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Biomedical subjects

V Valle

Publications and source records attributed to V Valle.

At least 19 recordsLinked to original sources
PubMed1999

Usefulness of hospital admission risk stratification for predicting nonfatal acute myocardial infarction or death six months later in unstable angina pectoris. RESCATE Study Group. Resources Used in Acute Coronary Syndromes and Delays in Treatment.

The aim of this study was to assess the clinical course of unstable angina and the prognostic value of clinical and electrocardiographic variables measured during admission in a prospective, multicenter cohort study with 6-month follow-up. The population corresponds to 4 general teaching hospitals in Catalonia, Spain. The clinical course was analyzed in 839 consecutive patients aged up to 80 years with primary unstable angina, without myocardial infarction or previous coronary bypass. The main outcome measures were cardiac mortality and nonfatal myocardial infarction. Patients involved in the present analysis belonged to the Resources Used in Acute Coronary Syndromes and Delays in Treatment (RESCATE) study. Six-month overall mortality, cardiac mortality, and nonfatal myocardial infarction rates were 4.6%, 4.1%, and 3.9%, respectively. Six-month cardiac mortality or myocardial infarction rate did not differ among clinical forms of presentation. Peripheral artery disease (RR 3.5, 95% confidence interval [CI] 1.88 to 6.50, p = 0.0001), ST-T-wave electrocardiographic changes on admission (RR 2.22, 95% CI 1.13 to 4.36, p = 0.0203), and age >65 years (RR 1.74, 95% CI 1.04 to 2.91, p = 0.0356) independently predicted 6-month cardiac mortality or nonfatal myocardial infarction. Their positive predictive values were 21%, 10%, and 11%, respectively, whereas their negative predictive value was > or = 93% in all cases. Prevalences were 9%, 70%, and 41%, respectively. In this prospective study, patients with unstable angina without prior myocardial infarction have a relatively low, although not negligible, 6-month severe complication rate. Stratification risk can easily be established with clinical and electrocardiographic characteristics measured during admission. Their absence almost rules out future adverse events, while their presence does not necessarily imply bad prognosis.

Adult↗
PubMed1999

Six-month outcome in unstable angina patients without previous myocardial infarction according to the use of tertiary cardiologic resources. RESCATE Investigators. Recursos Empleados en el Síndrome Coronario Agudo y Tiempos de Espera.

OBJECTIVES: The study assessed whether varying accessibility of patients with unstable angina (UA) to coronary angiography and revascularization determined differing usages and outcomes. BACKGROUND: The appropriate use rate of coronary angiography and revascularization procedures in UA remains to be established. METHODS: A total of 791 consecutive patients with UA without previous acute myocardial infarction (AMI) admitted to four reference teaching hospitals (one with tertiary facilities) were followed for six months. End points were six-month mortality and readmission for AMI, UA, heart failure, or severe ventricular arrhythmias. RESULTS: Patients admitted to the tertiary hospital were 3.27 (95% confidence interval [CI] 2.32 to 4.62) times more likely to undergo coronary angiography after adjustment for comorbidity and severity than were those admitted to nontertiary facilities (overall six-month use rates 70.1% and 48.3%, respectively). Revascularization procedures were performed in 36.2% of patients in the tertiary hospital and 24.6% in the others (p = 0.0007); adjusted relative risk (RR) 2.37 (95% CI 1.55 to 3.63). Median delay for urgent coronary angiography was shorter in the tertiary hospital (24 h vs. 4 days, p < 0.0002). Six-month mortality and readmission rates were similar in tertiary and nontertiary hospitals: 3.9% versus 5.3% and 16.9% versus 21.2%, respectively. Adjusted RR of death or readmission for the nontertiary hospitals was 1.23 (95% CI 0.57 to 2.67). CONCLUSIONS: The use of coronary angiography and revascularization procedures in UA patients with no previous AMI is higher in tertiary than in nontertiary hospitals, but the more selective use of these procedures in nontertiary centers does not imply worse outcome.

Aged↗
PubMed1998

Mortality differences between men and women following first myocardial infarction. RESCATE Investigators. Recursos Empleados en el Síndrome Coronario Agudo y Tiempo de Espera.

CONTEXT: Mortality after acute myocardial infarction is worse in women than in men, even after adjustment for comorbidity and age dissimilarities between sexes. OBJECTIVE: To assess the influence of sex on survival after acute myocardial infarction. DESIGN: Inception cohort obtained in a prospective registry of patients with acute myocardial infarction from 1992 through 1994. SETTING: Four teaching hospitals in northeastern Spain. PATIENTS: All consecutive patients aged 80 years or younger with first acute myocardial infarction. A total of 331 women and 1129 men were included. MAIN OUTCOME MEASURE: Survival at 28 days and mortality or readmission at 6 months. RESULTS: Women were older (mean, 68.6 vs 60.1 years), presented more often with diabetes (52.9% vs 23.3%), hypertension (63.9% vs 42.3%), or previous angina (44.6% vs 37.4%), and developed more severe myocardial infarctions than men (acute pulmonary edema or cardiogenic shock occurred in 24.8% of women and 10.5% of men) (all P<.02). Men were more likely than women to receive thrombolytic therapy (41.3% vs 23.9%; P<.001), but rates of percutaneous transluminal angioplasty and coronary artery bypass graft surgery at 28 days were similar among men and women. The 28-day mortality rate was significantly higher among women (18.5% for women, 8.3% for men; P<.001). Revascularization procedures at 6 months were performed in a similar proportion of women and men. However, women had higher 6-month mortality rates (25.8% in women, 10.8% in men; P<.001) and readmission rates (23.3% for women, 12.2% for men; P<.001). After adjustment, women had greater risk of death than men at 28 days (odds ratio [OR], 1.72; 95% confidence interval [CI], 1.12-2.65) and at 6 months (OR, 1.73; 95% CI, 1.18-2.52). CONCLUSIONS: In this study population, women experienced more lethal and severe first acute myocardial infarction than men, regardless of comorbidity, age, or previous angina.

Aged↗
PubMed1998

[Obtaining myo-cardial perfusion images synchronized with the ECG (gated-SPEC) after injecting MIBI during exertion: comparative study with echocardiography in 95 patients for the assessment of left ventricular function].

Technical innovation has recently resulted in the routine use of gated-SPECT in myocardial perfusion imaging. In the present work we compare estimates of left ventricular function (LV cavity) by gated-SPECT with those of conventional echocardiography in a group of 95 ischemic patients, 49 of whom had previous myocardial infarction. Kappa analysis showed correlation coefficients of 0.67 for global function in the whole group and of 0.68 in patients with MI, as well as of 0.56 in the anterior wall, and 0.55 in the inferior wall. With these data, we believe that the technique is useful and it adds to the conventional perfusion SPECT imaging. Also, it is conveniently validated against echocardiography in our hands.

Adult↗
PubMed1997

Six-month outcome in patients with myocardial infarction initially admitted to tertiary and nontertiary hospitals. RESCATE Investigators. Recursos Empleados en el Síndrome Coronario Agudo y Tiempos de Espera.

OBJECTIVES: The aim of the present study was to ascertain whether the degree of accessibility to coronary angiography and revascularization results in differing usages or outcomes, or both, in the setting of a high coverage national health system. BACKGROUND: The selective use of coronary angiography and revascularization procedures in the management of acute myocardial infarction (MI) remains controversial. METHODS: A cohort of 1,460 consecutive patients with a first MI admitted to four referral teaching hospitals (one with tertiary facilities) were followed up for 6 months after admission. Only patients initially admitted to each of the study hospitals were retained for analysis in the original hospital's cohort. End points were 6-month mortality and readmission for reinfarction, unstable angina, heart failure or severe ventricular arrhythmia. RESULTS: Patients admitted to the tertiary hospital were more likely to undergo coronary angiography (adjusted relative risk 4.22, 95% confidence interval [CI] 3.37 to 5.45) than those admitted to the nontertiary sites (use rate: 22.1% for nontertiary care, 55.5% for tertiary care). Revascularization procedures were performed in 21.2% of patients in the tertiary hospital and in 8.3% in the nontertiary hospitals (p < 0.0001). Median delay for emergency coronary angiography was shorter in the tertiary hospital (within 1 vs. 2 days, p < 0.0001). Six-month mortality or readmission rates were similar (23.7% and 24.7% for tertiary and nontertiary care, respectively). After adjustment for comorbidity and disease severity, the relative risk of death or readmission for the tertiary hospital was 1.03 (95% CI 0.69 to 1.53) times that of the nontertiary hospitals. CONCLUSIONS: Selective use of coronary angiography and revascularization procedures may be as effective as less restricted use in the management of acute MI.

Aged↗
PubMed1994

A crystal structure with features of an antiparallel alpha-pleated sheet.

A single-crystal x-ray diffraction analysis of Boc-L-Ala-D-aIle-L-Ile-OMe has been carried out. The analysis has shown (a) that the tripeptide molecules have in part an alpha-extended conformation, the torsion angles of the L-Ala and D-aIle residues being psi 1 = -75.1 degrees and psi 1 = -25.8 degrees and psi 2 = 67.3 degrees and psi 2 = 44.1 degrees, respectively, and (b) that the molecules are organized in rippled planes where they occur in relative antiparallel orientation linked together side by side by H bonds. This molecular organization of the tripeptide corresponds closely to that of an antiparallel alpha-pleated sheet, and likely constitutes the first example of a structure of this kind for which a characterization at the atomic level has been achieved. A molecular dynamics study has shown that the molecular conformation of the tripeptide in the crystalline state is determined primarily by intermolecular interactions.

Amino Acid Sequence↗
PubMed1985

Electrophysiologic effects of unilateral right and left stellate ganglion block on the human heart.

To determine the electrophysiologic effects of stellate ganglion (SG) block on the human heart, the two SGs were anesthetized separately, with a 24-hour interval between the two procedures, in 13 patients with episodes of supraventricular tachycardia (six had Kent bundles). Left SG block caused: (1) a lengthening of the AH interval, measured at fixed atrial rates of 10 +/- 12 msec (p less than 0.01); (2) a marked depression of the VA conduction in six of the seven patients with measurable VA interval (in two patients it produced complete VA block); (3) a slowing of 20 to 40 msec of the cycle of an electrically induced reciprocating tachycardia; and (4) failure to modify the QT interval duration. In contrast, right SG block produced asymmetric or opposite changes and prolonged the QT interval (7.6 +/- 8.8 msec, p less than 0.05). Atrial and ventricular refractoriness was not significantly altered by SG block. Retrograde effective refractory period of the Kent bundle changed 20 to 60 msec after unilateral SG blockade. Thus, this study suggests that the human conduction system and the Kent bundles receive an appreciable sympathetic influence from the SG. Like experimental studies, we also found an asymmetric response to unilateral SG block and a dominance, in most of our patients, of the left SG. The influence on myocardial refractoriness was less apparent.

Adult↗
PubMed1984

Shortening of ventriculoatrial conduction in patients with left-sided Kent bundles.

In six patients with electrophysiologic evidence of ventriculoatrial conduction through a left Kent bundle, we documented that programmed right ventricular stimuli falling within an interval of 60 to 160 msec from the end of the T wave propagated to the left atrium (distal coronary sinus unipolar lead) 10 to 20 msec earlier than the basic paced beats. This phenomenon could be reproduced 24 hours later in two patients, and it was abolished by procainamide and amiodarone in one instance. During this interval we were unable to induce reciprocating tachycardia. Our observations outline a new pattern in ventriculoatrial conduction in patients with left-sided Kent bundles. The findings suggest in addition, that (1) supernormal conduction may be responsible for the observed shortening in retrograde conduction and (2) this phenomenon does not facilitate induction of reciprocating tachycardia.

Adult↗
PubMed1984

Effects of intertrial interval, orientation, and adaptation on orientation discrimination measured with a yes-no signal detection paradigm.

Orientation discriminations were measured with a 3.8-cpd sinusoidal grating stimulus and a yes-no signal-detection procedure. Analysis showed that such discriminations are independent of light-adaptation conditions and of intertrial interval over the 2- to 8-sec. range of values explored. However, they are strongly influenced by the orientation where measurements are made (the "oblique effect").

Adaptation, Ocular↗
PubMed1983

Prognostic implications of early spontaneous angina after acute transmural myocardial infarction.

We investigated the clinical, electrocardiographic and hemodynamic features and the prognostic implications of early spontaneous angina in 31 consecutive patients after acute myocardial infarction. Re-elevation of ST segments in the area of infarction occurred during angina and during reinfarction in all but one patient. Depression of ST segments, when present during pain, involved the same leads as in the acute infarction. Blood pressure and double product tended to increase during pain in 23 patients. The magnitude of this change, however, often varied from crisis to crisis and there were no increases in these parameters in one or more attacks in 15 patients. Sublingual nitroglycerin, 1.0 mg, failed to relieve one or all anginal episodes in 17 of the 28 patients in whom it was given. In-hospital mortality rate was 10% (3/31) and always followed reinfarction. In-hospital reinfarction rate was 16% (5/31) and followed a larger number of anginal crises (7.2 +/- 1.3 vs 3.0 +/- 2.1, P less than 0.001) and a higher incidence of transient hypotensive episodes than in the rest of patients (3/5 vs 3/26). Three additional patients died after discharge. Of the remaining 25 patients and during a follow-up of 26 months (16-34) only one developed reinfarction. Early resting angina after a transmural infarction is almost invariably associated with ECG evidence of ischemia in the leads overlying the infarcted zone. The inconsistent changes in blood pressure and heart rate during pain render these hemodynamic changes an unlikely cause of this form of angina. While postinfarction angina did not carry a grave short- or long-term prognosis, patients with recurrent crises demonstrated as high a risk of reinfarction and death as those with spontaneous hypotension.

Angina Pectoris↗
PubMed1981

Right ventricular infarction: relationships between ST segment elevation in V4R and hemodynamic, scintigraphic, and echocardiographic findings in patients with acute inferior myocardial infarction.

The relationship between ST segment elevation on the right precordial lead V4R and the hemodynamic, echocardiographic, and myocardial scintigrapic signs suggestive of right ventricular (RV) infarction was studied in 42 patients with acute inferior myocardial infarction. Twenty-two patients had ST segment elevation in V4R. Among these patients, a significant correlation was demonstrated between V4R ST segment elevation and the hemodynamic (p less than 0.001), scintigraphic (p less than 0.001), and echographic (p less than 0.02) criteria for acute RV infarction. These results support the validity of this new electrocardiographic sign as a practical means in aiding the clinical detection of RV involvement with acute transmural inferior myocardial infarction.

Acute Disease↗
PubMed1980

Reciprocating tachycardia using bilateral anomalous pathways: electrophysiologic and clinical implications.

A patient who had disabling supraventricular tachycardia showed electrophysiologic evidence of coexistent right and left Kent bundles. The supraventricular tachycardia was accelerated by sequential antegrade and retrograde conduction over the right and left Kent bundles, respectively. Spontaneous blocking of the conduction through the right Kent bundle was associated with a slowing of the tachycardia and with the appearance of right bundle branch block (RBBB). Antegrade conduction was through the left bundle branch and was followed by an early retrograde atrial activation through the left Kent bundle, with consequent shortening of the ventriculoatrial (VA) interval. Thus, the coexistence of bilateral Kent bundles can be suspected whenever shortening of the VA interval in external electrocardiographic recordings occurs in the presence of a tachycardia with a RBBB pattern in a patient with right-sided preexcitation. Our data also showed that bilateral accessory pathways may have different electrophysiologic properties and that unequal response to antiarrhythmic drugs may be expected.

Adult↗