Manejo con control de temperatura en los cuidados posparada cardiaca: documento de expertos / Management of temperature control in post-cardiac arrest care: an expert report

Actualmente, el control estricto de temperatura mediante hipotermia inducida (entre 32 y 36 oC) se considera un tratamiento de primera línea en el manejo de pacientes con parada cardiaca recuperada que ingresan en Unidades de Cuidados Intensivos. Su objetivo es disminuir el daño neurológico secundario a anoxia cerebral. Aunque existen múltiples evidencias sobre sus beneficios, el empleo de esta técnica en nuestro país es pobre y todavía existen temas controvertidos como temperatura óptima, velocidad de instauración, duración y proceso de calentamiento. El objetivo de este trabajo es desarrollar la evidencia científica actual y las recomendaciones de las principales guías internacionales. El enfoque de este documento se centra también en aplicación práctica del control estricto de la temperatura en la parada cardiaca recuperada en nuestras Unidades de Cuidados Intensivos Generales o Cardiológicas, principalmente en los métodos de aplicación, protocolos, manejo de las complicaciones y elaboración del pronóstico neurológico. (AU)

Targeted temperature management (TTM) through induced hypothermia (between 32-36 oC) is currently regarded as a first-line treatment during the management of post-cardiac arrest patients admitted to the Intensive Care Unit (ICU). The aim of TTM is to afford neuroprotection and reduce secondary neurological damage caused by anoxia. Despite the large body of evidence on its benefits, the TTM is still little used in Spain. There are controversial issues referred to its implementation, such as the optimal target body temperature, timing, duration and the rewarming process. The present study reviews the best available scientific evidence and the current recommendations contained in the international guidelines. In addition, the study focuses on the practical implementation of TTM in post-cardiac arrest patients in general and cardiological ICUs, with a discussion of the implementation strategies, protocols, management of complications and assessment of the neurological prognosis. (AU)

Management of temperature control in post-cardiac arrest care: an expert report. / Manejo con control de temperatura en los cuidados posparada cardiaca: documento de expertos.

Targeted temperature management (TTM) through induced hypothermia (between 32-36 oC) is currently regarded as a first-line treatment during the management of post-cardiac arrest patients admitted to the Intensive Care Unit (ICU). The aim of TTM is to afford neuroprotection and reduce secondary neurological damage caused by anoxia. Despite the large body of evidence on its benefits, the TTM is still little used in Spain. There are controversial issues referred to its implementation, such as the optimal target body temperature, timing, duration and the rewarming process. The present study reviews the best available scientific evidence and the current recommendations contained in the international guidelines. In addition, the study focuses on the practical implementation of TTM in post-cardiac arrest patients in general and cardiological ICUs, with a discussion of the implementation strategies, protocols, management of complications and assessment of the neurological prognosis.

Role of coronary angiography in patients with a non-diagnostic electrocardiogram following out of hospital cardiac arrest: Rationale and design of the multicentre randomized controlled COUPE trial.

BACKGROUND: Coronary artery disease (CAD) is a major cause of out-of-hospital cardiac arrest (OHCA). The role of emergency coronary angiography (CAG) and percutaneous coronary intervention (PCI) following cardiac arrest in patients without ST-segment elevation myocardial infarction (STEMI) remains unclear. AIMS: We aim to assess whether emergency CAG and PCI, when indicated, will improve survival with good neurological outcome in post-OHCA patients without STEMI who remain comatose. METHODS: COUPE is a prospective, multicentre and randomized controlled clinical trial. A total of 166 survivors of OHCA without STEMI will be included. Potentially non-cardiac aetiology of the cardiac arrest will be ruled out prior to randomization. Randomization will be 1:1 for emergency (within 2 h) or deferred (performed before discharge) CAG. Both groups will receive routine care in the intensive cardiac care unit, including therapeutic hypothermia. The primary efficacy endpoint is a composite of in-hospital survival free of severe dependence, which will be evaluated using the Cerebral Performance Category Scale. The safety endpoint will be a composite of major adverse cardiac events including death, reinfarction, bleeding and ventricular arrhythmias. CONCLUSIONS: This study will assess the efficacy of an emergency CAG versus a deferred one in OHCA patients without STEMI in terms of survival and neurological impairment.

Mehran contrast nephropathy risk score: Is it still useful 10 years later?

BACKGROUND: Nowadays, contrast-induced nephropathy (CIN) is the third cause of acquired acute renal impairment in hospital. CIN is related to increased in-hospital morbidity, mortality, costs of medical care, and long admissions. Because of this, we hypothesized it would be useful to determine the risk of CIN with scores such as the Mehran score. The aim of this study was to validate the Mehran score in a contemporary cohort of Spanish patients with acute coronary syndrome (ACS). METHODS: We assessed the calibration and discriminatory capacity of Mehran score to predict CIN in a cohort of 1520 patients with a definitive diagnosis of ACS and who underwent coronary angiography between March 2008 and June 2012. We excluded patients on chronic dialysis and those without data of contrast volume. The calibration of the model was assessed with the Hosmer-Lemeshow goodness-of-fit test and discriminatory capacity was assessed by C-statistic, which is equivalent to the area under the receiver-operating characteristic curve. RESULTS: From the total group, 118 patients (7.8%) developed CIN. They were older, with higher rates of diabetes (DM) and hypertension and worse renal function and anemia (p<0.001). The odds ratios for different score components in Mehran's population versus our study were similar except for DM, hypotension, and intra-aortic balloon pump (1.6%, 2.68%, 2.55% vs 0.9%, 1.89%, and 2.86%, respectively). Calibration and discriminatory capacity of Mehran score were excellent with a Hosmer-Lemeshow p=0.7, C-statistic value >0.8. CONCLUSIONS: Mehran risk score has been validated in our study as a good score for predicting CIN in patients with ACS who underwent coronary angiography. According to this, we support its use in patients hospitalized for ACS in order to identify the ones at risk, and to optimize CIN prophylactic therapy prior to and after catheterization.

Evolution of hepatorenal syndrome after orthotopic liver transplantation: comparative analysis with patients who developed acute renal failure in the early postoperative period of liver transplantation.

OBJECTIVE: The purpose of this study was to ascertain the prognosis of patients with hepatorenal syndrome (HS) prior to orthotopic liver transplantation (OLT) by comparisons with a group of selected patients with normal renal function (NRF) pretransplantation who developed acute renal failure (ARF) in the early postoperative period. MATERIALS AND METHODS: Fifty-two OLT cases developed ARF in the early postoperative period between March 1999 and October 2004; 17 cases experienced HS prior to OLT. ARF was defined as serum creatinine level (Cr) >1.5 mg/dL or a creatinine clearance (CrCl) <50 mL/min. The immunosuppressive therapy was the same in both groups: low doses of tacrolimus were prescribed to reach trough levels of 5 ng/mL in the first week after OLT, where patients were administered monoclonal antibodies and corticosteroids. RESULTS: No differences were observed between the groups for gender, age or APACHE II Score in the first 24 hours after OLT. Patients with HS pretransplantation showed higher Cr and urea (U) levels than the other group (Cr: 2.1 +/- 0.8 HS vs 0.9 +/- 0.2, P = .000; U: 93.6 +/- 51.9 HS vs 42.1 +/- 19.3, P = .001). The ICU days of stay were similar (12.8 +/- 0.5 HS vs 19.7 +/- 15.2, P = .053). At the end of 1 year follow-up after OLT there were no differences in mortality (35% HS vs 26%), need for renal replacement therapy (23% HS vs 34%), infection (59% HS vs 51%), or rejection (6% HS vs 29%, P = .06). CONCLUSIONS: Patients with HS prior to OLT showed a similar prognosis to a group of selected patients with NRF pretransplantation, but developed ARF in the early postoperative period which was treated with monoclonal antibodies and low doses of tacrolimus.

Anaemia is associated with higher mortality among patients with heart failure with preserved systolic function.

OBJECTIVE: To investigate the prevalence of anaemia and its influence on mortality among hospitalised patients with congestive heart failure (CHF) with preserved left ventricular systolic function (LVSF). METHOD AND RESULTS: 210 patients with preserved LVSF admitted to the cardiology department of a tertiary hospital for CHF between 1 January 2000 and 31 December 2002 were analysed. Anaemic patients, who constituted 46% of the whole group, were older (75 v 72 years, p = 0.036); were in hospital longer (mean (SD) 13 v 11 days, p = 0.007); had a higher prevalence of ischaemic heart disease (54% v 35%, p = 0.009), left bundle branch block (12% v 4%, p = 0.018), and kidney failure (56% v 34%, p = 0.003); and had faster erythrocyte sedimentation rates (mean (SD) 50 v 26 mm in the first hour, p < 0.001), a tendency to lower serum cholesterol concentration (mean (SD) 4.65 v 5.22 mmol/l, p = 0.073), and smaller body mass index (mean (SD) 27 v 29 kg/m2, p = 0.126) than their non-anaemic counterparts. Kaplan-Meier analysis showed the anaemic group to have significantly poorer survival (p = 0.0001), with a one year survival rate of 72.2% versus 90.5% in the non-anaemic group. Multivariate analysis showed anaemia to be the most powerful independent predictor of mortality, increasing the risk of death by a factor of 2.7 (p = 0.007). CONCLUSION: Anaemia is a very prevalent condition in hospitalised patients with CHF with preserved LVSF and is independently associated with higher mortality. Appropriately designed randomised studies are needed to determine whether the prevention or treatment of anaemia can improve survival of these patients.

Características clínicas y pronóstico de la insuficiencia cardíaca de origen isquémico e hipertensivo / Clinical characteristics and prognoses of ischemic and hypertensive heart failure

Objetivos. Nos propusimos evaluar las características clínicas y la supervivencia de pacientes con insuficiencia cardíaca de origen isquémico o hipertensivo que requirieron ingreso hospitalario. Métodos. Analizamos las características clínicas de 229 pacientes con insuficiencia cardíaca en clase III-IV debida a cardiopatía isquémica o hipertensión arterial (en este grupo se excluyeron los hipertensos con lesiones coronarias o manifestaciones clínicas de cardiopatía isquémica, así como los casos debidos a otras cardiopatías) que requirieron ingreso hospitalario entre el 1 de enero de 1991 y el 31 de diciembre de 1994. Su situación vital se evaluó mediante consulta o contacto telefónico en los meses de abril y mayo de 1998, con un período medio de seguimiento de 4 años. Se obtuvieron datos de 144 pacientes con insuficiencia cardíaca de origen isquémico y 69 pacientes de etiología hipertensiva. La edad media del grupo total era de 70 ñ 11 años, 70 ñ 9 de los 69 pacientes incluidos en el grupo hipertenso y 69 ñ 11 años en el isquémico. Resultados. El 49 por ciento de los isquémicos era también hipertenso. El 72 por ciento de los hipertensos y el 73 por ciento de los isquémicos se encontraban en clase IV en el ingreso hospitalario. La presencia de edema (periférico y pulmonar) era significativamente más frecuente en los pacientes con insuficiencia cardíaca hipertensiva, 49 por ciento frente al 20 por ciento; p = 0,0001, así como la existencia de cardiomegalia en radiografía de tórax: 97 por ciento frente al 84 por ciento, p = 0,01. También la hipertrofia ventricular izquierda en ECG (58 por ciento frente al 31 por ciento; p = 0,0001) y la fibrilación auricular (47 por ciento frente al 19 por ciento; p = 0,0001) eran significativamente más frecuentes en el grupo hipertenso. La disfunción sistólica de ventrículo izquierdo (FE < 50 por ciento) fue más frecuente, aunque no de forma significativa, en los pacientes que tenían cardiopatía isquémica (82 por ciento frente al 68 por ciento; p = 0,057). No se observaron diferencias en la supervivencia de ambos grupos con una supervivencia a 3 años del 58,5 por ciento y 58,6 por ciento de los pacientes incluidos en el grupo hipertenso e isquémico y a los 5 años del 47,7 por ciento y 45,9 por ciento, respectivamente. Conclusiones. El grupo de pacientes con insuficiencia cardíaca de etiología isquémica ingresados en nuestro hospital presenta, a largo plazo una elevada mortalidad similar a la del grupo hipertensivo, siendo la supervivencia a cinco años menor del 50 por ciento en ambos grupos (AU)

Disección coronaria espontánea: aspectos diagnósticos y terapéuticos / Spontaneous coronary dissection: diagnostic and therapeutic approach

Presentamos dos casos de disección espontánea coronaria, que corresponden a dos mujeres sin factores de riesgo que presentaron un síndrome coronario agudo que cursó con importantes cambios electrocardiográficos. Se realizó en ambos casos una coronariografía urgente, que demostró una disección del tronco de la coronaria izquierda en el primer caso y una disección del segmento proximal de la arteria descendente anterior en el segundo. Ambos casos fueron revascularizados quirúrgicamente. (AU)

[Coronary ischemia caused by pseudoxanthoma elasticum and myocardial revascularization with double arterial graft]. / Isquemia coronaria producida por seudoxantoma elástico y revascularización miocárdica con doble injerto arterial.

We present a case of an 18 year-old woman with pseudoxanthoma elasticum, who had a biopsy taken from a lesion. Although she was asymptomatic, we tried to rule out myocardial ischemia with a treadmill and cardiac gammagraphy with Talio. The isotopic studies and the ergometry were positive and the patient underwent coronariography. This study showed a severe triple-vessel disease. We did an angiography of the supraaortic arteries, mamarian artery, and mesenteric artery. These studies showed no obstructive lesions. The treatment of patient was a double by-pass with internal mammary artery and one by-pass with safena vein grafts with satisfactory results.

Infarto agudo de miocardio y trombosis coronaria inducidos por cocaína / Acute myocardial infarction and coronary thrombosis induced by cocaine

Un joven de 28 años con antecedentes de ulcus gástrico sufre un infarto agudo de miocardio anterolateral después de haber consumido en los días previos gran cantidad de cocaína. La coronariografía evidenció la presencia de un trombo oclusivo en el segmento proximal de la arteria descendente anterior, que se extendía hacia la porción distal del tronco de la coronaria izquierda. Se decidió realizar trombolisis intracoronaria con urocinasa. El trombo fue parcialmente lisado y la evolución posterior fue satisfactoria. En el control angiográfico se observaron unas arterias coronarias epicárdicas sin lesiones obstructivas (AU)

Step-down of enalapril treatment for arterial hypertension.

Enalapril treatment (20 mg every 12 hours) of 24 patients with essential hypertension and left ventricular (LV) hypertrophy established normal blood pressures after 8 weeks, and after 5 years, it had reduced LV mass index by 39% (from 148+/-34 to 90+/-16 g/m(2)) and had normalized LV structure and function and QT dispersion. Stepwise reduction of the enalapril dosage from 40 to 30, 20, 10, and 5 mg/d during the eighth year caused no significant change in blood pressure, LV structure, LV systolic function, or QT dispersion, which all likewise remained unaltered during an additional 2-year period of the 5-mg/d regimen. We conclude that for hypertensive patients in whom prolonged treatment with high doses of enalapril has normalized blood pressure, LV structure, LV function, and QT dispersion, the dose may be reduced as much as 8-fold without detriment to cardiovascular control. The use of smaller doses is evidently advantageous from the point of view of health costs.

Haemodynamic performance of aortic pericardial bioprostheses and bileaflet prostheses at rest and during exercise: implications for the surgical management of patients with small aortic roots.

OBJECTIVE: To determine the haemodynamic behaviour, at rest and during exercise, of aortic valve pericardial bioprostheses and different sizes of bileaflet prosthesis. DESIGN: Observational study. SETTING: Tertiary medical centre. PATIENTS AND INTERVENTIONS: 74 patients (33 women, 41 men; mean age 64 years) in whom 40 pericardial bioprostheses and 34 bileaflet prostheses sized 19, 21, or 23 mm had been implanted to replace aortic valves. MAIN OUTCOME MEASURES: Doppler echocardiography at rest and at peak exercise, between 12 and 47 months after surgery. RESULTS: All patients achieved a significant increase in heart rate, systolic blood pressure, and cardiac output with exercise. Transvalvar pressure fall, valve area, and left ventricular systolic and diastolic function indices also underwent significant changes with exercise. Reductions in peak and mean transvalvar pressure, at rest and at peak exercise, were greater in patients with small valves (p < 0.05). Valve areas and effective area index were greater in the patients with larger valves (p < 0.001). There were no significant differences between patients with mechanical and biological prostheses with regard to transvalvar pressure fall and valve areas at rest and at peak exercise. CONCLUSIONS: 19 mm and 21 mm aortic prostheses and bioprostheses continue to create significant obstruction, particularly with exercise.

Maintenance of blood pressure control and left ventricular performance with small doses of enalapril.

Enalopril treatment (20 mg every 12 hours) of 24 patients with essential hypertension and left ventricular (LV) hypertrophy established normal blood pressure (BP) after 8 weeks, and after 7 years had reduced LV mass index by 39% from 148 +/- 34 to 90 +/- 16 g/m2, and had normalized LV structure and function and QT dispersion. Stepwise reduction of the enalapril dosage from 40 to 30, 20, 10, and 5 mg/day during the eighth year caused no significant changes in BP, LV structure, LV systolic function, or QT dispersion, which all likewise remained unaltered during a further year of the 5-mg/day regimen. We conclude that for hypertensive patients in whom prolonged treatment with standard doses of enalapril has normalized BP, LV structure and function, and QT dispersion, significantly smaller doses are sufficient to maintain these cardiovascular achievements.

Reduction of QT and QTc dispersion during long-term treatment of systemic hypertension with enalapril.

We report, in conjunction with other findings, the evolution of the dispersion of QT and QTc in patients who for the last 7 years have been treated with enalapril for systemic hypertension with left ventricular (LV) hypertrophy. Twenty-four essential hypertensive patients who had received no previous treatment took enalapril (20 mg twice daily) for 7 years. In a pretreatment placebo phase and 8 weeks and 1, 3, 5, 6, and 7 years after the start of therapy, cardiovascular parameters were determined by two-dimensional guided M-mode echocardiography, and the QT interval and corrected QT interval (QTc) and their dispersions were obtained from amplified standard 12-lead electrocardiograms. Therapy rapidly reduced blood pressure (BP) from 156/105 mm Hg to normal values; at 7-year follow-up, BP was 130/84 mm Hg (p <0.001 with respect to the placebo phase). LV mass index decreased progressively until at 5-year follow-up the reduction had reached 39% (p <0.001), after which neither LV mass index nor any structural parameter underwent any further significant change. LV pump function was also significantly better after 7 years of treatment. During this time, QT and QTc decreased significantly, as did the dispersion of both QT (from 61+/-21 to 37+/-14 ms) and QTc (from 67+/-27 to 41+/-16 ms). We conclude that long-term enalapril treatment of hypertensive patients with LV hypertrophy not only induces marked regression of LV mass and improved LV systolic function, but also reduces the dispersions of QT and QTc, which probably reduces the likelihood of ventricular arrhythmias and improves prognosis.

Effects on left ventricular mass and function of low doses of enalapril for systemic hypertension.

After 7 years of treatment with 20 mg of enalapril twice daily, regression of the initial left ventricular hypertrophy in a group of 24 patients with essential arterial hypertension was achieved: gradual reduction in the dosage to 10 or 5 mg twice daily caused no worsening of either blood pressure or ventricular structure or function.

Evolution of left ventricular hypertrophy and function during long-term treatment of systemic hypertension with enalapril.

Continued treatment of hypertensive patients with enalapril reduced left ventricular (LV) hypertrophy steadily over a period of 5 years (by which time gross structural parameters were normal) and produced no further reduction during the following 2 years. Temporary suspension of treatment after 5-year follow-up gave rise to an increase in blood pressure, and to deterioration of LV isovolumic relaxation time and deceleration of the ventricular filling E wave, both of which chiefly reflect the active relaxation of the ventricle.

[Influence of systemic arterial hypertension on mid-term survival of patients with acute myocardial infarction treated with fibrinolytic agents]. / Influencia de la hipertensión arterial sistémica en la supervivencia a medio plazo de los pacientes con infarto agudo de miocardio que han recibido tratamiento fibrinolítico.

BACKGROUND: The purpose of this study to asses the effect of systemic arterial hypertension on mid-term survival of patients with acute myocardial infarction who received thrombolytic treatment. PATIENTS AND METHOD: We studied 202 consecutive patients with acute myocardial infarction, admitted in the Coronary Care Unit of the Hospital Xeral de Galicia who received intravenous thrombolytic therapy within six hours from the onset of symptoms. The thrombolytics used were: urokinase (79.7%), rt-PA (9.9%), streptokinase (4.9%) and APSAC (5.5%). Left heart catheterization with coronary angiography was performed in 162 patients at 2 weeks after infarction. Patency of the infarction-related artery (IRA) was classified according to Thrombolysis in Myocardial Infarction (TIMI) criteria. A patent artery weas defined as having TIMI grades 2 or 3 antegrade flow. RESULTS: Systemic arterial hypertension was found in 34.7% of patients. IRA patency (TIMI 2-3) was demonstrated in the 75.3% of the patients. Early mortality (first month) was 5.4%. Multivariate analysis identified cardiogenic shock as the only variable with independent predictive value for early mortality. Mean follow-up was for 24 +/- 19 months. Late mortality was 5.2% and cardiac death occurred in 4.2% of patients. Reinfarction occurred in 3.1% of patients. Congestive heart failure, arterial hypertension and reinfarction adversely affected prognosis. Actuarial survival at the end of follow-up period was significantly lower in patients with systemic arterial hypertension (70.4% vs 85.9%; p < 0.05). CONCLUSIONS: These data suggest that systemic arterial hypertension adversely affects mid-term prognosis in patients with acute myocardial infarction who received thrombolytic treatment.

[Left ventricular structure and (systolic and diastolic) function in hypertensive patients without atherosclerotic coronaropathy]. / Estructura y función (sistólica y diastólica) ventricular izquierda en hipertensos sin coronariopatía aterosclerosa.

INTRODUCTION AND OBJECTIVES: Electrocardiographic (ECG) ST-T segment abnormalities in hypertensive patients are traditionally associated with hypertrophy and/or ischaemia and a higher cardiovascular risk. Hypertensive patients with typical or non-typical chest discomfort and a normal coronarographic study underwent an echocardiographic and Doppler study in order to assess left ventricular structure and (systolic and diastolic) function. MATERIAL AND METHODS: Hypertensive patients with ST-T changes were classified as follows: Control group (CG) was made up of 12 hypertensive patients (6 women, 6 men, mean age 59.6 +/- 7.4 years) with normal ECG; Group A (GA), 10 patients (6 women, 4 men, mean age 63.1 +/- 6.8 years) with ECG image of strain; Group B (GB) (9 women and 8 men, mean age 61.3 +/- 10.1 years) with other ST-T alterations. We assessed by echocardiographic and transmitral flow Doppler study left ventricular structure and (systolic and diastolic) function. RESULTS: Interventricular septum thickness, left ventricular posterior wall thickness, left ventricular mass and mass index were significantly higher in the GA and GB than in the CG, without differences between GA and GB groups. No differences in left ventricular systolic function parameters were observed between the groups. In comparison with the CG, the GA and GB showed significant differences in E wave deceleration velocity and deceleration time, A wave deceleration time and isovolumetric relaxation time. Between GA and GB differences were observed in A wave deceleration time and isovolumetric relaxation time. CONCLUSIONS: In hypertensive patients without atherosclerotic coronaropathy, ST-T changes identify a group with greater left ventricular mass and worse left ventricular diastolic function. The patients with a ST-T strain pattern showed the impaired diastolic function.

The influence of the design on the medium to long-term hemodynamic behavior of 19 mm pericardial aortic valve prostheses.

BACKGROUND AND AIMS OF THE STUDY: The hemodynamics of five designs of 19 mm pericardial aortic valve bioprosthesis were examined by Doppler echocardiography in 48 resting patients at medium or long term follow up. METHODS: The salient differences among the five designs are that valve leaflets are mounted inside the support frame in one (the Carpentier-Edwards valve, evaluated in five patients) and outside the frame in the other four (the Ionescu-Shiley (14 patients), Mitroflow (six patients), Bioflo (eight patients) and Labcor-Santiago (15 patients)); and that two models have either total (Bioflo) or partial (Labcor-Santiago) protective pericardial sheaths on the stent, while the other three do not. The hemodynamic parameters determined included transvalvular pressure drop, valve area, left ventricular outflow tract diameter, subvalvular/valvular velocity ratio and subvalvular/valvular velocity-time integral ratio. RESULTS: There were no significant differences among the various valves as regards left ventricular outflow tract diameter, subvalvular/valvular velocity ratio or subvalvular/valvular velocity-time integral ratio. Negative correlation between left ventricular outflow tract diameter and subvalvular velocity (r = -0.63, p < 0.001) confirmed the need to correct for prevalvular velocities when using the Bernoulli equation to calculate the pressure drop across small pericardial aortic valve bioprostheses. The Bioflo design caused significantly greater pressure drops (peak 49.6 +/- 11.3 mmHg, mean 28.1 +/- 6.1 mmHg) and provided smaller areas (0.80 +/- 0.16 cm2) than the Ionescu-Shiley (26.7 +/- 6.6 and 15.2 +/- 4.1 mmHg, 1.17 +/- 0.17 cm2) and Labcor-Santiago (24.8 +/- 5.9 and 15.1 +/- 3.7 mmHg, 1.24 +/- 0.12 cm2) valves. CONCLUSIONS: Of the currently available 19 mm bovine pericardium heart valve bioprostheses, the Mitroflow and Labcor-Santiago valves, in both of which the leaflets are mounted outside the stent, have better hemodynamics in the aortic position than the Carpentier-Edwards valve, which has internal leaflet mounting. Sheathing the stent totally in pericardium, as in the withdrawn Bioflo valve, gives rise to relatively poor hemodynamics.