Severe pulmonary hypertension: data from the Swiss Registry. (65/595)

BACKGROUND: Severe pulmonary hypertension (PH) is a rare disease with a dismal prognosis if untreated. Progress in diagnosis and in the development of effective therapeutic options has created new interest in this pathology. There are, however, only limited data on the prevalence of severe PH unrelated to chronic left ventricular failure or COPD, on the associated conditions and on the parameters with a prognostic impact. With the aid of a retrospective registry we have collected data from 5 centres in Switzerland and attempted to answer the above questions. METHODS: Data on patients with PH from 4 university facilities (Zurich, Basle, Geneva and Lausanne) and one well-defined geographical area (Ticino) were retrospectively collected and analysed up to December 1999. Clinical and haemodynamic parameters and associated diseases were noted. We were also interested in the age distribution of the patients and the year of diagnosis of PH. RESULTS: We found 106 patients with severe PH (43 men, 63 women, median age 43 years); 79% were in NYHA class III or IV. There was a steep rise in diagnosis of PH after 1995. In 74% PH was either primary or associated with collagen vascular disease or thromboembolic disease. By the end of the observation period 30% of the patients had died. The best distinguishing parameters between surviving patients and those who eventually died were the 6-minute walking test (363 vs. 235 metres, p = 0.002), the NYHA class (II vs III/IV, p = 0.015), and mixed venous saturation (66.5 vs. 57.9%, p = 0.006). Therapy consisted of calcium antagonists in 18% and of (inhaled) prostanoids, chiefly iloprost, in 33%. Seven patients underwent lung transplantation. CONCLUSIONS: We conclude that PH is diagnosed more often as diagnostic and therapeutic options improve; that primary forms, and those associated with collagen vascular disease and with chronic venous thromboembolism, make up three-quarters of the aetiologies; and that the 6-minute walking test, the functional class and mixed venous saturation are the best prognostic parameters.  (+info)

Sympathetic stimulation using the cold pressor test increases coronary collateral flow. (66/595)

BACKGROUND: Little is known about the vasomotor function of human coronary collateral vessels. The purpose of this study was to examine collateral flow under a strong sympathetic stimulus (cold pressor test, CPT). METHODS: In 30 patients (62 +/- 12 years) with coronary artery disease, two subsequent coronary artery occlusions were performed with random CPT during one of them. Two minutes before and during the 1 minute-occlusion, the patient's hand was immerged in ice water. For the calculation of a perfusion pressure-independent collateral flow index (CFI), the aortic (Pao), the central venous (CVP) and the coronary wedge pressure (Poccl) were measured: CFI = (Poccl - CVP)/(Pao - CVP). RESULTS: CPT lead to an increase in Pao from 98 +/- 14 to 105 +/- 15 mm Hg (p = 0.002). Without and with CPT, CFI increased during occlusion from 14% +/- 10% to 16% +/- 10% (p = 0.03) and from 17% +/- 9% to 19% +/- 9% (p = 0.006), respectively, relative to normal flow. During CPT, CFI was significantly higher at the beginning as well as at the end of the occlusion compared to identical instants without CPT. CFI at the end of the control occlusion did not differ significantly from the CFI at the beginning of occlusion with CPT. CONCLUSIONS: During balloon occlusion, collateral flow increased due to collateral recruitment independent of external sympathetic stimulation. Sympathetic stimulation using CPT additionally augmented collateral flow. The collateral-flow-increasing effect of CPT is comparable to the recruitment effect of the occlusion itself. This may reflect a coronary collateral vasodilation mediated by the sympathetic nervous system.  (+info)

Usefulness of transcutaneous Doppler jugular venous echo to predict pulmonary hypertension in COPD patients. (67/595)

Pulmonary hypertension is an important factor that determines the prognosis of chronic obstructive pulmonary disease (COPD) patients. Echocardiography is a noninvasive and useful bedside method for measurement of pulmonary artery pressure. However, this method is sometimes difficult because of the overinflated lungs in COPD patients. This study attempted to estimate pulmonary hypertension in COPD patients using transcutaneous Doppler jugular vein flow velocity recording. The mean pulmonary artery pressure (MPAP) of 64 COPD patients was examined using cardiac catheterization. The right jugular vein flow velocity was measured within 24 h using transcutaneous Doppler echo, after which the ratio of diastolic flow (Df) and systemic flow (Sf) velocity was calculated. Subsequently, the statistical correlation of MPAP and the Df/Sf ratio was examined. MPAP was also measured using standard cardiac echo methods and the results were compared. The Df/Sf velocity ratio showed significant correlation with MPAP in COPD patients (r=0.844, p<0.0001). The sensitivity was 71.4%, and the specificity 95.3% (cut-off ratio= 1.0). Jugular venous Doppler echo could be performed in all patients while other cardiac echo methods could not be performed in all patients. The specificity of the methods used was higher than other cardiac echo methods. Transcutaneous jugular vein flow velocity measurement may be applicable to bedside prediction of pulmonary hypertension in chronic obstructive pulmonary disease patients.  (+info)

Annulus paradoxus: transmitral flow velocity to mitral annular velocity ratio is inversely proportional to pulmonary capillary wedge pressure in patients with constrictive pericarditis. (68/595)

BACKGROUND: The early diastolic velocity of the mitral annulus (E') is reduced in patients with diastolic dysfunction and increased filling pressures. Because transmitral inflow early velocity (E) increases progressively with higher filling pressures, E/E' has been shown to have a strong positive relationship with pulmonary capillary wedge pressure (PCWP) and left ventricular end-diastolic pressure. However, previous studies have primarily involved patients without a pericardial abnormality. In constrictive pericarditis (CP), E' is not reduced, despite increased filling pressures. This study evaluated the relationship between E/E' and PCWP in patients with CP. METHODS AND RESULTS: We studied 10 patients (8 men; mean age, 64+/-7 years) with surgically confirmed CP. Doppler echocardiography was performed to measure early and late diastolic transmitral flow velocities. Tissue Doppler echocardiography was performed to measure E'. PCWP was measured with right heart catheterization. All patients were in sinus rhythm. Mean E and E' were 91+/-15 cm/s and 11+/-4 cm/s, respectively. Mean PCWP was 25+/-6 mm Hg. E' was positively correlated with PCWP (r=0.69, P=0.027). There was a significant inverse correlation between E/E' and PCWP (r=-0.74, P=0.014). Despite high left ventricular filling pressures, E/E' (mean, 9+/-4) was <15 in all but 1 patient. CONCLUSIONS: Paradoxical to the positive correlation between E/E' and PCWP in patients with myocardial disease, an inverse relationship was found in patients with CP.  (+info)

The relationship between obesity and mortality in patients with heart failure. (69/595)

OBJECTIVES: The study aimed to evaluate the role of obesity in the prognosis of patients with heart failure (HF). BACKGROUND: Previous reports link obesity to the development of HF. However, the impact of obesity in patients with established HF has not been studied. METHODS: We analyzed 1,203 patients with advanced HF followed in a comprehensive HF management program. The patients were subclassified into categories of body mass index (BMI) defined as: underweight BMI <20.7 (n = 164), recommended BMI 20.7 to 27.7 (n = 692), overweight BMI 27.8 to 31 (n = 168) and obese BMI >31 (n = 179). This sample size allows the detection of small effects (0.02), with a power of 0.80 and an alpha level of 0.05 for comparing one-year survival between BMI groups. RESULTS: The four BMI groups had similar profiles in terms of ejection fraction (mean 0.22), sodium, creatinine and smoking. The obese and overweight groups had significantly higher rates of hypertension and diabetes, as well as higher levels of cholesterol, triglycerides and low density lipoprotein cholesterol. The four BMI groups had similar survival rates. Ejection fraction, HF etiology and angiotensin-converting enzyme inhibitor use predicted survival on univariate analysis (p < 0.01), although BMI did not. On multivariate analysis, cardiopulmonary exercise tests, pulmonary capillary wedge pressure and serum sodium were strong predictors of survival (p < 0.05). Higher BMI was not a risk factor for increased mortality, but was associated with a trend toward improved survival. CONCLUSIONS: In a large cohort of patients with advanced HF of multiple etiologies, obesity is not associated with increased mortality and may confer a more favorable prognosis. Further studies need to delineate whether weight loss promotion in medically optimized patients with HF is a worthwhile therapeutic goal.  (+info)

Effect of two anaesthetic regimens on airway nitric oxide production in horses. (70/595)

There is evidence that halothane inhibits nitric oxide synthase in vitro, but the effect of intravenous anaesthetic agents is less clear. This study was undertaken to compare the rate of exhaled nitric oxide production (VNO) in spontaneously breathing horses anaesthetized with halothane or an intravenous regimen. Seven adult horses were studied twice in random order. After premedication with romifidine 100 microg kg(-1), anaesthesia was induced with ketamine 2.2 mg kg(-1) and maintained with halothane in oxygen (HA) or by an intravenous infusion of ketamine, guaiphenesin and romifidine (IV). Inhaled and exhaled nitric oxide (NO) concentrations, respiratory minute ventilation (VE), pulmonary artery pressure (PPA), fractional inspired oxygen concentration (FIO2), end-tidal carbon dioxide concentration (E'CO2), cardiac output (Q) and partial pressures of oxygen and carbon dioxide in arterial blood (PaO2, PaCO2) were measured. Exhaled nitric oxide production rate was significantly lower (40 min, P<0.01; 60 min, P<0.02) during HA [40 min, 1.4 (SD 1.4) pmol l(-1) kg(-1) min(-1); 60 min, 0.7 (0.7) pmol l(-1) kg(-1) min(-1)] than during IV [40 min, 9.3 (9.9) pmol l(-1) kg(-1) min(-1); 60 min, 12.5 (13.3) pmol l(-1) kg(-1) min(-1)). Mean pulmonary artery pressure was significantly higher (40 min, P<0.01; 60 min, P<0.001) during HA [40 min, 5.9 (1.1) kPa; 60 min, 5.9 (0.9) kPa] compared with IV (40 min, 4.4 (0.4) kPa; 60 min, 4.4 (0.5) kPa]. NO is reduced in the exhalate of horses anaesthetized with halothane compared with an intravenous regimen. It is suggested that increased mean pulmonary artery pressure during halothane anaesthesia may be linked to the differences in NO production.  (+info)

Impaired cardiac functional reserve and left ventricular hypertrophy in adult sheep after prenatal dexamethasone exposure. (71/595)

We have shown that exposure of pregnant ewes to dexamethasone (11.5 mg/d for 2 days) at 27 days of gestation (term, 150 days) led to increased blood pressure and cardiac output in adult offspring. In this study, we hypothesized that dexamethasone-induced hypertension is associated with left ventricular hypertrophy and a reduced cardiac functional reserve (CO(max-0)). Six control animals (group C) and five dexamethasone-exposed animals (group D) were volume-loaded with Hemaccel until the wedge pressure was 13 mm Hg (baseline). The wedge pressure was held constant during an infusion of dobutamine at incremental doses (0.4 to 12 microgram/kg/min) while blood pressure and cardiac output were measured. The same protocol was repeated in each animal 5 days later under mild general anesthesia (1.5% isoflurane), when transthoracic echocardiography (M-mode) was obtained. Group D showed a reduced CO(max-0) in response to dobutamine during both conscious (89+/-22 versus 150+/-25 mL/kg/min in control; P<0.01) and anesthetized states (91+/-38 versus 156+/-56 mL/kg/min in control; P<0.05). Reduced CO(max-0) in group D was associated with higher left ventricular mass index compared with group C (2.6+/-0.67 versus 1.8+/-0.51 g/kg; P<0.05). In addition, group D showed a reduced cardiac contractility reserve (FS(max-0)) in response to dobutamine (21+/-22% versus 54+/-34% in group C; P<0.05). An impaired cardiac functional reserve in group D was associated with increased left ventricular type I collagen content. In conclusion, brief prenatal exposure to dexamethasone led to the development of hypertension, left ventricular hypertrophy, and reduced cardiac functional reserve in adult life.  (+info)

Single atriocaval cannulation is associated with increased incidence of hypercirculatory failure after cardiopulmonary bypass. (72/595)

Cardiopulmonary bypass (CPB) can lead to hypercirculatory cardiac failure (HCF). Despite the activation of inflammatory mediators, the infusion of cardioplegic solution into the systemic circulation may result in decreased systemic vascular resistance and thus may cause HCF. The present prospective study was conducted to investigate in cardiac surgical patients the effects of single atrial versus bi-caval venous drainage and intraoperative hemofiltration on the incidence of HCF. METHODS AND RESULTS: 120 patients undergoing coronary artery bypass surgery (CABG) were randomized in 3 groups: A- single atrial cannulation; B- single atrial cannulation and intraoperative zero fluid balance hemofiltration; C- bi-caval cannulation. Myocardial protection was performed using cold crystalloid cardioplegia (Bretschneider's HTK) administrated into the aortic root and moderate hypothermia (32 degree C). Hemodynamics, fluid balance, vasoactive drugs, body temperature, and hemoglobin/hematocrit ratio were recorded during and up to 12 hours after surgery. We noted a significantly increased incidence of HCF in-group A (32%, n=13) and B (40%, n=16) when compared to group C (10%, n=4, p<0.05), with significantly increased requirements for vasoactive medication in patients developing HCF. CONCLUSION: The present study results demonstrate that single atrial cannulation is associated with a significantly higher incidence of HCF. This is presumably caused by infusion of cardioplegic solution into the systemic circulation.  (+info)