[Influence of sex on the prognosis of high risk acute coronary syndromes treated by early angioplasty]

The aim of this study was to evaluate the influence of sex on the prognosis of high risk acute coronary syndromes treated early with angioplasty. Over a period of two years, 694 consecutive patients (151 female, 543 male) underwent revascularisation within the first 24 hours of an acute coronary syndrome without permanent ST elevation (ST depression (52.5%) or relapse of angina despite medical treatment (47.5%). The females were older than the males (67.9 vs 62.3 years; p < 0.0001), smoked less (7.3 vs. 32.8%; p < 0.001) and had a higher prevalence of hypertension (53 vs. 42.1%; p = 0.017). The angiographic characteristics were equivalent in both sexes, except for a lower frequency of thrombus in the females (6.9 vs. 15.2%; p < 0.0001). All lesions were treated with endoprosthesis implantation. The angiographic success rate was comparable (94 vs. 93.7%) as was the rate of major cardiac events while in hospital (3.8 versus 4%). With an average survival of 2 years, the incidence of major cardiac events remained identical in both sexes (15.4 vs 15.7%: p = 0.43): cardiac mortality (3.2 vs 2%; p = 0.18), myocardial infarction (7.3 vs 6.7%; p = 0.37), further revascularisation (8.3 vs 7.2%; p = 0.47). The survival without major cardiac event was comparable at 1 year (87 +/- 0.1 vs 88 +/- 0.3%) and at 2 years (78 +/- 0.2 vs 83 +/- 0.3%; p = 0.58). In conclusion, the progression both in hospital and at two years with a strategy of early revascularisation for high risk acute coronary syndromes was comparable in males and females.

[Prognosis scores to help revascularization for ischemic heart failure]

AIMS

Patients suffering from coronary heart disease with ventricular systolic dysfunction present a bad prognosis and should be potentially revascularized. Up to now, surgery appeared to be the most feasible revascularization technique for such patients. Aims of this study were to assess the influence of different treatments (surgery, angioplasty or exclusively medical treatment) on clinical outcome and to establish a prognostic score practitioners to select the most appropriate therapy adapted to their patient profiles.

METHOD

From 1995 to 2000, 492 patients were included in this cohort: 365 in the angioplasty group, 96 in the surgical group and 31 in the medical group. Kaplan Meier curves were made with a multivariate analysis to determine the significant predictive factors of mortality and major adverse cardiac events.

RESULTS

After a mean follow-up of 32 +/- 19 months, there was no statistical difference in mortality rate between the groups. However, the survival rate without MACE is higher in the surgical group, intermediate in the angioplasty group and lower in the medical group. Using the significant predictive factors of MACE in multivariate analysis, a prognostic score has been established in order to discriminate three categories of severity. For each category, angioplasty was compared with surgery in terms of the event-free-survival rate. For the two extreme categories (severe and non-severe), both treatments were equal. For the intermediate category, surgery obtained greater results.

CONCLUSION

This prognostic score could help physicians in choosing the appropriate revascularization technique to treat patients with severe ischemic heart failure.

[Effects of bradykinin in the cardiovascular effects of angiotensin-converting enzyme inhibitors]

The role of bradykinin in the cardiovascular effects of angiotensin converting enzyme inhibitors remains difficult to establish. On their haemodynamic effects, bradykinin acts during their acute administration, participating in their vasodilatation action, while during their chronic administration they act slightly or not at all. On their trophic effects, the action of the tissue kallikrein-kinin system, suggested by the results of animal experimentation, is yet to be demonstrated in man. For their effects on cardiovascular morbidity and mortality the role of bradykinin remains under discussion. Nevertheless, besides ACE inhibitors, the other therapeutic agents which increase the levels of bradykinin, such as neutral endopeptidase inhibitors, have a significant field of development in the course of cardiovascular pathologies.

Rehabilitation of patients with congestive heart failure with or without beta-blockade therapy

BACKGROUND

Management of heart failure includes beta-blockade (betaB) therapy and cardiac rehabilitation. The aim of this study was to compare the exercise training response of patients with congestive heart failure (CHF) receiving betaB therapy with that of patients not receiving treatment.

METHODS AND RESULTS

Thirty-four consecutive patients with CHF were included in a 4-week training program at their ventilatory threshold (VT); 6 patients received betaB treatment and 18 did not. The patients underwent a cardiopulmonary exercise test before and after training. Oxygen uptake (VO(2)) at peak exercise and at VT increased in both groups (P < or =.0001) without any significant differences between the groups. The same results were found after adjustment to ejection fraction and VO(2) at the start of the training program. There was no difference in VT improvement, measured as a percentage of utilization of maximal oxygen uptake, between the groups. After training, heart rate and ventilation decreased (P < or =.0001) at submaximal levels in both groups without significant differences between the groups.

CONCLUSIONS

betaB therapy does not impair functional improvement induced by a rehabilitation program in patients with CHF. betaB therapy does not interfere with exercise training prescription if patient exercise evaluations are made at the time of therapeutic intake.

[Atrial flutter: a possible early sign of acute rejection in heart transplantation. A case report]

The authors report the case of a cardiac transplant patient with a recurrence of atrial flutter two months after electrical cardioversion and despite long-term preventive treatment with amiodarone. Early investigation for signs of rejection with 4 endomyocardial biopsies was negative. Aggravation of the haemodynamic status due to flutter with a rapid ventricular response led to an attempted radio-frequency ablation. Endocavitary mapping confirmed persistence of sinus activity in the native atrium and the presence of a circuit of type I isthmic flutter (anticlockwise circuit) in the donor atrium. Ablation by radio-frequency in the same procedure was successful. A fifth myocardial biopsy the same day finally confirmed stage 3A acute rejection. No signs of recurrent rejection or arrhythmia have been observed after 24 months' follow-up in this patient. This preliminary experience confirms the need to look for graft rejection by repeated myocardial biopsies in cardiac transplant, patients with atrial flutter and the efficacy of radio-frequency ablation in cases of resistance to conventional therapy.

Prognostic value of heart rate variability in time domain analysis in congestive heart failure

AIMS

Analysis of heart rate variability is a noninvasive tool that allows to study autonomic control of the heart. Several studies have shown disturbed heart rate variability in patients with chronic heart failure (CHF). We sought to assess the prognostic value of time domain measures of heart rate variability in CHF.

METHODS AND RESULTS

We prospectively enrolled 190 patients with CHF in sinus rhythm, mean age 61+/-12 years, 109 (57.4 %) in NYHA class II and 81 (42.6 %) in class III or IV, mean cardiothoracic ratio 57.6+/-6.4 % and mean left ventricular ejection fraction 28.2+/-8.8 %, 85 (45 %) with ischemic and 105 (55 %) with idiopathic dilated cardiomyopathy. Time domain measures of heart rate variability were obtained from 24 h Holter ECG recordings. During follow-up (22+/-18 months), 55 patients died. In multivariate analysis, independent predictors for all-cause mortality were: ischemic heart disease, cardiothoracic ratio > or =60 % and standard deviation of all normal RR intervals <67 ms (RR=2.5, 95 % CI 1.5--4.2).

CONCLUSIONS

Depressed heart rate variability has independent prognostic value in patients with CHF.

[Prophylactic value of automatic implantable defibrillators: a case report of a patient with asymptomatic Brugada syndrome]

The authors report the case of an asymptomatic 32 year old man with no family history of sudden death but with ECG changes suggesting Brugada's syndrome. He underwent implantation of an automatic defibrillator after inducible syncope ventricular fibrillation had been demonstrated during electrophysiological investigation. The later occurrence of three episodes of ventricular fibrillation treated by the defibrillator confirmed a posteriori the logic of this therapeutic approach.

Depressed low frequency power of heart rate variability as an independent predictor of sudden death in chronic heart failure

AIMS

Identification of patients with chronic heart failure at risk for sudden death remains difficult. We sought to assess the prognostic value for all-cause and sudden death of time and frequency domain measures of heart rate variability in chronic heart failure.

METHODS AND RESULTS

We prospectively enrolled 190 patients with chronic heart failure in sinus rhythm, mean age 61+/-12 years, 109 (57.4%) in NYHA class II and 81 (42.6%) in classes III or IV, mean cardiothoracic ratio 57.6+/-6.4% and mean left ventricular ejection fraction 28.2+/-8.8%, 85 (45%) with ischaemic and 105 (55%) with idiopathic dilated cardiomyopathy. Time and frequency domain measures of heart rate variability were obtained from 24 h Holter ECG recordings, spectral measures were averaged for calculation of daytime (1000h-1900h) and night-time (2300h-0600h) values. During follow-up (22+/-18 months), 55 patients died, 21 of them suddenly and two presented with a syncopal spontaneous sustained ventricular tachycardia. In multivariate analysis, independent predictors for all-cause mortality were: ischaemic heart disease, cardiothoracic ratio > or =60% and standard deviation of all normal RR intervals <67 ms (RR = 2.5, 95% CI 1.5-4.2). Independent predictors of sudden death were: ischaemic heart disease and daytime low frequency power <3.3 ln (ms(2)) (RR = 2.8, 95% CI 1.2-8.6).

CONCLUSION

Depressed heart rate variability has independent prognostic value in patients with chronic heart failure; spectral analysis identifies an increased risk for sudden death in these patients.

[Anticoagulant treatment and cardiac insufficiency]

In cardiac failure, should conventional therapy be associated systematically with anticoagulant or antiplatelet therapy? Embolic complications are uncommon (1 to 2.5% per year) and the benefit/risk ratio seems to be marginal. The absence of prospective randomised controlled trials makes it impossible to give a definitive reply to this question. The indications of oral anticoagulants are based on experience, good sense, the recognition of known embolic risk factors: severe cardiac failure, atrial fibrillation, EF < 0.30 and low VO2 max, mitral valve disease or prosthetic valve, detection of intracavitary thrombus or spontaneous contrast on transoesophageal echocardiography. Aspirin does not seem to be mandatory even if it reduces the thromboembolic risk non-significantly. In this elderly population with a high co-morbidity, the risks of haemorrhage cannot be ignored, and, if oral anticoagulants are prescribed, biological surveillance must be intensive.

[Utilization of heart rate at the ventilatory threshold for the prescription of intensity of exercise training in cardiac failure]

Physical exercise is a treatment for cardiac failure but a large range of intensities of exercise is proposed. The aims of this study were to determine the range of intensities of effort used and to individualize the intensities used. Thirty patients with stable cardiac failure (NYHA Classes II-III, age: 53 +/- 2.1 years, ejection fraction: 31 +/- 1.4%) underwent a cardiorespiratory exercise stress test before and after individualized training at the ventilatory threshold. However, before and after the training period, standard methods of calculation of the intensities at the ventilatory threshold showed individual differences greater than +/- 2 standard deviations, indicating different metabolic stimulations. After the individualized training programme, peak oxygen consumption on exercise (1679 +/- 100 vs 1487 +/- 89 ml.min-1, p = 0.0001) and at ventilatory threshold increased (1365 +/- 85 vs 1133 +/- 65 ml.min-1, p = 0.0001), the ventilatory threshold/peak exercise ratio increased (81.2 +/- 1.3 vs 76.7 +/- 1.4%, p = 0.0008), and there was a decrease in heart and ventilatory rates at submaximal metabolic levels (p = 0.0001). The authors conclude that protocols using intensity of effort at the ventilatory threshold give similar results with respect to improvement of aerobic capacity as other methods of indirect calculation, based on maximal heart rate of oxygen consumption. The value of this particular method lies in the adequation between aerobic capacity of the patient and the intensity of training. The results obtained attain the physiopathological aims of rehabilitation.

[Congestive cardiomyopathies originating from arrhythmia]

Arrhythmia-induced cardiomyopathy is partially or totally reversible left ventricular dysfunction after normalisation of the tachycardia or arrhythmia. On the one hand, there are pure forms in which the arrhythmia occurs in apparently normal hearts and, on the other hand, the more common form in which there is minimal underlying cardiac disease associated with the arrhythmia. Total or partial recovery after reduction of the arrhythmia or "ablation" of its substrate remains a key feature of the diagnosis. Many experimental studies of the functional and structural myocardial and neurohormonal effects of prolonged tachycardias or tachyarrhythmias have provided insight into the modes of occurrence and the characteristics of this type of "reversible" left ventricular dysfunction. But, in fact, there is a lack of anatomical, clinical and follow-up data of this syndrome, the diagnosis of which is always difficult and essentially retrospective after recovery of left ventricular function.

[Hyperinsulinism, heart rate variability and circadian variation of arterial pressure in obese hypertensive patients]

AIMS

During insulin resistance, sympathetic nerve activity is increased. However insulin resistance is a common feature of obesity and essential hypertension, it is unclear if chronic hyperinsulinemia per se contributes to sympathetic overactivation. The purpose of our study was to explore++ the relationships between chronic hyperinsulinemia and heart rate variability (HRV), a non-intensive tool to assess autonomic function, in obese and hypertensive subjects.

METHODS

24 hours Holter ECG for HRV time and frequency domain analysis was performed in 77 patients, mean age 53 +/- 10 years, 52 men and 25 women, free of diabetes, without beta-blockers, divided in four groups according to three parameters, body mass index (BMI > 27 kg/m2 in man and > 25 kg/m2 in woman defined obesity), arterial pressure and insulinemia (fasting insulinemia > 25 mUI/L defined hyperinsulinemia): 27 patients obese, hypertensive, with hyperinsulinemia; 28 patients obese, hypertensive, without hyperinsulinemia; 12 patients non obese, hypertensive, without hyperinsulinemia; 10 patients obese, normotensive, without hyperinsulinemia.

RESULTS

In comparison with the three other groups, patients with hyperinsulinemia showed a significant decrease (p < 0.05) of SDNN and the power of total spectrum (0.01-1 Hz) band, which are indexes of global HRV, and a significant decrease (p < 0.005) of SD and the normalized power of the low frequency (0.04-0.15 Hz) band, both indexes reflecting sympathetic modulation of HRV. In contrast, no significant difference was observed between the four groups for indexes of HRV reflecting parasympathetic tone. These relations were independent of mean RR. Fasting insulinemia was significantly (p < 0.0001) related with HRV in time domain (SDNN; r = -0.43; SD: r = -0.49) and spectral domain (total spectrum: r = -0.49; low frequency: r = -0.52).

CONCLUSION

Chronic hyperinsulinemia appears to be an important determinant of HRV, particularly for the indexes reflecting sympathetic influence, independent of obesity and hypertension.

[Treatment of cardiac insufficiency: does treatment depend on whether its cause is ischemic or idiopathic?]

Angiotensin converting enzyme (ACE) inhibitors are associated with a greater reduction in mortality in non-ischaemic cardiomyopathy than in ischaemic cardiomyopathy after the results of the V-HeFT-II and SOLVD trials in symptomatic patients. However, a recent analysis of the global, symptomatic and therapeutic, results of the SOLVD trials, demonstrated a similar reduction in mortality with ACE inhibitors in ischaemic and non-ischaemic cardiomyopathies. Moreover, after myocardial infarction, the beneficial effects of ACE inhibitors have been well established in patients with left ventricular dysfunction. Betablockers, especially bisoprolol in the CIBIS-I trial, also seem to be more effective in non-ischaemic cardiomyopathy. However, CIBIS-II and the US Carvedilol Heart Failure Trial Program clearly showed that the benefits of betablockade were identical whether ischaemic or not. The beneficial effects of betablockers in the post-infarction period are more marked when left ventricular dysfunction is severe. The PROVED and RADIANCE trials suggest that digitalis is more effective in non-ischaemic cardiomyopathy. These results were not confirmed by the DIG trial which showed a significant reduction in the combined criterion, mortality and hospital admission for aggravation of cardiac failure, both in ischaemic and in non-ischaemic cardiomyopathy. However, the use of digitalis should be prudent during ischaemic cardiomyopathy, the neutral effect on global mortality in the DIG trial masking divergent results with a tendency to reducing mortality due to aggravation of cardiac failure and a significant increase of other causes of cardiac death, especially from myocardial infarction and arrhythmias. Amiodarone could also be useful in non-ischaemic cardiomyopathy. The reduction in risk of death in the GESICA study, which comprised 60% of patients with non-ischaemic cardiomyopathy, contrasting with the absence of an effect with this molecule in the STAT-CHF trial which only comprised 29% of patients with non-ischaemic cardiomyopathy. The new generation of calcium antagonists could also be more effective in non-ischaemic cardiomyopathy. Although amlodipine significantly reduced mortality in the PRAISE trial in non-ischaemic cardiomyopathy, there was no favourable effect with felodipine in the V-HeFT-III tria. Finally, if in the earlier studies oral anticoagulants were more effective in non-ischaemic cardiomyopathy, the recent results of the SOLVD trial showed that warfarin decreased the mortality in both ischaemic and non-ischaemic cardiomyopathy. The value of anti-aggregant therapy is not questioned in coronary artery disease, but its role in dilated cardiomyopathy has not yet been established. In conclusion, apart from the use of digitalis which must be prudent in post-infarction cardiomyopathy or in patients with ventricular arrhythmias, the treatment of cardiac failure differs little with respect to its ischaemic or non-ischaemic aetiology, and should be based on the NYHA (New York Heart Association) classification.

[Evaluation of arrhythmic risk in coronary insufficiency]

Half of all deaths occurring in patients with heart failure are sudden deaths probably related to a malignant ventricular arrhythmia. The pathophysiological mechanisms of these arrhythmias are unclear, but left ventricular function, hypokalaemia accentuated by diuretics and treatments altering inotropism play a definite role. Because of the diversity of aetiologies generating heart failure, the multiplicity of fatal arrhythmias and the multifactorial origin of these arrhythmias, there is no formal marker for the risk of sudden death in patients with heart failure, at the present time. In addition to the NYHA classification and detection of episodes of syncope, assessment of these patients must be as complete as possible, at least including repeated evaluation of the ejection fraction, Holter ECG monitoring and detection of delayed ventricular potentials.

[The CAPITOL study (Captopril Post Infarction Tolerance). A trial of progressive titration of captopril after myocardial infarct with left ventricular dysfunction]

The objective of CAPITOL (Captopril Post Infarction Tolerance) multicentre open trial was to study the tolerance of a protocol of titration of Captopril in patients with recent myocardial infarction complicated by left ventricular dysfunction. Five hundred and four patients, with a mean age of 62 +/- 12 years, were included during the hospital period in the 74 participating intensive care units, 9 +/- 6 days after myocardial infarction (ejection fraction 34 +/- 6%). After a 6.25 mg test dose of Captopril, the dosage was progressively increased to the target dose of 150 mg at the end of the first month. Of the 504 patients included, 343 finished the trial and 161 stopped the trial prematurely. At the end of the hospital period, 73% received 75 mg/day: at the first follow-up visit (27 +/- 16 days after inclusion), 59% had attained 150 mg/day, this proportion increasing to 71% at the end of the trial (79 +/- 33 days after inclusion). There was no significant change in blood pressure for the whole study population. However, the systolic blood pressure of the patients receiving 150 mg/day of Captopril at the end of the trial was slightly higher than that observed at the end of the hospital period (126 +/- 17 mmHg and 116 +/- 17 mmHg respectively, p = 0.006). Severe Intercurrent events were observed in 89 patients: 24 deaths, 7 recurrent infarctions, 58 hospital admissions (21 for cardiac failure, 15 for recurrence of angina, 11 aorto-coronary bypass operations, 7 coronary angioplasties, 2 cerebro-vascular accidents, 2 systemic emboli). Of the benign complications, hypotension was observed in 25% of patients, nearly half of which occurred during the hospital admission. The drugs prescribed in association with Captopril were Aspirin (78%), betablockers (57%), nitrate derivatives (42%) and diuretics (27%). Multivariate analysis showed 3 factors associated with good tolerance of the 150 mg dosage of Captopril: Killip Class I or II on admission, an ejection fraction > 30% and an initial systolic blood pressure > 100 mmHg. In conclusion, in this trial of dose titration, 3 out of 4 patients with myocardial infarction and left ventricular dysfunction, tolerated the 150 mg/day dosage of Captopril. Patients in the trial could also be treated with drugs recommended after myocardial infarction, in particular the betablockers. Arch Mal Coeur 1999: 92: 395-403.

[Sudden death and chronic cardiac insufficiency]

Sudden death accounts for about 35% of the mortality of cardiac failure and its incidence does not decrease with the use of angiotensin converting enzyme inhibitors. Non-sustained ventricular tachycardia on Holter monitoring, late ventricular potentials and tachycardia induced by programmed ventricular stimulation have no formal predictive value of sudden death, underlining the varied character of the mechanisms underlying sudden death during cardiac failure. Sustained ventricular tachycardia degenerating to ventricular fibrillation is only one of the rhythmic factors implicated together with inaugural ventricular fibrillation, bradyarrhythmias and electromechanical dissociation. The underlying cardiac disease plays a role in the initiation of the fatal arrhythmia. In coronary artery disease, recurrent acute ischaemia is the principal trigger factor in patients who often have triple vessel disease. This explains the fact that classic markers of arrhythmia in the post-infarction period, which are only the reflection of the arrhythmogenic substrate of ventricular tachycardia, usually due to reentry around the fibrous scar of the infarct, are not valid in patients with progressive ischaemic cardiomyopathy. The most effective antiarrhythmic treatment in this type of patient is the prevention of ischaemia, when possible. In primary dilated cardiomyopathy, the mechanism underlying sudden death could be different at each stage. In NYHA Stages I and II, ventricular tachyarrhythmias could play a major part in unexpected sudden death in patients whose stable haemodynamic status suggested a more prolonged survival. The value of an implantable defibrillator would seem to be proved in this group of patients, at least in secondary prevention. In Stages III and IV, ventricular arrhythmias only indicate the degree of ventricular dysfunction and sudden death may follow bradyarrhythmias and electromechanical dissociation due to the precarious haemodynamic status.

[Is the treatment of left ventricular systolic dysfunction different according to the etiology?]

Cardiac failure is the terminal stage of evolution, the finality of many valvular, vascular, myocardial, general, congenital or acquired conditions. The therapeutic decisions should be based on the search for a curable cause of a predisposing factor and the evaluation of the severity of the cardiac failure. At advanced stages of ventricular dysfunction when the myocardial lesions are constituted, when cardiac and vascular remodelling has occurred, the aetiological treatment, which is the constant objective, is unfortunately too late. The treatment is the same, whatever the aetiology, in order to improve functional problems. At early stages, and, if possible, preventively, surgery, revascularisation techniques, the correction of an arrhythmia, the suppression of a cardiotoxic factor, are essential. The different therapeutic classes used could have different efficacies depending on the aetiology, but, finally, this point is negligible: the medications are based on the results of large scale, controlled, therapeutic trials.

[Functional decoupling of left ventricular beta-adrenoceptor in a canine model of obesity-hypertension]

OBJECTIVE

To assess cardiac beta-adrenoceptors (beta-AR) in an obesity-hypertension model.

METHODS

Six male beagle dogs (aged 35 +/- 5 months) receiving during 30 weeks a high-fat diet with 60% uncooked beef fat were compared to 6 normal beagle dogs. With right auricular and left ventricular samples we analysed cardiac beta-AR density through binding study using [125I]-cyanopindolol. beta 1 and beta 2 densities were obtained by competition with CGP 20712A. Affinity state of beta-AR was assessed by competition with isoproterenol. Noradrenaline plasma level was assayed by HPLC. Left ventricular mass (LV mass) was measured by echocardiography. Results are expressed as mean +/- SE. All comparisons were performed using a variance analysis (*: p < 0.05).

RESULTS

Systolic blood pressure was significantly higher in obesses (245 +/- 8 vs 197 +/- 10 mmHg in controls). Diastolic blood pressure did not differed between both groups (93 +/- 3 vs 84 +/- 3 mmHg in controls). Noradrenaline plasma levels were similar in both groups (276 +/- 30 vs 235 +/- 50 pg/mL in controls). Obesses were characterized by higher LV mass (80 +/- 24 vs 67 +/- 15 g in controls*). Right auricular and left ventricular beta-AR densities were not different in obesses (57 +/- 6 and 67 +/- 4 fmoles/mg protein) and in controls (68 +/- 7 and 63 +/- 9 fmoles/mg protein). The beta 1-AR proportion was the same in obesses and controls in right auricule (63 +/- 4 vs 64 +/- 3% in controls) and left ventricule (59 +/- 3 vs 60 +/- 4% in controls). The proportion of beta-AR receptors in a high affinity state was similar in right auricular samples (69 +/- 4 vs 67 +/- 3%) in controls) but was significantly different in left ventricule (28 +/- 6 vs 74 +/- 6%) in controls).

CONCLUSION

Left ventricular beta-adrenoceptors came under a specific desensibilisation independent of plasma noradrenaline levels. This functional decoupling of beta-adrenoceptors may account for the progressive systolic dysfunction of hypertensive cardiomyopathy.

QT interval dispersion as a predictor of arrhythmic events in congestive heart failure. Importance of aetiology

AIMS

Identification of patients with congestive heart failure at risk of sudden death remains problematic and few data are available on the prognostic implications of QT dispersion. We sought to assess the predictive value of QT dispersion for arrhythmic events in heart failure secondary to dilated cardiomyopathy or ischaemic heart disease.

METHODS AND RESULTS

Twelve-lead ECGs calculated for QT dispersion, 24 h Holter ECGs and signal-averaged ECGs were prospectively recorded in 205 heart failure patients in sinus rhythm. The 86 patients with ischaemic heart disease and the 119 with dilated cardiomyopathy were not significantly different as regards NYHA grades (51 vs 49% in grades III-i.v.), cardiothoracic ratio (57 +/- 7 vs 57 +/- 6%) and ejection fraction (28 +/- 8 vs 29 +/- 9%). The mean QT dispersion (66 +/- 29 vs 65 +/- 27 ms), the frequency of non-sustained ventricular tachycardia (37 vs 38%) and ventricular late potentials (41 vs 40%) were not significantly different in patients with ischaemic or dilated cardiomyopathy. QT dispersion was significantly related to other arrhythmogenic markers. During follow-up (24 +/- 16 months), 66 patients died, 22 of them died suddenly and seven presented a spontaneous sustained ventricular tachycardia. In patients with dilated cardiomyopathy, in multivariate analysis, only a QT dispersion > 80 ms was an independent predictor of sudden death (RR: 4.9, 95% CI 1.4-16.8, P < 0.02) and arrhythmic events (RR: 4.5, 95% CI 1.5-13.5, P < 0.01). In patients with ischaemic heart disease, no studied parameter was found significantly related to sudden death or arrhythmic events.

CONCLUSIONS

In congestive heart failure, abnormal QT dispersion can identify patients with dilated cardiomyopathy who are at high risk of arrhythmic events.

Nasal nitric oxide concentration is decreased in heart failure patients receiving nitrates

Nitric oxide (NO) is a free radical gas and a short-lived messenger which has many paracrine functions. Direct assessment of NO production is very difficult in vivo. However, the paranasal cavities generate a high amount of NO which diffuses in the nasal cavity where it can be easily measured. Several studies have suggested alterations of the NO production in heart failure. Thus, we assessed nasal NO concentration in normal subjects and in heart failure patients. The nasal NO concentration averaged 227 +/- 10 ppb in the control group (n = 20), and 210 +/- 10, 198 +/- 20 and 159 +/- 54 ppb in New York Heart Association (NYHA) class II (n = 30), III (n = 28) and IV (n = 7) patients, respectively (mean +/- standard error [SE], not significant using analysis of variance [ANOVA]). Nasal NO level was not influenced by age, sex or etiology of the heart failure or by treatment with frusemide, angiotensin-converting enzyme inhibitor or digoxin. However, treatment with NO-releasing drugs (nitrates or molsidomine) significantly decreased the nasal NO level in heart failure patients. A two-way ANOVA revealed that treatment with a NO-releasing drug influenced nasal NO concentration (P = 0.0005), whereas NYHA class did not (P = 0.23), with a trend towards an interaction between the two parameters (P = 0.09): the inhibitory effect of NO-releasing drug on nasal NO concentration was more pronounced in severe heart failure. In an additional group of 12 patients (NYHA class II or III), the nasal NO concentration was 174 +/- 19 ppb during NO-releasing drug treatment and increased to 231 +/- 27 ppb 3 days after withdrawal of the nitrates (P = 0.0007 using paired t-test). Conversely, the nasal NO concentration in another group of seven patients (NYHA class II or III) was 219 +/- 32 ppb without nitrate treatment and decreased to 188 +/- 28 ppb 7 days after nitrate addition (P = 0.02 using paired t-test). In contrast, the nasal NO concentration in another group of ten ischemic patients without heart failure was 203 +/- 25 ppb without nitrate treatment and was similar (207 +/- 28 ppb) 7 days after nitrate addition (not significant using paired t-test). In conclusion, nasal NO production is normal in heart failure, except in patients receiving NO-releasing drugs. Nasal NO concentration could be useful for investigating the mechanism(s) by which exogenous NO donors decrease endogenous NO production.

[Treatment of rhythmic and thromboembolic complications of cardiac failure]

Functional and structural alterations of heart in heart failure result in high risk of arrhythmias and emboli. Detection of high risk patients is based on clinical, electrophysiologic and neuro-hormonal factors. Treatment is disappointing all antiarrhythmic drugs having deleterious effects. Amiodarone and beta-blockers seem useful. Implantable cardiovector-defibrillators may benefit for high risk subjects. For preventing or treating intracardiac thrombi and emboli, antithrombic drugs may be used in large heart dilations, atrial fibrillations, ventricular aneurysms, dilated cardiomyopathies and patients with embolic history.

Prognostic value of ventricular arrhythmias in systemic hypertension

OBJECTIVE

Hypertensive left ventricular hypertrophy is associated with an increased risk of arrhythmias and mortality. However, no clinical study has demonstrated a significant relationship between ventricular arrhythmias and mortality in systemic hypertension.

DESIGN AND METHODS

To evaluate the prognostic value of arrhythmogenic markers, we included, prospectively, 214 hypertensive patients aged (mean+/-SD) 59.1+/-12.8 years, without symptomatic coronary disease, myocardial infarction, systolic dysfunction or electrolyte disturbances. At inclusion, a 12-lead electrocardiogram (ECG) with QT dispersion calculation, a 24 h Holter ECG (204 patients) with Lown classification of ventricular arrhythmias, echocardiography (reliable in 187 patients) and a signal-averaged ECG (125 patients) with ventricular late potentials were recorded.

RESULTS

At baseline, echocardiographic left ventricular hypertrophy was found in 63 patients (33.7%). Non-sustained ventricular tachycardia (Lown class IVb) was recorded in 33 patients (16.2%) and late potentials in 27 patients (21.6%). After a mean follow-up of 42.4+/-26.8 months, all-cause mortality was 11.2% (24 patients); 17 patients died of cardiac causes (7.9%); of these, nine (4.2%) died suddenly. In univariate analysis, age, Lown class IVb and a QT dispersion > 80 ms were significantly related to global, cardiac and sudden death (P < 0.01). The left ventricular mass index was related to cardiac mortality (P= 0.002). In multivariate analysis, only Lown class IVb was an independent predictor of global and cardiac mortality, increasing the risk of global death 2.6-fold (95% confidence interval 1.2-6.0) and cardiac death 3.5-fold (95% confidence interval 1.2-9.7).

CONCLUSION

In hypertensive patients the presence of non-sustained ventricular tachycardia has prognostic value.

Prognostic value of arrhythmogenic markers in systemic hypertension

OBJECTIVE

To evaluate the prognostic value of arrhythmogenic markers in hypertensive patients.

DESIGN

Two hundred and fourteen hypertensive patients without symptomatic coronary disease, systolic dysfunction, electrolyte disturbances or anti-arrhythmic therapy were included. Recordings were made of 12-lead standard ECGs with calculations of QT interval dispersion, 24 h Holter ECGs (204 patients), echocardiography (187 patients) and signal-averaged ECGs (125 patients).

RESULTS

BASELINE DATA

echocardiographic left ventricular hypertrophy was found in 63 patients (33.7%), non-sustained ventricular tachycardia (Lown class IV b) in 33 patients (16.2%), ventricular late potentials in 27 patients (21.6%). Mortality: after a mean follow-up of 42.4 +/- 26.8 months, global mortality was 11.2% (24 patients), cardiac mortality 7.9% (17 patients), sudden death 4.2% (nine patients). Univariate analysis: predictors of global, cardiac and sudden death were age > or = 65 years, ECG strain pattern, Lown class IV b and QT interval dispersion > 80 ms (P < or = 0.01). Left ventricular mass index was closely related to cardiac mortality (P = 0.002). Multivariate analysis: only Lown class IV b was an independent predictor of global (RR 2.6, 95% CI 1.2-6.0) and cardiac mortality (RR 3.5, 95% CI 1.2-9.7).

CONCLUSION

In hypertensive patients, non-sustained ventricular tachycardia has a prognostic value.

[Prognostic value of ventricular arrhythmia in hypertensive patients]

OBJECTIVE

Hypertensive left ventricular hypertrophy (LVH) is associated with increased risk of arrhythmias and mortality. However, no clinical study demonstrated a significant relation between ventricular arrhythmias and mortality in systemic hypertension.

DESIGN AND METHODS

To evaluate the prognostic value of arrhythmogenic markers in systemic hypertension, we included between 1987 and 1993. 214 hypertensive patients, 59.1 +/- 12.8 years old, without symptomatic coronary disease, myocardial infarction, systolic dysfunction, electrolyte disturbances or antiarrhythmic therapy. At inclusion, an ECG, a 24 h Holter ECG (204 patients) with Lown classification of ventricular arrhythmias, an echocardiography (reliable in 187 patients) with left ventricular mass index and ejection fraction calculation, a SAECG (125 patients, enrolled after 1988) with ventricular late potentials (LP) were recorded. QT interval dispersion (QTd) was calculated on 12 leads standard ECG and LVH was appreciated.

RESULTS

At baseline echocardiographic LVH was recorded in 63 patients (33.7%) with normal ejection fraction (75 +/- 7.4%). Non-sustained ventricular tachycardia (Lown IVb) was found in 33 pts (16.2%) and LP in 27 patients (21.6%). After a mean follow up of 42.4 +/- 26.8 months, all-cause mortality was 11.2% (24 patients); 17 patients died of cardiac causes (7.9%); of these 9 patients (4.2%) died suddenly. In univariate analysis, age, strain pattern of LVH, advanced Lown classes and abnormal QT dispersion (> 80 ms) were significantly related to global, cardiac and sudden death (p < or = 0.01). Left ventricular mass index was closely related to cardiac mortality (p = 0.002). LP failed to predict mortality. In multivariate analysis, only Lown class IVb was an independent predictor of global and cardiac mortality, increasing the risk of global death 2.6 fold [1.2-6.0] (CI 95%) and the risk of cardiac death 3.5 fold [1.2-9.7] (CI 95%).

CONCLUSIONS

In hypertensive patients the presence of non-sustained ventricular tachycardia on 24 h Holter has a prognostic value.

[Left ventricular repercussion of obesity-induced arterial hypertension in the dog]

Obesity and hypertension are frequently associated. The aim of our study was to assess the effects of high fat diet on weight, blood pressure and left ventricule in dogs. We studied 6 male Beagle dogs before and after 7 weeks of hypercaloric hyperlipidic diet. Echocardiography was used to measure left ventricular wall thickness, volumes, ejection fraction and mass. Results are expressed as % of variation of initial values. After 20 weeks, dogs presented abdominal obesity with increased body weight (11.9 +/- 2.3 to 15.2 +/- 2 kg; p < 0.03) associated with an increasing of systolic (196.5 +/- 14.6 to 260.1 +/- 17.5 mmHg; p < 0.03), diastolic (76.6 +/- 9 to 110.6 +/- 10.2; p < 0.004) and mean blood pressure (128.8 +/- 7 to 152.7 +/- 7.6 mmHg; p < 0.004). There were non significant changes concerning diastolic thickness of septum and posterior wall. Left ventricular volumes increased in diastole (41.1 +/- 4.5 to 48.9 +/- 10.3 cm3; p < 0.03) and systole (12.2 +/- 1.7 to 14.9 +/- 3.2 cm3; p < 0.03). So, despite any changes in wall thickness, we observed an increased of ventricular mass (67 +/- 15 to 80 +/- 24.3 g; p < 0.03). Ejection fraction remained unchanged.

CONCLUSION

it appears that hight fat diet induces obesity and hypertension in dogs; changes in left ventricule suggest a volodependent hypertension.

[Cardiac insufficiency with normal systolic function. Physiopathology and therapeutic implications]

Heart failure is a very common disease with ageing of the population and represents the leading cause of admission to hospital. The consequences of ageing, the frequency of ischaemic heart disease and hypertension predispose to the development of heart failure. Ageing promotes arterial, aortic and cardiac remodelling, resulting in an increase of cardiac work, myocardial hypertrophy and progressive alteration of ventricular function. The elderly heart has a reduced compliance, and loses its preload reserve and its chronotropic reserve. It adapts poorly to effort, arrhythmias and loss of atrial systole. Heart failure can be atypical with neurological and pulmonary or gastrointestinal signs. Radiological examination, and especially echocardiography, are essential. There is often a very predominant alteration of diastolic function (abnormalities of relaxation and compliance). Treatment is made difficult by the presence of multi-organ disease, which reduces the safety margin of digitalis alkaloids, diuretics and ACE inhibitors. Blood digoxin, creatinine and potassium levels must be regularly monitored. Revascularization techniques should not be abandoned and aortic valve surgery, in particular, gives good results when it is not performed too late. ACE inhibitors and vasodilators are generally well tolerated.

[Cardiac failure and nitrates]

Nitrates remain largely prescribed in heart failure. Their haemodynamic effects, a consequence of venous vasodilatation, have been clearly demonstrated in the acute situation, where they induce a fall in pulmonary pressure and left ventricular end-diastolic pressure, associated, at high doses, with an arterial vasodilator effect. Haemodynamic escape phenomena are observed during chronic administration and the peripheral vasodilator effect, in particular, tends to fade. Although, together with depletion of sulfhydryl radicals, activation of vasoconstrictor neuroendocrine systems, associated with haemodillution, plays an important role in this escape, coprescription of angiotensin converting enzyme inhibitors or diuretics has been shown to be unable to prevent these effects. The effects of nitrates on the exercise capacity remain controversial, although the combination of isosorbide dinitrate-hydralazine induced a significantly greater increase of maximal oxygen consumption than enalapril, together with a more marked increase in the ejection fraction. No trial has assessed the effects on mortality of nitrates, used as the only vasodilator agent, in heart failure, but in studies V-HeFT 1 and 2, the combination of isosorbide dinitrate-hydralazine significantly improved survival, with a 38% reduction of mortality at one year compared to placebo or prazosin groups. However, this reduction remained less than that obtained with enalapril. In the case of contraindication or impossibility of using angiotensin converting enzyme inhibitors, a combination of high doses of nitrates and hydralazine may be justified. On the other hand, when angiotensin converting enzyme inhibitors are already prescribed, nitrates can only be considered to improve symptoms in the case of persistence of dyspnoea. However, due to the hypotension which they can induce, their use should not interfere with the administration of the high doses of angiotensin converting enzyme inhibitor required. The dose of nitrates should then be determined as a function of their efficacy on symptoms and the blood pressure tolerance, while allowing an intervel of at least ten hours in order to attenuate the escape phenomenon.

Lack of haemodynamic effects of nitric oxide on post-capillary pulmonary hypertension induced by acute sino-aortic denervation

1. The aims of the present experiments were to define a new experimental model of pulmonary hypertension induced by a post-capillary mechanism and to assess the haemodynamic effects of nitric oxide on post-capillary pulmonary hypertension. 2. Cardiopulmonary variables of 28 male beagle dogs, anaesthetized with chloralose, 16 spontaneous breathing and 12 with assisted ventilation, were studied before and after sino-aortic denervation (SAD). The haemodynamic effects of inhaled nitric oxide (25 p.p.m., 10 min). N(omega)-nitro-L-arginine methyl ester (20 mg kg-1, i.v.), urapidil (0.5 mg kg-1-, i.v.) and propranolol (300 micrograms kg-1, i.v.) were studied after SAD. 3. SAD induced an acute and transient pulmonary hypertension, more marked in spontaneous breathing dogs. This pulmonary hypertension involved a post-capillary mechanism, secondary to the left ventricular haemodynamic effects of the acute increase of left ventricular after-load induced by systemic hypertension. In fact, the increase of mean pulmonary arterial pressure after SAD and the decrease of this parameter after urapidil or propranolol were strongly correlated with the variations of pulmonary capillary wedge pressure. Furthermore, no significant change in pulmonary vascular resistance was found after SAD or administration of alpha or beta-adrenoceptor antagonists. 4. Inhaled nitric oxide did not reverse pulmonary hypertension induced by SAD. N(omega)-nitro-L-arginine methyl ester had no significant haemodynamic effect of pulmonary circulation. 5. In conclusion, the lack of effect of inhaled nitric oxide and nitric synthase inhibitor on pulmonary circulation parameters SAD suggest that endothelium-derived oxide is not involved in the mechanisms leading to post-capillary pulmonary hypertension.

[Correlation between QT interval dispersion and ventricular arrhythmia in hypertension]

OBJECTIVE

To evaluate the correlation between QT interval dispersion (QTd) and ventricular arrhythmias in hypertensive patients (pts) with or without left ventricular hypertrophy (LVH). A secondary aim was to investigate correlations of QTd with other markers of arrythmogenic propensity: ventricular late potentials (LP) and heart rate variability (HRV).

METHODS

We retrospectively measured the QTd on the 12 standard surface ECG leads in 230 hypertensive pts (94F, 136M; 59.6 +/- 12.7 years old). A 24 hours ECG Holter recording was performed in 218 pts and ventricular arrhythmias were appreciated using the Lown classification. Left ventricular mass was determined by echocardiography (LVM-Devereux formula) and left ventricular mass index (LVMI) were determined in 202 subjects. LP (122 pts) and HRV (55 pts) were investigated.

RESULTS

The QTd varied between 20 and 160 msec (57.8 +/- 32.7 msec). The distribution of pts classified using Lown criteria was: 29 pts (13.3%) class O; 106 pts (48.6%) class I; 8 pts (3.6%) class II; 13 pts (6%) class III; 29 pts (13.3%) class IVa; 33 pts (15.1%) class IVb; 116 pts (69.5%) had LVH determined by echocardiography. The QTd was strongly correlated with the Lown classes (p < 0.0001). The QTd was significantly broader in Lown classes III, IVa and IVb compared to classes O, I and II cumulated (p < 0.002); there was no difference concerning QTd between Lown classes III, IVa and IVb. The QTd was also correlated with the absolute number of premature ventricular depolarizations/24 hours (p = 0.02; r = 0.16). The 75 pts with an increased LVMI had significantly elevated QTd compared to pts without it (p < 0.0001). Qtd was correlated with LVMI (r = 0.37; p < 0.0001). There was no correlation between QTd and the existence of LP (which were correlated with the Lown classes; p < 0.03) and HRV parameters.

CONCLUSION

Elevated QT interval dispersion is associated with more severe ventricular arrhythmias in hypertensive subjects with LVH. The mechanism of an increased inhomogeneity of repolarisation is probably related to the anatomic modifications induced by LVH. No significant correlation between QTd, LP and HRV was observed.

[Angiotensin converting enzyme inhibitors and ischemic heart diseases]

Experimental studies and molecular biological techniques have demonstrated the importance of angiotensin II in ventricular and vascular remodelling and in atherogenesis. Large scale clinical trials analysing the effects of converting enzyme inhibitors on the mortality and morbidity in post-infarction left ventricular dysfunction, have shown beneficial effects of these agents on major events of coronary artery disease. Experimental studies have shown reduction of intimal thickening and of the multiplication and migration of smooth muscle cells and of vascular fibrosis. Converting enzyme inhibitors seem to restore endothelial function by acting as donors of NO and could play a role in the stabilisation of atheromatous plaque, the prevention of platelet aggregation and on the activation of intravascular fibrinolytic systems. Large scale clinical trials (SOLVD and the prevention and treatment arms of SAVE) have also shown a 23% reduction in the risk of reinfarction and a 15% reduction in the risk of unstable angina. The results of ongoing trials in patients with coronary artery disease without cardiac failure are awaited with great impatience.

[Treatment of heart failure]

Heart failure is a disease which involves not only the heart but the entire circulatory system. Progression is directly related to interactions between myocardial disorders and neurohormonal and circulatory phenomena. Advances in treatment have resulted more from the development of vasodilator drugs with neurohormonal effects than from drugs with a direct effect on the myocardium. Diuretics are essential due to their rapid functional effect and the reduction in pressure on the ventricle wall. The effectiveness of digitalics is recognized not only in patients with atrial fibrillation, but also in those in sinus rhythm with ischemic heart disease. Conversion enzyme inhibitors are useful in all stages of heart failure, improving both quality of life and life expectancy as well as limiting myocardial and vascular remodeling and retarding progression of ventricular dysfunction. As current progress in the treatment of heart failure has not greatly reduced mortality, prevention is the major challenge facing all physicians. Treatment of asymptomatic ventricular function is one rational approach.

[Ventricular arrhythmias and arterial hypertension]

Hypertension has two major consequences on the heart: left ventricular hypertrophy and morphological and functional alterations of the coronary macro- and microvessels. These two cardiac modifications are responsible for three types of complications: myocardial ischaemia, left ventricular dysfunction and electrical instability which are involved in the pathogenesis of ventricular arrhythmias in hypertensive patients. The mechanisms of ventricular arrhythmias in hypertension, their incidence and severity, and their therapeutic and clinical implications will be discussed in this review article.

Prognostic value of late potentials in patients with congestive heart failure

To investigate whether detection of ventricular late potentials could provide prognostic information in patients with congestive heart failure with or without bundle branch block, we prospectively obtained a signal-averaged ECG from 151 patients with congestive heart failure, using specific criteria in 57 patients with bundle branch block. Late potentials were detected in 49 patients (32.5%); their incidence was not significantly different in patients without (31%; 29 patients) or with bundle branch block (35%; 20 patients). Late potentials were present in 25 of 73 patients (34%) with idiopathic dilated cardiomyopathy, in 20 of 57 patients (35%) with ischaemic cardiomyopathy and in four of 21 patients (19%) with hypertensive heart disease (ns). Age, NYHA class, ejection fraction and use of amiodarone were not statistically different among patients with or without late potentials. In contrast, patients with late potentials had more past episodes of sustained ventricular tachycardia (8.2%; four patients) than those without late potentials (1.9%; two patients). Twenty four hour ambulatory ECGs were obtained in 135 patients (89%). Non-sustained ventricular tachycardia was not correlated with the presence of late potentials found in 45 of 88 patients (51%) without late potentials and in 29 of 47 patients (62%) with late potentials (ns). The mean follow-up was 27 +/- 12 months; 51 patients died, 31 from progressive congestive heart failure and 13 suddenly; seven prospectively had sustained ventricular tachycardia. The total mortality rate, the cardiac mortality rate and sudden death risk were not significantly related to the presence of late potentials; their incidence were respectively 35% (36 patients), 32% (33 patients) and 10% (10 patients) in patients without late potentials and 31% (15 patients), 23% (11 patients) and 6% (three patients) in those without late potentials. The incidence of sustained ventricular tachycardia during follow-up was 2% (two patients) in patients without late potentials and 10% (five patients) in those with late potentials. The incidence of sustained ventricular tachycardia experienced by the patients before the study or seen during follow-up was significantly increased in the presence of late potentials: 18% (nine patients) vs 2% (two patients) in the absence of late potentials (P < 0.001). Removal from the study of data from patients with bundle branch block, patients with severe congestive heart failure (NYHA 3 or 4) or patients taking amiodarone did not alter these results. Thus, signal-averaged ECG results only improved risk stratification for sustained ventricular tachycardia in patients with congestive heart failure and failed to identify patients at high risk for sudden death.

[Coronary artery disease in octogenarians: contribution of coronary angiography and evaluation of therapeutic possibilities]

An increasing number of octogenarians is being referred for coronary angiography with a view to myocardial revascularisation. Based on a retrospective study of 168 octogenarians undergoing coronary angiography between January 1987 and December 1992, the authors reviewed the indications, the risks and therapeutic decisions taken in those patients with significant coronary artery disease. The population studied had acute myocardial ischaemia in 88.7% of cases, a low incidence of previous myocardial infarction and severe extracardiac pathology. Significant coronary lesions were observed in 90% of patients (151) with multiple vessel diseases in 57.8% of cases. The mortality attributed to coronary angioplasty was 0.59% (1 case) and the morbidity was 4.7%. The number of disease vessels did not influence the decision as 75.5% of single vessel, 75% of double vessel and 77.3% of triple vessel disease patients were referred for coronary surgery or angioplasty. Of the patients undergoing a revascularisation procedure (n = 108), those referred for surgery (n = 22) had more severe coronary disease than those referred for angioplasty (p < 0.05). The hospital mortality was high about 8%, irrespective of the therapeutic decision. The 3 year actuarial survival was 70% in the group undergoing myocardial revascularisation (whether by angioplasty or coronary surgery) and 53.6% in subjects treated medically. These results show that coronary angiography in a selected elderly population is possible although the mortality and morbidity should not be underestimated. A high proportion of these patients (72%) is referred for myocardial revascularisation.

[Atrial insertion of accessory pathways in permanent reciprocating junctional tachycardia]

Permanent reciprocating junctional tachycardia (PRJT) is an uncommon type of Tachycardia, usually associated with a retrogradely conducting accessory pathway situated near to the ostium of the coronary sinus. This study reports the localisation of the site of atrial insertion of the accessory pathway, confirmed by the efficacy of intracardiac catheter ablation. Five patients (4 men), aged 14 to 45, experienced PRTJT at rates of 120 to 150/mn over a period of 2 to 15 years. 4 patients were normal, expected in 2 patients in whom they were 16 and 20%. One of these suffered a thromboembolic complication after pharmacological interruption of the tachycardia. The presence of an accessory pathway with decremential retrograde conduction was confirmed in all cases. Catheter ablation was successful in the medio-septal (2 cases), posteroseptal (1 case), lateral (1 case) and anteroseptal (1 case) regions. Six to 30 applications of 20 to 30 watts of radiofrequency energy were used in the 5 cases. In one case (right lateral accessory pathway), a fulguration procedure was necessary with a cathodic shock of 160 Joules. The AV conduction was preserved and retrograde conduction was normalised in all cases. All patients remained asymptomatic for a period of 10 to 43 months without antiarrhythmic therapy. The ejection fractions of the two patients with left ventricular dysfunction returned to normal. The authors conclude that the accessory pathways of PRJT may be situated in different regions of the right atrium. The efficacy of catheter ablation was 100 % in this form of tachycardia.

[Absence of the effect of nitric oxide on pulmonary and systemic hypertension induced by sino-aortic denervation]

Inhaled nitric oxide, a selective pulmonary vasodilator, reverses hypoxic pulmonary vasoconstriction and is an effective treatment in some cases of human pulmonary hypertension. Localization of nitric oxide synthase had indicated a neural role for nitric oxide. Thus, we studied the interactions between inhaled nitric oxide and systemic and pulmonary vascular reactivity in acute neurogenic hypertension. In 6 male beagle dogs (mean weight: 15 +/- 1 kg), anesthetized by chloralose (8 cg/kg) and in spontaneous ventilation, the hemodynamic effects on systemic and pulmonary circulation of inhaled nitric oxide (12 ppm) were studied before and after acute sino-aortic denervation. The hemodynamic effects of intravenous propranolol (300 micrograms/kg) were studied after denervation. Mean arterial pressure (MAP), pulmonary capillary pressure (PCP), mean arterial pulmonary pressure (MAPP), cardiac input (CI) and oxygen venous saturation (SvO2) were measured. [table: see text] Sino-aortic denervation causes an acute and transitory pulmonary hypertension due to a double mechanism: a post-capillary hypertension (increase PCP) secondary to an increase left ventricular post-charge by systemic hypertension and a precapillary hypertension. In fact, vascular pulmonary resistances increase from 1.8 +/- 0.1 to 3.4 +/- 0.8 uW after denervation (p < 0.05). Change in pulmonary vascular reactivity induced by catecholamines is probably involved. Propranolol but not inhaled nitric oxide reverse pulmonary hypertension due to sino-aortic denervation.

[Myocardial infarction in non-menopausal women. Coronary lesions and prognosis]

Between 1977 and 1990, 64 premenopausal women, under 50 years of age (42 +/- 5.6 years), were admitted for typical acute myocardial infarction with pathological Q waves. Twenty one patients had attempted myocardial revascularisation either by intravenous thrombolysis or primary angioplasty (n = 3). All patients underwent coronary angiography with selective left ventriculography during their hospital admission. This group of 64 women was characterised by the association of coronary risk factors (2.8 per patient): smoking (89%), hyperlipidaemia (67%), diabetes (45%) and oral contraception (35%). Coronary angiography showed single vessel occlusion in 86% of patients receiving oral contraception, multiple vessel disease in 36.5% and single or double vessel disease in 31.7% of the other patients. There were 3 deaths during the hospital period (4.6%), 12 cases of left ventricular failure, 2 ventricular aneurysms, 2 operated ischaemic mitral regurgitations and 9 recurrences of pain treated by angioplasty. During follow-up (36.5 +/- 4 months), 22 patients were readmitted to hospital and there were 3 further deaths, 12 cases of persistent cardiac failure, 10 cases of latent ventricular dysfunction and 9 ischaemic reoccurrences treated by angioplasty or surgery. The results in this group of patients suffering from myocardial infarction at an unusually early age for women showed that although the mortality was similar to that observed in men of the same age (9%) there was a very high morbidity and a high risk of cardiac failure. The prognosis of myocardial infarction in women, though better than 10 years ago, should improve with immediate revascularisation, the correction of cardiovascular risk factors and the rapid application of all techniques of modern cardiology.

[Changes in myocardial beta adrenergic receptors in left ventricular hypertrophy caused by barometric and volumetric overloads]

While most prior studies examined late stages of heart failure, we determined initial changes of beta-adrenergic receptors (beta-AR) during left ventricular chronic volume and pressure overload. We investigated right auricular (RA) and left ventricular (LV) beta-AR density (Bmax, fmoles/mg protein) and beta 1-AR percentage in two groups of patients undergoing valve replacement without LV systolic dysfunction (LV ejection fraction > or = 60%), with normal plasma catecholamine levels and echocardiography LV hypertrophy. These results were compared with the values of a control group, composed by 8 patients with mitral stenosis and 5 cardiac transplant donors, and the values of 5 patients undergoing heart transplantation because of end-stage idiopathic dilated cardiomyopathy. These results show that, before alteration of LV systolic function occurs, left ventricular chronic overload induces a selective down-regulation of LV beta 1-AR compensated by an increase in beta 2-AR. These variations may be due to LV hypertrophy induced by volume or pressure overload.

Relationship between arterial blood pressure disturbances and alpha adrenoceptor density

To investigate the influence of blood pressure disturbances on human platelet alpha 2-adrenoceptor density, we studied 7 normotensive Parkinsonians with orthostatic hypotension and 23 mild essential hypertensive patients. Plasma catecholamine levels were measured by HPLC and alpha 2-adrenoceptor number and affinity determined by [3H]-yohimbine binding. Alpha-adrenergic reactivity was investigated by blood pressure response to noradrenaline infusion in Parkinsonians and by adrenaline-induced platelet aggregation in hypertensive patients. In Parkinsonians with orthostatic hypotension, in comparison with Parkinsonians without orthostatic hypotension and normotensive control subjects age and sex matched, noradrenaline plasma levels were significantly lower (62 +/- 11, 195 +/- 14 and 219 +/- 13 pg. ml-1 respectively, p < 0.05), platelet alpha 2-adrenoceptor number was significantly higher (313 +/- 52, 168 +/- 9 and 174 +/- 4 fmol.mg-1 protein respectively, p < 0.05) and the noradrenaline dose required for a 25 mm Hg increase of systolic blood pressure significantly lower (0.19 +/- 0.03, 0.86 +/- 0.11 and 0.68 +/- 0.10 microgram.Kg-1 respectively, p < 0.05). In hypertensive patients, in comparison with normotensive control subjects age and sex matched, plasma noradrenaline levels remained unchanged (306 +/- 68 vs 246 +/- 28 pg.ml-1) whereas both platelet alpha 2-adrenoceptor number (137 +/- 15 vs 177 +/- 15 fmol.mg-1 protein, p < 0.05) and velocity of adrenaline-induced platelet aggregation were significantly decreased. These results indicate that platelet alpha 2-adrenoceptor density is related to blood pressure values. In Parkinsonians with orthostatic hypotension, the up-regulation of alpha 2-adrenoceptors was induced by the decrease of endogenous catecholamines. In contrast, in essential hypertension a down-regulation of alpha 2-adrenoceptors was observed in spite of no significant increase of catecholamine levels. These results suggest that only sustained abnormal plasma noradrenaline levels could allow the development of alpha 2-adrenoceptor regulatory mechanisms.

[Inferior wall myocardial infarction and atrioventricular block; angiography and prognosis]

This study was based on 42 cases of 2nd or 3rd degree atrioventricular block out of 292 cases of inferior wall myocardial infarction. The criteria of selection were monitoring in the intensive care unit during the acute phase, selective coronary angiography in the first 48 hours to 5 days, and regular clinical follow-up during the first year after infarction. The conduction defect was either immediately recorded on the first ECG, delayed (between the 12th and 24th hour) or late (after the 3rd day). These 42 inferior wall infarcts with atrioventricular block (incomplete in 14 and complete in 28 cases) differed from inferior infarction without block by: - the severity of the clinical signs during the acute phase (35% with cardiac failure, 19% with cardiogenic shock); - the severity of the coronary lesions (71.4% with triple vessel disease in infarction with atrioventricular block compared with 32% in those without block, p < 0.02); - the prevalence of the association of > 70% stenosis of the right coronary and left anterior descending arteries; - the alteration of left ventricular function (53% patients with atrioventricular block had ejection fraction of under 30%); - the severity of these infarcts was not related to the atrioventricular block which regressed in 95% of cases but to the severity of the coronary disease, the left ventricular dysfunction and the advanced age of the patients (72.3 +/- 8 years).

Cardiac beta-adrenoceptors and adenylyl cyclase activity in human left ventricular hypertrophy due to pressure overload

The effect of left ventricular hypertrophy (LVH) due to chronic pressure overload on right atrial (RA) and left ventricular (LV) myocardial beta-adrenergic receptor (beta-AR) density and subtypes, adenylyl cyclase (AC) activity and ADP-pertussis toxin ribosylated proteins was investigated in humans with LVH due to aortic stenosis and in patients without LVH undergoing heart surgery for mitral stenosis or coronary artery disease taken as controls. Both groups presented normal systolic function or plasma catecholamine levels. In LVH and controls, beta-AR density was similar in RA (62 +/- 6 vs 77 +/- 12 fmol.mg-1 protein) and LV (39 +/- 7 vs 32 +/- 2 fmol.mg-1 protein). In LVH, beta 1-AR percentage was < than in controls in LV (35 +/- 11 vs 73 +/- 5%, P < 0.05) but not in RA (79 +/- 5 vs 73 +/- 8%). Basal AC activity in RA (19 +/- 4 vs 21 +/- 6 pmol.mg-1 protein) and LV (22 +/- 5 vs 27 +/- 3 pmol.mg-1 protein) was similar in LVH and in controls. Isoprenaline-induced stimulation of AC in RA was similar in LVH and in controls (51 +/- 18 vs 36 +/- 18%) but < in LV of LVH (7 +/- 6 vs 45 +/- 6%, P < 0.05). In the presence of ICI-118,551 (a beta 2-adrenoceptor antagonist), isoprenaline failed to induce any increase in cAMP in LVH. The quantification of ADP-pertussis toxin ribosylated proteins indicated a lower concentration of substrates in LV myocardial membranes from LVH. These data indicate that in LVH due to pressure overload, there is a down-regulation of beta 1-AR and an increase in beta 2-AR density. This is associated with alterations of the transmembrane signalling marked by a decreased capacity of isoprenaline to stimulate AC and an impaired expression of Gi proteins.

[Prognosis of silent myocardial ischemia]

Asymptomatic or silent myocardial ischemia (SI) is frequent in coronary heart disease and its prognostic value is controversial. The aim of our study is to compare coronary atherosclerosis, left ventricular function and clinical out come of 110 patients with S.I. (A group) and 210 patients with stable angina (B group). The 320 patients were submitted: to symptom limited exercise stress-test with permanent electrocardiographic control by a Case 12-15 digitalized system with ST segment depression interpretation. A test was considered positive for ischemia if there was ST depression of > 1 mv in magnitude from baseline, persisting for 0.08 sec or exercise angina and ischemia: to selective coronarography by Seldinger technic, with left ventricular cineangiography in 2 incidences. A significant coronary stenosis was defined as > 50% reduction of luminal diameter; to medical treatment with betablockers (87.5% of patients), calcium inhibitors (12.5%), aspirin (90%) and nitrates; to regular medical surveillance. During the follow-up (42.4 +/- 5 months in mean) the number of deaths, myocardial infarctions, heart failure, unstable angina and revascularizations were analyzed. Patients of A group with S.I. had a high percentage of risks factors (diabetes mellitus 55%, nicotinism 85%, dyslipidemia 22.5%) and history of previous myocardial infarction in 33% of cases. There are not significant differences between severity and extension of coronary disease, or ventricular dysfunction in patients of A group or B. The percentages of deaths (2.10 versus 3%), acute myocardial infarctions (9.5 versus 8.5%), heart failures (2.72 versus 3%), surgical indications (14.7 versus 15.7%) are not significantly different between the 2 groups. In A group, 34% of patients were treated by angioplasty versus 40% of patients in group B (p < 0.02). S.I. has a bad prognostic and the clinical out come of coronary heart disease is not dependent of presence of angina during exercise testing and daily activities.

Efficacy and acceptability of perindopril in mild to moderate chronic congestive heart failure

The aim of this 3-month double-blind, placebo-controlled, multicenter trial was to evaluate the clinical efficacy and safety of perindopril, a new long-acting angiotensin-converting enzyme inhibitor in the second-line treatment of mild to moderate chronic congestive heart failure. After a run-in period of at least 14 days, 125 patients with grade II or III New York Heart Association chronic congestive heart failure on baseline diuretic therapy were randomized to perindopril, 2 mg (n = 61), or placebo (n = 64), once daily. Assessment was at 2-week intervals for the first month and then monthly for the 2 following months. After 2 weeks, active treatment was increased to perindopril, 4 mg once daily, if systolic blood pressure was 100 mm Hg or greater. Apart from sex, the two groups were homogeneous before treatment. As shown by the end-point analysis, the increase in exercise time was greater with perindopril than with placebo for both the ergometric bicycle (+111 +/- 21 versus +16 +/- 20 seconds; p = 0.002) and the treadmill (+171 +/- 39 versus +36 +/- 42 seconds; p = 0.024). Compared with placebo, this increase in exercise tolerance with perindopril was accompanied by an improvement in New York Heart Association functional class (p = 0.009), overall heart failure severity score (p < 0.001), and cardiothoracic ratio (p = 0.05). Of the 12 withdrawals from the study, seven were attributed to adverse events, two in the perindopril group and five, including one death, in the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

[Beta-adrenergic receptivity and left ventricular hypertrophy caused by pressure overload in man]

The effect of left ventricular chronic pressure overload on right atrial (RA) and left ventricular (LV) myocardial beta-adrenoceptor (beta-AR) density and subtypes ([I125] cyanopindolol binding), adenylate cyclase activity (AC) and ADP-pertussis toxin ribosylated proteins was investigated in 13 patients with aortic stenosis (AO) and compared with the results obtained in 10 patients with mitral stenosis (MI) taken as controls. None of the patients included had any impairement of systolic function or increased plasma catecholamine levels. The total number of beta-AR in RA (62 +/- 6 vs 77 +/- 12 fmoles/mg prot) and LV (39 +/- 7 vs 32 +/- 2 fmoles/mg prot) was similar in AO and in MI. The percentage of beta 1-AR was significantly lower in LV from AO (35 +/- 11 vs 73 +/- 5% in MI) but identical in RA (79 +/- 5 vs 73 +/- 8%). The basal activity of AC was similar in membranes from patients with AO (19 +/- 4 and 22 +/- 5 pmol.mg-1 prot in RA and LV) and in controls (21 +/- 6 and 27 +/- 3 pmol.mg-1 prot in RA and LV). Isoprenaline-induced stimulation of AC was significantly lower in LV membranes from patients with AO (7 +/- 6 vs 45 +/- 6% in MI) but remained identical in RA membranes (51 +/- 18 vs 36 +/- 18% in MI). The quantification of ADP-pertussis toxin ribosylated proteins indicated a lower substrate concentration in myocardial membranes from patients with AO when compared with controls.(ABSTRACT TRUNCATED AT 250 WORDS)

[Action of converting enzyme inhibitors on myocardial ischemia and reperfusion injuries]

During myocardial ischaemia, either in chronic coronary insufficiency or the acute phase of myocardial infarction, the renin-angiotensin system is activated which, by its deleterious cardiac effects, aggravates the ischaemia. Angiotensin Converting Enzyme (ACE) inhibitors, by their indirect effects (improved conditions of left ventricular load, negative inotropism, attenuation of catecholaminergic stimulation), reduce myocardial oxygen consumption, and by their direct coronary vasodilator effect reduce myocardial ischaemia. In addition, by attenuating the formation of oxygen-free radicals, by participating in the inactivation of some of them and protecting the lysosomal membranes, they combat reperfusion injury. In the animal model of acute myocardial infarction, they reduce myocardial infarct size and the prevalence of reperfusion arrhythmias. In the clinical situation, their effects on the ischemic response to effort in anginal patients remain controversial, appear to be more marked in abnormalities of the coronary micro-circulation especially in syndrome X and in hypertensive heart disease. In ischemic heart disease, long-term treatment may be beneficial by their trophic coronary and myocardial effects and two large scale trials report a decrease in the recurrence of myocardial infarction with ACE inhibitors. In the acute phase of myocardial infarction if their possible actions on reducing the infarct size and reperfusion arrhythmias require further confirmation, they do limit expansion of the infarct and decrease early left ventricular dilatation. However, the appreciation of tolerance is variable and the timing of their introduction remains controversial.