II) experienced anginal symptoms in the presence of electrocardiographic signs of ischemia. A pulpal test was carried out in all patients using an electrical dental stimulator commonly used in dentistry. Electrical current was delivered in increasing intensity from 10 to 500 mA, and the dental pain threshold and the reaction of the patients to maximal stimulation were determined. During the pulpal test, 71.2% of the patients in Group I did not experience pain, even at maximal stimulation (threshold 0), 11.5% were sensitive at threshold I (10 to 200 mA) and 17.3% felt pain at threshold II (210 to 500 mA). In Group II, 69.7% of the patients complained of dental pain at the low intensity test current (threshold I), 10.7% at threshold II and 19.6% at threshold 0. In Group I, 71.2% of patients did not have discomfort (reaction -), even at maximal stimulation, 21.1% had a mild reaction (reaction +) and 7.7% had an intense painful reaction (reaction ++). In Group II, 80.4% of patients were sensitive to the pulpar test (67.9% reported intense painful sensation at maximal stimulation, 12.5% had a mild reaction); 19.6% of patients had no reaction. The two groups of patients were similar with respect to age, sex and angiographic features.(ABSTRACT TRUNCATED AT 250 WORDS)