Lowering Pulmonary Wedge Pressure after Heart Transplant: Pulmonary Compliance and Resistance Effect / Redução da Pressão Capilar Pulmonar após Transplante Cardíaco: Complacência Pulmonar e Efeito Resistência

AbstractBackground:Right ventricular (RV) afterload is an important risk factor for post-heart transplantation (HTx) mortality, and it results from the interaction between pulmonary vascular resistance (PVR) and pulmonary compliance (CPA). Their product, the RC time, is believed to be constant. An exception is observed in pulmonary hypertension because of elevated left ventricular (LV) filling pressures.Objective:Using HTx as a model for chronic lowering of LV filling pressures, our aim was to assess the variations in RV afterload components after transplantation.Methods:We retrospectively studied 159 patients with right heart catheterization before and after HTx. The effect of Htx on hemodynamic variables was assessed.Results:Most of the patients were male (76%), and the mean age was 53 ± 12 years. HTx had a significant effect on the hemodynamics, with normalization of the LV and RV filling pressures and a significant increase in cardiac output and heart rate (HR). The PVR decreased by 56% and CPA increased by 86%. The RC time did not change significantly, instead of increasing secondary to pulmonary wedge pressure (PWP) normalization after HTx as expected. The expected increase in RC time with PWP lowering was offset by the increase in HR (because of autonomic denervation of the heart). This effect was independent from the decrease of PWP.Conclusion:The RC time remained unchanged after HTx, notwithstanding the fact that pulmonary capillary wedge pressure significantly decreased. An increased HR may have an important effect on RC time and RV afterload. Studying these interactions may be of value to the assessment of HTx candidates and explaining early RV failure after HTx.

ResumoFundamento:A pós-carga do ventrículo direito (VD) é um fator de risco importante para avaliar a mortalidade decorrente de transplante cardíaco (HTx) e resulta da interação entre a resistência vascular pulmonar (RVP) e a complacência pulmonar (CPA). Acredita-se que o produto da interação, o RC-time, seja constante. Entretanto, é exceção a hipertensão pulmonar devido às elevadas pressões de preenchimento do ventrículo esquerdo (VE).Objetivos:Ao utilizar o HTx como modelo para redução crônica das pressões de preenchimento do VE, nosso objetivo foi avaliar as variações nos componentes pós-carga do VD após o transplante.Métodos:Foram estudados, retrospectivamente, 159 pacientes com cateterismo cardíaco direito realizado antes e após o HTx. O impacto do HTx nas variáveis hemodinâmicas foi avaliado.Resultados:A maioria dos pacientes foi do sexo masculino (76%) e a média de idade foi 53 ± 12 anos. O HTx teve um efeito significativo na hemodinâmica, com normalização do VE e das pressões de preenchimento de VD e no aumento significativo do débito cardíaco e da freqüência cardíaca (FC). A RVP diminuiu 56% e a CPA aumentou 86%. Em vez de aumentar como era esperado, o RC-time não alterou significativamente e teve papel secundário em relação à normalização da pressão capilar pulmonar (PECP) após o HTx. O aumento esperado no RC timecom PWP reduzido foi atenuado pelo aumento da FC (devido à denervação autonômica do coração). Esse efeito ocorreu independentemente da diminuição da PCPConclusões:O RC-time permaneceu inalterado após HTx, entretanto a PECP diminuiu significativamente. O aumento da FC pode ter impacto importante no RC-time e na pós-carga do VD. O estudo dessas interações pode ser de grande valor para avaliar os candidatos HTx e explicar a falência do VD ocorrida logo após o HTx.

Correlação da função diastólica com a capacidade máxima de exercício ao teste ergométrico / Correlation between diastolic function and maximal exercise capacity on exercise test / Correlación de la función diastólica con la capacidad máxima de ejercicio al test ergométrico

FUNDAMENTO: O aumento da pressão de capilar pulmonar (PCP) é um dos mecanismos de intolerância ao exercício. A avaliação da função diastólica pelo ecocardiograma (ECO) é capaz de estimar a PCP. OBJETIVO: Identificar variáveis determinantes da capacidade de exercício em paciente submetidos a teste ergométrico (TE) de rotina, ECO convencional e doppler tecidual (DT). MÉTODOS: Foram estudados, retrospectivamente, 640 pacientes submetidos a TE e ao ECO e DT. Pacientes com fração de ejeção < 55 por cento foram excluídos. As velocidades de Doppler mitral convencional foram obtidas em diástole precoce (E) e diástole tardia (A), e o DT do anel mitral mediu as velocidades de diástole precoce (e’) e diástole tardia (a’). E/e’ > 10 foi considerada uma estimativa de aumento da PCP. A capacidade máxima de esforço foi avaliada pelo número de equivalentes metabólicos (MET). Para análise, os pacientes foram divididos em dois grupos: MET < 7 (n = 48) e MET > 7 (n = 572). O escore de Morise demonstrou uma população de baixo risco (60 por cento) para doença coronária (DAC). RESULTADOS: O número de pacientes com E/e’ > 10 foi significativamente maior no grupo MET < 7 em relação a MET > 7(41,7 por cento vs 9,4 por cento, p = 0,001), bem como a presença de algum grau de disfunção diastólica (76,6 por cento vs 34,1 por cento p = 0,001). Pela análise de regressão logística, as variáveis independentes de baixa capacidade de exercício (MET < 7) foram a idade, o sexo feminino e a velocidade de A (diástole tardia). CONCLUSÃO: A disfunção diastólica determinada pelo ECO, sexo feminino e idade estão associados com a menor capacidade de exercício em uma população de baixo risco de DAC.

BACKGROUND: Increased pulmonary capillary pressure (PCP) is one of the mechanisms of exercise intolerance. Assessment of the diastolic function by echocardiography (ECHO) enables estimation of PCP. OBJECTIVE: To identify variables that determine the exercise capacity in patients undergoing routine exercise test (ET), conventional ECHO, and tissue Doppler imaging (TD). METHODS: A total of 640 patients undergoing ET, ECHO, and TD were retrospectively studied. Patients with ejection fraction < 55 percent were excluded. Mitral annulus velocities by conventional Doppler imaging were obtained in early diastole (E) and late diastole (A), and TD of the mitral annulus measured early diastole (e’) and late diastole (a’) velocities. E/e’ > 10 was considered an estimate of increased PCP. Maximal exercise capacity was analyzed by the number of metabolic equivalents (MET). The patients were divided into two groups for analysis: MET<7 (n=48) and MET>7 (n=572). Morise score showed a population at low risk (60 percent) for coronary artery disease (CAD). RESULTS: The number of patients with E/e’ > 10 was significantly higher in the MET < 7 group in relation to the MET > 7 group (41.7 percent vs 9.4 percent, p=0.001), and so was the presence of any degree of diastolic dysfunction (76.6 percent vs 34.1 percent p=0.001). Using logistic regression analysis, age, female gender and A velocity (late diastole) were the independent variables related to a low exercise capacity (MET < 7). CONCLUSION: Diastolic dysfunction as determined by ECHO, female gender, and age are associated with a lower exercise capacity in a population at low risk for CAD.

FUNDAMENTO: El aumento de la presión de capilar pulmonar (PCP) es uno de los mecanismos de intolerancia al ejercicio. La evaluación de la función diastólica por el ecocardiograma (ECO) es capaz de estimar la PCP. OBJETIVO: Identificar variables determinantes de la capacidad de ejercicio en paciente sometido a test ergométrico (TE) de rutina, ECO convencional y doppler tisular (DT). MÉTODOS: Fueron estudiados, retrospectivamente, 640 pacientes sometidos a TE y al ECO y DT. Pacientes con fracción de eyección < 55 por ciento fueron excluidos. Las velocidades de Doppler mitral convencional fueron obtenidas en diástole precoz (E) y diástole tardía (A), y el DT del anillo mitral midió las velocidades de diástole precoz (e') y diástole tardía (a'). E/e' > 10 fue considerada una estimativa de aumento de la PCP. La capacidad máxima de esfuerzo fue evaluada por el número de equivalentes metabólicos (MET). Para análisis, los pacientes fueron divididos en dos grupos: MET < 7 (n = 48) y MET > 7 (n = 572). El escore de Morise demostró una población de bajo riesgo (60 por ciento) para enfermedad coronaria (EAC). RESULTADOS: EL número de pacientes con E/e' > 10 fue significativamente mayor en el grupo MET < 7 en relación a MET > 7(41,7 por ciento vs 9,4 por ciento, p = 0,001), así como la presencia de algún grado de disfunción diastólica (76,6 por ciento vs 34,1 por ciento p = 0,001). Por el análisis de regresión logística, las variables independientes de baja capacidad de ejercicio (MET < 7) fueron la edad, el sexo femenino y la velocidad de A (diástole tardía). CONCLUSIONES: La disfunción diastólica determinada por el ECO, sexo femenino y edad están asociados con la menor capacidad de ejercicio en una población de bajo riesgo de EAC.

Rol del ecocardiograma en el estudio de la hipertensión arterial pulmonar / Role of echocardiography in the study of pulmonary arterial hypertension

La presencia de una presión arterial pulmonar media >25 mmHg en reposo y >30 mmHg en ejercicio, con una presión en cuña igual o menor de 15 mmHg y una resistencia vascular pulmonar >3 mmHg /L/ min (Uds. Wood) condiciona una entidad clínica heterogenea denominada hipertensión arterial pulmonar que tiene un amplio rango de causas o enfermedades que llevan a cambios estructurales de las pequeñas arterias pulmonares ocasionando un aumento progresivo de la presión arterial pulmonar y de la resistensia vascular pulmonar, produciendo finalmente una sobrecarga del ventrículo derecho, insuficiencia cardíaca y muerte. Es una entidad clínica con síntomas muy inespecíficos en sus etapas más tempranas y se necesita un buen criterio clínico para llegar a su diagnóstico más rápidamente. En este sentido es que adquiere valor el uso de la ecocardiografía, método que permitirá o solo cuantificar los valores de presión arterial pulmonar, sino también determinar la causa del problema, una adecuada evaluación anatómica y funcional del lecho pulmonar y de las cavidades derechas del corazón, predecir el pronostico de estos pacientes y vigilar el efecto terapéutico de tratamientos muy específicos al ayudar a detectar estados preclínicos de la enfermedad. Revisamos la utilidad y el papel del ecocardiograma en el estudio de la hipertensión arterial pulmonar.

The presence of Medium Arterial Pulmonary Pressure >25 mmHg at rest or >30mmHg during exercise associated with a wedge pulmonary pressure equal or less than 15mmHg, and a Pulmonary Vascular Resistance > 3 mmHg/L/min (Wood units) entails a heterogeneous clinical entity known as Pulmonary Arterial Hipertension which has a very wide spectrum of causes or diseases which produce estructural changes in the walls of the small pulmonary arteries causing a progressive increase of the arterial pulmonary pressure as well as the pulmonary vascular resistence, ultimately producing right ventricular overload, heart failure and death. It is a clinical entitywith very unspecific symptoms at the early stages. Wich makes the physician´s good clinical criteria needed to diagnose itsooner. In this way comes to great value the use of echocardiography, method that would allow not only to measure the arterial pulmonary pressure but would help to carify the cause of the disease, getting an adequate anatomical and funtional evaluation of the pulmonary bed and right heart chambers, predict the outcome in these patients by detecting pre-clinic stages of the disease. We reviewed the utility and role of the Echocardiogram in the study of Pulmonary Arterial Hypertension.

Monitoreo inalámbrico de presión arterial pulmonar en pacientes con insuficiencia cardíaca / Wireless pulmonary artery pressure monitoring in patients with congestive heart failure

Antecedentes: El monitoreo continuo y remoto de presiones intracardiacas ha sido reportado de utilidad en el manejo y prevención de hospitalización en pacientes con Insuficiencia Cardíaca (IC). Objetivos: Describir la técnica y las complicaciones en el seguimiento a mediano plazo de un sensor inalámbrico(Sensor CardioMEMS Heart Sure®) pulmonar; evaluar la exactitud de la determinación de la presión en arteriapulmonar (PAP) después de un año de implante y su correlación con la presión estimada por cateterismo cardíaco convencional (catéter de Swan-Ganz).Método: Fueron incluidos en el estudio pacientes con IC avanzada con al menos una hospitalización en el año previo al implante de este sensor. Se realizaron mediciones simultáneas con catéter de Swan-Ganz (SG) durante el implante y a los 60, 180 días y un año de seguimiento. Se empleó análisis de regresión lineal como una medida de la correlación entre los métodos. La variabilidad entre las técnicas se evaluó mediante análisis del Bland-Altman.Resultados: En este reporte fueron incluidos 27 pacientes, 24 hombres con edad promedio de 64+/-14.1 años y FE promedio de 25 por ciento, la gran mayoría en clase funcional III de la NYHA. Un paciente falleció 190 días post implante por causa extra cardíaca y otro falleció 45 días post implante por shock cardiogénico. La PAP sistólica, diastólica y media cuantificada a 60 días, 6 meses y un año post implante tuvo una correlación adecuada cuando se comparó con el cateterismo de SG preservando la calidad de la curva de presión obtenida desde el sensor. La calidad de la señal se ha mantenido hasta más de un año de seguimiento. Conclusión: Existió muy buena correlación entre las presiones obtenidas con el sensor y las mediciones del catéter de SG. Es necesario validar este sistema en un número mayor de enfermos y establecer su papel en el manejo de la IC crónica.

Background: Continuous and remote intracardiac pressure monitoring has been reported to be useful to manage patients with congestive heart failure (CHF) and to prevent rehospitalization. Aim: To describe the technical aspects and complications in the use of a wireless pulmonary artery pressure sensor (CardioMEMS Heart Sure© ) in a medium term follow up. Also, to evaluate de precision of pulmonary artery pressure (PAP) measurement one year after implantation of the device. Methods: Patients with advanced CHF with at least one hospitalization in the preceding year were included. PAP was measured through Swan Ganz catheterization at the time of device implantation and after 60 days, 6 months and one year of follow up. Linear regression was used to estimate inter method correlation and Bland-Altman analysis to estimate variability among methods Results: Twenty-seven patients (24 men) aged 64 +/-14.1 (SD) years, most of them in functional class III were included. The mean ejection fraction was 25 percent. One patient died 190 days after implant due to non cardiac causes and another 45 days post implant from cardiogenic shock. Systolic, diastolic and mean PAP was measured 60 days, 6 months and 1 year post implant. The correlation with Swan Ganz catheter measurement was adequate. The quality of the signal obtained from the PAP sensor was maintained at one year of follow up. Conclusion: A very good correlation between wireless and Swan Ganz measurements of PAP was observed. More extensive assessment of this method is needed to establish its usefulness in the management of patients with chronic CHF.

Función de los músculos inspiratorios, parámetros hemodinámicos y disnea en pacientes con estenosis mitral / Inspiratory muscle function, hemodynamic parameters and dyspnea in patients with mitral valve stenosis

Background: The mechanism involved in dyspnea in patients with mitral valve stenosis (MS) is not completely understood. Aim: To evaluate in patients with MS, changes in hemodynamic parameters during the assessment of inspiratory muscle endurance (IME) and the relationship between IME, hemodynamics and dyspnea. Subjects and methods: We studied 13 patients (9 in NYHA class II and 4 in class III). Endurance was evaluated using a two minute incremental threshold loading test, to obtain the maximal sustainable inspiratory pressure (SIP), and maximal inspiratory load (MIL). During the test, cardiac output (CO), mean pulmonary and capillary pressures (PAP and PCP, respectively), were evaluated. Results: Compared to six normal subjects, MS patients had reduced SIP and MIL (p <0.01), which correlated with baseline index of dyspnea (r= 0.57 and r=0.52, respectively, p <0.05). At the end of the test period, basal CO, cardiac index (CI), PAP and PCP increased from 3.4 to 4.0 l/min-1; 2.1 to 2.5 l/min-1/m-2; 15 to 25 and 11 to 18 mmHg, respectively (p <0.01). No relationship between IME and hemodynamic parameters was found. Conclusions: IME is reduced and is closely related to dyspnea in these patients with MS. The observed low CI, suggests that muscle underperfusion could contribute to this dysfunction during the inspiratory effort.

Caracterización clínica, funcional y hemodinámica de la población con hipertensión pulmonar arterial evaluada en el Instituto Nacional del Tórax / Clinical, functional and hemodynamic features of patients with pulmonary arterial hypertension

Background: Pulmonary Arterial Hypertension is a rare, progressive and devastating disease with severe consequences in quality of life and survival. Aim: A clinical, functional and hemodynamic assessment of patients with pulmonary arterial hypertension and categorization according to severity. Material and methods: Prospective registry of patients with arterial pulmonary hypertension, hemodynamically defined. Clinical evaluation was performed using World Health Organization functional score (I to IV) and Borg dyspnea scale. Six minute walking test, echocardiography and right heart catheterization were used for functional and hemodynamic assessment. Intravenous Adenosine was used to assess vascular reactivity during the hemodynamic evaluation. Results: Twenty nine patients were included (25 women, age range 16-72 years). Pulmonary hypertension was idiopathic in 11, associated to connective tissue disease in seven, associated to congenital heart disease in nine and associated to chronic thromboembolism in two. The mean lapse of symptoms before assessment was 2.9 years and 100% had dyspnea (Borg 5.1). Functional class I, II, III and IV was observed in 0, 5, 21 and 3 patients respectively. Six minutes walking test was 378±113 m. Mean pulmonary pressure was 59.4±12.2 mmHg, cardiac index was 2.57±0.88 and pulmonary vascular resistance index: 1798.4±855 (dyne.sec)/cm5. Nine patients had a mean pulmonary arterial pressure >55 mmHg and a cardiac index <2.1, considered as bad prognosis criteria. Adenosine test was positive in 17%. Conclusions: This group of patients with Pulmonary Arterial Hypertension was mainly conformed by young females, with a moderate to severe disease.

Volumen sanguíneo intratorácico versus presión arterial de oclusión pulmonar como estimadores de precarga cardíaca en pacientes críticos / Intrathoracic blood volume versus pulmonary artery occlusion pressure as estimators of cardiac preload in critically ill patients

Background:Monitoring of cardiac preload by determination of pulmonary artery occlusion pressure (PAOP) has been traditionally used to guide fluid therapy to optimize cardiac output (CO). Since factors such as intrathoracic pressure and ventricular compliance may modify PAOP, volumetric estimators of preload have been developed. The PiCCO system is able to measure CO and intrathoracic blood volume (ITBV) by transpulmonary thermodilution. Aim: To compare a volumetric (ITBV) versus a pressure (PAOP) determination to accurately estimate cardiac preload in severely ill patients. Patients and Methods: From June 2001 to October 2003, 22 mechanically ventilated patients with hemodynamic instability underwent hemodynamic monitoring with pulmonary artery catheter (PAC) and PiCCO system. ITBV index (ITBVI), PAOP and CI were measured simultaneously by both methods. One hundred thirty eight deltas (D) were obtained from the difference of ITBVI, PAOP, CI-PAC and CI-PiCCO between 6-12 am and 6-12 pm. Linear regression analysis of DITBVI versus Ð CI-PiCCO and Ð PAOP versus DCI-PAC were made. Results: Mean age of patients was 60.8 ± 19.4 years. APACHE II was 23.9 ± 7. Fifteen patients met criteria for acute respiratory distress syndrome (ARDS). Delta ITBVI significantly correlated with DCI-PiCCO (r=0.54; 95% confidence interval = 0.41-0.65; p <0.01). There was no correlation between DPAOP and Ð CI-PAC. Conclusion: ITBVI correlated better with CI than PAOP, and therefore it seems to be a more accurate estimator of preload in unstable, mechanically ventilated patients.

Predictive accuracy of commissural morphology and its role in determining the outcome following Inoue balloon mitral valvotomy.

BACKGROUND: Commissural morphology is an important predictor of outcome following balloon mitral valvotomy. The aim of this prospective study was to assess if the site of commissural splitting could be reliably predicted by echocardiography and whether the extent of commissural split affected the result of balloon mitral valvotomy. METHODS AND RESULTS: A total of 140 patients (mean age 29.1+/-8.6 years) were studied. Prediction of splitting was done based on the presence of echolucent dark zones as seen in the parasternal short-axis view on echocardiography. Of 102 patients in whom a split of both commissures was predicted, the prediction was accurate in 86% (88/102). Of 33 patients with a predicted unilateral split, the accuracy of prediction was 82% (27/33). In the 5 patients with bilateral commissural fibrosis (in whom none of the commissures were predicted to split), all had a unilateral split. Overall, 93 patients (66%) had a bilateral commissural split, 43 (31%) had a unilateral split, and 4 had no commissural split. All the latter 4 developed moderate-to-severe mitral regurgitation. Those with bilateral commissural split following balloon mitral valvotomy had lower transmitral gradients (5.53+/-1.46 v 7.4+/-1.2 3 mmHg, p = 0.03) and greater mitral valve area (1.83+/-0.15 v. 1.64+/-0.15 cm2, p<0.02), as compared to those with unicommissural split. The incidence of an increase in mitral regurgitation by > or = grade 1 was also lower in the former group (7.5% v. 28%). An optimal result with the first dilatation (using a balloon size <2 mm of the predicted size) was achieved more frequently in those with a bilateral split (18% vs 8%). Oversizing of the balloon by 2 mm (of the predicted size) was done more frequently (19% v. 7%) in those with unicommissural split. CONCLUSIONS: We conclude that the assessment of commissural morphology is possible with excellent predictive accuracy. In this study, those with bilateral commissural split had more favorable hemodynamic results with lower transmitral gradients. greater mitral valve area and lesser frequency of mitral regurgitation in contrast to those with unicommissural split.

Beneficial effect of balloon mitral valvotomy in reducing severity of associated tricuspid regurgitation.

This study was done to find out whether successful balloon mitral valvotomy (BMV) reduces the severity of associated functional tricuspid regurgitation (TR), and if so, which variables predict this reduction. Of the 177 consecutive patients who underwent BMV, 53 were found to have functional TR. 2D echocardiography (Echo) with color Doppler was done before and 24-48 hours after BMV. Using the apical four-chamber view, the severity of TR was assessed by comparing the ratio of maximal tricuspid regurgitant jet area (TRA) to right atrial area (RAA). There was a significant reduction in TRA:RAA, after BMV (0.26 to 0.12; p < 0.05). Stepwise multiple regression analysis showed that the predictors of TR reduction were: age less than 24 years (r = 0.56, p < 0.004), cardiothoracic ratio measured on chest X-ray > 60% (r = 0.43, p < 0.002) and pre-BMV pulmonary artery systolic pressure (PASP) > 50 mm Hg (r = 0.51, p < 0.001).

Adenosine-induced chest pain: is it due to myocardial ischaemia? Clinical, electrocardiographic, haemodynamic and metabolic study.

Adenosine has recently been demonstrated to be a mediator of angina in human beings. The present study was undertaken to document the presence or absence of myocardial ischaemia on clinical, haemodynamic, electrocardiographic and metabolic evidences after intracoronary administration of adenosine. Fifteen patients with chronic stable angina (12 males and 3 females), positive exercise stress test and documented significant stenosis of the left anterior descending coronary artery (LAD) were included in the study. The surface and intracoronary electrocardiograms (ECGs), pulmonary artery diastolic pressure and coronary sinus lactate levels were monitored at baseline and after intracoronary administration of adenosine in all patients. Adenosine was administered intracoronary in doses of 1000-8000 microgram depending on the provocation of chest pain. Typical angina was observed in all patients. There were no signs of ischaemia on surface or intracoronary ECG. There was no statistically significant difference between the pulmonary artery diastolic pressure and coronary sins lactate levels at baseline and post-adenosine administration (p > 0.05). It is concluded that intracoronary administration of adenosine produces chest pain in patients with chronic stable angina by mechanism other than myocardial ischaemia.

Determination of left ventricular end-diastolic pressure using doppler mitral regurgitant gradient: validation by simultaneous catheterization

The close relationship between left ventricular end-diastolic [LVEDP] and mean pulmonary artery wedge pressures is widely accepted, and the method for estimating left atrial pressure in patients with mitral regurgitation [MR] using Doppler-echo and systolic blood pressure has been documented. To test the hypothesis which approximate noninvasively LVEDP with mitral regurgitant signal, continuous wave Doppler-echo and dual catheterization were performed simultaneously in 36 patients with MR and normal pulmonary vascular resistance. Doppler-derived LVEDP was calculated by systolic blood pressure minus MR peak gradient. A high correlation [r = 0.942, y = 1.044x -0.057, P <0.001] and a close agreement [d +/- s =0.8 +/- 3.0 mm Hg] were observed between noninvasive and invasive LVEDPs. It is concluded that Doppler-echo coupled with a sphygmomanometry provide a feasible and accurate technique and another important window for the noninvasive assessment of LVEDP

Noninvasive estimation of pulmonary artery wedge pressure by dual-M-mode-echocardiography.

Pulmonary artery wedge pressure (PAWP) measurement is invasive, associated with complications, contraindications and its high cost limits its use in clinical practice. We evaluated the use of dual-M-mode-echocardiography as a possible noninvasive alternative method in 20 patients for estimating the PAWP. The interval from the Q-wave of the electrocardiogram (ECG) to the mitral valve closure on the mitral valve M-mode-echocardiogram (Q-MVC), the interval between the aortic valve closure and mitral valve E point (AVC-E) on aortic and mitral valve M-mode-ECG respectively and the ratio of these intervals (Q-MVC/AVC-E) was correlated to the mean PAWP measured at catheterization. The mean PAWP correlated excellently with Q-MVC/AVC-E ratio [r = 0.89, p < 0.0001, y = 14.51 (Q-MVC/AVC-E) + 6.71]. The estimation of PAWP by a dual-M-mode-ECG offers a useful estimate of mean PAWP noninvasively.

Efecto de la administración de furosemida en la tasa de filtración de líquido y en la presión de la arteria pulmonar en el pulmón aislado de conejo / Effects of the administration of furosemide on the fluid filtration rate and in pulmonary artery pressure in rabbit isolated lungs

Para estudiar los posibles efectos de la Furosemida a nivel pulmonar se estudiaron dos grupos de preparados de pulmón aislado de conejo. El grupo experimental fue sometido a un edema pulmonar de origen hidrostático el cual se obtuvo al aumentar la presión de aurícula izquierda (PAI) de 0.45ñ0.74 a 11.8ñ2.9 cm de H2O, esto provocó un aumento en la TFL de 0.45ñ0.51 g/min; cuando fue sostenido, se procedió a inyectar una dosis de Furosemida de 2 mg/Kg cada 10 minutos y se registraron los cambios en PAP,PAI,PVA,TFL,PaO2,PaCO2 y pH. Durante la infusión de la Furosemida no se observaron cambios significativos en dichos parámetros, el mismo efecto se repite en el grupo control en donde los preparados se mantuvieron en condiciones basales y sin edema. Estos resultados sugieren que la Furosemida no tiene efecto cardio-pulmonar de una manera directa sobre la vasculatura pulmonar, sino más bien indirectamente al favorecer la diuresis a nivel renal.

Echocardiography and pulmonary artery pressure: correlation in chronic obstructive pulmonary disease.

The aim of this study was to assess whether 2 dimensional echocardiography can provide reliable parameters to quantitatively estimate pulmonary hypertension (PH) in patients with chronic obstructive pulmonary disease. Twenty subjects, 16 males and 4 females, mean age 54.5 year +/- 4.92 were evaluated. Right ventricular dimensions were measured using subcostal 2- dimensional (2D) approach viz. right ventricular maximum short axis (Rv) and tricuspid annulus (TA). Free right ventricular anterior wall (AW) was measured by M-Mode. A 2D Index was calculated RV x TA + Aw and the same correlated with mean pulmonary artery pressure (r = 0.97). This appears to be a useful non-invasive method foe estimating PH in cases of COPD.

Pulmonary artery diameter and distensibility are correlated to pulmonary pressure and flow in schistosomal corpulmonale

Pulmonary artery diameter [PAD] was reported to be correlated with P. hypertension [PH] in some disease states, but the relations of wall motion distensibility to P. pressure [PPr] and flow [PF] in schistosomal corpulmonale [SchC] were not studied before. 10 patients with SchC, 10 patients with mitral stenosis [MS] and clinically detectable pH, as well as 10 normal controls were studied by Doppler echo. The following data were assessed: PAD in systole and diastole, distensibility = cross sectional area in systole-cross sectional area in diastole [CSAD] / CSAd x 100, mitral valve area [MVA], peak mitral gradient [MG], mean PPr calculated from acceleration time [ACT] and ejection time [ET]- 87 - 152 x [ACT/EY]. In 4 patients, PPr was measured also by catheterization, there was good agreement between PPr as measured by catheter and by this Doppler equation. Results indicated that: PAD > 28 mm was present in 7 patients in group I, and in 2 patients in group II. Distensibility in group I was 41, in group II was 27. In SchC: Distensibility versus PPr r= 0.7, P <0.02, PPr versus Pulm. flow r= 0.76, P <0.01. In MS: MVA 2D versus PPr r= 0.7, P <0.01. It was concluded that in SchC pulmonary distensibility, flow and pressure were correlated together. The increase distensibility and flow may be due to the shunts reported before in SchC

Effect of cold challenge on alveolar capillary blood volume in normal individuals.

The effect of immersion of both the hands and the feet in water at 10 degrees C on lung transfer factor for carbon monoxide (Tlco) and on pulmonary capillary blood volume (Vc) was investigated in 20 normal young adult males immediately, 60 min and 120 min after the end of the cold challenge. Vc was significantly reduced immediately and the reduction was aggravated at 60 min. Tlco was significantly reduced only at 60 min. All the values returned to baseline at 120 min. It is concluded that the cold-induced changes in Tlco and Vc are physiological responses and not unique to patients with Raynaud's phenomenon as suggested by some workers.