Recovery of global systolic function after primary angioplasty. Influence of coronary flow velocity reserve measured by transthoracic echocardiography.

BACKGROUND: Our objective were to know whether coronary flow velocity reserve measured by transthoracic Doppler echocardiography, as marker of microvascular integrity, affects the recovery of global systolic function. Secondly, we intended to define the best cut-off point of coronary flow velocity reserve to predict recovery of global systolic function. METHODS: We studied 57 patients with coronary flow recorded by transthoracic Doppler echocardiography, after suffering a first anterior acute myocardial infarction and undergoing a successful primary percutaneous coronary intervention (TIMI 3 flow). We measured, at discharge and at 1 month: ejection fraction, volume indexes and anterior wall motion score index. Coronary flow in left anterior descending artery was detected by transthoracic Doppler echocardiography and coronary flow velocity reserve was calculated. RESULTS: After applying ROC curves, 1.54 was the best cut-off value of coronary flow velocity reserve for detection of recovery of global systolic function. Ejection fraction only increased significantly in patients with normal coronary flow velocity reserve. Only end-systolic volume index increased significantly at 1 month in patients with impaired coronary flow velocity reserve. CONCLUSION: We showed that coronary flow velocity reserve, measured by transthoracic Doppler echocardiography, influence the recovery of global systolic function, mainly by ventricular dilation. Furthermore, a quite lower value of coronary flow velocity reserve than that used for diagnostic purpose should be used to predict improvement of systolic function.

The exercise test that indicates a low risk of events. Differences in prognostic significance between patients with chronic stable angina and patients with unstable angina.

OBJECTIVES: The objective of this prospective study was to determine the differences in the prognostic significance of an exercise test (ET) that indicates a low risk of events (low-risk exercise test [LRET]) between patients with unstable angina (UA) and those with chronic stable angina (CSA). BACKGROUND: It is not known whether the prognostic significance of an LRET is influenced by the disease; that is the reason for performing exercise testing. METHODS: All patients not presenting with high-risk criteria were submitted to a prognostic ET. The ET was performed by patients with CSA and patients with primary UA stabilized with medical therapy. Medical therapy was planned for all patients. A combined end point was defined as cardiac death, nonfatal acute myocardial infarction or hospital admission for UA. Multivariate analysis was performed to determine the independent predictors of events. RESULTS: Low-risk criteria were fulfilled by 105 patients with UA and 86 patients with CSA. The mean follow-up time was 347 +/- 229 days. The event rate was higher in the UA group than in the CSA group (28% vs. 9%, p = 0.001). The CSA group showed worse ET results. Performance of ET by patients with UA was the principal predictor of events (odds ratio 4.2, p = 0.0005). CONCLUSIONS: Among patients who underwent an LRET, those with UA had a rate of events significantly higher than that of patients with CSA, despite the worse results of ET in patients with CSA.

Effects of early use of atenolol or captopril on infarct size and ventricular volume: A double-blind comparison in patients with anterior acute myocardial infarction.

BACKGROUND: beta-Blockers and ACE inhibitors reduce early mortality when either one is started in the first hours after myocardial infarction (MI). Considering the close correlation between morphological changes and prognosis, we aimed to investigate whether the benefit of both beta-blockers and ACE inhibitors might reside in a similar protective effect on infarct size or ventricular volume. METHODS AND RESULTS: In a randomized, double-blind comparison between early treatment with captopril or atenolol in 121 patients with acute anterior MI, both drugs showed a similar reduction in mean blood pressure. However, only the atenolol-treated patients showed a significant early reduction in heart rate. Infarct size, obtained from the perfusion defect in resting single photon emission imaging, was higher in captopril-treated patients than in atenolol-treated patients: 29.8+/-12% versus 20.8+/-12% (P:<0.01) by polar map and 28.3+/-13% versus 20.0+/-13% (P:<0.01) by tomography. Changes from baseline to 1 week and to 3 months in ventricular end-diastolic volume, assessed by echocardiography, were as follows: 58+/-14 versus 64+/-19 (P<0.05) and 65+/-21 mL/m(2) (P<0.05), respectively, with captopril, and 58+/-18 versus 64+/-18 (P<0.05) and 69+/-30 mL/m(2) (P<0.05), respectively, with atenolol. Neither group showed significant changes in end-systolic volume. Among patients with perfusion defect >18% (n=51), those treated with atenolol showed a significant increase of end-systolic and end-diastolic ventricular volumes, whereas captopril-treated patients did not. CONCLUSIONS: Although early treatment with atenolol or captopril results in similar overall short- and medium-term preservation of ventricular function and volumes, in patients with larger infarctions, a beta-blocker alone does not adequately protect myocardium from ventricular dilatation.

[Role of adenosine triphosphate (ATP) in head-up tilt-induced syncope]. / Papel del adenosín trifosfato (ATP) en la inducción de síncope mediante test de basculación.

INTRODUCTION AND OBJECTIVES: Recent studies have demonstrated that adenosine is an endogenous modulator of the cardiac excitatory afferent nerves, and could provoke a vasovagal response during head-up tilt test. Isoproterenol has been the drug of choice to increase the sensitivity of this testing. The aim of the present study was to analyze the role of adenosine in head-up tilt-induced syncope in susceptible patients, and to compare the relative sensitivities of adenosine and isoproterenol. METHODS: Thirty patients with unexplained syncope (16 female and 14 male, mean age 37.1 +/- 18 years), no heart disease and negative baseline head-up tilt test were studied. After the baseline test, patients were randomized to receive adenosine triphosphate (bolus injections of 3, 6 and 9 mg/ 5 min) or isoproterenol (bolus injections of 2, 4 and 6 micrograms/5 min) and underwent a second tilt test. After 15 min at rest, patients received the alternative drug and a third test was performed. Eleven normal control subjects were tested with adenosine in the upright position to determine its effects. RESULTS: A vasovagal response was induced in 7 patients (23.3%) after ATP administration. Nine patients (30%) showed a positive response with isoproterenol. Only 2 patients (6.6%) showed a positive response with both drugs. Of the control subjects, one (9%) had a vasovagal response after ATP administration. CONCLUSIONS: We conclude that adenosine triphosphate seems to be a useful tool to provoke vasovagal reaction in susceptible patients during head-up tilt test.

[Long-term prognosis of patients with syncope of unknown origin in prolonged asystole induced by the head-up tilt test]. / Pronóstico a largo plazo de pacientes con síncope de origen desconocido y asistolia prolongada inducida mediante test de basculación.

INTRODUCTION AND OBJECTIVES: Prognosis and therapeutic assessment of patients with syncope and prolonged asystole during head-up tilt test remain unclear. The aim of the present study was to analyze the clinical evolution of patients with syncope of unknown origin, no heart disease and severe cardioinhibitory response induced by head-up tilt. METHODS: A prospective follow-up study was performed in 12 patients (6 male and 6 female, mean age 31 +/- 20 years) with recurrent syncope, no heart disease and affected by severe cardioinhibitory syncope induced by head-up tilt test. This was defined as syncope or near-syncope induced by baseline or isoproterenol tilt with asystole of > or = 3 seconds. All patients were re-tilted twice: with salt and fluid and with metoprolol (25 mg/b.i.d). According to the results of these tests, 5 patients were discharged with dietetic measures (salt & fluid) and 5 with metoprolol. In 2 patients who showed recurrent prolonged asystole a DDD pacemaker was implanted. RESULTS: After follow-up of 34 +/- 20 months all patients ae alive. The number of recurrences was small (2 syncopes and 2 near-syncopes). No relationship was observed between the number of syncopal recurrences and the applied treatment. CONCLUSIONS: We conclude that prolonged asystole induced by head-up tilt test does not confer an adverse prognosis in patients with syncope of unknown origin and no heart disease, thus, the clinical evolution of these patients is benign.

[Use of transdermal scopolamine in the prevention of neuro-cardiogenic syncope induced by the tilt test]. / Uso de la escopolamina transdérmica en la prevención del síncope neurocardiogénico inducido mediante test de basculación.

INTRODUCTION AND OBJECTIVES: The underlying mechanism of syncope induced by head-up tilt test is still incompletely understood. It has been proposed a sudden increase in parasympathetic's activity induced by the excessive activation of the cardiac mechanoreceptors. The aim of our study was to evaluate the clinical, electrocardiographic and hemodynamic responses to head-up tilt test before and after treatment with transdermal Scopolamine (anticholinergic agent). METHODS: We studied 17 patients (8 females, 9 males; mean age 43 +/- 19 years) with > or = 2 syncopal episodes of unknown origin and a positive tilt test (a positive response to tilt testing alone or in conjunction with an infusion of isoproterenol was defined as the appearance of syncope or presyncope associated to hypotension and/or bradycardia). Symptoms developed in 12 patients during the baseline tilt (Group I) and in 5 patients after infusion of isoproterenol (Group II). Mean time to symptoms was 8.5 +/- 7.9 minutes in group I. All patients were them treated with transdermal Scopolamine (1.5 mg/24 hours) and 48 hours later tilt test was repeated. RESULTS: In group I, 8 patients (66.6%) became tilt test negative and in the remaining 4 patients mean time before the appearance of symptoms was increased (8.5 +/- 7.9 vs 16.2 +/- 2.5 minutes; p < 0.05). In group II, 3 patients (60%) became tilt test negative and in the remaining 2 patients symptoms developed after an infusion of higher doses of isoproterenol than in the first study. So, with transdermal scopolamine 11 out of 17 patients became tilt test negative and time to symptoms was increased in all of the remaining 6 patients. CONCLUSIONS: Our study suggest that transdermal scopolamine is an usefull treatment in the prevention of neuro-cardiogenic syncope induced by head-up tilt test.

[Evaluation of a combination of a diuretic and nifedipine retard for the treatment of hypertensive patients refractory to nifedipine retard]. / Evaluación de la asociación de un diurético a nifedipina retard como terapia en pacientes hipertensos refractarios a nifedipina retard.

This study assessed the effectivity of the association between a diuretic, chlorthalidone, and retard nifedipine in the treatment of patients above 50 years of age with Arterial Hypertension refractory to retard nifedipine. A prospective study of a 3-month controlled intervention was designed, in which the patients were treated with retard nifedipine for 2 months and, if they did not respond to the treatment, chlorthalidone was associated for 1 month. Out of 235 patients selected at the beginning of the study, 28 dropped out voluntarily, 24 were excluded because they did not adhere to the protocol and 30 dropped out due to side effects. After the first two months of therapy, hypertension was controlled in 60.2% of the 181 patients, whereas in the third month, only in 20% of the 44 patients considered could be controlled. Significant differences were observed between the two treatments (p < 0.001) with a 95% CI in the percentage differences of 54% versus 26.4%. These results suggest that the association of chlorthalidone and retard nifedipine does not improve the treatment of Arterial Hypertension refractory to retard nifedipine.