Glycaemic fall after a glucose load. A population-based study.

BACKGROUND AND AIMS: A blood glucose (BG) fall after an oral glucose load has never been described previously at a population level. This study was aimed at looking for a plasma glucose trend after an oral glucose load for possible blood glucose fall if any, and for its impact on coronary mortality at a population level. METHODS AND RESULTS: In subjects from an unselected general population, BG and insulin were detected before and 1 and 2h after a 75-g oral glucose load for insulin sensitivity and ß-cell function determination. Blood pressure, blood examinations and left ventricular mass were measured, and mortality was monitored for 18.8±7.7 years. According to discriminant analysis, the population was stratified into cluster 0 (1-h BG < fasting BG; n=497) and cluster 1 (1-h BG ≥ fasting BG; n=1733). To avoid any interference of age and sex, statistical analysis was limited to two age-gender-matched cohorts of 490 subjects from each cluster (n=940). Subjects in cluster 0 showed significantly higher insulin sensitivity and ß-cell function, lower visceral adiposity and lower blood pressure values. Adjusted coronary mortality was 8 times lower in cluster 0 than 1 (p<0.001). The relative risk of belonging to cluster 1 was 5.40 (95% CI 2.22-13.1). CONCLUSION: It seems that two clusters exist in the general population with respect to their response to an oral glucose load, independent of age and gender. Subjects who respond with a BG decrease could represent a privileged sub-population, where insulin sensitivity and ß-cell function are better, some risk factors are less prevalent, and coronary mortality is lower.

Long term follow up of radiofrequency catheter ablation of atrial flutter: clinical course and predictors of atrial fibrillation occurrence.

OBJECTIVES: To evaluate the time to onset and the predictors of atrial fibrillation (AF) during long term follow up of patients with typical atrial flutter (AFL) treated with transisthmic ablation. DESIGN: Prospective multicentre study. METHODS AND RESULTS: 383 patients (75.4% men, mean (SD) age 61.7 (11.1) years) who underwent transisthmic ablation for typical AFL were investigated. In 239 patients (62.4%) AF was present before ablation. Ablation proved successful in 367 patients (95.8%). During a mean (SD) follow up of 20.5 (12.4) months, 41.5% of patients reported AF. The cumulative probability of postablation AF increased continuously as time passed: it was 22% at six months, 36% at one year, 50% at two years, 58% at three years, and 63% at four years. CONCLUSIONS: AF occurred in a large proportion of patients after transisthmic catheter ablation of typical AFL. The occurrence of AF was progressive during follow up. Preablation AF, age < 65 years, and left atrial size > 50 mm are associated with postablation AF occurrence.

Success of serial external electrical cardioversion of persistent atrial fibrillation in maintaining sinus rhythm; a randomized study.

AIMS: The aim of this prospective, randomized study was to determine the efficacy of a serial external electrical cardioversion strategy in maintaining sinus rhythm after 12 months in patients with recurrent persistent atrial fibrillation. METHODS AND RESULTS: Ninety patients with persistent atrial fibrillation lasting more than 72 h but less than 1 year were randomized in a one to one fashion to repetition of up to two electrical cardioversions in the event of relapse of atrial fibrillation detected within 1 month of the previous electrical cardioversion (Group AGG), or to non-treatment of atrial fibrillation relapse (Group CTL). ECGs were scheduled at 6 h, 7 days, and 1 month. Clinical examination and ECGs were repeated during the 6-month and 12-month follow-up examinations. Echocardiography was repeated during the 6-month follow-up examination. Clinical and echocardiographic characteristics were similar in the two groups. All patients were treated with antiarrhythmic drugs before electrical cardioversion and throughout follow-up. After 12 months, sinus rhythm was maintained in 53% of Group AGG patients and in 29% of Group CTL patients (P<0.03). After 6 months, left ventricular ejection fraction had recovered significantly only in Group AGG (56.8 +/- 9.0% at enrollment vs 60.4 +/- 9.4% at 6 months,P <0.001). CONCLUSION: These results demonstrate that an aggressive policy towards persistent atrial fibrillation by means of repetition of electrical cardioversion after early atrial fibrillation recurrence is useful in maintaining sinus rhythm after 12 months.

Electrophysiological properties of the atrioventricular node and ageing: evidence of a lower incidence of dual nodal pathways in the elderly.

AIMS: The purpose of this study was to investigate the relationship between the incidence of dual atrioventricular (AV) nodal pathways and age. Age-related changes in the AV node electrophysiological properties have rarely been investigated. AV nodal re-entrant tachycardia is more frequent in the young than in the elderly. METHODS AND RESULTS: From 1988 to 1998, premature atrial stimulation was performed in 1,435 patients referred to our institution for transoesophageal electrophysiological study. 1,276 patients (89%) with a diagnosis of ventricular pre-excitation, supraventricular arrhythmia or AV block were excluded. The study cohort consisted of the remaining 159 patients (11%) of the whole group) referred for syncope (8.2% of the subgroup), suspected ventricular pre-excitation (10.7%), suspected sinus node dysfunction (52.8%) or undetermined palpitations (28.3%). The 159 study patients were divided into 3 groups according to age: group A (11-30 years, 50 patients), group B (30-60 years, 35 patients) and group C (>60 years, 74 patients). A dual AV nodal pathway was found in 16 patients of group A (32.0%), 6 patients of group B (17.1%) and 8 patients of group C (10.8%), the difference between group A and group C being significant (P<0.05). CONCLUSION: The incidence of dual AV nodal pathways decreases with ageing, suggesting that the AV node undergoes age-related electrophysiological changes. This finding could explain the uncommon onset of AV nodal re-entrant tachycardia in the elderly.

The duration of atrial fibrillation influences the long-term efficacy of low-energy internal cardioversion.

BACKGROUND: It is commonly held that long-lasting atrial fibrillation (AF), especially if associated with marked enlargement of the left atrium, is a negative predictive factor for both the recovery and the maintenance of sinus rhythm. The aim of the present study was to identify the clinical features of patients who have a greater likelihood of success both in the acute phase and, especially, in the medium-long term. METHODS: Since June 1997, we have performed low-energy internal cardioversion to 93 patients (66 males, 27 females, mean age 62 +/- 9 years, range 26-80 years) with a mean duration of AF of 922 +/- 1032 days. Seventy-four patients had heart disease and 19 isolated AF. External cardioversion had been previously performed in 79 patients to no avail. All patients underwent antiarrhythmic therapy and were followed for a period of 13 +/- 7 months. RESULTS: Low-energy internal cardioversion proved efficacious, restoring sinus rhythm, in 92% of patients (86/93) and inefficacious in 8% (7/93). In 24% (21/86) the procedure, although efficacious, was followed by early recurrence of AF which proved to be intractable in 52% (11/21). At the end of the session, 81% (75/93) of the patients maintained sinus rhythm. At the end of follow-up, 40% (38/93) maintained sinus rhythm. Of all the parameters considered in the two groups, the duration of AF was the only one which differed significantly between the group in sinus rhythm and that in AF, with regard to both the efficacy of the procedure in the acute phase (755 +/- 868 vs 1618 +/- 1359 days, p < 0.001) and the long-term outcome (655 +/- 5.8 vs 1107 +/- 1098 days, p < 0.05). CONCLUSIONS: AF lasting more than 2 years constitutes a negative predictive factor for both the recovery and the long-term maintenance of sinus rhythm.

Blood pressure and metabolic profile after surgical menopause: comparison with fertile and naturally-menopausal women.

In 1978 a random sample (367 men and 568 women aged 18-65 years) taken from the general population of a north-eastern Italian town was screened for cardiovascular risk; 16 years later, the women were invited to a second screening. Three groups were identified at the initial screening (fertile, naturally menopausal and surgically menopausal) and four in the longitudinal study (137 remained fertile during the whole study, 205 became naturally menopausal, 56 were ovariectomised and 127 were already going through the menopause). The protocol included a questionnaire, blood pressure (BP) measurement, and blood exams. Continuous variables were adjusted for confounders. Systolic BP, prevalence of hypertension, cholesterol, glycaemia and uricaemia were similar, whereas diastolic and triglycerides (TG) were lower in surgically-menopausal than in fertile women (P < 0.001). No significant difference in 16 years' variation from baseline was observed between the four groups, although women who remained fertile showed the smallest increases. In particular, neither systolic or diastolic BP increases differed between the women who were oophorectimised and those who remained fertile. 'Fertile status' was rejected from the logistic equation of incidence of hypertension, and 'age of menopause' was also rejected when this analysis was repeated in ovariectomised women. New coronary artery disease (angina pectoris or myocardial infarction) was observed in one ovariectomised woman, in three naturally menopausal, and in 13 already menopausal women which seemed to reflect the age trend. No new cases were observed in women who remained fertile. In conclusion, in Italian women surgical menopause, similarly to natural menopause, is devoid of any negative prognostic effect. Journal of Human Hypertension (2000) 14, 799-805

Cardioversion of persistent atrial flutter in non-anticoagulated patients at low risk for thromboembolism.

BACKGROUND: The true risk of thromboembolic events after cardioversion of atrial flutter was not addressed carefully. Nevertheless, thromboembolic events were thought to be rare and less likely to occur after cardioversion of atrial fibrillation. The aim of this study was to prospectively evaluate if the interruption of persistent typical atrial flutter could be safely performed without anticoagulation in a group of patients at low risk for thromboembolic events. METHODS: We studied 64 subjects selected among 138 consecutive patients with persistent typical atrial flutter (minimal duration 72 hours) in whom a transesophageal atrial pacing was performed in our electrophysiology laboratory from October 1994 to May 1999. Exclusion criteria included: anticoagulation therapy during the previous 4 weeks; previous history of atrial fibrillation; recent (< 1 month) myocardial infarction; history of thromboembolic events; left ventricular ejection fraction < 40%; presence of moderate or severe mitral regurgitation or stenosis; induction of sustained (> 6 hours) atrial fibrillation during transesophageal atrial pacing. Patients in whom atrial flutter persisted in spite of transesophageal atrial pacing underwent external direct current cardioversion or right atrial overdrive pacing within 24 hours. Thromboembolic events were checked for 4 weeks after the restoration of sinus rhythm. RESULTS: Sinus rhythm was restored in 54 patients by transesophageal atrial pacing, in 8 patients by electrical cardioversion, and in 2 by right atrial pacing. The mean duration of atrial flutter was 18 +/- 19 days, the mean left atrial size 41.3 +/- 6.2 mm, and the mean left ventricular ejection fraction 54.8 +/- 7.3%. During the study period no episodes of thromboembolism were recorded. CONCLUSIONS: Cardioversion of persistent typical atrial flutter in non-anticoagulated patients at low risk for thromboembolic events appears safe.

[Extrahospital cardiac arrest: the experience of Mestre Emergency Service]. / Arresto cardiaco extraospedaliero: l'esperienza di Mestre Emergenza.

BACKGROUND: Out-of-hospital cardiac arrest (AC) is one of the leading causes of death in industrialized countries. AC-related mortality can be reduced by rapid intervention. We report the experience of the emergency medical service (EMS) of Mestre on the management of out-of-hospital AC. METHODS: We analyzed 80 cases of out-of-hospital AC observed consecutively by the EMS of Mestre from February 1996 to September 1997: 72 cases (90.0%) involved cardiac etiology and 8 (10.0%) non-cardiac etiology. The 72 cases involving cardiac etiology were divided in three groups: group A) 12 unwitnessed ACs (16.7%); group B) 12 ACs witnessed by EMS personnel (16.7%); group C) 48 bystander-witnessed ACs (66.6%). RESULTS: In group A, in which 4/12 patients (33.3%) presented ventricular fibrillation (FV) or pulseless ventricular tachycardia (TV) as initial rhythm, return of spontaneous circulation (ROSC) was obtained in one patient with FV and in one patient with asystole. In group B, 7/12 patients (58.3%) presented FV or TV as initial rhythm; in this subgroup, ROSC was obtained in 71.4% of cases (4 cases with FV and one case with TV) and discharge in 42.9%, while in the subgroup with other rhythms the rate of ROSC was 40.0% (two patients with pulseless electrical activity later died). In group C, 35/48 patients (72.9%) presented VF or TV as initial rhythm; in this subgroup, ROSC was achieved in 42.9% of cases (13 cases with FV and 2 cases with TV) and discharge in 14.3%, while in the subgroup of bystander-witnessed AC with other rhythms the rate of ROSC was extremely low (7.7%) (one patient with asystole later discharged). In group C, bystander cardiopulmonary resuscitation (CPR) was performed in 20/48 patients (40.1%). In these patients, FV or TV were more frequently recorded as initial rhythm (80.0 vs 67.9%; p < 0.05). In patients without bystander CPR, the interval between the time of collapse and the time of the first defibrillation was shorter in the patients who were admitted than in patients who died (6.0 +/- 1.4 vs 10.9 +/- 4.4 min; p < 0.05). Considering all patients with FV or TV as initial rhythm and the interval between the collapse and the first defibrillation exactly recorded, the percentage of ROSC decreased when the interval between the collapse and the first defibrillation increased. CONCLUSIONS: Our data confirm that early defibrillation is the key factor in the prognosis of out-of-hospital AC. The data suggest that the immediate delivery of bystander CPR could extend the interval in which defibrillation is effective.

Structural abnormalities and not diastolic dysfunction are the earliest left ventricular changes in hypertension. HARVEST Study Group.

It has been claimed that diastolic dysfunction is the earliest cardiac abnormality in hypertension, preceding the development of left ventricular (LV) structural abnormalities. To detect early signs of hypertensive cardiac involvement 722 subjects (533 men and 189 women), 18-45 years old, with stage I hypertension, were studied by M-mode and Doppler echocardiography. Blood pressure was measured by 24-h ambulatory monitoring. Ninety-five normotensive individuals of similar age and gender distributions were studied as controls. Significant, though modest, changes of LV mass and geometry were found in the participants in comparison with the normotensive controls. The increment was +10.4 g/m2 for LV mass index, +1.8 mm for LV wall thickness, and +0.032 for relative wall thickness. A slight increase in atrial filling peak velocity was found in the hypertensive subjects at Doppler analysis of transmitral flow, but the ratio of early to atrial velocity of LV diastolic filling did not differ between the two groups. In multiple regression analyses, which included age, body mass index, heart rate, smoking, and physical activity, 24-h mean blood pressure emerged as a significant predictor of LV mass index (men, P = .003; women, P = .04) and wall thickness (men, P = .03; women, P = .004) in the hypertensive subjects, whereas no index of diastolic filling was significantly associated with ambulatory blood pressure in either gender. The present data indicate that changes in LV anatomy are the earliest signs of hypertensive cardiac involvement. Left ventricular filling is affected only marginally in the initial phase of hypertension.

The effects of alcohol consumption on ambulatory blood pressure and target organs in subjects with borderline to mild hypertension. HARVEST Study Group.

The objective of this study was to examine the relationship of alcohol consumption to target organ involvement and ambulatory blood pressure (BP) in a population of young borderline to mild hypertensive subjects. Participants were 793 male subjects, aged 18-45 years, from the HARVEST Study. The analysis was performed in three age-matched groups with similar body mass index. Casual and 24-h ambulatory BP monitoring, routine biochemistry, echocardiography, and albumin excretion rate were measured. The men were divided into three groups: 1) nondrinkers, 2) drinkers of < 50 g/day, and 3) drinkers of > or = 50 g/day. Office systolic BP was not significantly different among the three groups, whereas 24-h and daytime BPs increased progressively from the first to the third group (group 1 v 3; P = .01 for 24-h systolic BP and P = .02 for daytime systolic BP). These differences remained significant even after adjusting for smoking. Left ventricular mass index, interventricular septum thickness, and wall thickness increased progressively from group 1 to group 3; this difference also remained significant after adjusting for smoking and 24-h BPs. The albumin excretion rate was much higher in group 3 than in group 1 (P = .003), but when 24-h BP was added to the model the difference was no longer significant. These results indicate that alcohol has a detrimental effect on the heart and the kidney. Alcohol's effect on LV wall thickness appears to be direct, whereas its action on albumin excretion rate seems to be mediated mainly by its effect on BP.

Target organ damage and ambulatory blood pressure in stage I hypertension. The Hypertension and Ambulatory Recording Venetia Study.

According to recent international guidelines the decision on whether to treat young subjects during the early phase of hypertension should be based not only on their office blood pressure but also on their ambulatory blood pressure and whether target organ damage has occurred. Few data on the prevalence of hypertensive complications in young subjects with mild hypertension are available. In the Hypertension and Ambulatory Recording Venetia Study (HARVEST), a multicenter trial conducted in northeast Italy, the percentage of young borderline-to-mild hypertensive subjects with echocardiographic left ventricular hypertrophy was 4.5% and the percentage with concentric remodeling was 4%. Clear differences in cardiac size and geometric adjustment to ambulatory systolic pressure between the two sexes were found. The impact of blood pressure on the walls of the left ventricle and on the left ventricular mass was remarkable in women but weak in men. The assessment of left ventricular systolic function confirmed that many young mild hypertensive subjects have an increased ejective performance. The left ventricular contractility evaluated by midwall measurement was, however, found to be depressed in 9.2% of the HARVEST participants. Their left ventricular diastolic function was similar to that of 50 normotensive controls. The prevalence of microalbuminuria [albumin excretion rate (AER) > 30 mg/24 h) was 6.1%, only slightly higher than that found by other authors among normotensive subjects and much lower than that observed among patients with more severe hypertension. For our stage I hypertensives, however, the AER was correlated to the 24 h blood pressure with high statistical significance, whereas we found no relationship between the AER and left ventricular mass index either for all of the subjects taken together or for the men and women considered separately. The results suggest that renal and cardiac involvement do not occur in parallel during the initial phase of hypertension.

Efficacy of intravenous propafenone in termination of atrial flutter by overdrive transesophageal pacing previously ineffective.

Fifty patients with symptomatic type I atrial flutter in whom termination of the arrhythmia with transesophageal stimulation was unsuccessful were randomized to undergo a repeat procedure after intravenous propafenone (n = 25) or placebo (n = 25). Immediate sinus rhythm recovery rate was 36% in the propafenone group and 4% in the placebo group (p = 0.005), indicating that intravenous propafenone increases the rate of successful transesophageal stimulation and can be used when a first attempt at conversion is ineffective.

Lack of influence of menopause on blood pressure and cardiovascular risk profile: a 16-year longitudinal study concerning a cohort of 568 women.

OBJECTIVE: To analyse the effect of menopause on blood pressure and cardiovascular risk. DESIGN: From an Italian general population, 568 women (408 pre- and 160 post-menopausal) were screened twice, in 1978 and 16 years later. METHODS: Cross-sectional analyses both in 1978 and in 1994, and longitudinal analysis in the 1978-1994 period. RESULTS: For the general analysis the cohort was reduced to 525 women with paired data in 1978 and 1994. In both cross-sectional studies, unadjusted blood pressure and cardiovascular risk were higher after than they were before menopause, but any difference disappeared after adjustment or matching for age. In 1994 we studied three groups of women: those who were still premenopausal, those who were fertile in 1978 but postmenopausal in 1994 and those who were already postmenopausal in 1978. The 16-year blood pressure increment was similar in all three groups. The incidence of myocardial infarction and angina pectoris was greater in those who were already postmenopausal than it was in those who had their menopause during the study period. An analysis of mortality was performed for all of the 568 women. Forty-three of them died, 14 from cardiovascular causes (six before and eight after menopause), 18 from neoplasia (two before and 16 after menopause) and 11 from other diseases. Menopausal status was rejected from the Cox equations both of overall and of cardiovascular mortality, showing a significantly predictive value only for neoplastic mortality. CONCLUSION: Menopause has no influence on high blood pressure and cardiovascular risk. The greater blood pressure levels, mortality and morbidity observed in postmenopausal women are simply attributable to their older age and are no longer detectable in an age-matched sample.

Relationship between albumin excretion rate, ambulatory blood pressure and left ventricular hypertrophy in mild hypertension.

OBJECTIVE: To study the relationship of urinary albumin excretion to ambulatory blood pressure and other cardiovascular risk factors in borderline to mild hypertension. PATIENTS AND METHODS: We studied 779 patients with borderline to mild hypertension (mean +/- SEM age 33 +/- 0.3 years; mean +/- SEM office blood pressure 146 +/- 0.4/94 +/- 0.2 mmHg) at 17 hypertension clinics in northeast Italy. Office and 24-h blood pressures were recorded with simultaneous urine collection for albumin measurement. In 510 subjects, left ventricular mass was measured by echocardiography. RESULTS: Subjects with overt (> or = 30 mg/24 h) and borderline (16-29 mg/24 h) microalbuminuria had similar 24-h blood pressure levels, higher than those in the subjects without microalbuminuria. In the univariate and multiple regression analyses the albumin excretion rate was closely correlated with 24-h systolic blood pressure and not related to age, body mass index, metabolic parameters, lifestyle factor and degree of left ventricular hypertrophy. CONCLUSIONS: Borderline values of urinary albumin excretion (16-29 mg/24 h) may be clinically relevant in subjects with borderline to mild hypertension. Renal and cardiac damage do not develop in parallel in the initial phases of hypertension.

Evaluation of atrial vulnerability with transoesophageal stimulation in patients with atrioventricular junctional reentrant tachycardia. Comparison with patients with ventricular pre-excitation and with normal subjects.

The aim of our work was to evaluate the inducibility of atrial fibrillation in a group of patients with atrioventricular junctional reentrant tachycardia and to compare it with that of patients with a Kent-type ventricular pre-excitation (Wolff-Parkinson-White syndrome) and a control group. One hundred and twenty-five subjects were separated into groups. Group 1 comprised 49 Wolff-Parkinson-White patients, with a mean age of 26.4, range 10-66 years; group 2, 51 patients with atrioventricular junctional reentrant tachycardia inducible by transoesophageal atrial stimulation and/or clinically documented, with a mean age of 43.4, range 16-78 years; group 3, 25 control subjects with a mean age of 26.4, range 13-76 years. Each subject underwent atrial transoesophageal stimulation with the following protocol: programmed atrial stimulation with 1 and 2 stimuli during atrial pacing of 100.min-1 and 150.min-1; atrial stimulation for 10 s at a rate of 200-300-400-500-600.min-1 with intervals of 10 s between stimulations, five successive 'ramp-up' atrial stimulations for 9 s with the rate increasing from 100 to 800.min-1 with intervals of 10 s between stimulations. The end point was the completion of the protocol or induction of sustained atrial fibrillation (> 1 min). The chi-square test was used for statistical analysis. Our results showed that in group 1 atrial fibrillation was induced in 27/49 patients (55.1%); this was sustained in 13/49 (26.5%) and non-sustained in 14/49 (28.5%); in group 2, atrial fibrillation was induced in 22/51 patients (43.0%); it was sustained in 7/51 (13.7%) and non-sustained in 15/51 (29.4%); in group 3, sustained atrial fibrillation was not induced in any subject and in only one subject was a non-sustained atrial fibrillation (4 s) induced. The chi-square test showed that group 2 vs group 1 were non-significant, while group 2 vs group 3 and group 1 vs group 3 were significant (P < 0.003 and P < 0.0007, respectively). Therefore group 2 patients showed a greater atrial vulnerability in comparison to the control subjects and a similar vulnerability to group 1 patients. It is possible that the greater atrial vulnerability in the patients of group 2 was due to the double nodal pathway.

Ambulatory blood pressure in mild hypertensive women taking oral contraceptives. A case-control study.

The aim of the present study was to compare the ambulatory blood pressure levels in mild (stage 1) hypertensive women using oral contraceptives and respective values in nonusers of oral contraceptives with similar office blood pressure. The study group consisted of 24 mild hypertensive patients taking low dosage estrogen-progestogen oral contraceptives. Seventy women of similar age and body mass index who had never used oral contraceptives served as a control group. Both daytime and nighttime systolic blood pressure values were significantly higher in oral contraceptive users. There was an average 8.3 mm Hg difference (95% confidence interval, 3.0 to 13.7 mm Hg; P = .003) for the daytime and 6.1 mm Hg difference (95% confidence interval, 0.4 to 11.8 mm Hg; P = .04) for the nighttime. No significant differences in ambulatory diastolic blood pressure between the two groups were found. These data provide evidence that hypertensive oral contraceptive users with the same office blood pressure as that in hypertensive noncontraceptive users have a significantly higher ambulatory systolic blood pressure. Our results support the opinion that alternative methods of contraception should be considered for hypertensive women in place of oral contraceptives.

[The ST/HR slope and coronary stenoses]. / ST/HR slope e stenosi coronariche.

BACKGROUND: The heart rate adjustment of ST depression (ST/HR Slope) has been shown by some authors to markedly improve the accuracy of treadmill exercise electrocardiogram for identifying and quantifying coronary artery disease. However, other authors have obtained different results. In the present study the results of our exercise electrocardiography laboratory are compared with the data obtained from the literature. METHODS: Fifty patients (46 males and 4 females, age range 60 +/- 7 years) with suspect or certain coronary artery disease were referred for a routine treadmill exercise electrocardiogram, and subsequently underwent cardiac catheterization and selective coronary cineangiography to assess the severity of coronary obstruction. All patients exercised according to a recently reported modification of the standard Bruce protocol, proposed by Kligfield et al, for a more accurate evaluation of the ST/HR Slope, which was calculated in real time by a computerized system. Patients with coexisting valvular heart disease, cardiomyopathy, left bundle-branch block on the resting ECG, myocardial infarction within 8 weeks, diabetes mellitus, hypertensive response during exercise testing (diastolic blood pressure > 95 mm Hg and/or systolic blood pressure > 190 mm Hg), abnormalities or variations of the coronary arteries, were excluded from this study. RESULTS: This method correctly identified 13 of 14 patients with multivessel coronary artery disease and 35 of 36 with less severe disease: one patient was false negative and another one false positive. Thus, in our exercise electrocardiography laboratory this approach shows a sensitivity of 93%, a specificity of 97%, a positive predictive value of 93% and a negative predictive value of 97% for the detection of severe coronary disease. CONCLUSIONS: These findings suggest that, in patients selected as in this study, the ST/HR slope is a good method which improves the clinical usefulness of the treadmill exercise electrocardiogram in coronary artery disease.

[The endocavitary and transesophageal electrophysiological findings in idiopathic atrial fibrillation]. / Rilievi elettrofisiologici endocavitari e transesofagei nella fibrillazione atriale idiopatica.

BACKGROUND: We studied 105 patients (pts) in order to help clarify the pathogenetic mechanisms of idiopathic atrial fibrillation (AF). Eighty of these pts (Group I) had experienced paroxysmal AF, and 25 were normal control subjects (Group II). Twenty-two pts out of Group I had idiopathic paroxysmal AF (Group IA), while the remaining 58 (Group IB) presented with a heart disease or a WPW pattern. METHODS: All pts underwent endocavitary (EEPS) (69) or transesophageal (TEPS) (36) electrophysiologic study. In all pts the inducibility of a sustained AF (greater than 1 min) was tested by aggressive stimulation protocols including high frequency atrial bursts. RESULTS: In Group I a sustained AF was induced in 82% of cases vs 4% of Group II cases (p less than 0.001). In Group I there was no difference between pts with or without idiopathic AF (IA 73% vs IB 86%, NS). In two pts with idiopathic AF a concealed Kent bundle was identified and a reciprocating atrioventricular tachycardia was induced, which in one case spontaneously degenerated into AF. Four athletes with idiopathic AF were studied before and after autonomic blockade. AF was induced in all during the basal state, lasting several hours, and after autonomic blockade in 3 pts, lasting again for several hours. In 1 patient (pt) the arrhythmia spontaneously resolved within 50 sec. CONCLUSIONS: 1) The induction of a sustained AF by EEPS or TEPS is a pathologic phenomenon which is frequently observed in pts with clinical episodes of paroxysmal AF, while it is very rare in normal control subjects. 2) Pts with idiopathic AF have an electrophysiologic behaviour similar to pts with non-idiopathic AF. This fact suggests that among the former, most cases probably have a concealed atrial anomaly. In some cases this atrial anomaly can be related to the existence of a Kent bundle. 3) In athletes with paroxysmal AF the inducibility of a sustained AF both in the basal state and after autonomic blockade suggests that the vagal prevalence typical of such subjects probably plays a secondary role.

[The behavior of the arterial pressure at rest and under exertion in normotensive and hypertensive subjects exposed to acute hypoxia at a median altitude]. / Comportamento della pressione arteriosa a riposo e da sforzo in normotesi e ipertesi sottoposti a ipossia acuta da media quota.

In order to evaluate blood pressure changes at rest and during effort in response to moderate altitude acute hypoxia, we performed noninvasive blood pressure monitoring and maximal bicycle stress testing in 10 normotensive and 13 untreated mild hypertensive subjects at sea-level and in a mountain resort (m. 2572). Blood pressure was measured every 10 minutes by the Spacelabs 5200 pressurometer and bicycle stress test was performed at initial workload of 50 watts and steps of 50 watts every 3 minutes until exhaustion. Mean systolic blood pressure resulted unchanged in the normotensive subjects (120.8 +/- 10.6 vs 121.5 +/- 6.9 NS) while in the hypertensive ones it increased slightly at 2572 m. (131.0 +/- 12.3 vs 137.0 +/- 13.1 NS). Mean diastolic blood pressure did not increase significantly at 2572 m in either group (respectively from 74.5 +/- 90 to 80.1 +/- 7.9 NS and from 88.3 +/- 10.2 to 94.7 +/- 10.7 NS) even if blood pressure increase was relevant in some hypertensive subjects. During the monitoring, heart rate increased at 2752 m in both groups, even if this difference was significant in the hypertensive group only (respectively 82.8 +/- 11.8 vs 94.3 +/- 13.2 in normotensive subjects-NS-and 88.0 +/- 6.3 vs 104.0 +/- 7.8 in hypertensive subjects-p less than 0.001). During the ergometric test submaximal systolic blood pressure (100 and 150 watts) increased slightly in both groups, but this difference was significant in hypertensive subjects at a workload of 150 watts only (208.3 +/- 18.2 vs 219.3 +/- 19.2 p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)