Correlates of diastolic filling abnormalities in hypertension: a Doppler echocardiographic study

Hypertension and aging are both associated with changes of left ventricular (LV) diastolic filling and increased LV mass. To determine whether diastolic filling abnormalities are present in hypertension independent of aging and significant hypertrophy, we studied 19 hypertensive patients following a period of 4 weeks when they were not receiving therapy and 18 normotensive subjects matched for sex, age, and LV mass. All subjects had normal systolic function and ejection fraction as assessed by radionuclide angiography. We measured peak velocity of early filling (E), late filling (A), and their ratio (E/A) by Doppler echocardiography. Filling indices were abnormal in hypertensive patients, but none of the filling indices were significantly correlated with LV mass. E was inversely related to age (r = -0.62; p less than 0.01) and diastolic blood pressure (r = 0.45; p less than 0.05) in normotensive individuals, but these correlations were not significant in hypertensive patients. E was not significantly correlated to LV mass or wall thickness. In contrast, A was influenced by septal wall thickness and blood pressure in both groups. E/A correlated inversely with age in both normal individuals (r = -0.74) and hypertensive patients (r = -0.51). These findings indicate that diastolic filling abnormalities in hypertension are not solely caused by either LV hypertrophy or by aging and therefore must be in part related to the hemodynamic load or altered myocardial or chamber properties.     

Soliciting views of various communities on health research: a prelude to engagement in specific research projects

BackgroundMembers of the public are increasingly engaged in health‐service and biomedical research and provide input into the content of research, design and data sharing. As there is variation among different communities on how research is perceived, to engage all sectors of the general public research institutions need to customize their approach.ObjectiveThis paper explores how research institutions and community leaders can partner to determine the best ways to engage different sectors of the public in research.DesignFollowing a literature review, a research institution engaged with four different sectors of the public through their respective representative community‐based organizations (CBOs) by interviews with leaders, community member focus groups and a joint project.SettingSan Diego and Imperial Counties, California, United States of America (USA).ConclusionBefore embarking on more specific research projects, investigators can gain valuable insights about different communities'' attitudes to, and understanding of, health services and biomedical research by interacting directly with members of the community, collaborating with community leaders, and jointly identifying steps of engagement tailored to the community.     

QT interval prolongation and increased plasma catecholamine levels in patients with mitral valve prolapse

The heart rate corrected QT interval (QTc) and plasma catecholamine (CA) and norepinephrine (NE) levels were measured in 15 symptomatic patients with idiopathic mitral valve prolapse (MVP) and in 19 control subjects. MVP patients showed longer mean QTc and were divided into two groups: group A normal QTc (greater than 440 msec) and group B prolonged QTc (less than 440 msec). In supine resting conditions CA levels were as follows: group A 0.420 +/- 0.035 ng/ml and group B 0.619 +/- 0.104 ng/ml (p less than 0.05); both were greater than control values (0.348 +/- 0.017 ng/ml, p less than 0.005). NE levels were as follows: group A 0.350 +/- 0.031 ng/ml and group B 0.376 +/- 0.052 ng/ml (NS); both were greater than control values (0.242 +/- 0.025 ng/ml, (p less than 0.05). When a standing position was assumed, CA and NE levels increased significantly in all groups but this was most marked in group B as compared to control levels (CA: 1.039 +/- 0.123 ng/ml versus 0.625 +/- 0.037 ng/ml; NE: 0.737 +/- 0.076 ng/ml versus 0.504 +/- 0.031 ng/ml) (p less than 0.001 and p less than 0.05, respectively). Thus the longest QTc was observed in patients with MVP who had the highest levels of CA and NE, in both supine and standing positions. These data may account, in part, for the occurrence of severe ventricular arrhythmias in some patients with MVP and may offer a rationale for adrenergic blockade in that subset of patients with MVP and markedly prolonged QTc.     

Pneumococcal peritonitis in adult patients: report of 64 cases with special reference to emergence of antibiotic resistance

BACKGROUND: Few data are available regarding pneumococcal peritonitis. We studied the clinical characteristics of intra-abdominal infections caused by Streptococcus pneumoniae and its prognosis in relation to antibiotic resistance. METHODS: We reviewed all cases of culture-proved pneumococcal peritonitis. Patients with liver cirrhosis and primary pneumococcal peritonitis were compared with patients with Escherichia coli peritonitis. RESULTS: Between January 1, 1979, and December 31, 1998, we identified 45 cases of primary pneumococcal peritonitis in patients with cirrhosis and 19 cases of secondary (or tertiary) pneumococcal peritonitis. Patients with cirrhosis and primary pneumococcal peritonitis vs those with primary E coli peritonitis had more frequent community-acquired infection, 73% vs 47%; pneumonia, 36% vs 2%; and bacteremia, 76% vs 33%; and higher attributable mortality (early mortality), 27% vs 9% (P<.05 for all). Secondary (or tertiary) pneumococcal peritonitis was associated with upper or lower gastrointestinal tract diseases; in most cases, the infection appeared after surgery. A hematogenous spread of S pneumoniae from a respiratory tract infection might be the most important origin of peritonitis; also, S pneumoniae might directly reach the gastrointestinal tract favored by endoscopic procedures or hypochlorhydria. There was an increased prevalence of penicillin and cephalosporin resistance up to 30.7% and 17.0%, respectively, although it was not associated with increased mortality rates. CONCLUSIONS: Primary pneumococcal peritonitis in patients with cirrhosis more often spread hematogenously from the respiratory tract and was associated with early mortality. In secondary (and tertiary) pneumococcal peritonitis, a transient gastrointestinal tract colonization and inoculation during surgery might be the most important mechanisms. Current levels of resistance were not associated with increased mortality rates.     

Effect of diltiazem on left ventricular mass and diastolic filling in mild to moderate hypertension

It is still uncertain whether antihypertensive therapy with calcium antagonists in general, and diltiazem in particular, can reduce left ventricular (LV) mass index and improve LV diastolic filling in hypertension. Therefore, 24 patients with mild to moderate hypertension (diastolic blood pressure 95 to 114 mm Hg before therapy) were randomly assigned to receive either a sustained-release preparation of diltiazem (n = 13) or placebo (n = 11) for 16 weeks in a double-blind, parallel-group protocol. M-mode and pulsed Doppler echocardiograms were performed at baseline and at the end of monotherapy. Echocardiograms were read blindly by 2 independent observers. The patients who received placebo exhibited no change in blood pressure, cardiac dimensions or LV function. Diltiazem significantly reduced both systolic pressure (151 +/- 14 to 139 +/- 12 mm Hg) and diastolic pressure (101 +/- 4 to 90 +/- 7 mm Hg, both p less than 0.05). Posterior wall and septal wall thicknesses decreased, but the changes were not statistically significant. End-diastolic dimension was reduced by diltiazem from 53 +/- 5 to 51 +/- 5 mm (p less than 0.05). LV mass index decreased significantly with diltiazem by 10%, from 125 +/- 21 to 113 +/- 23 g/m2 (p less than 0.05). The LV wall thickness to radius ratio remained unchanged during both diltiazem and placebo treatments. Changes in LV mass index and blood pressure did not correlate, suggesting that this response is influenced by factors other than pressure reduction alone.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diagnostic accuracy of exercise thallium-201 scintigraphy in men with asymptomatic essential hypertension.

Coronary artery disease is responsible for much of the morbidity and mortality in patients with essential hypertension, and these complications have proven to be relatively resistant to antihypertensive therapy. However, the diagnosis of coronary disease in the hypertensive population has been considered problematic. In the present study, 30 asymptomatic patients with mild to moderate hypertension with positive exercise electrocardiograms (ECG) or stress thallium-201 scintigrams underwent coronary angiography to determine the accuracy of these tests for coronary artery disease. The exercise ECG was positive in 25 subjects, of whom 15 had significant coronary lesions and 10 did not. Thallium-201 scintigraphy proved more accurate: 17 of 18 patients with reversible abnormalities had significant obstructive coronary disease anatomically corresponding to the defect, one patient with a fixed defect had normal coronary arteries and was found to have an idiopathic cardiomyopathy, and 9 of 11 without defects had no significant lesions. The results were similar in populations with and without echocardiographic criteria for left ventricular hypertrophy. These findings indicate that despite previous suggestions to the contrary, thallium-201 scintigraphy can accurately diagnose coronary artery disease in most patients with asymptomatic essential hypertension, and that most asymptomatic hypertensive patients with physiologic evidence of myocardial ischemia have associated coronary artery disease.     

Nosocomial outbreak due to extended-spectrum-beta-lactamase- producing Enterobacter cloacae in a cardiothoracic intensive care unit

Enterobacter cloacae has been associated with several outbreaks, usually involving strains that overproduce chromosomal beta-lactamase or, uncommonly, strains expressing extended-spectrum beta-lactamases (ESBL). Only sporadic cases of ESBL-producing E. cloacae have been identified in our hospital in recent years. We describe the epidemiology and clinical and microbiological characteristics of an outbreak caused by ESBL-producing E. cloacae in a cardiothoracic intensive care unit (CT-ICU). Prospective surveillance of patients with infection or colonization by ESBL-producing E. cloacae among patients admitted to the CT-ICU was performed during the outbreak. Production of ESBL was determined by decreased susceptibility to expanded-spectrum cephalosporins and a positive double-disk test result. Clone relatedness was determined by pulsed-field gel electrophoresis (PFGE). From July to September 2005, seven patients in the CT-ICU with ESBL-producing E. cloacae were identified (four males; median age, 73 years; range, 45 to 76 years); six patients had cardiac surgery. Four patients developed infections; three had primary bacteremia, one had ventilator-associated pneumonia, and one had tracheobronchitis. ESBL-producing E. cloacae showed resistance to quinolones and aminoglycosides. PFGE revealed two patterns. Five isolates belonged to clone A; two carried a single ESBL (pI 8.2 and a positive PCR result for the SHV type), and three carried two ESBLs (pIs 8.1 and 8.2 and positive PCR results for the SHV and CTX-M-9 types). Isolates belonging to clone B carried a single ESBL (pI 5.4 and a positive PCR result for the TEM type). Review of antibiotic consumption showed increased use of cefepime and quinolones during June and July 2005. The outbreak was stopped by the implementation of barrier measures and cephalosporin restriction. ESBL production could be increasingly common in nosocomial pathogens other than Escherichia coli or Klebsiella pneumoniae.     

Pulmonary blood volume: relationship to changes in left ventricular end-diastolic pressure during atrial pacing

Little data exist about the relationship between changes in cardiac end-diastolic pressure and changes in pulmonary blood volume. To assess this relationship, we studied 11 patients with coronary heart disease during atrial pacing in an attempt to produce multiple pressure-volume points. During catheterization, we obtained Millar pressure recordings of end-diastolic pressure along with equilibrium radionuclide angiograms. Cardiac output, ejection fraction, and pulmonary blood volume were obtained by means of recently validated radionuclide techniques. During pacing, substantial changes in pulmonary blood volume occurred only with marked increase in end-diastolic pressure volume (greater than or equal to 15 mm Hg) and rarely exceeded 15% of control pulmonary blood volume. Cardiac output did not change, while ejection fraction declined during pacing. There was a fair correlation between the absolute change in pulmonary activity (or pulmonary blood volume) or the percentage of change in pulmonary activity over the control value with end-diastolic pressure when all the data points were evaluated (n = 74, r greater than 0.70). However, the scatter in the data precluded making accurate estimates of pressure changes from changes in radionuclide volume changes. We conclude that large changes in cardiac filling pressure must occur during atrial pacing, where cardiac output does not change, before visible pulmonary blood volume changes occur. This may limit the extrapolation of presumed pressure changes from known pulmonary blood volume when changes are small.